Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 291213

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
613 AM CST Tue Nov 29 2016

.UPDATE...For 12z Aviation discussion below


.SHORT TERM...(Today and tonight)
Issued at 330 AM CST Tue Nov 29 2016

The vertically stacked low is centered over the tip of west central
Minnesota early this morning, and it will begin to fill and meander
south and east to reach the southeastern border of the state by
Wednesday morning. As this occurs, the deformation zone of
precipitation will shift into western Minnesota, where 60-80 percent
precip chances have been included for a good portion of today and
tonight. Farther east across central and south central MN,
precipitation will be more scattered in nature, with isolated
activity over west central WI. The infiltration of colder air will
also be sufficient to transition rain and rain/snow over to mainly
snow overnight. We could see around one inch snow accumulation in
west central MN by daybreak Wednesday.

Given the extensive cloud cover and the low overhead, diurnal
warming will be stunted, but readings will still be well above
climatological normal. Highs in the upper 30s to lower 40s are
expected, with low/mid 30s for lows tonight.

.LONG TERM...(Wednesday through Monday)
Issued at 340 AM CST Tue Nov 29 2016

Very similar forecast in the extended period with high confidence
of above normal temperatures through the week, and into next
weekend. Lower confidence in temperatures past next week, but
there remains the general trend of much colder air beginning to
spill southward across the Canadian Prairies, and into the
Northern Plains next week. How far eastward this much colder air
mass moves in terms of timing and extent remains questionable. The
general consensus remains favorable for temperatures to at least
fall back to near normal the week of December 7th. The coldest air
holds just east of the Rockies, and into the Northern Plains. The
air mass in this area will be 10 to 15 degrees below average next

Forecast concerns deal with a cutoff upper low expected to form in
the desert southwest this weekend, and move slowly eastward.
Although the consensus in the deterministic models favor a more
southern jet stream interaction, vs. the northern stream, I have
doubts based on the ensemble means of both the GEFS/NAEFS.
Confidence remains low on how this will affect the Upper Midwest
the ladder part of the upcoming weekend, and into early next week.
Currently our region should remain mostly dry with the best chance
of widespread precipitation southeast across the Ohio Valley. This
system does need to be watched as it has the potential of
generating lots of unsettled weather including a large swath of snow
on the northwest side of the storm system.


.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 613 AM CST Tue Nov 29 2016

MVFR and IFR ceilings will prevail through the period under the
influence of the low pressure center overhead. Widely scattered
rain/snow showers are expected as well, eventually becoming more
organized tonight. MVFR/IFR visibility reductions are expected
attendant with the precip. Western sites (KAXN and KRWF) will be
the most affected by precipitation and lower visibilities, which
will expand eastward across the MN sites between 00z and 06z.

KMSP...Expect MVFR cigs to prevail through the majority of the
period. The main window for precipitation chances arrives
tonight, with rain around 05z mixing with snow by 09z and lowering
visibilities to IFR.

Wed...MVFR/IFR. Chc -RA/-SN. Wind NW 5-10 kts.
Thu...MVFR. Wind NW 5-10 kts.
Fri...MVFR. Wind NW 5-10 kts.




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