Moorhead State University, Minnesota Weather Forecast Discussion

470
FXUS63 KFGF 180841
AFDFGF
Area Forecast Discussion
National Weather Service Grand Forks ND
341 AM CDT Thu Sep 18 2025
.KEY MESSAGES...
- Prolongued period of showers spreading north today and pulling
  out Saturday. 70 percent or higher chance of 1 inch or more of
  rain in southeast North Dakota thru Friday night.
&&
.DISCUSSION...
Issued at 315 AM CDT Thu Sep 18 2025
...Synopsis...
The focus the next 48 hours will be movement, development of 500
mb low over the N Plains and rainfall amounts. Overall it is not
looking like rainfall amounts spread out over 48 hours will be
enough to cause any impacts in terms of flooding or river
flooding. Impacts due to general wet weather present due to
impacts to ongoing harvest, depending on crop, and also impacts
to outdoor activities.
Early this Thursday morning, 500 mb low is slowly moving south
and near Saskatchewan Montana border and overall in the past day
it has tracked southwest. Meanwhile 500 mb low is seen in
central south central South Dakota with deformation zone
rainfall in south central ND into west central SD. During the
course of the day today as the upper low in Montana/Sask border
region drops south and upper low in South Dakota moves north and
then tonight into Friday eventual consolodation with upper low
in south central or northeast SD. Rain showers will continue to
advance north and then west around the upper low today as as the
upper low in SD moves north there will be a gradual north
advance of showers. Dry slot mid level working up into southeast
and east central SD and southwest MN may move into southeast
fcst area and for a time this afternoon or evening limit
precipitation. But also expect at that time likely lower clouds
and potential drizzle in that dry slot area. There is some 500
j/kg CAPE in the dry slot area near the ND/MN/SD border region
at 00z so a few t-storms are possible. I dont forsee any strong
or severe storms. Anytime you have an upper low nearby having a
brief funnel cloud isnt unusual.
Models in agreement in taking a separate short wave in Kansas
early this morning northeast into western Iowa and then
northward tonight into Friday, and with this will be a surge of
deeper moisture and increased rainfall rates spreading into the
area later tonight into Friday.
Upper wave does seem to be more northeast now into NW Ontario
withy showers Saturday focused in northern MN into NW Ontario
and eastern Manitoba. Rain chances may linger into Sunday in
north central MN.
Next week is indicating an upper trough moving into B.C. with a
broad upper ridge building into south central Canada and north
central US on the north side of an upper low Tues-Thu period.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1051 PM CDT Wed Sep 17 2025
Conditions are expected to go down hill dramatically overnight
into Thursday morning, with VFR giving way to MVFR, eventually
turning to IFR at multiple sites. Even if IFR is not prevailed
at a specific sites TAF, pockets of IFR will likely be roaming
around throughout Thursday, leading to brief instances of lower
ceilings. At this time, it remains too early to add a TEMPO or
PROB30 to account for this outside of where IFR is expected to
prevail. Showers will also be passing through. Visibilities
will change very little in areas where it is raining vs areas
where it is not, as a mix of drizzle/mist will likely persist in
between the periods of rain. Ceilings will lower again Thursday
night. How low they go is uncertain, but places where we see
persistent IFR Thursday afternoon (such as KDVL) could see LIFR
by Thursday night.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
DISCUSSION...Riddle
AVIATION...Rafferty

NWS FGF Office Area Forecast Discussion