260
FXUS63 KFGF 220925
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
425 AM CDT Sun Sep 22 2024

.KEY MESSAGES...

- There is potential for localized frost in portions of west-
  central Minnesota Sunday night into Monday morning.

&&

.DISCUSSION...
Issued at 425 AM CDT Sun Sep 22 2024

...Synopsis...

A cooler continental airmass migrates near the
Canadian Border filtering in cooler dry air as the Northern Plains
sits in northwest flow. We transition to a more westerly flow
increasing the amount of dry over the Northern Plains. A shortwave
will bring us some breezy conditions but the dry air at the lower
levels will likely continue our dry pattern. Following the shortwave
a ridge pattern sets up and temperatures look to rise slightly above
normal.

Sunday Night: A dry airmass will filter in from Northern Canada and
move near the Northern Plains. While some of the cooler dry air will
filter over the Northern Plains, 850mb temperatures look to remain
near 9 degrees celsius at the coldest over the Northern Plains. 925
temperatures also look to be around 10 degrees at the coldest as
well. Surface Dewpoints look to drop into the low 40`s/upper 30`s
for the majority of the forecast area. 00Z run of the HREF does
depict a 30-40% probability of reaching 36 degrees by 5am Monday
morning South of I-94. With cloud cover moving in from the Northwest
this would be the most likely area to have temperatures develop
frost if it stays cool enough to due so. To add to the uncertainty
most of the models dont have us reaching the 36 degree threshold
most likely due to the warmer 850/925 temps and encroaching cloud
cover. So I did not go with a Frost advisory for tonight as
conditions look to remain too warm for frost production.


Monday and Tuesday:

Monday, we will stay dry with westerly flow aloft filtering dry air.
Monday evening into Tuesday, a weak shortwave migrates through the
region. Some of the deterministic models show precipitation moving
into over area. However, Model soundings show a dry layer extending
up to 700mb. With this much dry air the most likely scenario will be
some cloudy skies and windy conditions developing but any
precipitation may evaporate long before it hits the ground.

Wednesday through Friday: Riding pattern sets in to bring increasing
temperatures following Tuesday`s shortwave. The ridge will likely
advect some moisture into atmosphere to raise the humidity into the
40`s and 50`s but doesnt look like any chances of rain for the rest
of the week with that area of high pressure sitting over us.


&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1128 PM CDT Sat Sep 21 2024

VFR conditions should prevail through the TAF period. Clearing
skies/light winds raises the potential for patchy fog early in
the TAF period, but the amount of dry air immediately off the
surface (and no guidance highlighting development) lowers
confidence in impacts/coverage.

Surface gradient remains weak through the day Sunday.
Prevailing winds should increase with mixing in the west-
northwest direction (6-10kt) for most locations and there is a
low chance for 5000 FT AGL CU redeveloping in northeast ND
during the afternoon (ceiling development unlikely at the CU).

&&

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

&&

$$

DISCUSSION...MM
AVIATION...DJR