Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 230358

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1058 PM CDT Mon May 22 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 335 PM CDT Mon May 22 2017

After a week of rainy weather, the air mass has dried out quite a
bit today with mostly sunny skies over much of southern MN into West
Central Wisconsin. However, two areas of incoming clouds and precip
will affect the area. Mid clouds and some showers had already moved
into southwest MN with associated short wave coming from the
northwest. There might be some thunder in south central MN and have
kept those in the grids. That area will slide across our southern
counties tonight. The other area of clouds and light showers will
drop southward later tonight and Tuesday as upper trough drops
south. This will affect central into southwest MN, and eventually
east central MN into Wisconsin later Tuesday morning and
afternoon. The GFS is rather bullish with more rain and clouds
then most models, but have kept the grids a little quieter than

.LONG TERM...(Tuesday night through Monday)
Issued at 335 PM CDT Mon May 22 2017

A much drier pattern will take hold from the middle of the week
onward, with only two main chances of precipitation - one with a
front Thursday night into Friday and the other Sunday into Monday.

Cyclonic flow will finally be on the way out Tuesday evening.
Clearing skies will follow for midweek although temperatures
remain cool in the wake of the impressively deep trough heading
toward the East Coast. Temperatures rebound back toward normal
Thursday in advance of the front and Friday/Saturday in the wake
of the front where temperatures aloft actually warm a bit. Poor
lapse rates should limit the thunder threat Thursday night/Friday
and the GFS appears to be a bit too aggressive with precip
coverage. Continued with 30-40 PoPs.

Confidence diminishes Memorial Day weekend with GFS maintaining a
closed low over the central U.S. while the GEM/ECMWF are much
farther northeast with the system over the Great Lakes and a
ridge building eastward into the High Plains. Either way,
temperatures will trend back below normal and odds of a weekend
washout appear low.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1058 PM CDT Mon May 22 2017

At 11pm, we are finally starting to see spotty MVFR cigs in
northern MN, though the LAMP and HRRR were both saying this should
be a widespread IFR/MVFR field. As mentioned in 00z discussion,
there was concern the LAMP was overdoing its cig forecast and
certainly trends this evening support that, with forecast
conditions slowly improving in the LAMP. Based on SREF probs, MVFR
cigs are most likely west of MSP, so continued to only have
prevailing MVFR cigs at AXN/STC/RWF. In addition have trends for
these airports more optimistic than what LAMP has. For precip, it
looks to be of the hit- and- miss, on- and- off through the day
Tuesday. Given that expectation, have prolonged periods of VCSH at
all terminals.

KMSP...Confidence is increasing in main MVFR cloud mass remaining
west of MSP this period. Based on HRRR and other CAMs, expect
diurnally driven scattered showers to develop late Tuesday
morning and persist through the rest of the daylight hours.

Wed...VFR. Wind NE 5-10 kts.
Thu...VFR. Wind SE 5-10 kts.
Fri...VFR. Chc MVFR/-SHRA. Wind SW 5-10 kts.




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