Was Florida hit by a Tropical Storm or a Non Tropical Gale Force?

October 11, 2011

If you were following SWAT’s updates on Facebook (www.Facebook.com/SWATChasers) Sunday Night, you should be well aware that a large area of disturbed weather struck the East Coast of Florida, packing heavy rain and strong winds in excess of 60-70 mph. During the day on Sunday, a weather feature began to develop over the Bahamas. This feature began to show signs of developing into a closed low pressure system within a larger, more synoptically driven weather system/pattern.  By Sunday Evening, the circulation had tightened on  radar, and velocity data was showing upwards of 70+ mph winds. A semi apparent eyewall like feature also became evident just East of Palm Bay, Florida.

There was much debate in the meteorology community as to whether this area of disturbed weather should have been classified as a Tropical Storm or not. Winds gusted to over hurricane force in several reporting stations along the Eastern Florida Coast, but the National Weather Service and National Hurricane Center remained persistent that the disturbed weather was nothing more than a Non Tropical Gale Force.

Radar data/loops clearly showed a well defined center of circulation/eyewall feature as stated above off the Eastern Florida Coast. Without knowing what you were being shown, at first glance, the radar image below looks like several prior landfalling tropical systems.

So besides the well defined center of circulation off the Florida Coast, why do I believe that this area of disturbed weather should have been classified as a tropical storm? There are several reasons, but for starters, here is what I posted Sunday Evening on the SWAT Facebook page.

“I rarely criticize the National Weather Service/National Hurricane Center, but this area of low pressure center has obviously gained tropical storm characteristics. The area of low pressure system has formed over warm sea surface temperatures, has organized convection over the center of circulation, has surface winds over 35 knots and the strongest winds are near the center. This all combined with Cape Canaveral recently reporting a 69 mph wind gusts is blatantly obvious evidence that we have at least a tropical depression if not a tropical storm off the East Florida Coast. Our viewers in Eastern Florida should be prepared for heavy rain, very strong winds and coastal flooding through the morning hours.”

Shortly after I published that update on the SWAT Facebook page, several reports of 75 mph wind gusts were received along the Eastern Florida Coast from the United States Air Force weather observing stations. The winds were strong enough that the National Weather Service was forced to not only issue High Wind Warnings but also Storm Warnings for the adjacent waters. Storm Warnings are extremely rare in the Southeast during Hurricane Season.

In addition to radar data and reports of winds gusting well over 70+ mph at several official reporting stations, the pressure also began to rapidly drop. Cape Canaveral, Florida saw pressures rapidly fall as the area of disturbed weather approached.

The center of circulation passed very close to Cape Canaveral and their pressure bottomed at 999.5 millibars, a pressure reading commonly found in tropical storms. Nearly all (if not all) of the characteristics needed for a storm to be classified as a tropical storm had been met, so why did the National Hurricane Center and National Weather Service choose not to classify or upgrade the storm to a “tropical storm”? There is still some doubt in the meteorology community whether the area of disturbed weather attained a warm core. A definition of tropical cyclones is that they must have a warm core, which means the temperature in the vertical core of the cyclone extending up through the atmosphere is higher than in the air surrounding it. With the area of disturbed weather over extremely warm sea surface temperatures, I personally believe that at the very least, a shallow warm core was likely present.

The second possible reason that the National Weather Service/National Hurricane Center did not upgrade the storm to an official “tropical storm” could be based off of the logistical nightmare surrounding a possible late evening upgrade. The following was posted by a National Weather Service Melbourne, Florida Meteorologist on an online forum.

“You probably don’t realize what a logistical nightmare this would cause our office to name this thing at such a late hour. We would have to cancel the Gale Warning, High Surf Advisory, Wind Advisory and Lake Wind Advisory that have been up now for two days and replace them with Subtropical Storm Warning. We would need to put out products cancelling the current advisories, and then issue a Subtropical Storm Local Statement, update the Zone Forecasts, Coastal Waters Forecast Hazardous Weather Outlook, our blog and Short term Forecast. Local graphics would have to be updated as well as our forecast grids.”

While I understand his point, I do not agree with the decision. If the storm truly was a tropical storm, tropical storm warnings grab the attention of the public far better than high wind warnings or storm warnings. This area of “disturbed weather/non tropical gale force” caused significant damage and as seen via multiple social media outlets, the public appeared to have had no real idea that inclement weather was likely. Granted, high wind warnings were in place, but again, tropical storm warnings have much more significance on public perception than a high wind warning does.

Needless to say, I 100% believe the area of disturbed weather off the Florida Coast Sunday Night was a tropical storm. Hopefully the system is revisited/relooked at in post season analysis. This means that the National Hurricane Center can revisit and take a second look at the storm to decide if it was actually a tropical storm and add it to the list of 2011 tropical cyclones/historical data.

 

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Don is dead but Emily could soon be born

July 30, 2011

Unfortunately Tropical Storm Don did little in the way to offset the drought conditions in Texas and as a meteorologist, I can honestly say it was one of the most bizarre tropical storms I have ever tracked as the precipitation field just fell apart once the storm hit the Texas Coast. Another strong tropical wave is being monitored about 900 miles East of the Windward Islands. This tropical wave is likely to develop into a tropical storm (Emily) and eventually into a hurricane.

Here is the projected forecast paths of some of our forecast models showing where the future Emily may track.

I would look for the National Hurricane Center to initiate advisories on the future Tropical Storm later this afternoon. All interests along the Southeastern United States Coast should monitor the progress of this future tropical storm very closely.