Shoreview, Minnesota Weather Forecast Discussion

494
FXUS63 KMPX 182022
AFDMPX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
322 PM CDT Thu Sep 18 2025
.KEY MESSAGES...
- On and off chances for rain continue through the weekend.
  Most widespread activity this evening through Friday.
- Drying out next week, with temperatures remaining near normal
  this period.
&&
.DISCUSSION...
Issued at 321 PM CDT Thu Sep 18 2025
Water vapor imagery this afternoon shows our very sluggish upper low
still spinning over the Dakotas. Given how far west it and its
associated vorticity has remained, we`ve been stuck in a zone of
moisture, but limited forcing for precip, hence why for much of us,
we`re still waiting on it to actually rain in this supposedly active
pattern. The good news is we`re finally seeing signs of the more
active pattern moving into southern MN! The culprit is a shortwave
down by KC and a surge of moisture out ahead of it in Iowa. The
combination of this wave moving north and the Dakotas low moving
into western MN will all conspire to bring more widespread rainfall
chances this evening through the day on Friday. Definitely not a
washout, but something where you`ll want to keep an umbrella handy.
Through all of this, lapse rates will remain weak, which will
translate into limited instability and weaker updrafts. Add in
almost no deep layer shear and the severe risk will remain low.
However, with the surface low and remnant frontal boundary moving
across southern MN Friday, we will have to keep an eye out for
potential non-supercell tornado (NST) funny business, though it may
only end up being a funnel cloud festival wherever we can get some
low-level instability to line up with a boundary on Friday.
For the weekend, the upper low will be filling in as it crawls
across the upper MS valley. This will mean the highest PoPs on
Saturday will be found east of I-35, with the main moisture feed
shifting east of the MPX area for Sunday, tough with the trough
overhead, we`ll still be developing scattered diurnal activity on
Sunday. When all is said and done, most of the MPX area will have
seen a half to one inch of rain by the end of the weekend, with some
pockets of 2+ inches given the anomalous moisture (PWATs around
1.5"), slow movement of storms, and potential for multiple rounds.
However, high rainfall amounts like that will be quite isolated, so
hydro threats will be pretty minimal as well.
Next week, our blocky pattern will remain, with the northern stream
remaining well to the north across Canada. Within the broad ridging
over the CONUS, we`ll continue to see h5 lows get left wandering in
weak flow. Trends from the models for next week is for the next cut-
off h5 low to be south of the MPX area, which trends us toward drier
weather, with temperatures running a little above normal. In other
words, very pleasant conditions. Looking at the ensembles, there are
no signs of any cold air for the next 2 weeks, with the weather
remaining pretty quite for the rest of September once we get past
this more active period that will last into early next week.
&&
.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1200 PM CDT Thu Sep 18 2025
An MVFR/IFR stratus deck will lift north/west as the cutoff low
pressure spins over the Dakotas. This low will gradually move
eastward over the TAF period and finally lead to an uptick in
covers for showers this evening/tonight. There is still a
window of -TSRA this evening I`ve addressed by PROB30 given the
uncertainty in coverage. Sites will return to VFR cigs/vis this
afternoon and remain VFR until tonight. MVFR to IFR cigs build
in as the low pressure moves into W MN. This will coincide with
an uptick in -SHRA and MVFR vsbys. Likely MVFR through remainder
of the TAF period. Winds remain SE-erly throughout aob10kts.
KMSP... Biggest change was to push back the thunderstorm PROB30
to 03Z to better line up with the models. There is still
uncertainty if any TS will impact the terminal directly, but
there is a good signal we`ll have TS in the vicinity of KMSP.
Since there is still a fair amount of uncertainty, opted to
maintain a PROB30 as mentioned above. MVFR conditions are
expected to develop by early Friday morning with
-SHRA continuing. Cigs begin to rise after mid-morning but
 remain MVFR.
/OUTLOOK FOR KMSP/
SAT...Chc MVFR/-TSRA. Wind S 5-10 kts.
SUN...Chc MVFR/-TSRA. Wind SW 5-10 kts.
MON...Chc MVFR/-SHRA. Wind SW 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...MPG
AVIATION...BPH

NWS MPX Office Area Forecast Discussion