186
FXUS63 KFGF 260308
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1008 PM CDT Wed Sep 25 2024

.KEY MESSAGES...

- Near critical fire weather is expected Thursday across
  southeastern North Dakota. There is a 20% that critical fire
  weather conditions develop.

&&

.UPDATE...
Issued at 1000 PM CDT Wed Sep 25 2024

Quiet weather persists. Clear skies continue, dewpoints are dry
enough such that the probability of fog is low, and wind speeds
remain below 10 mph. No weather impacts are expected overnight.

UPDATE
Issued at 643 PM CDT Wed Sep 25 2024

Clear skies and limited wind will continue through the overnight
hours. No weather impacts are anticipated overnight tonight.

&&

.DISCUSSION...
Issued at 223 PM CDT Wed Sep 25 2024

...Synopsis...

Quiet weather will continue through the evening and overnight
hours due to upper level ridging. While ridging remains the
main story through the weekend, there is a shortwave that will
pass through on Thursday. As the ridge breaks down early next
week, a trough propagates eastward, bringing with it cooler
temperatures and very low chances for a few showers.

...Wind and Fire Weather Thursday...

As the shortwave progresses eastward, its associated tightening
pressure gradient in conjunction with a 40 knot 850 mb jet will
promote gusty southerly winds. The area of highest wind looks
to be confined to the Devils Lake Basin and far northern Red
River Valley. In these areas, there is a 70% chance of seeing
wind gusts of 40 mph or higher. Further south, winds are
expected to be lighter, as winds aloft will not be as strong due
to the more northern placement of the jet.

While winds will be lower across the south, they are still
anticipated to be breezy, with gusts up to 30 mph. RH values as low
as 25% raise concerns for near critical fire weather. The largest
limiting factor for critical fire weather is that the driest fuels
and lowest RH values are across southeastern ND, while the highest
forecasted winds are displaced to the north. Therefore, while
critical fire with is not anticipated, there is a 20% chance that
they do develop. This is most favored where the driest fuels
and RH values can overlap with the higher winds, as the HREF
shows when using dual probabilities for RH and sustained winds.

...Weekend and Beyond...

Behind the passing shortwave, ridging will continue through
Sunday with well above average temperatures. A trough coming
off of the Pacific Sunday night into Monday will bring high
temperatures down to their seasonal averages, which are in the
50s and 60s. Another period of breezy winds, this time out of
the northwest, is anticipated behind the cold front. While the
trough will bring enough forcing to provide some showers Monday
and Tuesday, the placement and coverage of these are unknown.
Therefore, POPs remain under 20% early next week, painting the
idea of scattered showers. One other thing to note, breezy winds
overnight should at least limit the frost risk. No clear signal
exists for widespread frost early next week behind the cold
front, but widespread low temperatures on either side of 40
degrees seems likely Tuesday and Wednesday mornings.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 1000 PM CDT Wed Sep 25 2024

Low level wind shear and wind gusts will continue to be the only
aviation impacts for the TAF period. Wind shear will continue
through 12z at DVL and possibly GFK. Winds will increase after
12z, gusting as high as 30-35 knots at all TAF sites except BJI.
Winds will diminish after 00z but remain above 12 knots for all
TAF sites. The wind direction will also slowly shift to 290-310
after 03z, with only DVL making it to its final wind direction
by the end of the TAF period. Winds will shift at all other TAF
sites after 06z.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.

&&

$$

UPDATE...CJ/Perroux
DISCUSSION...Rafferty
AVIATION...Perroux