From SPC….
MESOSCALE DISCUSSION 0086
NWS STORM PREDICTION CENTER NORMAN OK
0610 PM CST FRI JAN 25 2008
AREAS AFFECTED…NERN LA…SERN AR…NRN/CENTRAL MS…NRN/CENTRAL
AL…NWRN GA…SRN MIDDLE TN
CONCERNING…WINTER MIXED PRECIPITATION
VALID 260010Z – 260615Z
A MIX OF FREEZING RAIN/SLEET WILL DEVELOP EWD ACROSS MS/AL AND GA
THROUGH THE EVENING HOURS. HRLY ACCUMULATION RATES UP TO 0.10 INCH
WILL BE POSSIBLE ESPECIALLY ACROSS CENTRAL MS INTO CENTRAL AL
THROUGH 06Z.
LATEST SFC ANALYSIS SHOWS THE SFC FREEZING LINE EXTENDING FROM JUST
NORTH OF SHV ENEWD TO NORTH OF JAN NEWD TO NEAR HSV. VERY DRY AIR IN
THE LOW LEVELS /PER THE 00Z BNA/BHM SOUNDING/ WILL CONTINUE TO LIMIT
PRECIPITATION RATES ALONG THE LEADING EDGE OF A BROAD PRECIPITATION
SHIELD CENTERED OVER THE LOWER MS VALLEY. IN ADDITION…THE PRESENCE
OF AN ELEVATED WARM LAYER /CENTERED NEAR 800 MB/ WILL SUPPORT SLEET
OVER AL/SRN MIDDLE TN AND NWRN GA FOR THE NEXT SEVERAL HRS. SEVERAL
MORE HRS OF PRECIPITATION FALLING THROUGH THIS DRY LAYER WILL
SUPPORT SATURATION IN THE LOWER LEVELS ACROSS MS/AL. WHERE THE
STRONGEST WAA/ISENTROPIC LIFT OCCURS…COUPLED WITH ELEVATED
INSTABILITY…MODERATE PRECIPITATION RATES WILL BE POSSIBLE OVER
PORTIONS OF CENTRAL MS/CENTRAL AL…WITH HRLY ACCUMULATION RATES UP
TO 0.10 IN. AS UPPER SHORTWAVE OVER THE SRN PLAINS PROGRESSES
ENEWD…FREEZING RAIN SHOULD END OVER NERN LA/SERN AR BY 03Z. AS
SATURATION OCCURS WITHIN THE LOW LEVEL DRY AIRMASS…WET-BULB
COOLING SHOULD SUPPORT A SLOW SWD MOVEMENT OF THE SFC FREEZING LINE
ACROSS MS/AL THROUGH 06Z.
..CROSBIE.. 01/26/2008
