Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 202059

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
259 PM CST Tue Feb 20 2018

.SHORT TERM...(This evening through Wednesday)
Issued at 300 PM CST Tue Feb 20 2018

Relatively benign weather is expected through Wednesday, as
surface high pressure settles in across the area. Clouds will
continue clearing this evening, with mostly sunny skies and
lighter winds for Wednesday.

Sub-zero temperatures will occur generally west of the I-35
corridor tonight where there`s a fresh snowpack and skies will be
clear for the duration. East of I-35 across west central Wisconsin
expect lows in the single digits just above zero. Highs on
Wednesday will remain below normal, generally in the upper teens
to lower 20s.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 300 PM CST Tue Feb 20 2018

Active weather sets up for the long term forecast period as
shortwave energy ejecting out of the trough over the western
CONUS fosters precipitation chances every couple of days.

The first opportunity arrives Thursday as a mid-level wave passes
across the area. Given thermal profiles aren`t entirely saturated
in the key layer for ice crystal formation, at this point there
appears to be the potential for some freezing rain/drizzle again
with this event. The higher chances at this point look to be from
south central MN into west central WI, similar to where we had
icing issues with this last event. Snowfall ratios indicate the
potential for a 1-3 inch event.

Friday is our day in between systems, with surface high pressure
briefly in control. This looks to be the warmest day of the work
week, with highs in the upper 20s to mid 30s under clearing skies
and light westerly winds.

The next system is progged to eject across the Central Plains/MS
River Valley on Saturday. This wave packs more of a punch than the
one prior, including a surface low deepening to circa 980mb by the
time it reaches the Great Lakes (per the 20.12Z GFS). The 20.12Z ECMWF
was less wound up, but still featured a similar surface low
progression. The current model consensus would favor the
southeastern portion of the forecast area as having higher
probabilities of being impacted by this system. Definitely plenty
of time for this to shift however.

After this weekend the remainder of the period into early next
week looks pretty quiet with mid level ridging overhead.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1144 AM CST Tue Feb 20 2018

The precip has ended at most sites at TAF issuance, but the
MVFR/IVR deck will linger through the afternoon across the eastern
part of the area. VFR is already developing over west central MN,
and that will work eastward by evening. VFR is then expected this
evening and overnight, with clear skies for Wednesday. Northwest
winds between 10 and 15 knots (with gusts to between 20 and 25
knots at MN sites) will diminish this eve and back to westerly for
Wednesday (at speeds around 5-8 knots).

Expect to see cigs rise above 1700 feet by around 20Z, then become
VFR by 02Z. Northwest winds gradually back to west overnight, then
southwest Wednesday morning.

Thu...VFR in mrng, MVFR or lower in aftn. Chc IFR/-SN late. Wind
      SE 5-10 kts.
Fri...Mainly VFR. MVFR ceilings possible. Wind W 5 kts.
Sat...VFR in mrng, MVFR or lower in aftn. Chc IFR/-SN late. Wind
variable 5 knots or less.




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