SPC MD 590

MD 0590 CONCERNING HEAVY SNOW FOR NW IA…NE NEB…S-CNTRL/SW MN


MESOSCALE DISCUSSION 0590
NWS STORM PREDICTION CENTER NORMAN OK
0810 PM CDT WED MAY 01 2013

AREAS AFFECTED...NW IA...NE NEB...S-CNTRL/SW MN

CONCERNING...HEAVY SNOW

VALID 020110Z - 020515Z

SUMMARY...A BAND OF MODERATE TO HEAVY SNOW IS EXPECTED TO DEVELOP
ACROSS NE NEB NEWD INTO SRN MN DURING THE NEXT FEW HOURS. SNOWFALL
RATES OF 1 INCH PER HOUR ARE POSSIBLE.

DISCUSSION...UNIQUE LATE SEASON SETUP FAVORING A BAND OF HEAVY SNOW
IS COMING TOGETHER ACROSS PORTIONS OF THE MID MO RIVER VALLEY.
LATEST MESOANALYSIS/MODEL GUIDANCE DEPICTS A STRONG UPPER LEVEL JET
STREAK EXTENDING FROM SD NEWD THROUGH WRN ONTARIO WITH THE MID MO
RIVER VALLEY UNDER THE RIGHT ENTRANCE REGION. SURFACE COLD FRONT HAS
MOVED WELL SOUTH OF THE REGION AND EXTENDED FROM SRN WI SWWD THROUGH
NRN MO AND INTO N-CNTRL OK AT 00Z. PER MESOANALYSIS... SLOPING
FRONTOGENIC ZONE EXISTS FROM CNTRL MO/ERN KS NWWD INTO E-CNTRL
NEB/W-CNTRL IA. STRENGTHENING WARM CONVEYOR WILL RESULT IN CONTINUED
WAA ACROSS MUCH OF THE REGION WITH A BROAD AREA OF POST-FRONTAL
PRECIPITATION CONTINUING THROUGHOUT MUCH OF THE EVENING AND
OVERNIGHT. 00Z OAX SOUNDING SHOWS THE POTENTIAL FOR SOME MIXED
PRECIPITATION...PRIMARILY IP/SN...WITH A SHALLOW WARM NOSE OBSERVED
AROUND 700 MB. FARTHER N...MPX 00Z SOUNDING SHOWS A COLDER OVERALL
PROFILE...SUPPORTING ALL SNOW.

GIVEN ALL OF THESE FACTORS...CONFIDENCE IS HIGH THAT A BAND OF HEAVY
SNOW WITH SNOWFALL RATES AROUND 1 INCH PER HOUR...WITH BRIEF PERIODS
OF SLIGHTLY HIGHER RATES...WILL DEVELOP ACROSS THE MD AREA.

..MOSIER.. 05/02/2013

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

ATTN...WFO...ARX...MPX...DMX...FSD...OAX...GID...

LAT...LON   44239430 44489372 44549275 44309230 43629266 42469384
            42369396 41539510 41039624 40949695 41149747 41769765
            42759618 44059451 44239430

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md0590.html