Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 240817

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
317 AM CDT Wed May 24 2017

.SHORT TERM...(Today and tonight)
Issued at 315 AM CDT Wed May 24 2017

Surface analysis early this morning shows weak high pressure over
the Dakotas extending into the Deep South with one frontal system
over the Ohio River Valley and another over southern Alberta
province into the Pacific northwest. Aloft, the deep upper low
responsible for yesterday`s occasional showers has shifted into the
mid-Mississippi River valley while a NE-SW oriented ridge axis is
placed from western Ontario province through the Four Corners
region. Some low clouds are still shifting southeast through the
area in a last gasp of influence from the upper low. Otherwise, the
deep ridge of high pressure will slowly move east over the region,
allowing for a drier and warmer airmass to grab a hold of the
region`s weather for today into tonight. The ridge axis will shift
atop the area overnight then just off to the east by daybreak
Thursday morning. The western frontal system will have a stacked low
remain to the north of the international border but increased
moisture in advance of its warm front, expected to push into the
eastern Dakotas by Thursday morning, will allow for an increase in
cloud cover but be delayed enough to keep precipitation out of the
forecast through tonight. Highs today will climb to 60-65 degrees
across the WFO MPX coverage area. Lows tonight will range from the
lower 40s north and east to the upper 40s south, west and in the
Twin Cities metro.

.LONG TERM...(Thursday through Tuesday)
Issued at 315 AM CDT Wed May 24 2017

The overall concerns in the long term remain the frontal passage
Thursday night into Friday. Then the overall evolution of the
upper trough over the northern CONUS into the holiday weekend.

Initially we should see clouds increasing out ahead of the next
short wave and waa pattern Thursday. This should spread a small
chance of mainly elevated showers into the west and central
portions of the cwa during the afternoon. The front and trough
advance east over the region into the day Friday with a continue
threat of light showers. We do see moisture increase to around 1
inch precipitable water into Friday afternoon. This may be enough
to generate a few heavier showers with some thunder. The GFS is
faster with the front...moving into wester WI by 18z Fri with the
ECMWF about 6 hrs slower...holding off until later afternoon. The
EC builds better instability as well. Dewpoints should rise to
the mid 50s and temperatures will warm ahead of the front with mid
to upper 70s.

This system exits to the east Friday night but the deterministic
differ greatly in development and evolution of the northern CONUS
trough. The GFS brings in moisture ahead of the trough into
Saturday afternoon...with the ECMWF holding off until later
Saturday night/Sunday. We will hold onto the slight chance PoP for
mainly the west Saturday afternoon. This may be removed if trends
more toward the ECMWF in future model runs.

The better shot of ran will develop Sunday into Monday as the
upper trough drops south over the region. This will eventually
cool temperatures back below normal by Memorial day. The thunder
threat looks best for the area Sunday afternoon with the troughs
arrival. We may see some lingering chances for isolated thunder
to the east on Memorial Day depending on timing. Overall...little
threat of severe weather. Trending more like a typical Memorial
Day weekend.


.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 1027 PM CDT Tue May 23 2017

East/northeast flow is expected to usher stratus clouds in
during the early morning hours, with MVFR ceilings moving into
eastern sites (KEAU, KRNH, KMSP and possibly KSTC). Expect to see
scattering of the low clouds and a return to VFR conditions
between 15z and 18z Wednesday. East/northeast winds around 5-8
knots prevail through most of the period.

MVFR cigs expected to move in toward daybreak and linger through
Wednesday morning. Low confidence on winds but still expect a
slight backing to more of a northeast direction for tonight and

Thu...VFR. Slgt chc MVFR/shra late. Wind SE 5-10 kts.
Fri...VFR. Chc MVFR/-SHRA. Wind SW 5-10 kts.
Sat...VFR. Wind W 5-10 kts.




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