Tropical Storm Franklin For 8/9/2017 1900 CDT

The first hurricane of the season, Franklin, is getting ever closer to Mexico. It looks to be that way.

Franklin is a Category 1 hurricane with 75 mph 120 km/h 65 knots wind. It has gusts of 94 mph 150.4 km/h 82 knots. Further intensification is possible as shown in the forecast model. Two models keep Franklin as a hurricane despite being over the mountains of Mexico. I am not convinced that will happen as the mountains tend to weaken hurricanes.

I would not be surprised if Franklin becomes a Category 2 hurricane with 105 mph 168 km/h 90 knots wind right before landfall as looks to be intensifying further. Franklin is an average sized hurricane. Tropical storm force winds extend up to 140 miles 224 km/h 122 nautical miles. Hurricane force winds extend up to 35 miles 56 km/h 30 nautical miles. from the eye.

Most areas in Mexico will see at most tropical storm force winds with hurricane force winds. Hurricane force winds should be most likely confined to the coast. Here is a probability map of hurricane force winds.

If Franklin makes landfall as a 85 mph 136 km/h 74 knots hurricane, the strongest wind possible is 72 mph 115 km/h 63 knots with gusts as high as 108 mph 173 km/h 94 knots. I determine this by multiplying the strongest winds by 0.85. Land reduces wind by 15 percent. However, due to friction, gusts are higher as I multiply sustained winds by 1.5.

My main concern is heavy rain from Franklin. Franklin is moving as 12 mph, which means it can dump about 8 inches (20.32 centimeters) of rain. Many areas are likely to see 4 to 10 inches (10.16 to 25.4 centimeters) of rain. Mountains areas could see as much as 20 inches (50.8 centimeters) of rain. This amount is certainly going to lead to flooding that can be deadly.

Tropical Storm Franklin For 8/8/2017 2200 CDT

Tropical Storm Franklin has exited the Yucatan Peninsula as a tropical storm. It is over the Gulf of Mexico as I type. It looks to be intensifying. The intensity and where it goes forecast models are always interesting and challenging. There are different outputs from different forecast models.

Most keep Franklin as a tropical storm. Three of them have Franklin becoming a Category 1 hurricane. The National Hurricane Center has Franklin as a hurricane in 24 hours. It would be the first hurricane of the season. I think Franklin will be a hurricane as it is over the Gulf of Mexico. I do not think Franklin will be a major hurricane. At most a strong Category 1 hurricane. The next question is where Franklin will make its next landfall.

Most of the forecast models have Franklin going into Mexico by tomorrow afternoon. One model has it going northwest towards Texas. That looks very unlikely at this point. The general consensus is Franklin is going to make landfall somewhere on Mexico’s Gulf Coast. Franklin is likely to make landfall somewhere on Mexico as a Category 1 hurricane. By tomorrow night, Franklin will be over the mountains of Mexico. Heavy rain will be the main problem as mountainous areas tend to draw more moisture from clouds.

Many areas could see 4 to 8 inches (10.16 to 20.32 centimeters) of rain. Some areas could see as much as 20 inches (50.8 centimeters) of rain, especially in mountainous areas. Looking at Franklin, I think it will be more of a rain and flood event.

Tropical Storm Franklin For 8/7/2017 2200 CDT

Tropical Storm Franklin is about to make landfall on Yucatan Peninsula as I type. Franklin has 60 mph 96 km/h 52 knot winds. Gusts are high as 75 mph 120 km/h 64 knots. The highest wind at landfall should be 51 mph 81.6 km/h 44 knots with gusts as high as 77 mph 123 km/h 67 knots. Many areas will likely see tropical storm force winds and heavy rain. Many areas will see 4 to 7 inches (10.16 to 17.78 centimeters) of rain with isolated totals of 12 inches (30.48 centimeters). Tropical storm force winds extend up to 140 miles 224 km 122 nautical miles.

Where doe Franklin go after it passes Yucatan Peninsula and how strong will it be? Most of the forecast model has Franklin going over Bay of Campeche and into Mexico again. One forecast model has it heading towards the Central Texas Coast. However, I do not think Franklin will have much of an impact on Texas as it is likely to move westward. The heat map is generated from ATCF data file. The cone is from National Hurricane Center.

Looking at the heat map, there is a general consensus that Franklin is likely going to make landfall on Mexico again. Intensity is of most concern. Here is an intensity forecast from National Center for Atmospheric Research.

Most forecast models have Franklin as a tropical storm as it goes over Yucatan Peninsula. Once it enters the Gulf of Mexico, some forecast models have Franklin becoming our first hurricane of the season with 75 mph 120 km/h 65 knots winds. I think Franklin will be our first hurricane of the season. I would not be surprised if Franklin intensified into a Category 2 hurricane.

Tropical Storm Cindy For 6/21/2017 2200 CDT

Tropical Storm Cindy is getting closer to land. The latest position from National Hurricane Center is 95 miles or 153 kilometers from Port Arthur, Texas as of 10:00 PM or 2200 CDT. Here is the latest Doppler radar image out of NWS Lake Charles.

It is moving 7 mph or 11 kilometers north-northwest. Cindy could make landfall between 3:00 AM to 5:00 AM or 0300 to 0500 CDT at this rate. The question is where Cindy will make landfall.

The data is from UCAR, to be more specific from ATCF data file. I also included the 5 day cone from National Hurricane Center.Looks to make landfall in East Texas our Southwest Louisiana. Still cannot rule a landfall closer to Houston at this time as tropical cyclones tend to wobble. The area around the center of Cindy has produced heavy rain.

Many areas have seen 1 to 2 inches or 2.54 to 5.08 centimeters of rain per hour. Doppler radar estimates the heaviest rainfall rate is 4 inches or 10.16 centimeters per hour! Some areas could see as much as 5 inch or 12.7 centimeters per hour!

Many areas have seen 3 to 6 inches or 7.62 to 15.24 centimeters of rain based on Doppler radar estimates. The highest is 11 inches or 27.94 centimeters of rain. Again, Doppler radar tends to underestimate rainfall totals. I suspect the highest rainfall total is around 12 to 14 inches or 30.48 to 35.56 centimeters of of rain. I think Houston area could see rain from Cindy, especially later tonight. Rainfall total should be about 1 to 3 inches or 2.54 to 7.62 centimeters with amount as high as 5 inches or 12.7 centimeters of rain. I would not be surprised if thunderstorms form on the west side of Cindy and dumps heavy rain over the Houston area while you sleep.

Once Cindy makes landfall, where does it go? Could it stall out over Texas and dump more heavy rain like Tropical Storm Allison in 2001 did? Or could it just move away from Texas? Here is the next 5 day forecast model.

The cone and heat map has Cindy moving towards Arkansas. No forecast model has Cindy stalling over Texas. It can be possible that Cindy will stall over Texas, but that is unlikely at this point. The forecast models are divided where Cindy will go once inland. It can go to the Midwest and Canada or go all the way to the East Coast. Right now, we should keep an eye on Tropical Storm Cindy as it is getting closer to land.

Heavy Rain Part 2

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Heavy rain have returned to Texas this past weekend. It was indeed scary as it happened on Halloween. It is the second storm to hit Texas in a weekend in October. First it struck Central Texas with heavy rain as high as 17 inches in a short time! Many rivers flooded. The storms fire up and hit Southeast Texas dumping up to 16 inches of rain causing more floods on super saturated grounds from the previous weekend’s rain.

To make matters worse, there were multiple tornado touchdowns in the storms. The strongest was an EF-2, which has winds of up to 135 mph. That is equivalent to a Category 4 hurricane. Most of the tornadoes were in Brazoria County. They also had the strongest tornadoes reported.

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Here is a GIS map of 7 day rainfall total.

20151102_7Day_Rainfall_Total

The heaviest rain fell around San Marcos and Southern Travis County including Austin-Bergstrom International Airport, which saw 15 inches of rain. It is one of the highest rainfall measured in Austin. For Southeast Texas, the heaviest rain fell over Liberty County and Eastern Harris County. 12 to 16 inches of rain fell. Many areas in Houston saw 5 to 12 inches of rain, which is impressive.

Wonder what the past two week total has been?

20151102_14Day_Rainfall_Total

Many areas have seen over 5 inches of rain. The highest is 28 inches of rain. That is Navarro County, where some areas around Corsicana saw over 20 inches of rain! Some areas in the Houston area saw up to 25 inches of rain, mainly in Eastern Harris County and Liberty County.

Patricia And The Floods

20151023_VIIRS_I-Band5_Patricia20E_0523EDT

Hurricane Patricia underwent explosive intensification from a Category 1 to Category 5 hurricane in 24 hours. It went from 980 millibars to 879 millibars! That is the most rapid intensifying hurricane in the Western Hemisphere! To make matters worse, it has 200 mph wind! That is much stronger than Atlantic’s most intense hurricane, Wilma in 2005. To put that in perspective, Wilma peaked at 882 millibars. Patricia is about to barrel towards Mexico as a full blown Category 5 monster.

However, with any intense hurricanes, they tend to fluctuate in strength due to eyewall replacement cycle and wind shear. By the time Patricia makes landfall on Mexico, it has a central pressure of 920 millibars and 165 mph winds. On land that would be 141 mph due to a 15 percent reduction from friction. However, the friction increases the gust by a factor of 1.5, which would be 210 mph! A weather station in Chamela-Cuixmala Biosphere Reserve recorded 185 mph winds with gusts as high as 211 mph, which suggests the station got damaged. 185 mph sustained winds on land is 278 mph! That would be a nightmare anywhere! Think of that in a major city like Houston, New Orleans, Miami, or New York. It turns out that Patricia made landfall on Cuixmala, Jalisco, Mexico, which is between Manzanillo and Puerto Vallarta. Mostly small villages and towns were affected by Patricia’s strong winds. Also, people evacuated from the coast as storm surge is possible. The death toll at this writing is 13. Pretty low for a potentially catastrophic hurricane.

Patricia was an average sized hurricane. East Pacific hurricanes tend to be smaller than Atlantic hurricanes due to a smaller basin area compared to the Atlantic. At peak and landfall, hurricane force winds were 50 miles in diameter. In comparison, Hurricane Ike before it hit Southeast Texas had hurricane force winds of over 200 miles in diameter! Smaller sized hurricanes produce smaller storm surge. Larger sized hurricanes produce larger storm surge. One reason why Ike and Sandy were so bad despite not being strong like Patricia was their large size. Interesting to note that Katrina made landfall on the Mississippi Delta as a Category 3 hurricane with central pressure of 920 millibars. The reason for that is Katrina is a large hurricane like Ike.

So, what allowed Patricia to undergo explosive intensification?

It had large area of warm water. This is due to a strong El Nino and warm Pacific Decadal Oscillation (PDO).

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There was a large area of Precipitable Water (PW) over the Pacific near Mexico. The values are easily over 2 inches.

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The relative humidity was very humid. This is relative humidity at 10,000 feet or 700 millibar level. That is more favorable for tropical development. Dry air kills tropical development.

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As all strong hurricanes, they must weaken and in this case, the Sierra Madre Occidental sheared it apart. Mountains are deadly for hurricanes as they can cut through their circulation. Yet, mountainous areas see higher winds and heavier rain, especially on the windward side. Once Patricia is reduced to a tropical low, the moisture from it dumps heavy rain over Texas. The heavy rain affects a large area of Texas. The heavy rain is from a slow moving Pacific front and Gulf of Mexico and Pacific moisture.

North Texas sees some of the heaviest rain. Corsicana, Texas go hammered with the heaviest rain. Powell saw over 20 inches of rain in 24 hours! Southeast Texas saw widespread heavy rain with flooding. Many areas saw 5 to 10 inches of rain. Some areas saw over 12 inches of rain.

20151026_7Day_Rainfall_Total

Here is a GIS map I created from AHPS and US Drought Monitor. Notice the heaviest rains is around Corsicana. In the 7 days, many areas saw over 8 inches of rain with totals as high as 15 inches of rain. The rains are beneficial as Texas is in a severe drought. Corsicana and Dallas/Fort Worth Metroplex were in the severe drought. I expect they will be out of the drought by this week according to US Drought Monitor.

Oh No! (Tropical Storm Bill)

The National Hurricane Center (NHC) has issued their first advisory for Tropical Storm Bill. It is a tropical storm with 50 mph winds. It has tropical storm force winds extending up to 160 miles, especially east of the center.

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The cone has Bill going northwest towards Texas at 12 mph. This means it could make landfall by tomorrow morning on the Texas Coast as a tropical storm. Bill forecasted to be stronger to 60 mph. Here is a wind probability, by 34 knots, 50 knots, and 64 knots.

34 Knots
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50 Knots
20150615_02L_50KnotProbability_2300EDT

64 Knots
20150615_02L_64KnotProbability_2300EDT

Coast areas have the highest chance to see tropical storm force winds. As you are further inland, the tropical storm force winds diminish due to land interaction. That means the highest wind on land assuming it is at 60 mph using the 15 percent reduction rule is 51 mph. That means the highest gust could be 77 mph is we multiply by factor of 1.5. Most areas should see 30 to 45 mph winds with gusts of 45 to 68 mph. Hurricane force winds are less likely with Bill. Of course, storms like Bill can rapidly intensify in the Gulf of Mexico if conditions are right.

The waters in the Gulf of Mexico are quite warm. Here is the 26°C or 78.8°F depth map.

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Tropical Cyclone Heat Potential
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The warm water is quite deep. An area of very warm on the surface and deep layer of warm water is very favorable for tropical development if there are not a lot of wind shear. The conditions can allow Bill to intensify further. I would not be surprised if Bill did become a hurricane. I suspect more likely a tropical storm.

Rainfall is another issue. It is moving 12 mph, which means if we use the rule of thumb, 100 divided by the motion speed, which is 12, we get about 8 inches of rain. That means Bill could easily dump 8 inches of rain. I suspect Bill will be more of a rain event than a wind event. Many areas could see 5 to 10 inches of rain with isolated areas seeing up to 15 inches of rain. The grounds in Southeast Texas is very saturated from the May and Spring rains. That can allow more flooding to happen from heavy rain if it is prolonged. The ground cannot handle anymore water, which means, flooding risk goes up from Bill.