Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 162058

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
258 PM CST Thu Nov 16 2017

.SHORT TERM...(This evening through Friday)
Issued at 225 PM CST Thu Nov 16 2017

The surface high that was to our north early this morning has
begun shifting east, introducing southeasterly winds to the region
this afternoon. A narrow band of virga is showing up on radar this
afternoon, and we did add a chance of light snow and flurries to
the forecast to account for this. So far, nothing is reaching the
ground. This band will race through quickly and shouldn`t

The main feature of interest in the short term period is the low
pressure system that is currently progressing eastward across
Montana and will continue on an easterly course. Expecting two
surface lows to develop, one will go well north of us, and the
other will sag south of our area. With the southern low, the warm
front will remain just to our south. The low level theta-e
advection really ramps up tonight, as warmer and more moist air
advects north of the front.

The forecast has been pretty consistent in holding off the
development of precipitation until the trough has pushed well
into MN, meaning western MN will likely remain dry. Farther
east,thinking drizzle is a good bet tomorrow along with low
stratus. Did reduce high temps by a few degrees tomorrow given
that we expect the low clouds to remain in place at least across
the east.

Thankfully in terms of impacts, temepratures will warm above
freezing before the arrival of the drizzle tomorrow, so expect
just wet roads, no ice.

.LONG TERM...(Friday night through Thursday)
Issued at 225 PM CST Thu Nov 16 2017

The main theme of the long term is continued dry weather and a
roller coaster of warm and cold. By tomorrow night, we will be in
cooler northwesterly flow that will scour the the moisture out we
could actually see the sun in southern MN on Saturday morning. The
northwesterly flow pattern holds into through the weekend until a
clipper like system to our north puts us in the warm sector and
pulls warmer air northward into the state on Monday.

That warm up will be brief and as the next dry cold front slams
through Monday night. Highs Monday will be in the mid to upper
40s, but Tuesday will be in the 20s to low 30s. That cool looks to
last through Wednesday before we swing back the other way very
close to Thanksgiving. For Thanksgiving day itself, right now we
look to be in the transition zone of the cold trough to the east
and the warm ridge building in from the west. So, timing of these
features will really be the important part because a delay, or a
more progressive flow, will make the difference between it being
cold, near normal, or warm for Thanksgiving.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 255 PM CST Thu Nov 16 2017

Do expect some erosion of the western edge of the stratus into
western MN as the afternoon and evening progress, but give the
switch to the moist and warm flow, am more pessimistic than the
guidance particularly across eastern MN and western WI, including
MSP.  Thinking the clouds could easily halt the eastward progression
after dark and never reach MSP and areas east.  North of the warm
front, we could see widespread IFR cigs with -DZ, especially across
the east. Winds will be strongest tonight but begin slacking off
tomorrow. Cold frontal boundary reaches western MN near the end of
the period.

KMSP...Went more pessimistic than guidance as I feel the cloud layer
will halt its progress east give influx of higher dew point air this
evening and overnight.

Fri...MVFR with chance -DZ. Wind S becoming NW 5-15 kts.
Sat...VFR with MVFR early. Wind NW 10-20 kts.
Sun...VFR. Wind W at 10 kts.




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