Mesoscale Discussion 40

Issued

Feb 2, 2003, 9:06 PM EST (02:06 UTC)

Expired

Feb 3, 2003, 6:00 AM EST

In force

9 hr

Issued by

the Storm Prediction Center

The Green Bay radar (KGRB), 97 km from the middle of the area, began a volume at 02:08 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.

976 
ACUS11 KWNS 030207
SWOMCD
SPC MCD 030206 
WIZ000-MIZ000-031100-

MESOSCALE DISCUSSION 0040
NWS STORM PREDICTION CENTER NORMAN OK
0806 PM CST SUN FEB 02 2003

AREAS AFFECTED...NRN WI...AND FAR NRN LOWER MI/SRN U.P OF MI

CONCERNING...HEAVY SNOW 

VALID 030206Z - 031100Z

HEAVY SNOW WITH HOURLY ACCUMULATION RATES UP TO 1 INCH WILL MOVE
NEWD THROUGH FAR NERN WI INTO FAR NRN LOWER MI THROUGH 03/09Z.
ADDITIONAL HEAVY SNOW ASSOCIATED WITH DEFORMATION ZONE OVER SRN
MN WILL DEVELOP EWD ACROSS MUCH OF NRN WI.



LATEST RADAR MOSAIC SHOWS A BAND OF HEAVY SNOW EXTENDING FROM 20
S AUW TO 20 SW GRB. PRIMARY VERTICAL MOTION ACTING TO GENERATE
THIS BAND IS STRONG ISENTROPIC LIFT/FRONTOGENESIS IN THE 3-4 KM
LAYER WHICH IS COINCIDENT WITH MAX DENDRITE SNOW DEVELOPMENT. THE
DRY LAYER OBSERVED ON THE 00Z GRB SOUNDING SHOULD QUICKLY
SATURATE ALLOWING FOR CONTINUED NEWD PROGRESS OF THIS HEAVY SNOW
BAND INTO FAR NERN WI INCLUDING THE GRB AND DOOR PENINSULA AREA
THROUGH 03/05Z. OVER NRN LOWER MI INITIAL FRONTOGENETIC BAND OF
PRECIP OVER WCENTRAL MI WILL PROVIDE FOR LITTLE SNOW POTENTIAL
DUE TO A VERY DRY LOW-MID LEVEL COLUMN OBSERVED ON 00Z APX
SOUNDING. STRONGEST FRONTOGENETIC FORCING ASSOCIATED WITH THE
NERN WI HEAVY SNOWBAND SHOULD MOVE INTO FAR SRN U.P OF MI AND
NWRN LOWER MI AFTER 03/04Z. DURATION OF HEAVY SNOW WILL LIKELY BE
GREATEST OVER THIS AREA AS UPPER FORCING REMAINS QUASISTATIONARY
DUE TO REDEVELOPMENT PROCESS OF MID LEVEL DEFORMATION ZONE OVER
THE REGION LATER TONIGHT.



FARTHER WEST...MODERATE TO HEAVY SNOW WITH HOURLY RATES UP TO 1
INCH NEAR MSP...SUPPORTED BY STEEP 700-500 MB LAPSE RATES
ASSOCIATED WITH MAIN DEFORMATION ZONE...WILL CONTINUE TO
GRADUALLY SHIFT ENEWD INTO NWRN AND EVENTUALLY NCENTRAL WI. A
NARROW ZONE /20 MILES WIDE/ OF 6 INCHES OF SNOW WILL BE POSSIBLE
FROM THE NRN MSP METRO AREA EWD TO NEAR RHI THROUGH 03/08Z.



..CROSBIE.. 02/03/2003

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

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45858886

Mesoscale Discussions in Wisconsin, 2003Mesoscale Discussions in Michigan, 2003Every mesoscale discussion in 2003

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.