50% chance of #Tropical Depression forming in Central Atlantic … Not expected to threaten the US.

The National Hurricane Center has increased the probability to a 50% that a low pressure area in the Central Atlantic will develop into a Tropical Depression within the next 48 hours.

However, looking at the latest model data, this system is expected to stay out in the Atlantic and not threaten the US.

Severe Weather Update for Monday (08/13/12) evening

A cold front is approaching Tennessee and Mississippi this evening and showers and thunderstorms are out ahead of the front.  Severe thunderstorm warnings (depicted in yellow) are being issued this evening across western Tennessee and northern Mississippi.  The NWS Storm Prediction Center has coordinated with several local Weather Forecast Offices (WFOs) in the Southern Region to issue a Severe Thunderstorm Watch (depicted in cyan) for Western Tennessee, eastern Arkansas, and northern Mississippi.  The watch is valid until 0400Z (11 pm CDT).

Radar snapshot along with severe thunderstorm warnings (in yellow) and watch (in cyan).  Cold front depicted in blue approaching Tennessee and Mississippi.

Radar snapshot along with severe thunderstorm warnings (in yellow) and watch (in cyan). Cold front depicted in blue approaching Tennessee and Mississippi.

Severe Weather over TN/AL Monday (08/13/12) afternoon

A line of showers and thunderstorms has formed from south central TN southward into Alabama this afternoon. The NWS Huntsville WFO has issued Severe Thunderstorm warnings (depicted in yellow) for areas in south central Tennessee and north central Alabama. Also, the NWS Storm Prediction Center has issued a Severe Thunderstorm watch (depicted in cyan) for south central Tennessee and a large portion of Alabama that is valid until 0100Z (8pm CDT, 9pm EDT) this evening.
Radar snapshot over the TN Valley from Monday afternoon.  Also shown are the severe thunderstorm watches and warnings.

Radar snapshot over the TN Valley from Monday afternoon. Also shown are the severe thunderstorm watches and warnings.

Tropical Depression #7 Forms in Atlantic

The National Hurricane Center is now issuing advisories on Tropical Depression #7.   At this point, TD 7 looks like it will follow a path generally similar to Ernesto. The forecast path places the storm in the Caribbean Sea by Sunday and in the Central to Western Caribbean by Tuesday.
The NWS Southern Region Operations Center will monitor the development of this storm and expand our operations as needed.

Ernesto to strengthen, but remain well to the south

Based on the latest forecast advisory (#20) that NHC put out (see below) which was based on current satellite imagery (also below) and aircraft observations, Ernesto is expected to strengthen to near Category 2 Hurricane strength before landfall Wednesday morning near the Belize/Mexico border

Ernesto Forecast Advisory #20, Issued at 11am EDT, 08/06/2012

Ernesto Forecast Advisory #20, Issued at 11am EDT, 08/06/2012

Visible Satellite of Ernesto, valid at 15:15 UTC (10:15 am CDT), 08/06/2012


  

 

However, Ernesto is still expected to remain well south of TX as indicated by all the latest model runs (see below).

 

Ernesto model runs from Monday (08/06/2012) morning

Ernesto model runs from Monday (08/06/2012) morning

Monday (08/06) morning Ernesto Update: Significant Changes

There have been rather significant changes in the forecast overnight and the end result is that it is looking much more likely that Ernesto will have little to no impacts on the United States.
 
Below is an image that shows the evolution of Ernesto’s forecast from the National Hurricane Center (NHC) from Sunday night (8pm in upper left, 11pm in upper right) to Monday morning (2am in lower left, 5am in the lower right).
  
 
 
 
 
As you can see, the forecasts this morning compared to last night have shifted significantly to the south, even when including the cone of uncertainty.  Also, the overall strength of the storm has been reduced and Ernesto is now not expected to reach Hurricane strength.
 
 
The image below shows the latest Tropical Storm (TS) Force Wind Speed Probabilities graphic, which does take the cone of uncertainty into account.  
The graphic is not depicting any areas along the South Texas coast with a chance for TS Storm force winds, meaning that there is an extremely low chance that the South Texas coast will experience Tropical Storm force winds.  And, the 5% probability line is well south of the US/Mexico border.
Bottom line:  Ernesto is looking like it will be a non-factor for the United States and the main impacts from Ernesto will be limited to Central America and Mexico.

Ernesto to emerge in the Gulf mid to late next week

Ernesto to emerge in the Gulf of Mexico mid to late next week … Now is the time to prepare!

As of 5am EDT on Saturday August 4, 2012, Tropical Storm Ernesto was located in the eastern Caribbean.  Ernesto is expected to strengthen to a Category 1 Hurricane by tomorrow (Sunday) afternoon and then move into the Gulf of Mexico by mid to late next week. 

Ernesto forecast issued at 5am EDT (4am CDT) Saturday, 08/04/12

The current National Hurricane Center forecast has Ernesto emerging into the South Central Gulf of Mexico early Thursday as a Category 1 Hurricane.  The exact timing, strength, and location of Ernesto when it does emerge into the Gulf is low confidence at this point. 

Regardless, this is the time for those that live along the Gulf coast to make hurricane preparations.  See the “Are You Ready?” section of this brochure to see if you are ready.  http://www.nws.noaa.gov/os/hurricane/resources/TropicalCyclones11.pdf

New Tropical Storm

At 4 pm, Ernesto was centered at 12.8N, 56.6W, or about 300 miles east of the Windward Islands. Maximum sustained winds based on reports from USAF reconnaissance aircraft have increased to 50 mph. Ernesto is moving rapidly to the west at 22 mph an will not impact Puerto Rico. The future of Ernesto is still rather uncertain. Even though the system has become a tropical storm, it is still not particularly well organized, and many fast moving systems like this weaken as they move through the islands and eastern Caribbean Sea. No significant strengthening is forecast in the next couple of days. If Ernesto can survive beyond that time, conditions are expected to be more favorable for intensification in the western Caribbean Sea later this weekend and early next week. The system is currently forecast to be a minimal hurricane in the northwest Caribbean Sea in 5 days.

Monitoring The Tropics (08/01/2012)

The NWS Southern Region Headquarters Regional Operations Center (ROC) is monitoring the tropics closely.  A tropical wave (highlighted in the image below) may intensify into a tropical depression or tropical storm over the next day or two.  This system will generally move to the west-northwest and into the eastern Caribbean by Friday afternoon/evening.   The storm track beyond Friday is very uncertain at this point.  There is the potential that the ROC will need to go to extended hours support as this system approaches Puerto Rico.

Infrared/Water Vapor Satellite Image from Wednesday morning

Infrared/Water Vapor Satellite Image from Wednesday morning

Increased thunderstorm activity in AR, OK, and North TX…

We’re beginning to see increased thunderstorm activity along the front moving into AR, OK, and North TX.  Some of these storms are potentially severe….

Radar and Storm Warnings

Radar and Storm Warnings on July 26th at 3:50PM CDT

 

Radar data and warnings from the NSSL Real Time WDSS-II web page