000
ACUS11 KWNS 041240
SWOMCD
SPC MCD 041240
MOZ000-ARZ000-OKZ000-041745-

MESOSCALE DISCUSSION 0112
NWS STORM PREDICTION CENTER NORMAN OK
0640 AM CST WED MAR 04 2015

AREAS AFFECTED...NORTHEAST/EAST-CENTRAL OK INTO SOUTHERN MO/FAR
NORTHERN AR

CONCERNING...WINTER MIXED PRECIPITATION

VALID 041240Z - 041745Z

SUMMARY...MIXED WINTER PRECIPITATION WILL BECOME INCREASINGLY COMMON
BY LATE MORNING/EARLY AFTERNOON ACROSS EAST-CENTRAL/NORTHEAST OK
INTO SOUTHERN MO/FAR NORTHERN AR AS COLDER AIR TRANSITIONS
SOUTHEASTWARD. AT LEAST SOME SLEET/LIGHT ICE ACCUMULATIONS CAN BE
EXPECTED WITHIN THIS CORRIDOR ALONG WITH SOME SNOW ACROSS PARTS OF
NORTHEAST OK AND SOUTHWEST/SOUTH-CENTRAL MO.

DISCUSSION...DOWNSTREAM OF AN UPPER LOW OVER BAJA EARLY THIS
MORNING...FORCING FOR ASCENT WILL CONTINUE TO INCREASE IN TANDEM
WITH A SHARPENING/SOUTHEASTWARD-SHIFTING FRONTAL ZONE ACROSS THE
SOUTHERN PLAINS/OZARKS. SATELLITE AND REGIONAL RADAR/SURFACE
OBSERVATIONS EARLY THIS MORNING REFLECT INCREASINGLY COLDER CLOUD
TOPS AND INCREASING PRECIPITATION FROM NORTH-CENTRAL TX AND
SOUTHERN/EASTERN OK INTO THE OZARKS.

THE SURFACE WET-BULB 32F ISOLINE...WHICH LARGELY PARALLELS I-44 FROM
OK INTO SOUTHERN MO AS OF 12Z/6 AM CST...CONTINUES TO STEADILY
PROGRESS SOUTHEASTWARD AT AROUND 15-25 MPH. AS THIS TREND
CONTINUES...PROGRESSIVELY COLDER NEAR-SURFACE AIR WILL LEAD TO A
TRANSITIONAL COMBINATION OF WINTER MIXED PRECIPITATION TYPES BY LATE
MORNING/EARLY AFTERNOON ACROSS EAST-CENTRAL/NORTHEAST OK INTO
SOUTHERN MO/FAR NORTHERN AR.

SCATTERED/BRIEF BOUTS OF FREEZING RAIN ARE POSSIBLE...BUT A COOLING
ELEVATED WARM LAYER /ROUGHLY 825-700 MB/ SHOULD GENERALLY LEAD TO A
DOMINANT PRECIP TYPE OF SLEET ACROSS MUCH OF THIS CORRIDOR BY EARLY
AFTERNOON...WITH SOME SNOW ALSO ACROSS NORTHERN OK AND
SOUTHEAST/SOUTH-CENTRAL MO. THIS SCENARIO IS SUPPORTED BY RECENT
/12Z/ UPPER AIR OBSERVATIONS FROM SPRINGFIELD MO AND NORMAN
OK...WHERE WET-BULB TEMPERATURES WITHIN THE ELEVATED WARM LAYER WERE
OBSERVED TO BE AS MUCH AS 1 DEG C COLDER THAN 06Z NAM/RECENT HRRR
SOUNDINGS /FURTHER SUPPORTIVE OF A TREND TOWARD DOMINANT SLEET AND
SOME SNOW/.

..GUYER.. 03/04/2015

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA...OUN...

LAT...LON   37779041 37118941 36168979 35769333 34979536 35299665
            36669517 37779041