742
FXUS63 KFGF 040830
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
330 AM CDT Fri Jul 4 2025

.KEY MESSAGES...

- There is a level 2 out of 5 risk for severe storms in the
  afternoon and evening today. Main hazards will be flash
  flooding, wind gusts to 60 mph, and hail to the size of
  quarters, along with frequent lightning.

- Heat related impacts today due to high temperatures and high
  dew points.

&&

.DISCUSSION...
Issued at 308 AM CDT Fri Jul 4 2025

...Synopsis...

Outflow boundary with north-northeast winds has been dropping
south and and passed Devils Lake and will likely go through
Grand Forks, Thief River Falls with main rainfall activity and
t-storms holding farther north closer to the border.

This wind shift should wash out this early morning with winds at
12z likely turning back southeast or be light/variable in
northeast ND and far NW MN, with a south wind 10-25 kts in SE ND
and WC MN. Frontal boundary at 12z likely will still be well
northwest of the area from near Estevan into northeast Montana.
This frontal boundary moves east. It seems that short term
models want to develop t-storms early to mid aftn in the zone of
more variable wind right ahead of the front where it bumps up
with a steadier south wind. That boundary looks to be from about
Roseau to Grand Forks to Cooperstown at 00z.

Cooler and less humid airmass follows for the weekend.

...Severe risk and heavy rain potential for this afternoon and
tonight...

Models in general agreement in developing an axis of
thundertorms by 21z along a boundary from near Roseau/Warroad to
Grand Forks to Cooperstown to Jamestown/Bismarck. Sfc CAPE from
NBM 3km shows over 4000 j/kg just ahead of boundary at 21z where
temps likely in the mid 90s Bemidji to Fargo. Sfc CIN values at
that time becomes negligble, or foreast to be. Thus a rapid
increase in storms anticipated around 21z along the boundary and
the area of storms will grow and slide gradually east/southeast
in time thru the evening. PWATs around 2.3 inches would
certainly favor heavy rainfall potential with high rainfall
rates leading to potential for urban flooding. Most of the area
in June saw rainfall deficits of 1.50 to 3 inches in the area
where storms will form and where highest rainfall amounts are
forecast. Thus feel outside of rapid rainfall rate flooding in
areas of poor drainage, streets, the ground will be able to
absorb most of it where it falls on grassy surfaces, fields. No
flood watch issued at this time due to this and usual
uncertainity in exactly where heaviest rainfall will be.

Severe weather is more uncertain. Early on in the development of
the line, large hail and wind gusts 60 mph or higher is possible
before it turns into more of a heavy rain threat. SPC has area
in 2 pct tornado threat and think that would be short lived and
in the early stages of development.

Shower and t-storm chances linger in SE ND into MN into much of
Sunday before pushing east.

...Heat today...

Heat indices will reach the upper 90s to low 100s in most areas,
except DVL basin. So will maintain the heat advisory. Wet bulb
globe temp is in the high and extreme values (mid 80s).


&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1139 PM CDT Thu Jul 3 2025

Convection so far has stayed north and west of the TAF sites,
although still a chance that KDVL area could see some
development or storms moving in after 06Z. That airport has the
best chances for seeing storms as well as low level wind shear
as the jet strengthens over the area. A bit of a break during
the morning hours, then thunderstorms redevelop during the
afternoon and evening, this time over a wider part of our
forecast area. Have VCTS at most sites by the end of the period,
perhaps weakening to VCSH after 00Z. Winds will shift
southwestward and then to the northwest as a cold front starts
to drop down into the Red River Valley.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Heat Advisory from 11 AM this morning to 7 PM CDT this evening
     for NDZ027-029-030-038-039-049-052-053.
MN...Heat Advisory from 11 AM this morning to 7 PM CDT this evening
     for MNZ001>003-005>009-013>017-022>024-027>032-040.

&&

$$

DISCUSSION...Riddle
AVIATION...JR