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 152
< Previous MD         Next MD >
MD 152 graphic

   MESOSCALE DISCUSSION 0152
   NWS STORM PREDICTION CENTER NORMAN OK
   0248 PM CDT THU MAR 26 2015

   AREAS AFFECTED...PORTIONS OF SRN/E-CNTRL MS...SERN LA...SWRN/W-CNTRL
   AL

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

   VALID 261948Z - 262215Z

   PROBABILITY OF WATCH ISSUANCE...5 PERCENT

   SUMMARY...THE RISK FOR STRONG THUNDERSTORMS -- SOME POSSIBLY
   REACHING MARGINALLY SVR THRESHOLDS -- WILL INCREASE DURING THE NEXT
   COUPLE OF HOURS AND SPREAD EWD. THE MARGINAL/ISOLATED NATURE OF THE
   SVR RISK SHOULD PRECLUDE WW ISSUANCE.

   DISCUSSION...DESPITE WIDESPREAD CONVECTION NEAR AND OFF THE GULF
   COAST...ANTECEDENT POLEWARD FLUXES OF PARTIALLY MODIFIED GULF
   MOISTURE HAVE BEEN SUFFICIENT TO MAINTAIN LOWER 60S SFC DEWPOINTS
   FROM SERN LA NEWD INTO SWRN/W-CNTRL AL. TRANSLUCENCY IN HIGH-LEVEL
   CIRRUS DECKS AND EMBEDDED CLOUD BREAKS RELATED TO THE PREVIOUSLY
   MENTIONED CONVECTION HAVE ENCOURAGED MODEST SFC-LAYER HEATING AMIDST
   THE AFOREMENTIONED MOISTURE...SUPPORTING 500-1250 J/KG OF MLCAPE PER
   MODIFIED 12Z RAOBS ACROSS THE LOWER MS VALLEY.

   THE DIURNAL DIABATIC HEATING IS ALSO ENHANCING BAROCLINICITY ON THE
   LEADING EDGE OF AN EWD-ADVANCING BAND OF MIDLEVEL ASCENT MARKED BY
   SHOWERS AND ACCAS INVOF THE NATCHEZ TRACE PARKWAY CORRIDOR VICINITY.
   WITH MLCINH NEARLY ERODED E OF THIS BAND...CONVECTION IS DEEPENING
   WITH ISOLATED THUNDERSTORMS DEVELOPING ON THE ERN EDGE OF THE
   ACCAS/SHOWERS BETWEEN BATON ROUGE AND NATCHEZ VICINITY. ADDITIONAL
   CONVECTION HAS DEVELOPED FARTHER E ACROSS THE PINE BELT REGION IN
   SERN MS. ALL OF THIS ACTIVITY WILL HAVE THE POTENTIAL TO INTENSIFY
   WITH CONTINUED MODEST SFC HEATING...ESPECIALLY GIVEN THE EWD
   ADVECTION OF H7-H5 LAPSE RATES AROUND 7.0-8.5-C/KM -- SAMPLED
   UPSTREAM BY 12Z RAOBS AT SHV AND LCH RELATED TO A REMNANT EML.
   INCREASING LARGE-SCALE ASCENT PRECEDING A MIDLEVEL SHORTWAVE TROUGH
   AMPLIFYING INTO THE LOWER MS VALLEY WILL ALSO ENCOURAGE SUCH UPTICK
   IN CONVECTION...WHILE ALSO OFFERING 45-55 KT OF EFFECTIVE BULK
   SHEAR. OCCASIONALLY ORGANIZED CONVECTIVE STRUCTURES /POSSIBLE
   SUPERCELLS/ WITH GENERALLY MARGINALLY SVR HAIL MAY OCCUR...AND
   ISOLATED DMGG WIND GUSTS MAY ALSO BE POSSIBLE.

   HOWEVER...WIDESPREAD CONVECTIVE OUTFLOW FROM GULF-COASTAL CONVECTION
   IS STUNTING SFC HEATING/BOUNDARY-LAYER DESTABILIZATION TO SOME
   EXTENT...WHICH MAY MITIGATE THE OVERALL SVR-TSTM POTENTIAL.
   FURTHERMORE...AN APPROACHING BAROCLINIC ZONE FROM THE NW MAY ALSO
   EVENTUALLY UNDERCUT CONVECTION -- SUPPORTING AN EROSION OF CAPE
   AVAILABLE TO ANY ESTABLISHED UPDRAFTS. FOR THESE REASONS...WW
   ISSUANCE IS UNLIKELY.

   ..COHEN/MEAD.. 03/26/2015


   ATTN...WFO...BMX...MOB...JAN...LIX...

   LAT...LON   30519153 31009129 32288939 32918811 32728696 31878711
               30798844 30519153 

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: March 26, 2015
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities