Hurricane Ike 10 Years Later

Before Harvey flooded out Southeast Texas, there was Ike. It is hard to believe it has been 10 years since Hurricane Ike made landfall on Southeast Texas as a monsterous Category 2 hurricane in the early morning hours of September 13, 2008. Especially the fact this comes in light of Harvey. Ike pelted Southeast Texas and Southwest Louisiana with hurricane force winds and heavy rain. Ike was the last hurricane to hit Texas prior to Harvey. Almost a nine year gap of no hurricanes hitting Texas, let alone a major hurricane. The last major hurricane to hit Texas prior to Harvey was Bret in 1999, which is 18 years.

Thunderstorms over Sudan that later became Ike.

What is the origin of Hurricane Ike? Ike started as a mesoscale convective system (MCS) that formed over Sudan on August 19th. Most tropical waves come from thunderstorms that form in the Northeast part of Africa. They are set off by the Intertropical Convergence Zone (ITCZ) or monsoon. The ITCZ is where there is thunderstorms from the clash of trade winds. These thunderstorms often provide beneficial rains in tropical and subtropical areas. The thunderstorms in ITCZ can break away and travel away. One of those thunderstorms from the ITCZ managed to do that. The MCS traveled over Africa and entered the Atlantic Ocean as a tropical wave on August 29th. The tropical wave traveled across with multiple vortices competing. One of them would win out as the thunderstorms in the tropical wave get better organized on September 1, 2008. It is upgraded to Tropical Depression #9. Later that day, it is named Ike as it travels over the open Atlantic. Tropical Storm Ike has to deal with wind shear in the upper level early in its life. The wind shear blows tops of thunderstorms, especially westerly wind shear. Since 2008 season is Neutral to La Nina, conditions are more favorable as there is less westerly wind shear. If 2008 was El Nino, there would be more westerly wind shear, which is why generally El Nino Atlantic Hurricane seasons see less storms. Wind shear generally kills tropical development. The higher the storm clouds are, the cooler it is. Higher storm clouds also mean they are more intense.

However, Ike gets a reprieve as the wind shear weakens and encounter warmer waters on September 3rd. This allows Ike to rapidly intensify into a major hurricane. By the next day, Ike becomes 2008’s strongest hurricane with 145 mph 126 knots 233 km/h winds and central pressure of 935 millibars. Ike’s strength did not last as it encountered wind shear on September 5th. The wind shear weaken Ike to Category 2 strength.

Hurricane Ike around its peak.

Ike is pushed southwards into more favorable areas due to upper level ridge to the north. Ike becomes a Category 4 hurricane as conditions are more favorable. As it goes westward, Ike made its first landfall on Turks and Caicos Islands as a Category 4 hurricane on the early morning hours of September 7th. The Turks and Caicos Islands are the first to feel Ike’s violent wrath in the form of strong winds, heavy rain, storm surge, and high waves. The South Caicos and Grand Turk take the brunt of Ike. Despite Ike’s fury, there are no reports of fatalities.

Damage in Grand Turk.

While Ike is ravaging the Turks and Caicos Islands, the outer bands of Ike are dumping heavy rain on Haiti and Dominican Republic, which have been ravaged by Fay, Gustav, and Hanna. The flooding from Ike claims 74 lives in Haiti and 2 in Dominican Republic. Prior to Ike, Tropical Storm Hanna ravaged Haiti and Dominican Republic with heavy rain that led to massive flooding. The flooding claims 529 lives in Haiti, while just one dies in Dominican Republic. Why did Haiti see more fatalities than Dominican Republic? The lack of trees in Haiti makes it even more vulnerable to mudslides from the mountains. The heavy rain causes deadly mudslides that destroys houses and kill people.

Stranded Cubans following Ike.

Once Ike passes Turks and Caicos Island, Ike heads for Cuba. The hurricane makes landfall on Cabo Lucrecia, Holguín Province, Cuba. Cuba is in a very rough ride with Ike as it traverses over the entire island nation. Cuba is being pelted by heavy rain, strong wind, high waves, and storm surge. Briefly, Ike goes over the water only to make a second landfall on Punta La Capitana, Pinar del Río, Cuba on September 8th as a Category 1 hurricane. Ike claims 7 lives in Cuba.

Ike near its secondary peak in Gulf of Mexico.

Once Ike exits Cuba, it is a large Category 1 hurricane. Ike traveling over all of Cuba caused the storm to expand as energy is spread out from land interaction. It also disrupted Ike’s core. Ike enters large area of warm water in the Gulf of Mexico and is getting close to the Loop Current, which is one of the warmest spot. Ike rapidly deepen from 963 to 944 millibars on the night of September 10th as it was over the Loop Current. However, the wind did not strengthen much, only from 80 to 100 mph 70 knots to 87 knots 128 km/h to 161 km/h. The reason is Ike is a very large hurricane with hurricane force winds extending up to 125 miles 109 nautical miles 201 kilometers from the eye. The pressure gradient is not tight due to its large size. Normally, an Atlantic hurricane with central pressure of 944 millibars is a Category 3 or 4 hurricane.

On September 11th, as America remembers and reflects the seventh anniversary of the 9/11 Terrorist Attacks, Southeast Texas is sunny and dry. The west side of a hurricane in the Northern Hemisphere is usually the “clean” side. It blows in dry and sinking air from the north. The nice sunny day is very deceptive as Ike is ever inching closer. Meanwhile in the Gulf of Mexico, Ike is generating massive waves that are heading towards the Texas and Louisiana. Ike continues across the Gulf of Mexico as a large Category 2 hurricane. Waves are coming ahead of Ike in coastal Texas. People are evacuating from coastal areas including Galveston. Some choose to stay behind. The outer cloud banks of Ike are over Southeast Texas as winds start to pick up. By the afternoon of September 12th, some coastal areas are getting squally weather from the feeder bands entering Texas.

By the night of September 12th, conditions have gotten much worse. Meanwhile in Houston area, it is still windy with occasionally light rain. As the night progresses, Ike is getting closer to landfall. The hurricane force winds enter Texas around the late hours of September 12th. Ike is getting stronger and developing a more organized eyewall. Ike now has a central pressure of 951 millibars and 110 mph 96 knots 177 km/h winds. Ike is a large hurricane with hurricane force winds extending up to 125 miles and tropical storm force winds extending up to 260 miles 226 nautical miles 418 kilometers.

Ike at landfall on Southeast Texas.

Highest wind gust possible based on multiplying by factor of 1.5.

By the early morning hours of September 13th, Houston area is seeing stronger winds and heavier rain. Power starts to go out throughout Southeast Texas as power lines are being knocked by the strong wind. The coastal areas are seeing storm surge getting higher and higher. Anyone who stayed behind in Galveston or Bolivar Peninsula are doomed by the massive storm surge. Ike makes landfall on the eastern end of Galveston Island at 2:10 AM Central Time. People who are staying behind in the coastal areas are wishing they had evacuated as they are surrounded by rising storm surge. Ike travels to the northwest towards Houston. By 4:00 AM, Ike is over Baytown, which is flooded by storm surge. A large area of Southeast Texas is getting hurricane force winds including all of Houston.

Highest sustained winds during Hurricane Ike.

Bolivar Peninsula following Ike.

By the time the Sun rises, Ike is still ravaging Southeast Texas despite the fact it has weakened to Category 1 hurricane. Ike remains a monsterous and very dangerous hurricane. Many areas are still seeing heavy rain and strong winds. The wind blow down numerous trees and damage many buildings and houses. There is widespread flooding reported throughout Southeast Texas. Bayous and rivers are overflowing from widespread heavy rain. Coastal areas had storm surge as high as 25 feet/7.6 meters. It is one of the highest storm surge recorded in America and highest in Texas. It exceeds Camille, but below Katrina. Bolivar Peninsula saw the highest storm surge as the whole area looked like if a nuclear bomb had exploded. Once it is all over, many buildings and houses are damaged or destroyed, while many trees are uprooted. Coastal areas are utterly gutted from the massive storm surge. Millions of people are out of power for days. A large area saw 6 to 12 inches/15.2 to 30.5 centimeters of rain from Ike.

The damage is not just limited to Texas. Louisiana also felt the brunt of Ike, especially in Southwestern Louisiana. It is the same area that had been ravaged by Hurricane Rita in 2005. Many areas are flooded by Ike. There is even flooding in New Iberia, which is in Central Louisiana. It shows that Ike’s massive size had a huge impact over a large area from Texas to Louisiana. This is despite the fact that they only got tropical storm force winds. It shows that large, but not so strong hurricane is very dangerous as it produces massive storm surge and high waves.

Thunderstorms ahead of a cold front in the early morning hours of September 14, 2008.

The following night, a cold front passes, which allows thunderstorms to form from moisture left by Ike. The storms dumped 5 to 8 inches/12.7 to 20.3 centimeters of rain. The heavy rain causes more flooding on top of what Ike dumped in Southeast Texas. Once the rain ended, many areas saw a two day total ranging from 10 to 20 inches/25.4 to 50.8 centimeters of rain. Meanwhile, the remnants of Ike continue to wreak havoc in the Midwest. Ohio see hurricane force gusts, which causes more power outages. The remains of Ike continue into Canada and dump heavy rain in Ontario and Quebec. A total of 112 people lost their life with 34 unaccounted for in America. Most of the deaths are in Texas, where 84 people died.

Rainfall total from September 12, 2008 to September 15, 2008.

So, how was 2008 like prior to Ike. The winter of 2007-2008 is La Nina, so it is warmer and drier. Despite the La Nina, there are storms. Spring of 2008 is mostly dry. There were days of pleasant weather in Spring 2008. Summer of 2008 is average in terms of temperature and rainfall. Texas first brush with a hurricane is Dolly, which affected South Texas. The outer bands of Dolly dump heavy rain in the Houston area. Not too long after Dolly came, Tropical Storm Edouard pays a visit to Houston area. It is a rather unremarkable tropical storm that dumps up to 6 inches of rain. Edouard moves inland and gives beneficial rains to drought ridden Central Texas.

NHC Hurricane Ike Report
NHC Hurricane Ike Advisory Report
Morphed Integrated Microwave Imagery at CIMSS (MIMIC)

Advertisements

The Tropics Are Heating Up

Today is what is the peak date for the Atlantic Hurricane Season. No doubt today with Florence, Isaac, Helene, and Invest 95L, which maybe Joyce. 95L is an area of thunderstorms over the Caribbean south of Cuba. Tomorrow is September 11, which is the 17th anniversary of the devastating terrorist attacks in New York, Arlington, and Shanksville. It claimed 3,000 lives and reduced the World Trade Center to a smoldering and toxic rubble and left the Pentagon burning shooting out toxic smoke. I will be focusing on Florence as it is most likely to pose a threat to America. Invest 95L was declared earlier today, so there is not a lot of forecast models for it yet.

As of 11:00 PM AST from the National Hurricane Center (NHC), Florence has 140 mph 122 knots 225 km/h winds with gusts as high as 175 mph 152 knots 282 km/h. The central pressure is 944 millibars. It is a medium sized hurricane with hurricane force winds extending up to 40 miles 35 nautical miles 64 kilometers and tropical storm force winds extending up to 150 miles 130 nautical miles 241 kilometers.

The forecast intensity shows Florence being a Category 4 hurricane.

I think Florence will be a Category 5 hurricane. Here is why from NOAA-Tropical Cyclone Heat Potential and Weather Maps-Maximum Potential Hurricane Intensity.

The water where Florence is and probably where it will go is warm. It has plenty of warm and deep water to work with. The Maximum Potential Hurricane Intensity (MPI) supports a Category 5 hurricane if conditions are near perfect. This is despite the fact that Florence is likely to run into UW-CIMSS-Wind Shear. The wind shear is not that strong and since Florence is well structured and organized, it should have little effect.

The biggest question is where does Florence go? That is on everyone’s mind right now. The forecast paths are from NCAR-Tropical Cyclone Guidance.

I have the latest forecast track and ensemble from a previous forecast cycle. The consensus on both forecast models including the ensembles using the heat map within 300 mile/480 kilometers radius from the point show that North Carolina is most likely to have Florence making landfall later this week. What is most concerning is once it is over land, Florence could slow down and stall out. This leads to heavy rain and dangerous flooding. Hurricane Harvey lingered over Texas dumping heavy rain over a large area leading to massive flooding. Here are rainfall forecast models from Weather.US. They are EURO, GFS, Canadian, and German (ICON). They are all seven day rainfall total forecast.

The forecast models all agree that heavy rain will fall over North Carolina. Two have heavy rain over Virginia. The EURO has 19 inches/48.3 centimeters of rain. The GFS has (drum rolls please) 77 inches/195.6 centimeters of rain! Thankfully, that is over the ocean. North Carolina has 15 to 20 inches/38.1 centimeters to 50.8 centimeters of rain, which is still heavy. The Canadian has 39 inches/99 centimeters of rain. Like the GFS, it is over the ocean. The ICON has 29 inches/74 centimeters of rain. The 77 inches of rainfall forecast from GFS is assuming that Florence is stalled out over the ocean. If Florence was to stall out over land and 77 inches of rain did fall, it would be heavier than Harvey. I have never seen such high rainfall forecasts. The last time I saw something that high high was from Harvey. Some forecast models I saw had up to 70 inches/177.8 centimeters of rain over Texas!

The rainfall forecast does include Texas. They are all over the place in terms of rainfall forecast for the next 7 days. The EURO has 19 inches of rain west of Corpus Christi. The GFS has 5 inches/12.7 centimeters. The Canadian has 12 inches/30.5 centimeters of rain over Houston area. The ICON has 15 inches of rain northeast of Corpus Christi. This suggests at this point, the heaviest rain will be in South Texas depending on how organized Invest 95L. If it is not as organized, the heaviest rain would be east of the center and Southeast Texas would get the heaviest rain from 95L.

Here is what I think will happen.
-Florence could intensify into a Category 5 hurricane.
-Florence is looking to affect North Carolina the most.
-Strong winds, storm surge, and heavy rain will be the main problem from Florence.
-Deadly flooding will probably be main headline if Florence stalls out.
-Regardless if Invest 95L is Joyce or not, Texas could see more heavy rain this week to early next week.

Puerto Rico In Trouble

Hurricane Maria is a very dangerous Category 5 hurricane with 175 mph 280 km/h 152 knots. It has a central pressure of 909 millibars (mb). This is more intense than Hurricane Irma in terms of central pressure. Maria is now the top 10 most intense Atlantic hurricane known. I mean known as records go back to 1851.

Top 10 Most Intense Hurricane By Central Pressure
1.) Wilma 2005 882 mb
2.) Gilbert 1988 888mb
3.) Labor Day 1935 892 mb
4.) Rita 2005 895 mb
5.) Allen 1980 899 mb
6.) Camille 1969 900 mb
7.) Katrina 2005 902 mb
8.) Mitch 1998/Dean 2007 905 mb
9.) Maria 2017 909 mb
10.) Cuba 1932/Ivan 2004 910 mb

Wilma is the most intense hurricane to date. It ravaged Yucatan Peninsula and Florida. Gilbert and Rita caused a huge scare for Texas. Gilbert hit Jamaica, Yucatan Peninsula, and Mexico’s Gulf Coast. Rita hit east of Houston area in East Texas and Southwest Louisiana. Labor Day 1935 Hurricane likely had low central pressure. Allen made landfall on South Texas. Camille and Katrina ravaged the Gulf Coast in the same area. Katrina was larger as it produced higher storm surge in Mississippi and flooded out New Orleans. Mitch killed 22,000 from heavy rain and massive flooding in Central America. Mitch is the deadliest hurricane after the Great Hurricane of 1780, which claimed 30,000 lives. Dean hit Yucatan Peninsula and Mexico. Cuba 1932 is Cuba’s deadliest hurricane to this day. Ivan ravaged the the Caribbean before making landfall on Alabama and Florida. Ivan came back again and made landfall as a tropical storm on Texas/Louisiana border. That being said, Maria is getting ever so closer to St. Croix and Puerto Rico.

Doppler radar image out of Puerto Rico shows a formidable Hurricane Maria. Not often we see a Category 5 hurricane on ground based Doppler radar. It has a near prefect circular eye. The infrared satellite image of Hurricane Maria is very impressive and scary. It is going to be a rough night for St. Croix.

St. Croix is experiencing tropical storm force winds. Hurricane force winds should be later tonight for St.Croix. Puerto Rico should feel tropical storm force winds later tonight. Hurricane force wind comes early tomorrow morning. Hurricane force winds are up to 104 miles 166 km 90 nautical miles across from northwest to northeast quadrant. Tropical storm force winds are are up to 276 miles 442 km 240 nautical miles across from northwest to northeast quadrant. It has gotten larger from yesterday. The speed Maria is moving at, 10 mph 16 km/h 8.7 knots, tropical storm force winds could last up to nearly 28 hours, while hurricane force winds could last up to 10 hours. This prolonged wind could do a lot of damage for Puerto Rico and St. Croix.

Here is the heat map forecast from various forecast models and GFS ensemble track guidance for Maria up close with Puerto Rico.

It does not look good for Puerto Rico. Most of the forecast models have Maria making landfall and going over Puerto Rico. The intensity as it is is very concerning. I would not be surprised if Maria intensifies further right before it gets close to Puerto Rico later tonight. This is a very bad for Puerto Rico. If Hurricane Maria makes landfall as a Category 5 on Puerto Rico, it will be the first since 1928, the Okeechobee Hurricane. On September 13, 1928, the Okeechobee Hurricane made landfall on Puerto Rico as a Category 5 hurricane with 160 mph 256 km/h 139 knots. The gusts are as high as 240 mph 384 km/h 209 knots. It had a central pressure of 929 millibars. It was very likely the central pressure was lower and stronger. The hurricane was large as it ravaged Puerto Rico. The hurricane claimed 312 lives in Puerto Rico, while 1,200 lives were lost at Guadeloupe. The Okeechobee Hurricane made landfall near West Palm Beach as a Category 4 hurricane with 145 mph 232 km/h 126 knots on September 17, 1928. The highest wind on land would be around 123 mph 200 km/h 107 knots with gusts as high as 185 mph 296 km/h 161 knots. The hurricane stayed over Florida and claimed at least 2,500 lives and likely more. The Okeechobee Hurricane claimed more than 4,000 lives. The death toll is likely much higher. It is America’s deadliest hurricane since 1900 Galveston Hurricane that claimed 12,000 lives. In fact, Okeechobee Hurricane is the deadliest American disaster prior to 9/11 and Hurricane Katrina.

Once Maria passes Puerto Rico, where does it go?. This is the latest heat map from various forecast models and GFS ensemble track guidance for Maria. The GFS goes up to 10 days.

The forecast models have a westward trend from 24 hours ago. Dominican Republic and Bahamas could feel the impact of Maria. There is also a possibility that Maria could affect North Carolina and the Eastern Seaboard. That would be too early to tell at this time. This is on top of how strong Maria will be.

Most of the forecast models have Maria weakening after it passes Puerto Rico. One model has Maria intensifying back to a Category 5 hurricane in three days. Intensity forecast are notoriously difficult to forecast. All the forecast models are subject to change.

Here is what I think will happen.
-Maria could pose a major threat to Puerto Rico.
-Maria will likely impact Dominican Republic.

This is going to be very bad for Puerto Rico and St. Croix. I fear the damage will be epic and the death toll could be high. This comes at a bad time as Puerto Rico is mired in a serious financial crisis. This could make recovery difficult for Puerto Rico. I cannot imagine what it will be like during Hurricane Maria.

The forecast models came from NCAR-Tropical Cyclone Guidance, NOAA Tropical Cyclone Imagery – Storm Floaters, National Hurricane Center, and National Weather Service. Special thanks to all of them.

Epic Flood Day 4

Last night, East Texas and Southwest Louisiana got hit hard by heavy rain. Epic flooding that plagued Houston area is now plaguing East Texas and Southwest Louisiana. Here is a rainfall total map.

Many areas saw over 10 inches/25.4 centimeters of rain. The highest total is over 26 inches/66.04 centimeters of rain! Beaumont/Port Arthur got over 26 inches of rain on August 29 and got 3 inches of rain today. That means they saw at least 29 inches of rain!

000
CXUS54 KLCH 300819
CF6BPT
PRELIMINARY LOCAL CLIMATOLOGICAL DATA (WS FORM: F-6)

STATION: BEAUMONT PORT ARTHUR
MONTH: AUGUST
YEAR: 2017
LATITUDE: 29 57 N
LONGITUDE: 94 1 W

TEMPERATURE IN F: :PCPN: SNOW: WIND :SUNSHINE: SKY :PK WND
================================================================================
1 2 3 4 5 6A 6B 7 8 9 10 11 12 13 14 15 16 17 18
12Z AVG MX 2MIN
DY MAX MIN AVG DEP HDD CDD WTR SNW DPTH SPD SPD DIR MIN PSBL S-S WX SPD DR
================================================================================

1 88 77 83 0 0 18 0.07 0.0 0 6.5 15 80 M M 6 19 90
2 86 74 80 -3 0 15 0.29 0.0 0 6.2 16 130 M M 5 138 21 140
3 91 74 83 0 0 18 0.02 0.0 0 5.1 14 30 M M 7 1 17 20
4 90 75 83 0 0 18 0.26 0.0 0 3.6 14 160 M M 5 13 17 160
5 87 74 81 -2 0 16 0.34 0.0 0 4.1 14 150 M M 3 13 20 120
6 92 75 84 1 0 19 0.34 0.0 0 7.5 21 290 M M 3 138 30 240
7 84 74 79 -4 0 14 0.73 0.0 0 4.6 20 280 M M 1 13 26 140
8 87 74 81 -2 0 16 2.42 0.0 0 5.5 20 190 M M 8 13 25 180
9 85 74 80 -3 0 15 0.38 0.0 0 4.5 16 140 M M 7 1 21 140
10 92 75 84 1 0 19 0.00 0.0 0 4.2 14 250 M M 3 1238 26 210
11 91 77 84 1 0 19 0.01 0.0 0 5.8 14 190 M M 1 18 18 180
12 92 74 83 0 0 18 0.00 0.0 0 6.1 14 190 M M 1 12 19 180
13 92 74 83 0 0 18 0.00 0.0 0 6.3 16 180 M M 2 13 24 250
14 93 76 85 2 0 20 0.00 0.0 0 7.7 15 190 M M 2 20 180
15 89 77 83 0 0 18 1.23 0.0 0 7.2 22 200 M M 1 138 31 160
16 91 78 85 2 0 20 0.02 0.0 0 9.0 20 240 M M 2 8 26 260
17 94 76 85 2 0 20 T 0.0 0 7.8 14 190 M M 1 19 220
18 95 76 86 3 0 21 0.00 0.0 0 4.7 14 100 M M 2 13 17 100
19 97 75 86 3 0 21 0.00 0.0 0 3.7 12 180 M M 2 138 15 160
20 92 78 85 2 0 20 0.85 M 0 3.0 8 120 M M 2 13 M M
21 92 77 85 2 0 20 0.01 0.0 0 4.3 17 100 M M 3 38 27 330
22 91 75 83 0 0 18 0.23 0.0 0 3.4 16 110 M M 2 13X 19 100
23 89 76 83 0 0 18 0.02 0.0 0 4.2 17 30 M M 2 13 22 40
24 92 74 83 0 0 18 0.04 0.0 0 7.7 23 70 M M 1 3 29 70
25 80 73 77 -6 0 12 1.23 0.0 0 14.3 23 100 M M 5 13 32 90
26 81 74 78 -5 0 13 2.74 0.0 0 13.1 26 90 M M 8 13 34 90
27 78 73 76 -7 0 11 8.98 0.0 0 15.5 30 110 M M 10 13 42 80
28 82 72 77 -6 0 12 5.52 0.0 0 19.2 28 50 M M 9 13 39 50
29 74 69 72 -10 0 726.03 0.0 0 22.1 35 360 M M 10 13 46 360
================================================================================
SM 2567 2170 0 492 51.76 0.0 216.9 M 114
================================================================================
AV 88.5 74.8 7.5 FASTST M M 4 MAX(MPH)
MISC ----> # 35 360 # 46 360
================================================================================

The heavy rain that plagued East Texas and Southwest Louisiana happened at night in the form of core rains. The same type of rain that plagued Houston area. Here is the 7 day total.

The rainfall total are from multi-sensor (radar and rain gauge) precipitation estimates obtained from National Weather Service (NWS) River Forecast Centers (RFCs) and mosaicked by National Centers for Environmental Prediction (NCEP). There are areas that have gotten over 50 inches/127 centimeters of rain. Some areas have nearly gotten 60 inches/152.4 centimeters of rain! I would not be surprised by the end of the week, some areas get up over 60 inches/152.4 centimeters of rain! The rainfall data is from Advanced Hydrologic Prediction Service (AHPS).

As things are drying out and we enter September, the tropics are brewing. You did not misread that. There are two areas of concern. Let’s start with the one in the Gulf of Mexico. There is an area of thunderstorms in the Southwest Gulf of Mexico. Yes, that is an area that the National Hurricane Center (NHC) is watching.

The NHC gives that area a low chance of developing in the next 5 days. Here is the discussion from NHC.

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Wed Aug 30 2017

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical
Depression Harvey, located over central Louisiana and on Tropical
Storm Irma, located over the eastern Atlantic Ocean.

1. An area of low pressure could form over the southwestern Gulf of
Mexico by the weekend. Development, if any, of this system is
expected to be slow to occur as the low moves slowly northward.
If this system does develop, it could bring additional rainfall to
portions of the Texas and Louisiana coasts. However, any rainfall
forecast is uncertain at this time range and it is too soon to
determine any specific impacts. Interests in these areas should
monitor the progress of this system for the next few days.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

Public Advisories on Irma are issued under WMO header
WTNT31 KNHC and under AWIPS header MIATCPAT1.
Forecast/Advisories on Irma are issued under WMO header
WTNT21 KNHC and under AWIPS header MIATCMAT1.

Forecaster Avila

Let’s hope that does not develop into something tropical. If it does, that could mean more rain for flood ravaged Texas and Louisiana. That would be very bad. Regardless, I will keep an eye on that area.

There is also newly developed Tropical Storm Irma. The big question is where Irma goes. Here is the latest heat map from various forecast models and GFS ensemble track guidance. The GFS goes up to 10 days.

Looking at the forecast track, it is looking to move more to the northwest. It could affect Bermuda or the East Coast. None of the forecast models have it going into the Gulf of Mexico at this time. Here is the most recent satellite image of Irma.

Looking at Irma, it looks like it is intensifying. The circular pattern and spiral arms suggest that Irma is undergoing rapid intensification. Here is the intensity forecast for Irma.

The forecast models forecasts a Category 1 hurricane in 12 hours. I think Irma could be a major hurricane as early as tomorrow. Frankly, I would not be surprised if Irma becomes a Category 5 hurricane while out in the Atlantic.

Here is what I think will happen.
-The area of thunderstorms in Southwest Gulf of Mexico bears watching.
-Irma will become a major hurricane as early as tomorrow.

The forecast models came from Advanced Hydrologic Prediction Service (AHPS), NCAR-Tropical Cyclone Guidance, National Hurricane Center, Naval Research Laboratory Tropical Cyclone Page, Weather.US, Weather Prediction Center (WPC), and National Weather Service. Special thanks to all of them.

Harvey is not just a Houston area disaster. It is a Texas disaster. A disaster that everyone has feared has come true. A disaster of truly epic proportions of a magnitude that one cannot even imagine.

Epic Flood Day 3

The helicopters flying and boats rescuing people from their flooded out homes. A sight all too common in the Houston area. The Addicks and Barker are bursting with so much water that it has be released to avoid catastrophic and widespread flooding at the cost of flooding neighborhoods. It is on the 12th anniversary of Hurricane Katrina making landfall on Louisiana and Mississippi. I am completely overwhelmed by this disaster as a weather buff. Here is a 7 day rainfall total map from Advanced Hydrologic Prediction Service (AHPS). It is unbelievable amounts I have seen.

The rainfall total are from multi-sensor (radar and rain gauge) precipitation estimates obtained from National Weather Service (NWS) River Forecast Centers (RFCs) and mosaicked by National Centers for Environmental Prediction (NCEP). There are areas that have gotten over 50 inches/127 centimeters of rain. Some areas have nearly gotten 60 inches/152.4 centimeters of rain! I would not be surprised by the end of the week, some areas get up over 60 inches/152.4 centimeters of rain!

Another mind boggling aspect is the large area that received heavy rains.

The green is where at least 10 inches/25.4 centimeters of rain fell. A large area received at least 10 inches/25.4 centimeters or greater! This has to go down as one of the largest rain events in America. We should know once Harvey passes. In the meantime, East Texas and Southwest Louisiana is getting hit by heavy rain. The latest Doppler radar out of NWS Lake Charles shows heavy rain as the storm is over the Gulf of Mexico.

Here is the 24 hour rainfall forecast from GFS, Canadian, EURO, and Weather Prediction Center (WPC).

The forecast models have the heaviest rains east of Houston. This time it is over East Texas and Southwest Louisiana. They have been getting plenty of heavy rain as well.

GFS: 11 inches/27.94 centimeters
Canadian: 10 inches/25.40 centimeters
EURO: 15 inches/38.10 centimeters
WPC: 10.74 inches/27.28 centimeters

As for Houston area, they could see still see rain, including occasional heavy rain. Looking at more moderate rain for Houston. The heavy rain has shifted to East Texas and Southwest Louisiana. Even New Orleans area is getting heavy rain and there is concern for flooding. Some of the pumps are not working, which could flood again like what happened with Katrina.

The million dollar question is where Harvey goes. Here is a heat map from various forecast models.

There is now a consensus among forecast models that Harvey will go northeast after making landfall on Southwest Louisiana as a tropical storm. Here is the latest from the National Hurricane Center. It is as of 10:00 PM or 2200 CDT:
Location: 29.0°N 93.6°W
Moving: NE at 6 mph 9 km/h 5.2 knots
Min pressure: 994 mb
Max sustained: 50 mph 80 km/h 44 knots

I do not think Harvey will intensify as it makes landfall again as a tropical storm. The reason is the core is a swirl of clouds with no thunderstorms. All the thunderstorms are north and east of the center. Once it makes landfall, Harvey moves quickly to the northeast. I say good riddance to Harvey.

Here is what I think will happen.
-Heavy rain at night, especially near and east of the center, which is East Texas and Southwest Louisiana.
-Not ruling out Houston area getting rain again tonight. Looking not as heavy. More like moderate rain.
-Rainfall amounts could range from 10 to 15 inches/25.4 to 38.1 centimeters of rain with isolated totals approaching and exceeding 20 inches/50.8 centimeters.

The forecast models came from NCAR-Tropical Cyclone Guidance, Weather.US, National Hurricane Center, and National Weather Service. Special thanks to all of them.

I am at total loss of words of with Harvey. I cannot imagine what people are going through. This a disaster that I cannot comprehend. It defies any description.

2015-2016 Winter Forecast

Snowman01

It is this time of the year. Winter is coming as Christmas is coming. It seems like Christmas comes sooner and sooner each year. One huge factor for this winter is the strong El Nino. It is one of the strongest El Nino since 1997-1998 if we go back to 1950. There were strong El Nino before 1950. 1877-1878, 1888-1889, 1896-1897, 1902-1903, 1904-1905, and 1940-1941 had strong El Nino.

Other factors to consider are Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), and now Northeast Pacific Warm Pool (NEPWP). However, since this El Nino is large and strong and has significant impact, it will weigh in more than other factors listed. Since, we have a strong El Nino, here are my analog winters.

1877-1878
1888-1889
1896-1897
1902-1903
1940-1941
1957-1958
1972-1973
1982-1983
1991-1992
1997-1998

I choose these analog years because they are strong El Nino regardless of Eastern Equatorial or Modoki or Central Pacific. I did not include 1904-1905, 1987-1987, and 1992-1993 because the peak happened in Spring, unlike right now. Since, I go by divisional climate data, there is nothing before 1895, but there are local climate data before 1895, but it would be tedious to look at. However, I can look at upper air pattern and temperature anomaly in those analog years thanks to 20th Century Reanalysis Monthly Composites, which has 20CRV2c.

2015-2016Winter500mbGeopotentialAnomalyWorld

It shows troughing south of Alaska, which is a positive East Pacific Oscillation (EPO). A positive EPO is less favorable for freezes. Now, that does not mean the EPO will always be positive because it can go negative. A negative EPO would have ridging over Alaska, which means a better chance for cold blasts in the winter. There is also ridging off the east coast of Japan and surrounding Antartica.

So, how does it affect temperature and rainfall? Let’s start with temperature.

2015-2016_Analog_WinterTemperatureAnomaly_World

The Northern part of America is warm as the jet stream travels further south than normal. It is also warm throughout South America as El Nino is off the coast of South America. It is cold in the Arctic and Antartica region. El Nino also effects rain.

2015-2016_Analog_WinterPrecipitationAnomaly_World

In terms of rainfall, Southern and Western US, West Coast of South America, Central Africa, Northern Pakisan/Afghanistan, and Southeast China is wetter than normal. The wettest is the area over where El Nino is. Meanwhile, most of Eastern South America, Philpppines, Indonesia, Northern Australia, Southeast Africa, Madagascar, and Central America are going to be dry. Droughts are usually a huge problem during El Nino for those areas.

Keep in mind temperature and rainfall records often do not go back to the 19th Century in many parts of the world. Let’s take a look at divisional climate in America. The data goes back to 1895, so there will be no data available prior to 1894, which means no data for 1877-1878 and 1888-1889. Let’s start with rainfall.

2015-2016_Analog_Divisional_Rain_StandardizedAnomaly

Rainfall is heavier to the south as mentioned previously due to jet stream. The jet steam carries more storm systems over the Southern US. Meanwhile, the Northern US is drier as a result. Generally it is wetter, but not always. Here is the wettest and driest analog years.

America
Driest: 1896-1897 6.68
Wettest: 1997-1998 8.99
Analog Mean: 7.61
Analog Standard Deviation: 0.87
Overall Mean (1895-2015): 6.74
Overall Standard Deviation (1895-2015): 0.88

Texas
Driest: 1896-1897 3.49
Wettest: 1991-1992 12.72
Analog Mean: 7.09
Analog Standard Deviation: 2.63
Overall Mean (1895-2015): 4.82
Overall Standard Deviation (1895-2015): 1.83

Upper Texas Coast
Driest: 1896-1897 5.30
Wettest: 1991-1992 23.54
Analog Mean: 13.18
Analog Standard Deviation: 5.24
Overall Mean (1895-2015): 10.24
Overall Standard Deviation (1895-2015): 3.53

1896-1897 was dry overall for America including Texas and Upper Texas Coast. The wettest is 1991-1992 and 1997-1998. Overall, analog years are wetter than normal. How does temperature fare?

2015-2016_Analog_Divisional_Temperature_StandardizedAnomaly

The Southern US is cooler than normal. It is due to the perpetual cloud coverage and rain, which keeps things cooler than normal. There can also be cold blasts during a strong El Nino. Up north is warmer than normal in the winter. Some people would like it as those areas are cold in the winter. Here is the warmest and coolest analog years.

America
Coolest: 1902-1903 30.03°F
Warmest: 1991-1992 36.35°F
Analog Mean: 33.55°F
Analog Standard Deviation: 2.29
Overall Mean (1895-2015): 32.31°F
Overall Standard Deviation (1895-2015): 2.01

Texas
Coolest: 1972-1973 43.83°F
Warmest: 1991-1992 46.90°F
Analog Mean: 46.90°F
Analog Standard Deviation: 1.89
Overall Mean (1895-2015): 47.28°F
Overall Standard Deviation (1895-2015): 2.31

Upper Texas Coast
Coolest: 1972-1973 50.13°F
Warmest: 1997-1998 55.93°F
Analog Mean: 53.47°F
Analog Standard Deviation: 1.09
Overall Mean (1895-2015): 53.97°F
Overall Standard Deviation (1895-2015): 2.63

America is warmer overall in those analog years. That is due to the Northern US being warmer than normal. Texas and Upper Texas Coast is cooler than normal due to all the rain and clouds over the Lone Star State. The combination and cooler and wetter weather increases the chance for winter weather for Southeast Texas. What about snow?

In Southeast Texas, snow has occurred in these analog years.
1896-1897
1957-1958
1972-1973

The data record from Houston Weather Bureau (WB) in January 1897 has handwriting I cannot read too well. It says that snow and a blizzard happened in Houston on January 25, 1897. There was a hard freeze from January 25-29. It did not go above freezing between January 26-29. It is a freeze in par with other huge freezes in January/February 1951 and February 1989 freezes! February 12, 1958 saw a snow flurry. The Winter of 1972-1973 had three snowfall events of over one inches. That is unheard in Houston area! It is also one of the coldest winters on record for Upper Texas Coast on par with 1977-1978 and 2009-2010. There is no weather record from 1877-1878 in Southeast Texas, so I do not know what the weather was like that time. 1888-1889 had no snowfall recorded. There were some freezes in January and February of 1889. It was more of a wet winter that time. This is from Houston WB records.

Another thing to consider is severe weather. I created a GIS heat map of tornado, hail, and strong wind for those analog years. The tornado, hail, and strong wind is from the 1950s and later. They are all within 300 miles. Let’s start with tornadoes.

2015-2016_Winter_Analog_Tornado

Tornadoes are generally rare in the Winter, but they can happen. In analog winters, tornadoes are most common from Southeast Texas, Louisiana, Arkansas, and Missouri. The second hot spot is Central Florida. El Nino causes the jet stream to go further south, allowing storms to track over. These storms dump heavy rain and can produce severe weather. Let’s look at strong winds from storms.

2015-2016_Winter_Analog_Wind

The entire Eastern US is most at risk for strong winds. Also, Central California is at most risk for strong winds. Strong winds can from severe thunderstorms and storm systems, a tight pressure gradient of low and high pressure, or a cold front passes. So, what effect does El Nino have on hail in the winter?

2015-2016_Winter_Analog_Hail

The highest risk for hail is Texas, Oklahoma, Arkansas, Louisiana, Southern Kansas, and Southern Missouri. There is also a higher risk in Alabama and Georgia and Southern Florida. Not a good thing as severe weather is generally more common in an El Nino winter in the Southern US.

The heat map could give us a good idea where severe weather events could happen this winter. Frankly, I would be just as concerned about severe weather, especially in the Southern US. I would not be surprised if this winter will be known as the winter of severe weather besides winter weather.

Past El Nino does not guarantee that this El Nino will be similar. All El Nino’s are different. Regardless, I expect an interesting winter coming. So fasten your seatbelt tightly. It will be a rough ride for sure.

Northeast Pacific Warm Pool

NEPWP

I first noticed an area of warm water in the Northeast Pacific in the cold Winter of 2013-2014. I call it the Northeast Pacific Warm Pool (NEPWP) and created an anomaly data from NOAA ERSST v3. The NEPWP Region is between 35°N and 50°N and 165°W and 135°W. It goes back to 1870 and anomaly is based on 1981-2010 average. Here is the Northeast Pacific Warm Pool data I created from 1870 to 2014. Keep in mind, any data before 1950 should be taken with a grain of salt as they are not directly measured.

Here is what the 500 millibar (18,000 feet) Geopotential Height anomaly looked like this past winter winter.

20132014Winter_500mbGeopotentialHeight_Anomaly_NH

Notice a great deal of ridging over Alaska, Gulf of Alaska, and Siberia. The ridging over Alaska is the negative phase of East Pacific Oscillation (EPO). It is the Pacific equivalent to the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO). So, how does NEPWP and EPO correlate. Here is data for meteorological winter (December to February), spring (March to May), summer (June to August), and fall (September to November). The data is from 1948 to 2014 up to Summer. The EPO link is daily, but I converted it to monthly.

DJF NEPWP EPO
r = -0.45
p < 0.05

MAM NEPWP EPO
r = -0.47
p < 0.05

JJA NEPWP EPO
r = -0.37
p < 0.05

SON NEPWP EPO
r = -0.40
p < 0.05

NEPWP and EPO are strongly correlated. Cooler NEPWP is more favorable for positive EPO, while warmer NEPWP is more favorable for negative EPO. Warmer water allows ridging to develop over Alaska and Northwestern Canada. NEPWP could give us an idea about EPO even before 1948. A warm NEPWP have negative EPO, while cool NEPWP have positive EPO. Of course, correlation does not mean caustation, but it is a factor.

The ridging allows cold air to come down to the Lower 48, which lead to an Arctic blast and cold winters. As the Lower 48 froze, Alaska, Northern Canada, and Western US are warm due to the ridging. The previous two winters were quite warm compared to this past winter. Here is a surface temperature anomaly map of Winter 2013-2014.

20132014Winter_SurfaceTemperature_Anomaly_NH

Notice that the Eastern two-thirds of North America is quite cold. The polar regions are unusually warm as it is with the Western US. The ridging made those areas warm and caused the jet stream to pull in cold air that is normally in the polar regions. The ridging also plays a role in precipitation as a map shows which areas are drier and wetter than normal.

20132014Winter_PrepRate_Anomaly_NH

The Western US is very dry. No surprise they are in a drought, especially in California, which is really dire. The ridging shunts the low pressure systems away from California and Western US. Interesting to note that Alaska is not dry despite the ridging, but the Bering Sea and western point of Aleutian Islands are dry. Interesting fact, the Aleutian Islands are the westernmost and easternmost point in America as it crosses the 180 degree longitude. Some of the Aleutian Islands are west of 180 degrees longitude in the Eastern Hemisphere.

Wonder what the geopotential height anomaly is like at 18,000 feet (500 millibar level) during a moderate and strong warm NEPWP. I define moderate warm NEPWP is 0.5 to 0.899 or 5.0 to 8.99 above 1981 to 2010 mean, while strong warm NEPWP as 0.9 or 9.0 and above 1981 to 2010 mean. Here is a map of what it looks like. All anomaly maps from here are for winter from December to February and since 1950.

DJF_ModerateToStrongWarmNEPac_500mbGeopotentialHeight_Anomaly_NH

Notice ridging over Alaska, the warm water allows ridging to form, which is a negative EPO. There is troughing over Northern Canada and Greenland, which is a positive NAO. Interesting to note there is ridging over the Southeast US. How is winter temperature like during a moderate and strong warm phase of NEPWP?

DJF_ModerateToStrongWarmNEPac_SurfaceTemperature_Anomaly_NH

Interesting to note that Canada and Northern US is very cold when there is a moderate and strong NEPWP. The Southern US is warm, which is rather interesting. Overall, Southern US is warmer and Northern US and Canada is cooler during the winter with a moderate and strong NEPWP in place. The troughing over Canada and Greeland keeps Canada and Northern US colder, which bottles up cold air. A positive NAO gives the Southern US a warmer than normal winter. Opposite when NAO is negative, which is colder than normal.

Wonder what a warm NEPWP does to rainfall? Here is a precipitation rate map.

DJF_ModerateToStrongWarmNEPac_PrepRate_Anomaly_NH

The Western US and Canada is very dry. That is no surprise as California is in a severe drought at the time of this article. Parts of the Southeast, Midwest, to East Coast is wetter than normal. Overall, a warm NEPWP does not have much impact on precipitation in the winter.

Regardless, there have been big freezes and major winter events when there is a moderate and strong warm NEPWP. Late January to early February 1949 had a huge Arctic blast. January 1962 had a huge Arctic blast which is considered one of the big freezes in history as it set temperature and surface pressure records. Winter of 1978-1979 is one of the coldest winters on record for America since 1895. It occurred when America saw back to back cold winters in the late 1970s. December 1989 had a huge freeze that is on the level of 1886, 1895, 1899, and 1983. A year after the December 1989 freeze, another huge freeze hit in December 1990, which hit the Western US. An epic White Christmas came in 2004 for Texas.

It is opposite when the NEPWP is in a cool phase. I define moderate cool NEPWP is -0.5 to -0.899 or -5.0 to -8.99 below 1981 to 2010 mean, while strong cool NEPWP as -0.9 or -9.0 and below 1981 to 2010 mean. There is troughing over Alaska, Siberia, and Southeastern US. There is ridging over Northern Canada and Greenland. Troughing over Alaska is a positive EPO, while ridging over Northern Canada and Greenland is a negative NAO.

DJF_ModerateToStrongCoolNEPac_500mbGeopotentialHeight_Anomaly_NH

So, how is temperature affected by cool phase of NEPWP? Here is a temperature anomaly map.

DJF_ModerateToStrongCoolNEPac_SurfaceTemperature_Anomaly_NH

It is not as warm during cool NEPWP. As mentioned, since there is ridging over Northeastern Canada and Greenland, it shunts the cooler air down south. The ridging over Northeastern Canada and Greenland is a negative NAO. As a result of ridging, Northeast Canada and Greenland is warmer than normal. It is cold over Alaska, Northern Asia, and Siberia due the trough locking up cold air. Does cool NEPWP have the opposite affect on precipitation from warm NEPWP?

DJF_ModerateToStrongCoolNEPac_PrepRate_Anomaly_NH

Western US and Canada are wet, which is opposite from warm NEPWP. Southeast Texas, Southeast, and Northeast have wetter than normal winter. The Northeast is not affected by cool or warm NEPWP. It has more of an affect west of the Mississippi River. Cool and warm NEPWP have impact on rainfall on different areas. It could dry in one area and wet in the other area.

Even when the NEPWP is in a moderate to strong cool phase, freezes and major winter events have happened. Late January to early February 1951 had a huge freeze that covered North America and is one of the greatest freezes between 1949 to 1962. Houston had the longest below 32°F for 5 days in the 1951 freeze!

It shows that NEPWP is not the only factor when it comes to winter weather. There is El Nino Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO), NAO, AO, and EPO. NEPWP is certainly a factor and it influences EPO.