Valentine Appel Burial Plot, Minnesota Weather Forecast Discussion

717
FXUS63 KMPX 171827
AFDMPX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
127 PM CDT Wed Sep 17 2025
.KEY MESSAGES...
- Chances for thunderstorms increase this afternoon, which will
  begin a period of unsettled weather expected to last through
  the weekend.
- Slow moving storms and high atmospheric moisture content will
  likely lead to areas of heavy rain totals each of the next
  few days.
&&
.DISCUSSION...
Issued at 342 AM CDT Wed Sep 17 2025
Conditions are tranquil across the Upper Midwest early this
morning, aside from some patchy fog across central MN and
western WI. Widespread showers and thunderstorms are ongoing to
the south across west central IA and northeast and central NE.
The portion of the activity across eastern NE and western IA is
not moving much and is anchored north of an outflow boundary.
Heavy rain totals as depicted by MRMS have exceeded 3 to 5
inches in some areas since last evening. Models have not
handled this convection well and still don`t, especially in IA.
Synoptically, a trough and upper low over the central and
northern Plains will lift north today. Meanwhile, a pool of
deeper moisture characterized by pwats exceeding 1.5 inches will
overspread the region. Lapse rates will remain weak, but
forecast soundings depict moist low levels and an uncapped,
moderately unstable atmosphere. A stationary front draped from
western Lake Superior to southwestern MN may start slowly
advancing south as a cold front this afternoon as surface high
pressure builds southeast across south central Canada. Although
wind fields will remain weak, there will be at least some modest
convergence along the front during peak heating this afternoon.
Isolated to scattered thunderstorms will develop this morning
across southern MN, but the greatest concentration in coverage
should occur this afternoon and evening along the front across
central MN where better forcing is expected. Models seem to
handle this overall scenario well, but may not be handling the
degree of convective coverage as well. Wind profiles will remain
very weak and cells will remain nearly stationary or meander
around with convective outflows. The moist profile, moderate
CAPE, lack of dry air layers in the profile, and slow storm
motions will lead to high rain rates - possibly approaching 2
inches per hour. HREF ensemble max QPF highlights a corridor
from near Madison or Granite Falls eastward to the Twin Cities
metro as the primary threat area for convection and suggests a
few inches of rain in localized areas are possible through
tonight.
Low pressure will remain nearly stationary across the northern
Plains through the week, before making better progress to the
north this weekend as the trough opens up to the flow across
Canada. Additional rounds of showers and thunderstorms are
expected as we remain on the moisture-laden eastern side of the
system. The setup each day through Friday will feature modest to
moderate instability, a deeply moist profile, and slow storm
motions. Localized heavy rainfall totals will continue to pose a
threat for flooding.
&&
.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1252 PM CDT Wed Sep 17 2025
An area of low pressure will remain to the west of the MPX
terminals through this period. This will keep us in a continuous
feed of southerly winds into the area, with a moist and unstable
airmass remaining in place. This is a low confidence forecast
with respect to precip potential, with our current forecast
having 12+ continuous hours of 30% or higher PoPs at all of our
terminals. The first more enhanced chance for showers will come
this afternoon/evening along the weak boundary that is laid out
from roughly Granite Falls, to the Twin Cities, and up to
Ladysmith in WI. After that, much of the short term guidance
shows the wave and slug of moisture bringing the showers
currently over Iowa coming up across MN tonight into Friday
morning. Given the uncertainty, was pretty restrictive on when
to mention any precip chances until we have better confidence on
narrower (less than 4 hours long) windows of when precip may
happen. Also of lower confidence is the cig forecast for tonight
into Monday morning. RAP forecast sounding certainly have the
low level moisture profiles to support low clouds, but how
prolific and widespread the stratus would be is uncertain,
though chances for MVFR/IFR cigs increases the closer you get to
the surface low (so highest in western MN and lowest in western
WI).
KMSP...our current grids have at least 30% chances for rain from
23z this afternoon through the rest of the period, so they
support 25 consecutive hours for a prob30. Not wanting to have
never ending precip mention, tried to focus on the first chance
along this boundary this evening. Based on the RAP, pushed the
prob30 group back a bit, though the incoming bank of mid-level
moisture (clouds) an the building cu-field along the boundary in
the north metro do hint at precip chances possibly beginning
early than what we have.
/OUTLOOK FOR KMSP/
FRI...MVFR. -SHRA likely, chc -TSRA. Wind SE 5-10 kts.
SAT...Chc MVFR/-TSRA. Wind S 5-10 kts.
SUN...Chc MVFR/-TSRA. Wind S 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...Borghoff
AVIATION...MPG

NWS MPX Office Area Forecast Discussion