Skip Navigation Links weather.gov 
NOAA logo-Select to go to the NOAA homepage NOAA's National Weather Service   Select to go to the NWS homepage
Storm Prediction Center
navigation bar left  
  navigation bar end cap


 
USA.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.

Mesoscale Discussion 346
< Previous MD         Next MD >
MD 346 graphic

   MESOSCALE DISCUSSION 0346
   NWS STORM PREDICTION CENTER NORMAN OK
   0739 PM CDT FRI APR 17 2015

   AREAS AFFECTED...UPPER GULF COAST OF SE TX AND SABINE VALLEY

   CONCERNING...SEVERE THUNDERSTORM WATCH 68...

   VALID 180039Z - 180215Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 68
   CONTINUES.

   SUMMARY...RISK FOR DAMAGING WINDS...MARGINALLY SEVERE HAIL AND A
   BRIEF TORNADO WILL PERSIST WITH A TSTM CLUSTER APPROACHING THE SRN
   HOUSTON METRO AND GALVESTON BAY. UNCERTAINTY DOES EXIST WITH HOW FAR
   EAST THIS RISK WILL PERSIST BEYOND WW 68. MONITORING FOR POSSIBLE
   DOWNSTREAM WW ISSUANCE OVER THE SABINE VALLEY.

   DISCUSSION...AREAL EXTENT OF 50-DBZ BASE REFLECTIVITY HAS DIMINISHED
   WITH SLOWING OF FORWARD SPEED TO 35-40 KT. HOWEVER...WITH A SWATH OF
   45-55 KT INBOUND VELOCITIES...DAMAGING WINDS WILL BE THE PRIMARY
   HAZARD. A BRIEF TORNADO MAY ALSO OCCUR GIVEN THE STRUCTURE OF THE
   MCV AND SATURATED TROPICAL THERMODYNAMIC PROFILES COINCIDENT WITH
   SUBSTANTIAL VEERING OF THE DEEP-LAYER WIND PROFILE WITH HEIGHT. 

   DESPITE A LARGE SWATH OF LEADING STRATIFORM RAIN EXTENDING NEAR THE
   MOUTH OF THE SABINE RIVER...00Z LCH RAOB STILL DEPICTED MODERATE
   BUOYANCY AMIDST 700-500 MB LAPSE RATES AROUND 7 DEG C/KM. WITH
   STRONG MID/HIGH-LEVEL W/SWLYS EVIDENT IN HGX VWP DATA SUPPORTING
   60+-KT EFFECTIVE SHEAR...THIS CLUSTER WILL PROBABLY REMAIN ORGANIZED
   AS IT EVOLVES ALONG THE UPPER TX COAST THROUGH 03Z. WHETHER THIS
   RISK SHIFTS OFFSHORE OR REACHES COUNTIES E OF WW 68 IS UNCERTAIN.

   ..GRAMS/CORFIDI.. 04/18/2015


   ATTN...WFO...LCH...HGX...

   LAT...LON   29699552 29909502 30099368 29839360 29439373 29139449
               28679515 28869560 29159542 29349540 29699552 

Top/All Mesoscale Discussions/Forecast Products/Home
Weather Topics:
Watches, Mesoscale Discussions, Outlooks, Fire Weather, All Products, Contact Us

NOAA / National Weather Service
National Centers for Environmental Prediction
Storm Prediction Center
120 David L. Boren Blvd.
Norman, OK 73072 U.S.A.
spc.feedback@noaa.gov
Page last modified: April 18, 2015
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities