Future Harvey And Irma?

This is August and the tropics are heating up. We have Gert in the Atlantic, which does not pose a threat. Let’s cut to the chase and focus on Invest 91L and 92L. Let’s start with 91L. Here is a heat map from various forecast models and GFS ensemble track guidance. The GFS goes up to 10 days.

Looking at the forecast model of where 91L will go, most of have it heading into the Caribbean. There is convergence around Yucatan Peninsula and Belize. From there, it enters into the Gulf of Mexico. Another has it going into Georgia or Carolinas. It is too early to tell where 91L will go. Here is an intensity forecast model for 91L.

Most forecast models have 91L becoming a hurricane in the next 4 days. One model keeps it at barely tropical storm. Last night, one forecast model had Invest 91L as a Category 5 hurricane with 175 mph 280 km/h 150 knots wind!

That is really bullish right there! Forecast models, especially intensity forecasts are unreliable. We have a long way to go. Let’s now turn our attention to Invest 92L. Here is a heat map from various forecast models and GFS ensemble track guidance. The GFS goes up to 10 days.

92L has a more northwestward trend. The 10 day forecast has it affecting the East Coast to Canadian Maritime Provinces. Again, it is too early to tell where 92L will go. Here is an intensity forecast model for 92L.

Most forecast models have 92L as a tropical storm in two days. None have 92L as a hurricane. Since 92L is newly identified, the intensity forecast model is going to be on the low side.

The forecast models came from NCAR-Tropical Cyclone Guidance.

The tropics are heating up for sure. I think 91L will be Harvey, while 92L will be Irma.

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.

Atlantic Hurricane Season In August

It is now August and the season is heating up. Where do most August tropical storms and hurricanes form and end up going?

Here is a GIS heat map I created. This is all August tropical storms and hurricanes from 1870 to 2015. The heat map is from within 300 miles (480 kilometers) of a point.

The Main Development Region (MDR) heats up. The Windward Islands see more tropical cyclones making landfall. Interestingly, there is a dead area around Central Caribbean and Cuba. The Gulf of Mexico and Southeast is very active. Many tropical cyclones form near land in August and make landfall. Some of the of most devastating tropical storms and hurricanes made landfall in August:
Sea Islands (1893)
San Ciriaco (1899)
Monterrey (1909)
1945 Texas Hurricane (1945)
Camille (1969)
Amelia (1978)
David (1979)
Alicia (1983)
Bob (1991)
Andrew (1992)
Charley (1998)
Charley (2004)
Katrina (2005)
Dean (2007)
Irene (2011)

Despite Amelia making landfall on July 31, 1978, the worst aspect was heavy rain from August 1-4, 1978 in Central and West Texas, where up to 46 inches (116.84 centimeters) of rain fell. The costliest hurricane occurred in August, Katrina. The previous prior to Katrina was Andrew. August has produced some of the most devastating tropical storms and hurricanes.

Texas does get hurricane landfalls in August, including major hurricanes like Allen and Alicia. Allen was a Category 5 monster and almost made landfall on Port Mansfield as a Category 5 with 180 mph winds. Had that happened, that would of been really devastating. Allen made landfall as a Category 3 hurricane with 115 mph winds. Allen was a very large hurricane upon landfall. Alicia made landfall on Galveston as a Category 3 hurricane with 115 mph winds. It was Texas’s first billion dollar disaster. Alicia was a medium size hurricane, unlike Allen. Had Alicia been Allen, Carla, or Ike size, it would been much worse.

Atlantic Hurricane Season In July

It is now July and it is the halfway mark of the year. Where do most July tropical storms and hurricanes form and end up going?

Here is a GIS heat map I created. This is all July tropical storms and hurricanes from 1870 to 2015. The heat map is from within 300 miles (480 kilometers) of a point.

Most July tropical cyclones form in the Gulf of Mexico and off the Carolinas, Georgia, and Florida. Texas, Louisiana, Mississippi, and Alabama are at most risk to see a tropical cyclone making landfall in July. America’s 24 hour rainfall record is from a July tropical cyclone, Tropical Storm Claudette in 1979. Some of the biggest flood events from tropical storms have occurred in July like Alberto in 1994 and Danny in 1997. Alberto did form in late June, but most of its life was in July, so Alberto can be considered a July tropical cyclone.

Tropical Storm Cindy For 6/20/2017 2200 CDT

Potential Tropical Cyclone 3 is now Tropical Storm Cindy. Well, I think, it was Cindy since yesterday. Anyways, let’s cut to the chase. As of 10:00 PM CDT, Cindy is stationary. It has not moved much lately. This complicates forecasting where Cindy will go.

Here is a heat map forecast. It is from ATCF data file. The intensity forecast is also from the same link at UCAR. I also included the 5 day cone from National Hurricane Center.

The heat map is from various ensemble member run within 300 miles (480 kilometers) of a point. From there, a heat map is generated. There is an eastward trend. However, Texas is not out of any landfall risk. The 5 day cone encompass Southeast Texas. The National Hurricane Center states that tropical cyclones are within the cone 67 percent of the time, which means 33 percent of the time they deviate outside the cone. The heat map shows that it can deviate easily from the cone.

In terms of intensity it has increased to 60 mph with central pressure of 997 millibars. The forecast models keep Cindy as a tropical storm. I do not expect a hurricane. The intensity forecast is from

On top of it, Tropical Storm Cindy is a large tropical storm. It has tropical storm force winds extending up to 275 miles! The western half has tropical storm force winds extending up to 140 miles. Tropical storm force winds are 415 miles across! The east side has larger tropical storm force winds.

The main concern is rainfall. The Weather Prediction Center has a seven day total of up to 17 inches around Alabama. Southeast Texas could see to 3 to 7 inches of rain. I would not be surprised if areas see higher totals of 20 inches in some areas. Tropical Storm Cindy is more of a rain event if any. I would be most concerned with heavy rain than wind despite the large area of tropical storm force wind.

Where Cindy goes is anyone’s guess at this point. Forecast models are all over the place. We should know more by tomorrow.