Trommald, Minnesota Weather Forecast Discussion

272
FXUS63 KDLH 050547
AFDDLH
Area Forecast Discussion
National Weather Service Duluth MN
1247 AM CDT Fri Sep 5 2025
.KEY MESSAGES...
- A clipper will bring rain showers, heavy at times, to parts
  of east- central Minnesota and especially in northwest
  Wisconsin late today and through tonight, with a quarter to
  half inch or more of rainfall expected for these areas.
- Breezy on Friday in the wake of the clipper with northwest
  winds gusting to 25-30 mph with a few spots gusting as strong
  as 40 mph.
- Cooler conditions late this week will give way to warmer,
  more seasonable temperatures early next week. While frost
  remains possible for some spots each night through the
  weekend, a widespread freeze is unlikely through this weekend.
&&
.DISCUSSION...
Issued at 1153 AM CDT Thu Sep 4 2025
An area of low pressure over northwest Ontario today through
Saturday will result in northwest flow across the Northland that
will keep the cooler air in place through the weekend, then a broad
area of high pressure building into the Midwest Sunday into Monday
will usher a return to warmer southerly flow at low levels early
next week. The best chance for rain in the next 7 days will be with
the clipper tonight, with a focused area of a quarter to half inch
of more stretching from north-central Minnesota into northwest
Wisconsin, but dry for parts of northeast Minnesota (north/east of
the Iron Range). There will be frost potential each night, but
uncertainty with regards to cloud cover means confidence is low in a
frost occurring - but a freeze (reaching 32F across a widespread
area) is unlikely. A few record cool daily max temp records may be
broken (see climate section) but low temps will not be in jeopardy.
Primary concern for today`s forecast is the clipper tonight and the
breezy winds that will follow tomorrow, otherwise fairly
unremarkable weather through the rest of the forecast period.
The clipper approaching from the west today is over northeast North
Dakota this morning, with the surface low deepening over southern
Minnesota this afternoon and into central Wisconsin this evening
before exiting and lift north over the Upper Peninsula of Michigan
and into eastern Ontario early Friday. Forecast from the previous
shift is well on track, with rainfall amounts for northwest
Wisconsin trending a bit higher. This trend appears to be attributed
to the intensity of the seasonably potent vort max aloft leading to
very strong broad-scale lift as the low deepens over Wisconsin, and
rainfall amounts could approach an inch or more in a few spots.
While not seasonably unusual, heavy rainfall rates could lead to
some minor ponding/flooding in low lying areas (i.e. water across
some rural roads and minor brief flooding in more built-up areas
like Hayward). The ceiling for rainfall appears to be pretty low due
to the fast-moving nature of the clipper - almost a zero percent
probability of 2 inches of rainfall or more, for example - but an
inch of rain over a few hours could lead to some Flood Advisory-
level impacts in a worst-case scenario. Otherwise there may be some
rumbles of thunder with weak elevated instability present.
Rain ends west to east towards dawn in northwest Wisconsin, but with
cyclonic flow from the mature low in Ontario to north, a weak mid-
level trough and a vort max aloft will rotate around the low and
across the MN Arrowhead, which combined with low level moisture
advecting in from the north may result in off and on light rain
showers or sprinkles through the day Friday, though dry air near the
surface may end up leading to more virga than precip. Mostly cloudy
skies with increasing winds, gusts of 20-30 knots with perhaps a 35-
40 knot peak gust possible based on the expected mixing and low
level winds from guidance. Friday will be the coolest day of the
fall so far with highs as cool as the upper 40s in the MN Arrowhead
to low/mid 50s elsewhere, and a few record cool max temps could be
broken - see climate section.
Becoming warmer and generally dry through the rest of the forecast
period, with low and light precip chances on Monday night into
Tuesday morning with a warm front, otherwise dry through next week
until Friday when another, stronger warm front may lift east across
Minnesota.
&&
.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1247 AM CDT Fri Sep 5 2025
Widespread rain continues in northwest Wisconsin through much of
the remaining overnight hours, but will be ending at BRD/HIB/DLH
between now and 08Z. Expect VFR to MVFR visibilities and MVFR to
pockets of IFR ceilings with and behind the rain showers through
the remainder of the overnight hours. Another push of scattered
rain showers in a wrap-around region of an upper-level low
pressure over Ontario will primarily affect north-central and
northeast Minnesota from the early morning hours into evening
hours today. Some shortwave energy will also kick off some
isolated to scattered shower chances for the remainder of the
Northland this afternoon into evening. Ceilings will remain MVFR
for much of today, lingering longest at KDLH/KHYR before
gradually rising to VFR this evening.
&&
.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 1153 AM CDT Thu Sep 4 2025
Increasing west-northwest winds and a chance for rain showers as a
clipper moves west to east across western Lake Superior tonight,
with the strongest winds on Friday as strong as 20-30 knots. Gales
are not expected, with the highest potential for a gale-force gust
being north of Grand Marais where there is a 50 percent chance for a
gale-force gust on Friday. A broad upper low over northwest Ontario
will cause winds to remain out of the west to northwest through
Sunday but will not be as strong over the weekend, 10 to 15 knots.
High pressure builds in Sunday and Monday, with southwest to south
winds at 5 to 10 knots early next week. While small craft advisories
may be needed next week depending on the timing of another low
pressure system the probability for gales through the next 7-10 days
across western Lake Superior is very low (less than 10 percent).
For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.
&&
.CLIMATE...
Issued at 1153 AM CDT Thu Sep 4 2025
Record Low Maximum Temperatures for sites that have a forecast
within 3 degrees F of the record low maximum temperatures listed
below:
September 5:
KDLH: 52/1904 (Forecast: 54)
KINL: 53/1965 (Forecast: 53)
KBRD: 57/1962 (Forecast: 57)
KHIB: 54/2017 (Forecast: 54)
KASX: 56/1926 (Forecast: 57)
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory from 4 AM early this morning to 4 AM CDT
     Saturday for LSZ121-140-147-148-150.
     Small Craft Advisory from 4 AM early this morning to 11 PM CDT
     this evening for LSZ141>146.
&&
$$
DISCUSSION...JJM
AVIATION...Rothstein
MARINE...JJM
CLIMATE...JJM

NWS DLH Office Area Forecast Discussion