SPC MD 413

MD 0413 CONCERNING HEAVY SNOW FOR FAR NERN CO…WRN AND N-CNTRL NEB…ERN WY…SWRN/S-CNTRL SD


MESOSCALE DISCUSSION 0413
NWS STORM PREDICTION CENTER NORMAN OK
0646 PM CDT TUE APR 09 2013

AREAS AFFECTED...FAR NERN CO...WRN AND N-CNTRL NEB...ERN
WY...SWRN/S-CNTRL SD

CONCERNING...HEAVY SNOW

VALID 092346Z - 100445Z

SUMMARY...HEAVY SNOWFALL WITH RATES EXCEEDING 1-2 IN/HR WILL BE
POSSIBLE TONIGHT...INITIATING FIRST OVER FAR NERN CO...WRN NEB...ERN
WY AND SWRN SD THIS EVENING. HEAVY SNOWFALL WILL THEN EXPAND NEWD
ACROSS N-CNTRL NEB AND MUCH OF S-CNTRL SD LATER TONIGHT. IN
ADDITION...ISOLATED CONVECTIVE ELEMENTS MAY PRODUCE SOME SLEET.

DISCUSSION...LATEST WV IMAGERY SHOWS AN EMBEDDED SHORTWAVE TROUGH
PIVOTING N-NEWD INTO ERN CO AROUND AN UPPER TROUGH CENTERED OVER THE
FOUR CORNERS REGION. THE UPPER IMPULSE OVER ERN CO IS FORECAST TO
EJECT NEWD INTO KS THIS EVENING...AND THEN WRN/CNTRL NEB BY O6Z.
MODERATE TO STRONG DEEP-LAYER ASCENT WILL AID IN AN EXPANDING SHIELD
OF PRECIPITATION DEVELOPING OVER FAR NERN CO...WRN NEB...ERN WY AND
SWRN SD THIS EVENING...WHICH WILL THEN SPREAD INTO N-CNTRL NEB AND
S-CNTRL SD TONIGHT. MODEL FORECAST SOUNDINGS SHOW THE PRESENCE OF
ELEVATED CAPE ROOTED ABOVE 700 MB...WHICH WILL SUPPORT ENHANCED
PRECIPITATION RATES. THIS INSTABILITY COMBINED WITH MODERATE/STRONG
ASCENT...SUB-FREEZING FORECAST SOUNDINGS...AND INCREASINGLY
SATURATED THERMODYNAMIC PROFILES SUGGEST SNOWFALL RATES AOA 1-2
IN/HR WILL BE POSSIBLE.

..GARNER.. 04/09/2013

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

ATTN...WFO...FSD...ABR...LBF...UNR...BOU...CYS...

LAT...LON   43059837 41989953 40850176 40750312 41030412 41550469
            42850493 44070409 44680252 44769924 44169823 43059837

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md0413.html