586
FXUS63 KFGF 191148
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
648 AM CDT Sat Apr 19 2025

.KEY MESSAGES...

- Near critical fire weather is possible this weekend across
  portions of the area, especially Sunday. The highest
  probability will be in the Red River Valley and portions of
  northwest Minnesota.

&&

.UPDATE...
Issued at 648 AM CDT Sat Apr 19 2025

Adjusted cloud cover for current satellite trends, as some mid
level clouds continue to linger across the south and some lower
clouds have dropped into northwestern MN. Still should see some
clearing later on. Areas that are already clear across eastern
ND have dropped down to around 20, even the upper teens in
spots. Still should get into the upper 40s and 50s this
afternoon with strong April sun angle.

&&

.DISCUSSION...
Issued at 344 AM CDT Sat Apr 19 2025

...Synopsis...

The positively tilted trough from Ontario to the Four Corners
will become more split today as the northern branch portion
moves off to the east. Surface high pressure will move from the
Red River Valley into the upper midwest, keeping winds fairly
light until very late in the day. South winds will pick up
tonight into tomorrow as a surface trough develops to our west.
The southern branch upper low, will move from the Central Plains
into the upper midwest, with most precipitation and winds from
that system staying to our south and east. Brief ridging for
Monday, then another trough swings through on Tuesday, with low
pressure moving from North Dakota into Manitoba. Minimal impacts
with 30 to 60 percent probability of over a quarter of an inch
of rain. Behind that trough, near zonal flow sets up for the
rest of the week. Some weak shortwaves moving through the
central CONUS, but low predictability.

...Fire weather concerns today and Sunday...

While afternoon temperatures today are expected to climb into
the 50s from the Red River Valley westward and RH values falling
into the mid to upper 20s, winds are expected to be fairly
light. Some increase to around 10 kts in the western Devils Lake
basin by the end of the day, but by that point the RH values
will be starting to come up. Southerly winds will continue to
increase throughout the night and into the day on Sunday. Some
weak moisture advection but still expecting many locations to
get down close to 25 percent for afternoon RH values. The main
question will be winds. While model soundings show strong mixing
up to 700mb, by the time the boundary layer is fully mixed in
the afternoon the mid level winds will have decreased down to
the 20 to 25 kt range instead of around 35 kts. Joint
probabilities of RH values less than 25 percent and winds over
20 mph are 30 to 35 percent in some spotty areas tomorrow
afternoon. However, bumping up winds to 25 mph brings the
probability to near zero. HDWI is not very impressive for our
area even at the 75th percentile. While certainly think there
will be some areas approaching the near critical fire weather
threshold, confidence is not high enough for anything more so
will not increase messaging beyond what we have already done.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 648 AM CDT Sat Apr 19 2025

Some MVFR stratus around the KBJI for the next few hours, with
the rest of the forecast area remaining VFR with only mid-level
clouds. The lower ceilings will move out of our far eastern
forecast area by mid-day. Light and variable winds will pick up
out of the south to southeast by tonight.

&&

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

&&

$$

UPDATE...JR
DISCUSSION...JR
AVIATION...JR