Mesoscale Discussion 256

Issued

Mar 23, 2016, 7:15 PM CDT (00:15 UTC)

Expired

Mar 24, 2016, 1:15 AM CDT

In force

6 hr

Issued by

the Storm Prediction Center

The Minneapolis radar (KMPX), 131 km from the middle of the area, began a volume at 00:18 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

983 
ACUS11 KWNS 240016
SWOMCD
SPC MCD 240015 
WIZ000-IAZ000-MNZ000-SDZ000-NEZ000-240615-

MESOSCALE DISCUSSION 0256
NWS STORM PREDICTION CENTER NORMAN OK
0715 PM CDT WED MAR 23 2016

AREAS AFFECTED...EXTREME SERN SD...EXTREME NERN NEB...NRN IA...SRN
MN...W-CNTRL WI

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 240015Z - 240615Z

SUMMARY...FROZEN PRECIPITATION WILL CONTINUE TO INCREASE IN
COVERAGE/INTENSITY WITHIN A CORRIDOR FROM EXTREME NERN NEB/SERN SD
INTO W-CNTRL WI THROUGH THE EVENING HOURS. AREAS OF HEAVY
SNOW...ALONG WITH AREAS OF SLEET...ARE EXPECTED.

DISCUSSION...A RADAR LOOP SHOWS AN ARC OF DIURNALLY ENHANCED
CONVECTION EVOLVING WITHIN THE DCVA PLUME PRECEDING A COMPACT
MID-LEVEL CYCLONE OVER THE CNTRL GREAT PLAINS -- EVOLVING FROM WRN
IA TO FAR ERN KS. THIS ACTIVITY -- CONTAINING LIGHTNING -- WILL
CONTINUE TO SPREAD NEWD/NWD AND EVENTUALLY MERGE WITH AN EXTENSIVE
CYCLONE-RELATED DEFORMATION ZONE THAT BRANCHES ENEWD TO LOWER MI.
THESE FACTORS WILL SUPPORT AN INCREASE IN PRECIPITATION RATES DURING
THE NEXT SEVERAL HOURS ACROSS THE DISCUSSION AREA...AS THE MID-LEVEL
CYCLONE ADVANCES ENEWD. WITH SUB-FREEZING WET-BULB TEMPERATURES
EITHER ALREADY IN PLACE AT THE SFC...OR BECOMING ESTABLISHED AS
AIDED BY MODEST LOW-LEVEL COLD ADVECTION...FROZEN PRECIPITATION WILL
BE SUPPORTED.

IN GENERAL...SUFFICIENTLY DEEP SUBFREEZING PROFILES THROUGH THE
COLUMN WILL SUPPORT SNOW -- SOME HEAVY WITH RATES REACHING 1.0-1.5
INCHES PER HOUR AS STRONG FRONTOGENETIC ASCENT AND CONVECTIVE
PROCESSES EXTEND THROUGH THE DENDRITIC GROWTH ZONE ALOFT. BANDS OF
ONGOING MODERATE TO HEAVY SNOW ACROSS PARTS OF SRN MN INTO W-CNTRL
WI WILL CONTINUE THIS EVENING...WITH SNOW INCREASING IN
COVERAGE/INTENSITY FARTHER S THROUGH 03Z. HOWEVER...SLEET -- WITH
SLEET-ACCUMULATION RATES TO 0.25 INCH PER HOUR -- MAY AFFECT PARTS
OF N-CNTRL/NERN IA PARTICULARLY IN ASSOCIATION WITH CONVECTIVE
ELEMENTS...AS AN ELEVATED WARM LAYER WILL SUPPORT PARTIAL MELTING OF
DESCENDING HYDROMETEORS THAT WILL REFREEZE WITHIN THE BOUNDARY
LAYER. LIGHTNING COULD ACCOMPANY THE HIGHEST FROZEN PRECIPITATION
RATES...AS WELL. ALL OF THIS ACTIVITY WILL SPREAD ENEWD THROUGH THE
EVENING AND CONTINUE IN SOME AREAS INTO THE OVERNIGHT HOURS.

..COHEN.. 03/24/2016

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

ATTN...WFO...GRB...ARX...MPX...DMX...FSD...

LAT...LON   44318988 43539038 43069194 42579561 42689698 43199701
            43859610 44829264 44869055 44318988

Mesoscale Discussions in Iowa, 2016Mesoscale Discussions in Minnesota, 2016Mesoscale Discussions in Wisconsin, 2016Every mesoscale discussion in 2016

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.