Mesoscale Discussion 2221

Issued

Dec 8, 2009, 9:38 PM CST (03:38 UTC)

Expired

Dec 9, 2009, 3:45 AM CST

In force

6 hr

Issued by

the Storm Prediction Center

The Omaha radar (KOAX), 98 km from the middle of the area, began a volume at 03:39 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.

000 
ACUS11 KWNS 090339
SWOMCD
SPC MCD 090338 
IAZ000-MNZ000-MOZ000-KSZ000-NEZ000-SDZ000-090945-

MESOSCALE DISCUSSION 2221
NWS STORM PREDICTION CENTER NORMAN OK
0938 PM CST TUE DEC 08 2009

AREAS AFFECTED...ERN NEB...NRN MO...FAR NERN KS...MUCH OF IA...SRN
MN

CONCERNING...BLIZZARD 

VALID 090338Z - 090945Z

NORTH-NORTHWESTERLY WINDS ARE FORECAST TO STRENGTHEN THROUGH
12Z...WITH SUSTAINED WINDS AS HIGH AS 35 MPH AND GUSTS UP TO 40-50
MPH. SUBSTANTIAL BLOWING AND DRIFTING SNOW IS LIKELY WITH
VISIBILITIES REDUCED TO UNDER ONE QUARTER MILE.

NEGATIVELY TILTED UPPER TROUGH IS FORECAST TO LIFT NEWD FROM THE MID
MS VALLEY REGION INTO THE GREAT LAKES THROUGH 06-12Z. AS THIS TAKES
PLACE...SUBSTANTIAL DEEPENING OF THE LOW LEVEL CYCLONE IS FORECAST
TO OCCUR AS IT BEGINS TO OCCLUDE WHILE TRAVERSING ACROSS IL. SHORT
RANGE ENSEMBLE AND DETERMINISTIC MODEL GUIDANCE INDICATE THAT
SUSTAINED WINDS WEST OF THE LOW OVER ERN NEB/IA WILL APPROACH 35 MPH
DUE TO THE STRENGTHENING SURFACE PRESSURE GRADIENT. IN
ADDITION...FORECAST SOUNDINGS DEPICT 40-50 KT NLY FLOW DEVELOPING
NEAR THE TOP OF A SHALLOW /HALF KM DEEP/ WELL MIXED LAYER EXTENDING
ABOVE THE SURFACE...WHICH WILL FAVOR VERY STRONG WIND GUSTS. GIVEN
THE CONTINUED POTENTIAL FOR AT LEAST LIGHT SNOWFALL THROUGH THE
NIGHT...IN ADDITION TO THE SNOW COVERED GROUND...BLOWING AND
DRIFTING SNOW APPEARS LIKELY WITH VISIBILITIES REDUCED TO UNDER A
QUARTER MILE.

..GARNER.. 12/09/2009

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

...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...DVN...ARX...MPX...DMX...EAX...FSD...OAX...TOP...
GID...LBF...

LAT...LON   39529522 40169779 40739874 42019864 44179594 44669275
            43479124 40699193 39529522

Mesoscale Discussions in Iowa, 2009Mesoscale Discussions in Nebraska, 2009Mesoscale Discussions in Minnesota, 2009Every mesoscale discussion in 2009

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.