[MCD] SWOMCD

Sat Feb 18 03:14:40 UTC 2006

ACUS11 KWNS 180313
SWOMCD
SPC MCD 180313 
TNZ000-KYZ000-MOZ000-MSZ000-ARZ000-OKZ000-180915-

MESOSCALE DISCUSSION 0157
NWS STORM PREDICTION CENTER NORMAN OK
0913 PM CST FRI FEB 17 2006

AREAS AFFECTED...NERN/ECNTRL OK...NRN/CNTRL AR...EXTREME SRN
MO...FAR W KY...WRN TN AND EXTREME NWRN MS

CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION 

VALID 180313Z - 180915Z

WINTER PCPN WILL SIGNIFICANTLY INCREASE ACROSS ERN OK...SRN MO AND
NRN/CNTRL AR THROUGH 06Z...THEN FARTHER EWD INTO THE LWR OH
VLY/MID-SOUTH BETWEEN 06-09Z.  

WEAK H5 WAVE WAS ANALYZED OVER OK AT 00Z AND WILL QUICKLY TRANSLATE
EWD INTO THE LWR OH VLY LATER TONIGHT. SLY LOW-LEVEL FLOW WILL
CONTINUE TO STRENGTHEN AHEAD OF THE WAVE THROUGH THE
NIGHT...RESULTING IN INCREASING H85-H7 FRONTOGENESIS AND ISENTROPIC
LIFT. GPS PWAT VALUES HAVE INCREASED TO AROUND 3/4 OF AN INCH ACROSS
SRN AR/OK SINCE LATE AFTERNOON...AND GIVEN THE STRENGTHENING
ASCENT...THERE ARE STRONG INDICATIONS THAT PCPN RATES WILL INCREASE
SIGNIFICANTLY THROUGH LATE EVENING.

00Z SOUNDING ANALYSIS PLACES A WARM NOSE AROUND H85 AS FAR N AS
CNTRL OK AND NRN AR THAT WILL LIKELY REMAIN IN PLACE UNTIL THE UPPER
WAVE PASSES BY LATER TONIGHT.  00Z OBSERVATIONS ARE SOMEWHAT WARMER
THAN RECENT RUC GUIDANCE HAS SUGGESTED.  GIVEN SOME COOLING OF THE
COLUMN VIA WET BULB PROCESSES...A PHASE CHANGE FROM SLEET TO SNOW
SHOULD OCCUR ACROSS EXTREME NERN OK...SRN MO AND EXTREME NRN AR
THROUGH 06Z. HOURLY SNOWFALL RATES COULD APPROACH 1 INCH FOR A 1-3
HOUR PERIOD.

TO THE SOUTH...THE SURFACE FREEZING LINE WILL LIKELY DEVELOP SWD
WITH TIME AS THE LOWER PART OF THE COLUMN MOISTENS.  THIS COMBINED
WITH TEMPERATURES AROUND 3 DEGREES C WITHIN THE WARM NOSE ALOFT WILL
SUPPORT LIQUID RAIN MIXING WITH/CHANGING TO SLEET. LOCALLY HEAVY
SLEET COULD OCCUR ACROSS ECNTRL OK EWD THROUGH THE REMAINDER OF NRN
AR.

FARTHER S...00Z LZK SOUNDING SHOWED A PRONOUNCED WARM NOSE OF AROUND
6 DEGREES C JUST BELOW H7.  AS THE SURFACE TEMPERATURES GRADUALLY
APPROACH 32 DEGREES F LATER TONIGHT...RAIN WILL CHANGE TO FREEZING
RAIN SOUTH OF A KFSM-KBVX-NEAR KMEM LINE.  HOURLY RATES WILL BE
0.05-0.10 INCH.

PCPN WILL SPREAD/DEVELOP EWD EAST OF THE MS RVR...ESPECIALLY AFTER
06Z.  MAINLY SNOW IS EXPECTED N OF THE OH RVR...WITH SLEET ACROSS
WRN TN N OF KMEM.  MAINLY FREEZING RAIN CAN BE EXPECTED BY 12Z
ACROSS NWRN MS AND WRN TN S OF KMEM.

..RACY.. 02/18/2006

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

ATTN...WFO...OHX...PAH...MEG...LZK...SGF...TSA...

36219597 36719463 36779360 36779144 36769029 36808876
36508818 36038816 35548855 34758972 34509094 34889279
35089428 35409582 

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