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 37
< Previous MD         Next MD >
MD 37 graphic

   MESOSCALE DISCUSSION 0037
   NWS STORM PREDICTION CENTER NORMAN OK
   0523 AM CST TUE JAN 28 2014

   AREAS AFFECTED...SOUTHEAST TX...CENTRAL AND SRN LA...SRN MS...SRN
   AL...AND PART OF WRN FL PANHANDLE

   CONCERNING...WINTER MIXED PRECIPITATION 

   VALID 281123Z - 281630Z

   SUMMARY...LIGHT FREEZING RAIN IS EXPECTED TO TRANSITION TO MAINLY
   SLEET ALONG A CORRIDOR FROM SOUTHEAST TX INTO CENTRAL LA BY 12Z WITH
   SLEET PERSISTING THROUGH THE MORNING.  A SIMILAR TRANSITION IS
   EXPECTED TO OCCUR EWD OVER MUCH OF SRN MS AND EVENTUALLY INTO SRN AL
   BY 18Z AS PRECIPITATION BEGINS IN THESE AREAS FROM W-E.  

   MEANWHILE...FREEZING RAIN WITH RATES OF 0.05-0.1 INCH PER 3 HOURS IS
   EXPECTED TO BECOME THE PRIMARY PRECIP-TYPE AFTER 15Z OVER SOUTH
   CENTRAL TO SERN LA...EXCLUDING AREAS CLOSER TO THE COAST IN SERN
   LA...WITH FREEZING RAIN ALSO THE PRIMARY THREAT OVER FAR SERN
   MS...FAR SWRN-SRN AL AND ADJACENT WRN FL PANHANDLE.  FAR SERN
   LA...CLOSER TO THE COAST...SHOULD BE REMAIN RAIN THROUGH 18Z AS
   SURFACE TEMPERATURES PERSIST ABOVE 32 F.

   DISCUSSION...SATELLITE IMAGERY SHOWED A MIDLEVEL IMPULSE LOCATED
   OVER E TX/NRN LA EARLY THIS MORNING WITH THIS FEATURE EXPECTED TO
   SHIFT EWD THROUGH 18Z ACROSS THE LOWER MS VALLEY.  A 06Z RESEARCH
   SOUNDING AT TEXAS A&M /COLLEGE STATION TX/ INDICATED A WARM LAYER
   BETWEEN APPROXIMATELY 750-850 MB WITH THE 800 MB TEMPERATURE AT +6-7
   C.  UPWARD VERTICAL MOTION ATTENDANT TO THE MIDLEVEL IMPULSE AND
   LOWER LEVEL ISENTROPIC UPGLIDE HAVE RESULTED IN A SATURATION PROCESS
   BELOW 850 MB.  EVAPORATIVE COOLING WITHIN AN INITIALLY DRIER...COLD
   AIR MASS HAS RESULTED IN LIGHT FREEZING RAIN AT THE PRESENT TIME
   OVER PARTS OF SOUTHEAST TX INTO CENTRAL LA.  AS THE MIDLEVEL IMPULSE
   SHIFTS EWD THIS MORNING...LOW LEVEL COLD ADVECTION SHOULD RESULT IN
   A VERTICAL THERMODYNAMIC PROFILE MORE CONDUCIVE TO SLEET THAN
   FREEZING RAIN FROM SOUTHEAST TX THROUGH SWRN-CENTRAL LA.  A SIMILAR
   TRANSITION FROM FREEZING RAIN TO SLEET IS EXPECTED TO OCCUR FARTHER
   EWD OVER SRN MS TO SWRN AL BETWEEN 15-18Z. 

   MEANWHILE...THE PRIMARY PRECIP-TYPE WITHIN A NARROW CORRIDOR FROM
   SOUTH CENTRAL TO SERN LA THROUGH FAR SERN MS...AND FAR SWRN-SRN AL
   AND ADJACENT WRN FL PANHANDLE IS EXPECTED TO BE FREEZING RAIN.  LOW
   LEVEL WAA SHOULD BE PROLONGED THROUGH THE MORNING ACROSS THESE
   AREAS...WITH EVAPORATIVE COOLING RESULTING IN FREEZING RAIN AS
   SURFACE TEMPERATURES COOL TO SUB-FREEZING WET BULB TEMPERATURES
   ALREADY PRESENT.

   ..PETERS.. 01/28/2014


   ATTN...WFO...TAE...BMX...MOB...JAN...LIX...LCH...SHV...HGX...

   LAT...LON   30529479 31049343 31519180 31749060 31858916 32278784
               32238626 31418550 30688640 30328715 30228885 29868992
               29609066 29489163 29579264 29769347 29589430 29519468
               29589502 30089538 30529479 

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: January 28, 2014
Disclaimer
Information Quality
Help
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities