133
FXUS63 KFGF 111851
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
151 PM CDT Sat May 11 2024

.KEY MESSAGES...

- Near critical fire weather is expected today across much of
  the region as RH values fall into the 20 to 30 percent range
  along with wind gusts up to 25 mph.

- Widely scattered showers and isolated thunderstorms are
  possible late this afternoon and early evening for portions of
  far northeast ND and northwest Minnesota. A few storms could
  produce damaging wind gusts to 60 mph.

&&

UPDATE
Issued at 136 PM CDT Sat May 11 2024

RH values fell a bit faster than forecast, however Tds are now
increasing across our west (with BL moisture spreading east). We
may see RH values level off soon in MN (or increase a bit in our
west despite additional warming). We are seeing gusts generally
around 20 mph (isolated gusts 25-30 mph mainly along/west of
the RRV) and messaging of near critical fire weather conditions
seems to me on point. Main adjustments were to better capture
Td/T trends.

Other concern will be the potential for isolated strong to
severe thunderstorms later this afternoon and early evening.
Forecast instability profiles are marginal, but high mixed
layers in inverted-V type environment does raise the potential
for isolated marginally severe gusts (to 60 mph). Forcing will
be there with the weak shortwave and eventual cold front
passage, but the depth of the dry layer aloft does lower
confidence in coverage or even wetting rains (dry thunderstorms
may be more common).

UPDATE
Issued at 1012 AM CDT Sat May 11 2024

We are starting to see an increasing trend with Td`s in our west
that better matches guidance, while lower Tds/RH are still
lingering in our east. Earlier adjustments generally reflect
these trends and while clouds/high based weaker shower/storm may
still complicate Td/RH trends in some areas we should see many
locations see min RH around 25% with better potential to drop
below that in our MN counties. Based on these trends I went
ahead and reissued the SPS in MN for near critical fire weather
conditions through 02Z/9PM CDT.

UPDATE
Issued at 655 AM CDT Sat May 11 2024

The forecast remains mostly on track this morning. Currently
watching dew point observations against forecast values as the
air mass is a bit drier than most guidance. A few high clouds
are working across the Lake of the Woods region, along with weak
radar returns. Upstream observations remain dry this morning,
but will continue to monitor PoPs. Soundings remain rather dry
at the surface, which will serve to inhibit precipitation with
weaker showers and thunderstorms.

&&

.DISCUSSION...
Issued at 403 AM CDT Sat May 11 2024

Weak shortwave ridging traverses the region today, with a strong
response in temperatures this afternoon. Look for highs in the low
80s across much of the area; there is a 30% chance to reach 85
degrees in the northern Red River Valley. With low dew points
already in place, this will create a scenario for very low RH values
as low as 20 percent. Winds will not be as strong as yesterday;
however, we could still see a few gusts to 25 mph.

For the late afternoon and into the overnight period, shortwave
troughing moves progressively from northwest to southeast in
response to an H5 upper low moving across northern Manitoba. This
should provide an axis of instability and forcing starting late this
afternoon across portions of northwest Minnesota. Soundings indicate
an environment somewhat supportive of strong wind gusts where high
based thunderstorms are able to form. While SBCAPE looks to be
minimal, MUCAPE supports elevated thunderstorm development and will
be in the range of 800-1200 J/Kg. DCAPE is quite high as is expected
with the very dry air mass at the surface, and soundings show a
range of 900-1500 J/Kg. As such, any strong storm that develops
would most likely produce strong wind gusts, with lower chances for
hail.

Heading into Sunday and Monday, impact potential looks minimal in as
ridging builds into the Northern Plains. Highs will be in the 70s on
Sunday, with 60s to low 70s Monday.

For Tuesday and Wednesday, another H5 low pressure system brings
rain chances back into the area. Guidance has hinted at a deeper low
in the past several runs, which could slow the system and increase
the potential for higher rainfall amounts. Currently, amounts look
rather light, with a 70 percent chance for 0.10 inch and a 30
percent chance for 0.50 inch for the period covering late Tuesday
through early Thursday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 151 PM CDT Sat May 11 2024

VFR conditions should prevail across eastern ND and northwest
MN. The main aviation impacts from gusty southwest winds
decreasing this evening then shifting to the north and
increasing behind a front late tonight into Sunday morning.
Widely scattered (30% chance) high based (8000-12000 FT AGL)
showers and isolated (20%) thunderstorms will be possible after
21Z/4PM this afternoon through the early evening period. The
best chances are mainly in northwest MN.

&&

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

&&

$$

UPDATE...Lynch/DJR
DISCUSSION...Lynch
AVIATION...DJR