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000
FXUS63 KFGF 141738
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1238 PM CDT Sun Apr 14 2024

.KEY MESSAGES...

- Critical fire weather conditions are expected this afternoon
  and early evening across northeast North Dakota and far
  northwest Minnesota in the Red River Valley.

- There is a 50% chance for areas to see greater than an inch of
  rainfall Monday and Tuesday, with the highest chances across
  southeast North Dakota and west central Minnesota.

&&

.UPDATE...
Issued at 1238 PM CDT Sun Apr 14 2024

Winds are behaving as expected with with no changes to the
forecast needed. Speeds in the low 20s gusting up to 30mph this
afternoon combined with RH already in the mid 20s and falling
will certainly support the maintenance of the RFW with
decreasing winds this evening ending the threat. Tempered pops
for tomorrow with the expectation dry air in the low levels will
dominate ending up in mostly virga though a few of the heavier
cells could prevail leading to pops being capped at 30 to account
for these factors.

&&

.DISCUSSION...
Issued at 352 AM CDT Sun Apr 14 2024

We are in a brief period of northwest flow aloft  ahead of shortwave
ridging that will be followed by southwest flow later tonight into
Monday. Dry/warm temperatures are expected today, with another day of
upper 60s/lower 70s (maybe a few locations warmer) despite the
slightly lower temperatures in the post frontal air mass and
northwest BL flow.

The upper low to the southwest is still expected to shift east-
northeast through midweek, with a secondary mid/upper low moving
into southern Canada and possible into the Northern Plains/upper
Midwest late in the week. WAA and building instability should bring
increasing rain chases (isolated thunderstorms) later tonight into
Monday, though chances for more than 0.25" of rainfall 20-30% during
that period. The main period of rain and embedded thunderstorms
arrives later Monday night through Tuesday as the mid/upper lows
move into our region and deformation/inverted troughs help organize
several regions of positive frontogenesis. THe probability for at
least 0.25" during that period is 60-90% across our region, with the
24hr probability for 1"+ rainfall 50% (three day probs are around
60%). Based on the pattern my confidence in at least some locations
seeing 1-2" is high, but this will be dependent on where those rain
bands set up and pivot, along with the track of embedded
thunderstorms (20-30% coverage of thunderstorms). Skinny/elevated
instability profiles and weaker effective shear lower confidence in
any severe thunderstorm potential in our area.

Precipitation chances do linger as the southern mid/upper low
transitions east, but this will depend on the northern wave and how
it ultimately tracks. Precipitation during the nighttime periods may
mix/change to snow at times and there is a signal for light
accumulations in some ensemble data sets. Due to warm ground
temperatures and already large spread in evolution of
forcing/moisture during those periods of sub freezing
temperatures at night, the probability for impacts is low.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1238 PM CDT Sun Apr 14 2024

Winds continue to increase this afternoon with gusts already in
the 25+ knot range for GFK and TVF. This will continue through
the afternoon waning around sunset with BJI, DVL, and FAR seeing
gusts up to 20 knots from the northwest. Winds go light tonight
and pivot to the east before increasing tomorrow morning from
west to east. A few light showers and even thunder chances
tomorrow in the south and west though ceilings remaining VFR
except for in the heaviest cells.

&&

.FIRE WEATHER...
Issued at 352 AM CDT Sun Apr 14 2024

We should have much less cloud cover than previous days that should
allow for efficient mixing and temperatures and dewpoints have been
adjusted to account for previous biases and to reflect expected
mixing. This results in widespread afternoon RH values below 25
percent and some as low as 17%. A bit warmer temperatures/lower Tds
and we may actually see isolated locations at or below 15% (air mass
is a little cooler than previous days so confidence isn`t as high on
those lower values).

The question then is winds, and with northwest boundary layer flow
down the northern Red River Valley maximizing momentum transfer we
should be able to tap into 20-25kt winds and with this a 3hr period
of 20 mph sustained winds gusting as high as 30 mph becomes likely.
These higher winds aloft do transition east, but should linger in
the northern valley locations enough to achieve Red Flag Warning
criteria/critical fire weather conditions. Elsewhere, winds aloft
shouldn`t be as high and the window smaller lowering confidence in
reaching RFW criteria (though near critical is likely especially in
MN). A Red Flag Warning was issued for Noon-8PM for the northern
Red River Valley of northeast ND and northwest MN, and based on
partner coordination and SPS was issued to the south and east
in MN for near critical fire weather conditions.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Red Flag Warning until 8 PM CDT this evening for NDZ008-016-
     027-030.
MN...Red Flag Warning until 8 PM CDT this evening for MNZ001-002-
     004-005-007-008-013>015.

&&

$$

UPDATE...TT
DISCUSSION...DJR
AVIATION...TT
FIRE WEATHER...DJR