National Weather Service Twin Cities Area Forecast Discussion

Data Provided by the National Weather Service

000
FXUS63 KMPX 220348
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1048 PM CDT Mon Sep 21 2020

.UPDATE...
Issued at 1044 PM CDT Mon Sep 21 2020

Updated to include 06z aviation discussion below.

&&

.SHORT TERM...(This evening through Tuesday night)
Issued at 317 PM CDT Mon Sep 21 2020

Upper level shortwave energy moving across the forecast area is
producing some showers and thunderstorms from around the Twin
Cities metro area and to the northeast this afternoon along the
northern edge of a H850 moisture axis that bisects the CWA. This
batch of showers and thunderstorms will move off into northwest
Wisconsin. Tonight a surface boundary sliding slowly southeast
across the area may have just enough moisture available to produce
isolated showers across far southern portions of the forecast
area, as depicted by some of the CAMs, but confidence is not high.
The milky skies from the western US fires should thin out tonight
and tomorrow, but models show thicker elevated smoke will return
from the west towards the end of the short term period. Lows
tonight will drop into the 50s to near 60 and high temperatures
tomorrow will be a little warmer than today with the highs topping
out in the upper 70s to lower 80s.

.LONG TERM...(Wednesday through Monday)
Issued at 317 PM CDT Mon Sep 21 2020

The key message in the extended part of the forecast is the
changing weather conditions that are expected over the weekend
as a cold front moves through. Confidence is increasing that most
locations will see rain at some point between Saturday and Sunday.
This will be followed by cooler temperatures for the start of
next week.

Wednesday will be warm as southerly winds and sunshine allow
afternoon highs to reach the lower 80s. This warm air is located
ahead of a shortwave trough that will bring rising air, cloud, and
precipitation across the northern part of Minnesota and Wisconsin.
This system will be developing as it moves across the region, so
precipitation will not only propagate eastward, but also be
developing southward. Precipitation chances are highest north of
I- 94, but there does appear to be a southern shift with some of
the forecast guidance.

Thursday will be slightly cooler behind this system, but Friday
will be warm again as a thermal ridge sets up across the region
ahead of the next trough. Highs on Friday could be in the lower to
mid 80s. Looking ahead, this trough will also be strengthening as
it moves across the Upper Midwest. Forecast guidance has nearly
doubled the chance for precipitation, so if this trend continues
expect most locations to pick up rain over the weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1044 PM CDT Mon Sep 21 2020

Solid VFR conditions expected throughout this TAF set with high
confidence in SKC conditions for the majority, if not the entire
duration, of this TAF set for all sites. Winds to remain under
10kt throughout, with much of the time under 5kt, generally from
the southeast to south.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/
WED...VFR. Wind SW 10G20 kts.
THU...Chc MVFR. Wind S 5 kts.
FRI...VFR. Wind SW 15G25 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&

$$

UPDATE...JPC
SHORT TERM...CEO
LONG TERM...JRB
AVIATION...JPC

NWS MPX Office Area Forecast Discussion