Fort Snelling, Minnesota Weather Forecast Discussion

994
FXUS63 KMPX 161709
AFDMPX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1209 PM CDT Tue Sep 16 2025
.KEY MESSAGES...
- Warm and humid conditions continue before more seasonable
  temperatures return for the end of the week.
- Multiple chances for showers and thunderstorms exist late
  tonight through the weekend.
&&
.DISCUSSION...
Issued at 1205 PM CDT Tue Sep 16 2025
We`re well on our way to a hot & humid late Summer day. Latest
surface observations highlight temperatures in the low to mid 80s
with heat indices in the upper 80s to lower 90s. Afternoon highs
will be in the upper 80s and lower 90s with heat indices well into
the 90s despite the calendar date of September 16th. Aloft, the
ridge axis extends through the Great Lakes & into Ontario, Canada.
Meanwhile, the cut off low upstream over the Dakotas will begin it`s
slow trek eastward, leading to an uptick in storm and shower chances
beginning tonight and lasting through the weekend. Neither the cut
off low or the broad ridge want to move due to the amount of
blocking in the mid & upper levels. Our pattern & surface weather
will be slow to evolve due to that aforementioned blocking.
We`re watching an area of isolated showers & thunderstorms along our
western Minnesota border. The latest SPC SWO day 1 update removed
much of the Marginal (1 of 5) Risk from the MPX CWA (over western &
central Minnesota. There is a silver of Marginal that remains for
isolated severe wind & hail threat in Lac Qui Parle & Yellow
Medicine counties. The latest hi-res CAMs struggle to develop any
meaningful convection in our area. The few that do remain isolated
with sub-severe looking storms/showers. Forecast soundings have
2000+ j/kg of MLCAPE and 7.0+ C/km lapse rates through the evening,
but we`re dealing with enough capping & little to no synoptic
forcing & shear. This will effectively limit any convection to the
"general" thunder category IF something can develop.
The weather pattern will remain unsettled through the weekend with
daily chances for showers & thunderstorms. The forecast soundings
for Wednesday & Thursday aren`t indicative of a meaningful severe
threat given our placement with respect to the surface low feature,
but a mesoscale MCV that`s not depicted in global guidance could
always locally enhance the environment. SPC maintains general
thunder both days and any upgrade to a Marginal would likely be on
day 1 IF they have justification. Wednesday morning features an area
of higher 50-70+ PoPs for W/SW/SC Minnesota with 30-50 PoPs across
C/E MN & WC WI. 20 to 50 PoPs remain in the forecast through Monday,
signaling the degree of "unsettled" weather we`re in for over the
next week. QPF amounts will vary with the highest amounts (1"+)
over W/C Minnesota and 0.25" to 0.5" with locally higher amounts
for S/E MN and WC WI. Fortunately, the rain will be
intermittent over the next several days versus continuous, never
ending rain. Temperatures begin to cool down, too. Highs in the
80s Thursday with highs in the low to mid 70s through early
next week. This is still 5+ degree above our normal high
temperatures for this year, but much more tolerable than upper
80s with 70 degree dew points. Looking ahead, there isn`t much
signal for a big pattern change as we look remain in weak flow
as the jet remains to our north. This would support warmer
temperatures sticking around through the end of the month.
&&
.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 637 AM CDT Tue Sep 16 2025
VFR and dry overall. A few mid- to high-level clouds are
expected to develop through the course of this afternoon from west
to east. There is a non-zero chance for isolated -SHRA/TSRA to
develop as a remnant boundary lingers near AXN into NE MN this
afternoon. More prevalent rain chances can be expected across
all sites beginning tomorrow afternoon. South/southwesterly
5-10kt winds become light and variable overnight. Patchy fog is
possible to develop across our Wisconsin sites early tomorrow
morning thus continued mention of potential of IFR vsby
reductions.
KMSP...No additional concerns.
/OUTLOOK FOR KMSP/
THU-FRI...Chc MVFR/-TSRA. Wind SE 5-10kts.
SAT...Chc MVFR/-TSRA. Wind S 5-10kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...BPH
AVIATION...Dunleavy

NWS MPX Office Area Forecast Discussion