Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 042112
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
312 PM CST Mon Dec 4 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 313 PM CST Mon Dec 4 2017

The main change to the short term involved attempting to capture
the potential for an enhanced (narrow) band of snowfall over
central MN where favorable dendritic growth zone intersects
impressive omega as an impressive pocket of PV advection lifts
across east central MN and west central WI this evening. Did
increase snowfall ratios as well. All these factors considered led
to most locations west of I-35 (with the exception of along I-90)
having the potential for 2-3+ inches of snow falling in a
relatively short period of time, creating reduced visibilities and
slippery roads. Therefore transitioned much of central/west
central MN and a small portion of west central WI that was in a
wind advisory to a winter weather advisory...to better capture all
anticipated impacts. We also look to have some upright
instability so thundersnow will be possible this evening as well,
which could also enhance amounts.

.LONG TERM...(Tuesday night through Monday)
Issued at 313 PM CST Mon Dec 4 2017

Very few changes were made in the long term forecast period.
Northerly flow will prevail, which will mean the door will open
for cold air to move in from Canada. Temperatures through the
weekend will generally range around 5-10 degrees below normal.
Occasional shortwaves will clip the region, but little to no
attendant moisture and their quick- moving nature will limit
snowfall potential.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1153 AM CST Mon Dec 4 2017

MVFR conditions will degrade to IFR/LIFR this afternoon as a
storm system arrives. Rain will change over to snow as the cold
front passes, with a narrow band of heavy snow with very low
visibility. Snowfall rates could approach 1.5-2 inches per hour,
but would only last for 1-2 hours. Temperatures will be near the
freezing mark which could hold back accumulations slightly, but
falling temperatures overnight into Tuesday will freeze any
untreated surfaces. Winds will shift to the northwest and increase
behind the front. Sustained speeds of 25 to 35 knots with gusts
to between 40 and 50 knots will prevail through most of the
period.

KMSP...
We expect the ceiling to lower below 1800 feet by 21z, then lower
below 1000 feet by 23z. Drizzle/rain will transition to snow
between 02z and 03z, then diminish shortly after 06z. Could have
a brief 1-2hr window of moderate to heavy snow, with vsbys
lowering to near 1/2SM. Melting should hold back accumulations
toward 2 inches. Winds will increase later this evening with
gusts over 40 kts likely between 03z and 07z.

/OUTLOOK FOR KMSP/

Tue night...VFR. MVFR possible. Wind NW 15-25kts.
Wed...VFR. Wind NW 10-15G25kts.
Thu...VFR. MVFR possible late with Chc -SN.Wind NW 5-10kts.
Fri...VFR. MVFR possible early with Slgt Chc -SN. Wind NW 5-10kts


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory from 6 PM this evening to 4 AM CST
     Tuesday for WIZ014.

     Wind Advisory from 6 PM this evening to 6 AM CST Tuesday for
     WIZ015-016-023>028.

MN...Winter Weather Advisory from 6 PM this evening to 4 AM CST
     Tuesday for MNZ051>053-059>063-066>070-074>076-082-083.

     Wind Advisory until 6 PM CST this evening for MNZ051-052-059>063-
     066>070-074>076-082-083.

     Winter Storm Warning until midnight CST tonight for MNZ041-042-
     047-048-054>056-064.

     Winter Weather Advisory until 4 AM CST Tuesday for MNZ043>045-
     049-050-057-058-065-073.

     Wind Advisory until 4 AM CST Tuesday for MNZ077-078-084-085-
     091>093.

&&

$$

SHORT TERM...LS
LONG TERM...LS
AVIATION...LS



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