Casselton, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

881
FXUS63 KFGF 110406
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
1106 PM CDT Sat May 10 2025

.KEY MESSAGES...

- A red flag warning is in effect for all of North Dakota and
  much of Minnesota for Sunday for critical fire weather.

- Near critical to critical fire weather conditions continue for
  Monday and Tuesday.

&&

.UPDATE...
Issued at 916 PM CDT Sat May 10 2025

Thunderstorms continue across a low level jet this evening. With
limited instability, storms have struggled to organize and
sustain. This will continue overnight tonight as no air mass
changes are expected other than the thermal ridge beginning to
move over our area.

Relative humidity values will remain below 50% for the most part
tonight, so recovery will not be great. Winds will continue to
diminish in intensity overnight but remain fairly elevated
between 10-15 mph, so near critical conditions may continue to
exist for a few hours. In any case, the Red Flag Warning for
this evening has been allowed to expire.

UPDATE
Issued at 617 PM CDT Sat May 10 2025

Showers and storms have formed upstream in north-central North
Dakota. These may cause briefly gusty winds to 50 mph with DCAPE
pushing well past 1000 J/kg and the airmass being very dry. The
biggest concerns with these showers/storms will be the potential
for dry lightning and very gusty winds exacerbating red flag
conditions this afternoon and evening. New starts may arise and
spread quickly as a result of dry lightning. If storms do
precipitation to the ground, observations indicate really
quickly falling temperatures and rising relative humidity to the
mid-40s, so there will be briefly an improvement in weather
conditions, however this may be short-lived as mixing should
take hold again and lower the RH back down.

&&

.DISCUSSION...
Issued at 243 PM CDT Sat May 10 2025

...Synopsis...

Long wave ridging remains in place across the central CONUS this
weekend into early next week with EFI strongly pointing to record/near
record territory Sunday to Tuesday for many as EFI remains above 0.90
through that period. With thermal ridging in the low levels and strong
southerly flow really reiterating the strong mixing potential. With
record high temps in the upper 80s to mid 90s and reanalysis data
pointing to the coming airmass nearing the maximum of the all data for
the period. Combine this with strong winds and we are looking at slam
dunk critical fire weather for Sunday and Monday with red flags
warnings needed most likely. As for when to expect relief troughing
looks to bring rain chances back to the dakotas by Wednesday. Likely
not to be a drought buster but there is a high chance (>80%) for a
quarter inch or more. Exact timing and location of rain remains
uncertain but we will look forward to in nonetheless.

Chance for a few showers/weak thunderstorms this evening/overnight
north of highway 2 as the steep mid level lapse rates yield a few
hundred CAPE (<300 J/kg) with bulk shear near 20kts. Likely to be more
activity similar to that which rolled through this morning. With the
plentiful dry air near the surface it is unlikely much reaches the
ground with dry lightning possible (20% chance).

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1106 PM CDT Sat May 10 2025

Showers and a few thunderstorms may develop this evening and impact
TAF sites. The primary impact from these will be lightning. Outside
of this, the only impact overnight tonight will be wind shear from
the southeast, generally between 40 and 50 knots in intensity. Wind
shear will be replaced by increasing southwesterly gusty winds after
sunrise. Gusts by early afternoon should exceed 40 knots at times,
especially at FAR and GFK. Winds will diminish after sunset once
again tomorrow, which will then be replaced once more by wind shear.
Wind shear will be generally southwest between 45-55 knots.
Conditions will remain VFR for the entire TAF period with the only
potential ceiling/visibility impact coming from blowing dust
tomorrow afternoon. Given low confidence in this arising, it has
been left out of the current TAF.&&

.FIRE WEATHER...
Issued at 243 PM CDT Sat May 10 2025

- Today

As well mixed profiles beneath the mid thermal ridging and modest flow
through the boundary layer further aid mixing we have been consistently
seeing RH drop below 25 percent so far across eastern North Dakota. An
area of high clouds from morning showers has kept RH slightly higher
east of the Red River through still concerning at 25-30 percent. Winds
are little more variable with 10-15mph across west central MN, 15-20mph
across southeast ND, and 20-25mph in northeast ND. Not expecting
conditions to get notably worse but the thing to monitor will be an
area of locally lower RH currently in the northern Red River Valley of
10-15 percent. Expect this to slowly shift east with the axis of
steepest lapse rates and thus deepest mixing. As this overlaps with
winds near 20mph in NW MN through 7pm red flag conditions will become
more common. Marginal recovery in RH is expected overnight with MaxRH
crawling just over 40 percent so any fires that do start this afternoon
will still have relatively low humidity to work with in the overnight
before falling again Sunday.

- Sunday

Sunday has the potential to be some of the worse fire conditions in
recent memory with RH dipping widely into the mid 10s and winds
sustained in the mid to upper 20s and gusts frequently 35-40mph. NBM
QMD is showing gusts as high as 50 but with EFI only locally reaching
0.7 it seems unlikely we see anything much greater than that but
historically the largest fires in the county and even ND have happened
when winds/gusts exceed 50mph due to containment issues so even this
minor signal raises major concerns. As the 850mb wind increases
overnight past 30kts nocturnal near surface temperature inversions
should somewhat limit wind gusts between 06z and 15z through as mixing
returns Sunday morning critical fire weather conditions will almost
immediately be present. The potential worst case is if winds can mix
down around the noon timeframe as mixing really gets going with RH in
the low teens overlapping with winds of 35-40 gusts in excess of 50 mph
in northeast North Dakota and northwest Minnesota. According to recent
reports all fuel sources are primed for ignition should a fire start.

- Monday/Tuesday

Overnight recovery Sunday into Monday is less certain with MaxRH for
east central ND only getting back to 35 percent for some. With that
said a fire weather watch in is effect for all counties on Monday as
afternoon RH is forecast to dip near 20 percent again though winds will
be more in line with todays values that Sunday with speeds around 25-
30mph and gusts near 40 mph. Overall the dry fuels in
combination with low RH and windy conditions will lead to more
critical/near critical fire weather. Similar conditions again on
tuesday through maybe a tad improved as the core of the thermal
ridging shift east taking the best mixing potential more into
MN and Wisconsin.

&&

.CLIMATE...
Issued at 243 PM CDT Sat May 10 2025

Record High Temperatures:

May 11 (Sunday):
NWS FGF/UND: 95/1906
KGFK: 88/1977
KFAR: 93/1906
KPKD: 87/1900
KBDE: 83/1991

May 12 (Monday):
NWS FGF/UND: 95/1900
KGFK: 91/1977
KFAR: 96/1900
KPKD: 89/1906
KBDE: 85/1991

May 13 (Tuesday):
NWS FGF/UND: 92/1932
KGFK: 93/1977
KFAR: 95/1894
KPKD: 91/1900
KBDE: 88/1932

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Red Flag Warning from 11 AM to 10 PM CDT Sunday for NDZ006>008-
     014>016-024-026>030-038-039-049-052>054.
     Fire Weather Watch from Monday afternoon through Monday
     evening for NDZ006>008-014>016-024-026>030-038-039-049-
     052>054.
MN...Red Flag Warning from 11 AM to 10 PM CDT Sunday for MNZ001>009-
     013>017-022>024-027>032-040.
     Fire Weather Watch from Monday afternoon through Monday
     evening for MNZ001>009-013>017-022>024-027>032-040.

&&

$$

UPDATE...Perroux
DISCUSSION...TT
AVIATION...Perroux
FIRE WEATHER...TT
CLIMATE...TT