Post by SKYSUMMIT on Dec 19, 2012 11:21:11 GMT -6
The first blizzard for the plains....many areas already under Blizzard Warnings
MESOSCALE DISCUSSION 2176
NWS STORM PREDICTION CENTER NORMAN OK
1047 AM CST WED DEC 19 2012
AREAS AFFECTED...NERN/E-CNTRL CO...NWRN/W-CNTRL/N-CNTRL
KS...SWRN/S-CNTRL/CNTRL NEB
CONCERNING...BLIZZARD
VALID 191647Z - 192245Z
SUMMARY...BLIZZARD CONDITIONS WILL DEVELOP AFTER 19Z ACROSS PARTS OF
CO/NEB/KS...AND SPREAD EWD/ENEWD INTO THE EVENING.
DISCUSSION...DURING THE NEXT FEW HOURS...STRONG SFC CYCLOGENESIS
WILL OCCUR OVER SWRN KS AND THE OK PANHANDLE AS STRONG DCVA LEADING
AN APPROACHING PV MAX OVERTAKES A BROAD AREA OF LOW-LEVEL
BAROCLINICITY. THE DEVELOPING SFC LOW WILL TRACK EWD NEAR OR JUST
NORTH OF THE KS/OK BORDER THROUGH THIS EVENING...WHILE A VERY TIGHT
SFC PRESSURE GRADIENT W/NW OF THE CENTER OF THE LOW SUPPORTS
NNWLY/NLY WINDS OF 25 TO 40 MPH WITH GUSTS OF 45 TO 60 MPH. THESE
WINDS WILL SPREAD EWD/ENEWD ACROSS THE DISCUSSION AREA AFTER 19Z.
THE STRONGEST WINDS ARE FORECAST TO EXTEND FROM E-CNTRL/NERN CO EWD
ACROSS NWRN/W-CNTRL/N-CNTRL KS AND SWRN/S-CNTRL NEB. SUPPORT FOR
THESE WINDS WILL EMANATE FROM 40-50 KT OF 0-1-KM MEAN FLOW PER
FORECAST SOUNDINGS AMIDST STEEP SFC-1-KM-AGL LAPSE RATES DRIVEN BY
INCREASING COLD ADVECTION WITH HEIGHT JUST ABOVE THE SFC.
STRONG 850-500-MB FRONTOGENESIS OCCURRING WITHIN THE DEFORMATION
ZONE OF THE CYCLONE WILL SUPPORT ASCENT OVERLAPPING WITH THE
DENDRITIC GROWTH ZONE TO YIELD AN EWD/ENEWD-DEVELOPING BAND OF HEAVY
SNOW WITH RATES OF 1-1.5 IN/HR. THE LATEST SHORT-RANGE GUIDANCE
SUGGESTS THAT THIS BAND WILL DEVELOP EWD/ENEWD FROM PARTS OF NERN CO
INTO NWRN/N-CNTRL KS AND ACROSS SWRN/S-CNTRL NEB. WEAK ELEVATED
BUOYANCY MAY SUPPORT AN ISOLATED LIGHTNING STRIKE OR TWO WITHIN THE
HEAVIEST SNOW BURSTS.
THE AFOREMENTIONED FACTORS WILL SUPPORT BLIZZARD CONDITIONS
ASSOCIATED WITH VISIBILITIES BELOW ONE-QUARTER MILE AND BLOWING SNOW
ACROSS THE DISCUSSION AREA. THE AREA OF GREATEST CONCERN FOR
BLIZZARD CONDITIONS LIES WITHIN THE OVERLAPPING AREAS OF HIGHEST
CONFIDENCE FOR 1-1.5-IN/HR SNOW RATES AND STRONGEST WINDS -- I.E.
FROM NERN CO ENEWD INTO S-CNTRL NEB.
..COHEN.. 12/19/2012
MESOSCALE DISCUSSION 2176
NWS STORM PREDICTION CENTER NORMAN OK
1047 AM CST WED DEC 19 2012
AREAS AFFECTED...NERN/E-CNTRL CO...NWRN/W-CNTRL/N-CNTRL
KS...SWRN/S-CNTRL/CNTRL NEB
CONCERNING...BLIZZARD
VALID 191647Z - 192245Z
SUMMARY...BLIZZARD CONDITIONS WILL DEVELOP AFTER 19Z ACROSS PARTS OF
CO/NEB/KS...AND SPREAD EWD/ENEWD INTO THE EVENING.
DISCUSSION...DURING THE NEXT FEW HOURS...STRONG SFC CYCLOGENESIS
WILL OCCUR OVER SWRN KS AND THE OK PANHANDLE AS STRONG DCVA LEADING
AN APPROACHING PV MAX OVERTAKES A BROAD AREA OF LOW-LEVEL
BAROCLINICITY. THE DEVELOPING SFC LOW WILL TRACK EWD NEAR OR JUST
NORTH OF THE KS/OK BORDER THROUGH THIS EVENING...WHILE A VERY TIGHT
SFC PRESSURE GRADIENT W/NW OF THE CENTER OF THE LOW SUPPORTS
NNWLY/NLY WINDS OF 25 TO 40 MPH WITH GUSTS OF 45 TO 60 MPH. THESE
WINDS WILL SPREAD EWD/ENEWD ACROSS THE DISCUSSION AREA AFTER 19Z.
THE STRONGEST WINDS ARE FORECAST TO EXTEND FROM E-CNTRL/NERN CO EWD
ACROSS NWRN/W-CNTRL/N-CNTRL KS AND SWRN/S-CNTRL NEB. SUPPORT FOR
THESE WINDS WILL EMANATE FROM 40-50 KT OF 0-1-KM MEAN FLOW PER
FORECAST SOUNDINGS AMIDST STEEP SFC-1-KM-AGL LAPSE RATES DRIVEN BY
INCREASING COLD ADVECTION WITH HEIGHT JUST ABOVE THE SFC.
STRONG 850-500-MB FRONTOGENESIS OCCURRING WITHIN THE DEFORMATION
ZONE OF THE CYCLONE WILL SUPPORT ASCENT OVERLAPPING WITH THE
DENDRITIC GROWTH ZONE TO YIELD AN EWD/ENEWD-DEVELOPING BAND OF HEAVY
SNOW WITH RATES OF 1-1.5 IN/HR. THE LATEST SHORT-RANGE GUIDANCE
SUGGESTS THAT THIS BAND WILL DEVELOP EWD/ENEWD FROM PARTS OF NERN CO
INTO NWRN/N-CNTRL KS AND ACROSS SWRN/S-CNTRL NEB. WEAK ELEVATED
BUOYANCY MAY SUPPORT AN ISOLATED LIGHTNING STRIKE OR TWO WITHIN THE
HEAVIEST SNOW BURSTS.
THE AFOREMENTIONED FACTORS WILL SUPPORT BLIZZARD CONDITIONS
ASSOCIATED WITH VISIBILITIES BELOW ONE-QUARTER MILE AND BLOWING SNOW
ACROSS THE DISCUSSION AREA. THE AREA OF GREATEST CONCERN FOR
BLIZZARD CONDITIONS LIES WITHIN THE OVERLAPPING AREAS OF HIGHEST
CONFIDENCE FOR 1-1.5-IN/HR SNOW RATES AND STRONGEST WINDS -- I.E.
FROM NERN CO ENEWD INTO S-CNTRL NEB.
..COHEN.. 12/19/2012
