Atlantic Hurricane Season In June

As we are in June and hurricane season is heating up. Where do most June tropical storms and hurricanes form and end up going?

Here is a GIS heat map I created. This is all June tropical storms and hurricanes from 1870 to 2015.

Most June tropical storms and hurricanes form in the Gulf of Mexico, Southwest Caribbean, and off the Carolinas. No surprise that Texas and Florida are most vulnerable to tropical storms and hurricanes in June.

Leap Day 2016

It is Leap Day and it comes every four years. So, what is the weather like on Leap Day in Houston? Here is official weather records on February 29th.

Houston Weather Branch 1921-1968
Year High Low Average Rainfall
1924 67 42 55 0
1928 75 33 64 T
1932 85 64 75 0
1936 71 50 61 0
1940 82 57 70 T
1944 62 45 54 0
1948 72 59 66 0.01
1952 83 58 71 0
1956 68 50 59 0
1960 53 49 51 0
1964 60 45 53 0
1968 49 39 44 0

Bush Intercontinental Airport 1969-2010
Year High Low Average Rainfall
1972 72 61 67 0.33
1976 78 57 68 0
1980 82 63 73 T
1984 55 28 42 0
1988 82 58 70 T
1992 82 48 65 0
1996 47 39 43 0.53
2000 80 57 69 T
2004 72 56 64 0.49
2008 78 57 68 T
2012 84 71 78 0

From 1920 to 2012, only one (4.4%) Leap Day saw below 32°F, which was in 1984. The winter of 1983-1984 was one of the coldest winters on record. Seven out of 23 (31.8%) Leap Day saw at least 80°F days. The warmest Leap Day occurred in 1932. Interestingly, it snowed on March 10, the latest measurable snowfall recorded in Houston. Also, it is not very wet on Leap Day. In fact the record rainfall is 0.53 inches, which fell in 1996. It rained in 10 out of 23 (43.5%) Leap Day from 1924 to 2016. There is more chance to see rain than to see 80°F Leap Days in Houston.

Here are some interesting facts about Leap Day. Leap year occurs in year divisible by 4. However, there are exceptions when years that are divisible by 100, they are not leap unless they are divisible by 400. So the year 1900 is not Leap Year, while 2000 is Leap Year. The purpose of Leap Year is meant to keep calendar in alignment with the Earth’s revolutions around the Sun, which is every 365 days, 5 hours, 48 minutes, and 46 seconds or 365.242199 days. Happy Leap Day!

Weather In Review And Forecast For August 2, 2015

This week has been hot for Texas. Nor rain in sight either. Strange we had lots of rain in Spring to June. It is like if someone turned off the faucet. Typical of a developing strong El Nino summer.

20150803_July_ElNino_PrecipitationRate_NorthAmerica

Not surprised by it one bit. Texas is dry, while Florida is wet. In fact, it has been quite wet in Florda.

20150803_7Day_Rainfall_Total

The past 7 days has been wet in Florida, especially in the northwestern part of the state. They have seen over 15 inches of rain! There have been flooding reported in the Tampa area.

So, how will this week to next week be like? In lieu of forecast models, I will use analog forecast models courtesy of the Climate Prediction Center. 6 to 10 days forecast comes first.

20150803_6To10Day_AnalogForecast

8/17/1976-Tropical Storm Dottie makes landfall on South Florida and South Carolina. Many areas recorded 4 to 8 inches of rain with 10.68 inches in Fort Lauderdale. Four people lost their life from the storm. Hurricane Belle made landfall on Long Island, New York as a Category 1 hurricane on August 10. The storm did $100 million and claimed 12 lives.
8/25/1961-Southeast Texas closes August 1961 with rain everyday from summer thunderstorms. Hurricane Carla makes landfall near Port O’Connor on September 11th as a large Category 3/4 hurricane. Gusts as high as 175 mph are recorded with 19 inches of rain. 43 people lose their life from massive storm surge of 22 feet.
8/3/1991 & 8/9/1991-Hurricane Bob forms on August 16th ans skirts Outer Banks of North Carolina and becomes a Category 3 hurricane. Bob brushes Long Island and makes landfall near Newport, Rhode Island as a Category 2 hurricane. Than it makes a second landfall near Rockport, Maine, as a Tropical Storm. Bob does $1.5 billion in damages and claims 17 lives throughout the East Coast.
8/21/1981-Tropical Depression Eight makes landfall and dumps heavy rain on Texas and Oklahoma. Up to 21 inches of rain fell in 24 hours in Pine Springs, Texas. 5 people died from flooding.
8/7/1995 & 8/8/1991-Hurricane Erin first affects the Bahamas as a Tropical Storm and Category 1 hurricane. Than makes landfall on Vero Beach, Florida as a Category 1 hurricane. It enters the Gulf of Mexico as a Tropical Storm and intensifies into a Category 2 hurricane before it hits Fort Walton, Florida. Erin does $700 million in damages and claims 13 lives.

Many of those analog dates I mentioned had a tropical system make landfall on America. Does this mean it will happen in the next 6 to 10 days? No. We are entering the more active phase of the season. If something tropical that develops could make landfall on America. The forecast also suggests rain could return for Texas by next week.

Now, let’s look at the 8 to 14 day analog forecast.

20150803_8To14Day_AnalogForecast

8/23/2005 & 8/28/2005-Hurricane Katrina forms over Bahamas on August 23rd. Than makes landfall on South Florida on August 25th as a Category 1 hurricane. It enters the Gulf of Mexico as a Tropical Storm. From there, it undergoes rapid intensification as it gets stronger. On August 28th, Katrina is a Category 5 hurricane with 175 mph winds and central pressure of 902 millibars and heading towards New Orleans. Katrina makes landfall as a Category 3 hurricane on South Louisiana and Mississippi. The hurricane produces massive storm surge of over 30 feet! The same storm surge floods New Orleans and surrounding area. Many thousands are evacuated before and after the hurricane. The hurricane claims 1,836 lives and does $125 billion in damages, the most costliest natural disaster in America to date.
8/7/1998-Tropical Storm Charley forms on August 21st and makes landfall on near Corpus Christi, Texas on August 23rd as a weak tropical storm after intensifying as a strong tropical storm. Del Rio sees heavy rain from what was Charley on August 24th. Over 17 inches of rain fell in Del Rio, setting an all time record.
7/31/1991 & 8/8/1991-Hurricane Bob forms on August 16th ans skirts Outer Banks of North Carolina and becomes a Category 3 hurricane. Bob brushes Long Island and makes landfall near Newport, Rhode Island as a Category 2 hurricane. Than it makes a second landfall near Rockport, Maine, as a Tropical Storm. Bob does $1.5 billion in damages and claims 17 lives throughout the East Coast.
8/12/1953-Hurricane Barbara makes landfall on Cape Hatteras, North Carolina on August 13th as a Category 2 hurricane. Many areas see 5 to 10 inches of rain from Barbara with winds of 50 to 80 mph. Barbara claims 9 lives.

Like the 6 to 10 day analog forecast, something tropical happens. Two dates are infamous and they are in 2005. It is Hurricane Katrina, which happened ten years ago this month. Wow, I remember that nasty storm like yesterday. It was all over the news. It was the second disaster to claim over thousands of lives in America. The other being 9/11, which claimed 3,000 lives.

Even though we are in El Nino, do not let your guards down. It only takes one, like in the case with Hurricane Bob in 1991. That occurred with a developing El Nino, which became a strong Modoki El Nino.

Bill In Review And Forecast For June 21, 2015

20150616_02L_VIS_1955Z

We are now officially in Summer. The days are starting to get slowly shorter each day. Of course, it feels hot as it is Summer. Meanwhile, Southeast Texas got hit by Tropical Storm Bill last week. Some areas got a lot of rain, while others did not. It is the first time that a tropical cyclone made landfall on Texas coast since Ike in 2008. Well, Texas felt Hurricane Alex and Tropical Storm Hermine in 2010 and dried out Tropical Storm Don in 2011.

20150622_7Day_Rainfall_Total

The areas closer to the center of Bill got more rain. Some areas got nearly 20 inches of rain in the past 7 days as seen in the map! The areas northwest of Houston got a lot of rain as well in part due to Bill. Houston area got 2 to 6 inches of rain. Isolated areas got as much as 12 inches of rain.

With Bill gone, how is this week to next week going to fare? There are various ways to look at it. If we just use this week, we can use a surface map produced by the Weather Prediction Center (WPC).

20150622_WPC_SFC_CONUS_3to7Days

It shows a unusual summer cold front heading towards Houston by the weekend. Depending on where it goes over, someone could see thunderstorms fire up along the boundary. It just one forecast method use. Another is the analog upper air pattern. It goes up to 14 days. Let’s start with 6 to 10 days analog forecast.

20150622_6To10Day_AnalogForecast

7/2/2006-Southeast Texas has a wet Independence Day week.
7/2/1972-Hurricane Agnes ravages the Eastern US with strong winds and flooding. Many areas see 6 to 12 inches of rain with as much as 19 inches of rain in western Schuylkill County, Pennsylvania on 6/19 to 6/24.
7/1/1998-Galveston sees heavy rain on 6/28-29 from a tropical wave. Galveston: 11.64″; Bush Intercontinental: 0.62″; Hobby: 1.82″. Galveston records its wettest 6/28 (6.90″) and 6/29 (4.74″).
6/27/1987-Houston area sees rain from 6/29 to 7/2. Four day totals are Bush Intercontinental: 2.46″; Hobby: 3.98″; Galveston: 2.80″.
7/10/1961-Southeast Texas sees a wet July. Houston officially sees its wettest 7/9 of 2.39″. Hobby also sees its wettest 7/9 of 2.42″.
7/11/2007-Southeast Texas sees a wet July. Upper Texas Coast has second wettest July after 1900 of 12.29″.
7/10/1952-Galveston sees it wettest 7/17 of 4.91″.
6/26/2004-Texas is in midst of a wet June. June 2004 was the wettest month for Texas prior to May 2015.

Looking at those analog dates, this bodes a wet one for Texas. In the mean time, let’s look at 8 to 14 day analog forecast.

20150622_8To14Day_AnalogForecast

6/27/2006 & 7/2/2006-Southeast Texas has a wet Independence Day week.
7/11/1952-Galveston sees it wettest 7/17 of 4.91″.
6/30/1998-Galveston sees heavy rain on 6/28-29 from a tropical wave. Galveston: 11.64″; Bush Intercontinental: 0.62″; Hobby: 1.82″. Galveston records its wettest 6/28 (6.90″) and 6/29 (4.74″).
6/20/2004 & 6/26/2004-Texas is in midst of a wet June. June 2004 was the wettest month for Texas prior to May 2015.
7/2/1972-Hurricane Agnes ravages the Eastern US with strong winds and flooding. Many areas see 6 to 12 inches of rain with as much as 19 inches of rain in western Schuylkill County, Pennsylvania on 6/19 to 6/24.
6/28/1987-Houston area sees rain from 6/29 to 7/2. Four day totals are Bush Intercontinental: 2.46″; Hobby: 3.98″; Galveston: 2.80″.

The 8 to 14 day analog forecast is mainly similar to the 6 to 10 day analog forecast. This suggest this week to next week is going to be a wet one for Texas. I suspect this summer will be a wet and cool one.

2014-2015 Winter

Spring has arrived as days get longer each day. It has been a winter of really cold or warm. The Northeast basked in deep freezes and snow. The Western US was warm like if summer stayed. How did Winter 2014-2015 stack up? Let’s start with America.

America
Temperature: 34.44°F
Rainfall: 6.04

1895-2015 Winter Statistics
Winter Temperature Mean: 32.31°F
Winter Temperature Median: 32.48°F
Standard Deviation: 2.02

Winter Rainfall Mean: 6.74
Winter Rainfall Median: 6.69
Standard Deviation: 0.88

The average winter temperature is outside the standard deviation of the mean. It was an abnormally warm winter. The US had its 99th warmest winter on record, tying with 1932. In fact, it is in the top 20 warmest winters since 1895.

Top 20 Warmest Winter
1.) 1999-2000 36.48°F
2.) 1991-1992 36.35°F
3.) 2011-2012 36.34°F
4.) 1998-1999 36.27°F
5.) 1997-1998 35.90°F
6.) 2001-2002 35.66°F
7.) 1994-1995 35.56°F
8.) 2005-2006 35.49°F
9.) 2004-2005 35.46°F
10.) 1953-1954 35.33°F
11.) 1933-1934 35.28°F
12.) 1982-1983 35.27°F
13.) 1952-1953 35.25°F
14.) 1920-1921 34.80°F
15.) 1980-1981 34.73°F
16.) 1975-1976 34.59°F
17.) 1931-1932/2014-2015 34.44°F
18.) 1986-1987 34.42°F
19.) 2012-2013 34.32°F
20.) 1930-1931 34.03°F

How come despite the bitter cold winter in the Northeast. The Western US had a very warm winter. The Western US is much larger than the Eastern US. Here is a division temperature ranking.

2014-2015_WinterTemperatureDivisionalRanks

Notice the Eastern US had cold winters, while Western US had warm winters. I know that the Northeast had cold January and February as shown in this map.

201412_WinterTemperatureDivisionalRanks

201501_WinterTemperatureDivisionalRanks

201502_WinterTemperatureDivisionalRanks

Some areas had their coldest February on record. Winter came rather late. December 2014 was quite warm as seen this divisional map. It was like if winter did not want to come in December 2014.

So, why this happened you ask? Here is a upper level map at 18,000 feet of Northern Hemisphere.

2014-2015Winter500mbGeopotentialAnomaly

2014-2015_500mbGeopotentialHeightMean_NH

There is ridging over Alaska and Western US. The ridging over Alaska is the negative East Pacific Oscillation (EPO), West Pacific Oscillation (WPO), and positive Pacific North America Teleconnection (PNA). The ridging diverts cold air into the Northeast, where there is troughing. The persistant troughing allows cold air to come down south from the Arctic and Siberia. The troughing over Northeast Canada and Greenland is a positive North Atlantic Oscillation (NAO). Normally, a positive NAO favors warm winters for the US. However, since EPO and WPO are negative, while PNA is positive, it overpowered a positive NAO. It shows that NAO is not the only factor for cold winters. It is vice versa when NAO is very negative, while EPO and WPO are positive, while PNA is negative.

How did 2014-2015 Winter treat Texas?

Texas
Temperature: 47.77°F
Rainfall: 4.89

1895-2015 Winter Statistics
Winter Temperature Mean: 47.28°F
Winter Temperature Median: 47.27°F
Standard Deviation: 2.31

Winter Rainfall Mean: 4.82
Winter Rainfall Median: 4.72
Standard Deviation: 1.83

Winter was normal as it is close to the mean. It was nowhere like last winter, which was much colder. To make that up, it was wetter than last winter. More rain fell than last winter, which was a dry winter. That is a good thing as Texas is still reeling from the drought. How was the Upper Texas Coast like?

Upper Texas Coast
Temperature: 53.60°F
Rainfall: 9.64

1895-2015 Winter Statistics
Winter Temperature Mean: 53.96°F
Winter Temperature Median: 53.90°F
Standard Deviation: 2.63

Winter Rainfall Mean: 10.24
Winter Rainfall Median: 9.86
Standard Deviation: 3.53

Temperature and rainfall were within average even with a weak El Nino. There was snow in the Texas Panhandle and North Texas in February and even March. January was rather cold for the Upper Texas Coast. Despite it all, 2014-2015 was an average winter. A stark contrast from last winter for Texas, which was a cold and dry one.

So how did my forecast turn out? Let’s look at 2014-2015 temperature and precipitation.

2014-2015_WinterTemperatureAnomaly_NH

2014-2015_WinterPrecipitationAnomaly_NH

East of the Rocky Mountains was cooler, especially in the Northeast. The Western US was very warm like if Summer chose to stay in December. Also, Siberia was very warm, along with Europe. All the cold air went to the Eastern US this past winter. Many areas in the Western US had record warm winters for 2014-2015.

Most areas had near normal rainfall for Winter with the exception of British Columbia, Southern Mexico, and Mediterranean. The Western US drought situation is getting somewhat better. Better to have rain than no rain for sure.

Here’s the analog map for 2014-2015 Winter I created.

2014-2015_WinterTemperatureAnomaly_NH

2014-2015_WinterPrecipitationAnomaly_NH

The temperature anomaly for 2014-2015 looks similar to the analog temperature anomaly map, with the exception of colder winter over Siberia and Arctic. Some of those analog winters were very cold like 1972-1973, 1976-1977, and 2009-2010.

The precipitation anomaly map does not look similar in those analog winters. The exception is the Mediterranean and Southern Mexico, which had wet winters in those analog winters. The analog years for America have wet winters in the southern half of America. That was not the case for this past winter.

What could next winter be like? It could depend on how El Nino behaves. We are likely seeing a multi-year El Nino, which last happened in 1986 to 1988. A multi-year El Nino is much rarer than a strong El Nino like in 1982-1983 or 1997-1998. I should know more later this year.

2014-2015 Winter Forecast

christmas01

Winter is here again and Christmas is coming. It seems like Christmas comes sooner and sooner every year. This winter looks to be an interesting one.

What do I look at to predict what this coming winter will be like? I look at El Nino Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), and now Northeast Pacific Warm Pool (NEPWP).

Here is why I added NEPWP to the forecast. Last winter, the NEPWP was very warm, which created ridiging over Alaska and Northwestern Canada, which allowed cold air to go down south into the Lower 48. It allows the East Pacific Oscillation (EPO) or North Pacific Oscillation (NPO) to be in negative, which allows riding.

I have also included the temperature anomaly of Baffin Bay and Hudson Bay. I call it Baffin Hudson (BH). I used the same method for NEPWP. It is based on a weighted average with Baffin Bay being weighted more than Hudson Bay as Baffin Bay temperature is more likely to correlate with North Atlantic Oscillation (NAO) and Arctic Oscillation (AO).

20141222_SST_GlobalAnomaly

Since El Nino is developing, I do not put much weight on PDO as PDO warms up with El Nino, like it happened in 2009-2010. This past winter was a borderline Neutral/La Nina. Here are analog winters solely on El Nino with a previous winter that is Cool Neutral to Weak La Nina.
1888-1889
1972-1973
1976-1977
1994-1995
2002-2003
2003-2004
2004-2005
2009-2010

So, how was Winter like in those analog years? Let’s start with temperature as it is on everyone’s mind when it comes to Winter.

2014-2015_WinterTemperatureAnomaly_NH

East of the Rocky Mountains is a cold one in those analog years. However, if you are in the Western Canada and Alaska, it is a warm one. It is brutally cold over Canadian Arctic Archipelago, Arctic Ocean, Siberia, and most of Russia. Most of the cold air for America comes from Arctic and Siberia. It also colder than normal in Southern China. Believe it or not, it can snow in Hong Kong despite being in a tropical latitude. It occurs mostly in the mountains where the air is colder.

The reason for cold air in Hong Kong is the large Asian continent and to the north. Land does not allow cold air to moderate, unlike here in North America, where we have the Gulf of Mexico, Pacific, and Atlatnic on all sides. Asia only has the Pacific to the east and South China Sea to the south. There is no ocean to the west as it is all land mass. Okay, let’s get back on topic. I think we could see multiple cold blasts this winter as I will explain later. This time let’s look at precipitation in those analog years.

2014-2015_WinterPrecipitationAnomaly_NH

Winter is wetter the further south you are in America. It is dry in the Pacific Northwest and around Appalachia. I suspect that data is suspect as I included 1888-1889, in which data is limited. The wetter than normal winter is good news for drought ridden California, Arizona, New Mexico, and Texas. El Nino is generally more favorable for rain. El Nino usually causes water to be warmer off the West Coast of America. Warmer water generally means wetter because warm air from the ocean water carries more moisture. Also, warmer water causes jet stream to go further south due to gradients in temperature. The jet stream allows storms to go over southern half of America and can bring cold air. This also increases the chance for winter weather events from freezing rain, sleet, and yes snow. Miami saw snow in 1977, which is one of the analog years I have.

In Southeast Texas, snow has occurred in these analog years.
1972-1973
1994-1995
2004-2005
2009-2010

1972-1973 has the most over 1 inch snowfall for Houston. There were three snowfall events that winter! A rarity for Houston area for sure. I think this Winter could see more winter weather events including snow.

Let’s look at the upper level at 18,000 feet.

2014-2015_500mbGeopotentialHeightAnomaly_NH

There is a lot of ridging over Alaska, Canada, Greenland, and Russia. Ridging over the area is more favorable for cold air to be shunted southwards. All the cold air shunted southwards makes Alaska and Northwestern Canada warmer. This increases the liklihood for cold blasts in the winter. Ridging over Alaska is a negative East Pacific Oscillation (EPO), while ridging over Greenland is North Atlantic Oscillation (NAO) and Arctic Oscillation (AO). The ridging over Eastern Russia is the West Pacific Oscillation (WPO). There is also ridging over North Central Siberia, in a unnamed atmospheric oscillation. Perhaps, scientists will identify and name that one.

The warmer than normal waters in Baffin Bay, Bering Sea, and Gulf of Alaska are more favorable for upper leveling ridging. Last winter was cold in part because of the abnormally warm Gulf of Alaska, which I call it the Northeast Pacific Warm Pool.

So, what will Winter be like? Depending on where you live, it could be warm or cold. For Southeast Texas, it is looking to be a cold and wet winter. Here is a table of average temperature in those analog winters. 1888-1889 is missing as it is from divisional data. It only goes back to 1895.

2014-2015AnalogTemperatureTable

For America, analog winters are slightly warmer than normal. That is due to the Western US being warmer than normal. Texas is cooler as cold air is more likely to go east of the Rocky Mountains. It is also due to the fact that the jet stream is further south than normal, which allows clouds to go over. The clouds keep things cooler. This also applies to the Upper Texas Coast.

2014-2015AnalogPrecipitationTable

Not much difference in terms of precipitation for America as it is within the means. However, median is slightly higher than nromal in terms of precipitation. One of the analog winters, 1976-1977 is the driest on record. For Texas and Upper Texas Coast, it is wetter than normal. As mentioned, the jet stream is further south than normal, which allows storm systems to go over and dump rain. One good thing about El Nino is the rain for Texas.