011
FXUS63 KDLH 092042
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
342 PM CDT Wed Jul 9 2025

.KEY MESSAGES...

- Isolated thunderstorms are possible Thursday into Thursday
  night. A strong to severe storm or two capable of producing
  large hail can`t be ruled out, mainly Thursday night.

- Rain and thunderstorms with isolated strong to severe storms
  are expected Friday through Friday night. Large hail, gusty
  winds, and localized minor flooding can`t be ruled out.

- Occasional rain and storm chances are possible early next
  week, especially Tuesday and Wednesday.

&&

.DISCUSSION...
Issued at 1240 PM CDT Wed Jul 9 2025

Current weather synopsis:

Low stratus and fog this morning has cleared out, leading to areas
of diurnal stratus this afternoon. High pressure is in place
over Lake Superior, and we`re dealing with quiet weather this
afternoon as a result. Light onshore flow from Lake Superior
will keep temperatures cooler by the lake into tonight.

Tonight into Thursday:

Quiet weather continues through this evening. Ridging will
strengthen aloft going into Thursday with surface high pressure
slowly drifting east. Low-level warm air advection will bring
increasing instability into Thursday morning, though this
instability will be elevated. Warm frontal instability is
nevertheless expected to rise into the 1-2 kJ/kg (or perhaps a bit
higher) range and will introduce a chance (~20%) for some
thunderstorms in north-central Minnesota. Wind shear is expected to
be pretty weak (up to ~25 kt), so we`re not expecting much for
severe weather threats. There could be some smaller hail, if
anything, though freezing heights >12 kft may limit that potential.
CAMs are all over the place for how any storms may form and organize
Thursday morning, and perhaps rightfully so with rather weak
synoptic lift from a shortwave trough embedded within the broader
ridging aloft and uncertainties owing to capping at the surface.
Hence, PoPs remain low for Thursday morning, but some places could
get hit with some storms.

Things get cooking a little more in the afternoon as instability
continues to build, though the question remains if any instability
can become rooted at the surface, as continual warm air advection
may keep the inversion in place. Most places will probably end up
seeing another quiet weather day as a result, but the possibility
for a stray storm or two can`t be ruled out.

A cold front is expected to approach from the northwest later
Thursday night into early Friday morning, introducing some better
forcing for showers and thunderstorms. This should allow for the
instability that should still be hanging around to be realized.
Shear is expected to be minimal (up to 20 kt), so hail will be the
main threat, but even that is marginal again owing to higher
freezing levels. Most places in north-central Minnesota could pick
up a couple tenths of an inch or so of rain from this initial round.

Outside of rain chances, expect some toasty temperatures on Thursday
in the 80s across the region (cooler by Lake Superior) with all the
warm air moving in.

Friday through Saturday:

As the cold front slowly drifts southeast through the day, there
will be plenty of moisture available (PWATs to 1.5") for diurnal
heating to take advantage of during the afternoon. A solid
reinvigoration of showers and thunderstorms is expected out ahead of
the front Friday afternoon and evening. Model ensembles continue to
favor total amounts hovering around an inch to an inch and a half
for most places with some locally higher and lower amounts expected.
Some outlying models suggest some localized 2-3 inch and perhaps
approaching 4 inch amounts may not be out of the question. NBM
probabilities for 2" or greater remains at about 15-20%, so while
some higher amounts are not out of the question, that`s not the
likely solution. Thus, the risk for flooding remains marginal, and
WPC has most of the region highlighted for a marginal flooding
risk. Localized minor flooding may be possible.

Severe threats remain rather marginal for Friday afternoon and
evening as well as shear continues to be weak. Hail up to about
quarter size looks to be the main threat and gusty winds can`t be
ruled out. As the front moves southeast Friday night and diurnal
heating goes away, the coverage of showers and storms is expected to
fairly quickly decrease later Friday evening and night.

On Saturday, an upper level trough will pass through, and some
wraparound non-severe showers and storms could redevelop. Any
additional rainfall amounts from that should be pretty minimal.

Temperatures in the 70s to low 80s are expected for highs both
days.

Sunday into early next week:

Ridging starts to move in once again Sunday from the west with
flow becoming southwesterly. Temperatures should warm up a
smidge. We may see some quiet weather through Monday, then
perhaps another cold front bringing some rain/storm chances into
Tuesday and maybe lingering into Wednesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1240 PM CDT Wed Jul 9 2025

VFR conditions expected through the period with some diurnal
cumulus clouds scattered about this afternoon that should
dissipate after sunset. Light east to southeast winds below 10
kt, but occasional gusts to 15 kt. There is potential for
thunderstorms to develop sometime Thursday morning, but low
confidence as models are all over the place in terms of where or
if storms will develop at all. Handled this for now with some
PROB30 groups for Thursday morning at all terminals except HYR.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 340 PM CDT Wed Jul 9 2025

Northeast winds are expected to persist through Thursday. High
pressure should keep wind speeds on the lighter side with gusts
during the day up to 15 kt, maybe 20 kt on the high end.
Isolated thunderstorms are possible on Thursday, and any storms
could produce some small hail, heavy rain, brief gusty and
erratic winds, and cloud-to-water lightning. Winds shift a
little more easterly to perhaps southeasterly on Friday as high
pressure moves off to the east. Wind speeds are expected to
remain on the light side.


For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...None.

&&

$$

DISCUSSION...JDS
AVIATION...JDS
MARINE...JDS