MESOSCALE DISCUSSION 0108
   NWS STORM PREDICTION CENTER NORMAN OK
   0618 AM CST FRI FEB 13 2009
   
   AREAS AFFECTED...SRN HALF OF NEB
   
   CONCERNING...HEAVY SNOW 
   
   VALID 131218Z - 131615Z
   
   SNOWFALL RATES OF 1-2 IN/HR ARE EXPECTED TO DEVELOP THIS MORNING IN
   A WSW-ENE ORIENTED BAND OR TWO FROM SWRN TO EAST CENTRAL NEB.  THE
   GREATEST INTENSITY SHOULD OCCUR BETWEEN 15-18Z WHEN CONVECTIVE
   ENHANCEMENT IS POSSIBLE...RESULTING IN POTENTIAL FOR LOCALLY HIGHER
   SNOWFALL RATES.
   
   EARLY MORNING WATER VAPOR IMAGERY SHOWED A PROGRESSIVE...
   COMPACT...SHORT WAVE TROUGH EMERGING FROM THE CENTRAL ROCKIES INTO
   WRN KS.  MODEL DATA AGREE WITH THE TRACK OF THE SHORT WAVE TROUGH
   ACROSS NRN KS TODAY...REACHING WRN IA BY 14/00Z.  REGIONAL RADAR
   DATA INDICATED AN INCREASE IN COVERAGE OF REFLECTIVITIES NWD FROM
   NRN KS INTO SRN NEB.  THIS IS LIKELY INDICATIVE OF MOISTENING
   OCCURRING IN THE MID LEVELS ATOP AN INITIALLY DRY BOUNDARY LAYER AS
   INCREASING VERTICAL MOTION SPREADS EWD.  LOWER TROPOSPHERIC CYCLONE
   DEEPENING /700 MB CLOSED LOW MOVING ENEWD ALONG THE KS/NEB BORDER/
   IS EXPECTED THIS MORNING AND SUGGESTS THE HIGHEST PROBABILITY FOR
   HEAVY SNOWFALL RATES SHOULD EXTEND FROM SWRN TO EAST CENTRAL NEB
   THROUGH 18Z.  AS THE LOWER TROPOSPHERIC CYCLONE DEEPENS...SSELY LOW
   LEVEL WINDS UP TO 700 MB WILL BE MAINTAINED AT 35-45 KT...RESULTING
   IN STRONG WAA ACROSS SWRN-ERN NEB ALONG AND NORTH OF A STRENGTHENING
   LOW-MID LEVEL THERMAL BOUNDARY.  FORECAST SOUNDINGS SUGGEST
   STRONGEST MID LEVEL UVVS WITHIN THE DENDRITIC SNOW GROWTH REGION. 
   THIS COMBINED WITH STEEPENING MID LEVEL LAPSE RATES WOULD SUGGEST
   THE INCREASED LIKELIHOOD FOR ENHANCED SNOWFALL RATES...WITH THE
   POTENTIAL FOR A COUPLE RUMBLES OF THUNDER GIVEN ELEVATED MUCAPE
   50-100 J/KG.
   
   ..PETERS.. 02/13/2009
   
   
   ...NOTICE...
   SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
   SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
   TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
   FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.
   
   ATTN...WFO...OAX...GID...LBF...GLD...
   
   LAT...LON   40170098 40550115 40930099 41459903 41709737 41669609
               40649578 40469664 40079841 40040068 40170098