269 
FXUS63 KMPX 101741
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1241 PM CDT Fri Sep 10 2021

.UPDATE...
Issued at 1241 PM CDT Fri Sep 10 2021

Updated to include 18Z aviation discussion.

&&

.SHORT TERM...(Today through Saturday)
Issued at 346 AM CDT Fri Sep 10 2021

Temperatures during the short term will be more summer than fall 
like, with the next 2 days featuring a couple of good opportunities 
to see highs top 80 south of I-94. It will also be dry during the 
short term, with the lack of forcing beyond surface convergence and 
strong capping keeping the front coming through tonight through 
Saturday morning a dry one.

Water vapor imagery this morning shows a potent shortwave moving 
across Alberta. This wave will work over to James Bay by the end of 
the short term, which will help drive a cold front across our area 
tonight into Saturday morning. We look to be in the core of the 
thermal ridge overnight tonight, so we'll miss seeing the thermal 
ridge during peak heating, though 925mb temps in the 22C 
to 24C range will support highs into the mid 80s over western MN 
today, then along the I-90 corridor for Saturday.

No precipitation is expected this period. We'll have WAA through 
much of today, but it will lack much of a moisture feed from the 
south, with the best forcing remaining closer to the shortwave up 
in Canada. Saturday, we'll see a rather unstable environment develop 
down near the Iowa border with the arrival of a very warm EML, with 
MUCAPE values likely to be around 4000 j/kg. However, that EML will 
have h7 temps up around 15C, so nothing will make it through that 
cap during the day on Saturday.

&&

.LONG TERM...(Saturday night through Thursday)
Issued at 346 AM CDT Fri Sep 10 2021

Low precipitation chances continue to look possible overnight 
Saturday into Sunday, as a weak front stalls out over the mid-
Mississippi Valley. Most guidance keeps this boundary to our south 
across Iowa, which along with fairly strong capping north of the 
boundary, should keep the bulk of precipitation with this feature 
south of the area. More favorable conditions may develop Sunday 
night as a weak low-level jet develops and provides some forcing 
aloft,but this would still likely only lead to a few scattered 
showers and thunderstorms across southern Minnesota. More likely 
chances for precipitation come Monday night into Tuesday, as a 
trough moves through the Upper Midwest. Forcing aloft is much 
stronger with this system and deterministic/ensemble guidance are in 
fair agreement with a widespread region of precipitation developing 
over the Dakotas and continuing eastwards through Minnesota and 
Wisconsin. Increased PoPs during the Monday night and overnight 
hours, but these will likely need to be increased further once we 
see a bit more consistency on timing among the guidance. A 
stationary front along the Gulf coast will limit moisture return 
into the region and as a result, PW values show little in the way of
an anomalous signal. Rainfall amounts on the order of a quarter to 
half an inch look most likely. A return to ridging aloft over the 
central CONUS should keep conditions dry midweek, but low 
precipitation chances return by the weekend as models depict the 
potential for another shortwave but differ on its strength.

Temperatures will remain fairly seasonal through the period as the 
flow remains predominately zonal aloft, with a few transient and low-
amplitude troughs and ridges. Temperatures will likely range a few 
degrees below normal early in the week under the influence of the 
trough aloft, and a few degrees above normal midweek under brief 
ridging.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1241 PM CDT Fri Sep 10 2021

Southerly winds remain as a front will pass through late tonight.
Some high clouds are anticipated to move in this evening before
beginning to clear near the end of the period. Fog is possible Saturday
morning for EAU, but leaving out for now.

KMSP...Timing of the front looks to be between 15z and 18z Monday
morning.

/OUTLOOK FOR KMSP/
SAT...VFR. Winds W becoming N 5-10 kts. 
SUN...VFR. Winds NE 5-10 kts. 
MON...VFR. Chc -shra/-tsra late. Winds SE 10G20 kts.

&&

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

$$

UPDATE...
SHORT TERM...MPG 
LONG TERM...ETA 
AVIATION...PEM