NYE 2020 Enhanced Risk

[cheese007]

Looking like good potential for severe weather from southeast TX into southwestern MS per the title.

 

[Chinook]

It certainly seems like this could be a regional tornado outbreak, with SRH values of over 300-400 m2/s2 and shear values of 60 kt, and CAPE values of 500 J/kg to 1500 J/kg in southern Louisiana. Convection allowing models show a squall line or at least quite a few cells in western Louisiana, and several more isolated cells near the LA/MS border

[kayman]

NOLA and Baton Rouge seems to have the greatest threat of tornadic activity as nightfall approaches later on today. 

[OKTWISTER]

First Tornado Watch issued:  

 

URGENT - IMMEDIATE BROADCAST REQUESTED
   Tornado Watch Number 520
   NWS Storm Prediction Center Norman OK
   740 AM CST Thu Dec 31 2020

   The NWS Storm Prediction Center has issued a

   * Tornado Watch for portions of 
     The upper Texas coastal plain
     Coastal Waters

   * Effective this Thursday morning and afternoon from 740 AM until
     300 PM CST.

   * Primary threats include...
     A few tornadoes possible
     Scattered damaging wind gusts to 70 mph possible
     Isolated large hail events to 1 inch in diameter possible

   SUMMARY...Thunderstorms will increase in coverage and intensity
   through the morning while spreading inland across the upper Texas
   coast.  The storm environment will gradually become more favorable
   for supercells inland, with an attendant threat for a few tornadoes
   and damaging winds through early to mid afternoon.

   The tornado watch area is approximately along and 40 statute miles
   north and south of a line from 25 miles west southwest of Angleton
   TX to 20 miles north northeast of Port Arthur TX. For a complete
   depiction of the watch see the associated watch outline update
   (WOUS64 KWNS WOU0).

   PRECAUTIONARY/PREPAREDNESS ACTIONS...

   REMEMBER...A Tornado Watch means conditions are favorable for
   tornadoes and severe thunderstorms in and close to the watch
   area. Persons in these areas should be on the lookout for
   threatening weather conditions and listen for later statements
   and possible warnings.

   &&

   AVIATION...Tornadoes and a few severe thunderstorms with hail
   surface and aloft to 1 inch. Extreme turbulence and surface wind
   gusts to 60 knots. A few cumulonimbi with maximum tops to 400. Mean
   storm motion vector 21035.

 

[WhirlingWx]

Storms off the Texas coast have some rotation already, but it also looks like they might be moving almost due north (heading towards or a little east of the Houston metro). Regardless, they have special marine warnings on them for waterspout threats. 

[Sydney Claridge]

42 minutes ago, TexMexWx said:

Storms off the Texas coast have some rotation already, but it also looks like they might be moving almost due north (heading towards or a little east of the Houston metro). Regardless, they have special marine warnings on them for waterspout threats. 

There’s quite the temperature divide across the Houston metro this morning, with 50s in the far west suburbs (Katy), with 40s not too much further west, but generally upper 60s over the rest of the metro.  Definitely cannot rule out severe storms in the Houston area until the front passes through (which it should do in the next few hours as the storm system moves NE).

 

The storm coming ashore at Surfside Beach looks slightly isolated and now has a severe thunderstorm warning with “tornado possible” wording indicated.

[janetjanet998]

so far not much

 

new watch

 

URGENT - IMMEDIATE BROADCAST REQUESTED  
TORNADO WATCH NUMBER 521  
NWS STORM PREDICTION CENTER NORMAN OK  
120 PM CST THU DEC 31 2020  
  
THE NWS STORM PREDICTION CENTER HAS ISSUED A  
  
* TORNADO WATCH FOR PORTIONS OF   
  SOUTHWEST LOUISIANA  
  FAR SOUTHEAST TEXAS  
  COASTAL WATERS  
  
* EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 120 PM UNTIL  
  900 PM CST.  
  
* PRIMARY THREATS INCLUDE...  
  A FEW TORNADOES AND A COUPLE INTENSE TORNADOES POSSIBLE  
  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE  
  
SUMMARY...SQUALL LINE ACROSS THE NORTHWEST GULF THROUGH SOUTHEAST  
TEXAS SHOULD ADVANCE NORTH-NORTHEAST, WITH ADDITIONAL CELLS POSSIBLE  
AHEAD OF IT. LOW-LEVEL SHEAR IS FAVORABLE FOR EMBEDDED SUPERCELLS  
CAPABLE OF PRODUCING TORNADOES IN ADDITION TO DAMAGING WINDS WITH  
THE LINE.  
  

[Santa Clause]

Tornado warning west of Baton Rouge

[Sydney Claridge]

Aside from a few warnings here and there, this was a complete bust.  There were no severe weather reports at all per SPC (at the time of this post), quite surprising for a day that started out with an Enhanced risk (and a 10% tornado contour), albeit this was later downgraded.