Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 141722

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1122 AM CST Wed Feb 14 2018

.SHORT TERM...(Today and tonight)
Issued at 336 AM CST Wed Feb 14 2018

Confidence is now high that we will have a fog/stratus free day
today, so updated forecast highs for this afternoon toward the
warmest guidance, which happens to be the ECMWF. The biggest
increase to highs was out in west central MN. Looking back at
satellite imagery from Tuesday afternoon, what little snow that was
out in this part of MN is now mostly gone. Add on full sunshine and
a favorable southwest wind direction for warming to the bare ground
and see no reason why what the ECMWF has been showing for highs out
there for days does not happen, which is places out by Madison and
Montevideo get into the lower 50s. For the rest of the area, there
was only a degree or two increase in forecast highs as the deeper
snow cover will help hold highs back in the mid 30s to lower 40s.
Record highs for today at our primary climate sites are 52 (1921,
STC), 50 (1882, MSP), and 49 (1934, EAU) and they look pretty safe.
Meager snow cover at STC means they could certainly over achieve
with temperatures, but doubt they will out perform the current
forecast high of 41 by 11 degrees.

Tonight, the GFS looks to be a fast outlier in bringing the arctic
air back in out toward Alexandria/Morris, with everything else
bringing the good push of CAA in Thursday morning, so warmed lows
out in the northwest corner of the MPX coverage area. The slower
arrival of the front also means a slower arrival to snowfall
potential in it`s wake, so kept the forecast dry through 12z
Thursday for the entire MPX area.

.LONG TERM...(Thursday through Tuesday)
Issued at 336 AM CST Wed Feb 14 2018

The long term period starts out with semi-zonal flow, and then
transitions to a highly amplified trough over the western CONUS
and a strong eastern ridge for early next week. This shift will
likely translate to an active weather pattern.

Thursday a weak front drops across the area combined with upper
jet forcing. This isn`t anything too impressive, but progged
forcing looks to warrant 30-40 pops. Could also see a bit of rain
mix in, but overall mainly snow is expected with trace to half
inch accumulations.

Friday temperatures briefly retreat back below normal, with highs
from the mid teens to lower 20s.

Over the weekend the southwest CONUS trough begins to slowly
amplify. This will cause heights to gradually rise over the
central CONUS, which will allow temperatures to moderate back into
the mid 20s to mid 30s. Medium range models begin to diverge with
respect to the degree of amplification of the trough. Associated
precipitation on Sunday is well north of the region according to
the ECMWF, while the Canadian places the bullseye over central MN.
Meanwhile, the GFS is in between the two. Therefore confidence on
Sunday POPS is rather low, but decent on Monday night and Tuesday
as the trough ejects into the central CONUS.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1115 AM CST Wed Feb 14 2018

No aviation concerns through this evening as south/southwest wind
will become more west/west-southwest this evening. After 06z,
conditions will begin to deteriorate from central Minnesota by
9-12z, and across southern/east central Minnesota and west central
Wisconsin by 12-18Z. Light snow is possible as cigs lower to
MVFR, or possibly IFR at times, but restrictions with the snow
will be 5SM or greater.


May concern this afternoon is the potential higher wind speed
around 10 kts from the southwest, or a direct crosswind. Between
15-18z, conditions will begin to deteriorate with MVFR cigs
likely along with -SN. Winds will shift to the west overnight, and
to the northwest by morning. Gusty winds of 18-22kts are likely
by Thursday afternoon from the northwest.


Fri...VFR. Winds W 5-10 kts, bcmg SW.
Sat...VFR. Chc -SN/MVFR in mrng. Winds SW bcmg W 10G20 kts.
Sun...MVFR, possibly IFR in SN. Winds S bcmg SW 10-15kts.



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