681
FXUS63 KFGF 121932
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
232 PM CDT Thu Sep 12 2024

.KEY MESSAGES...

-Wind gusts up to 45mph this afternoon and evening for eastern
 North Dakota.

&&

.DISCUSSION...
Issued at 230 PM CDT Thu Sep 12 2024

...Synopsis...

500 mb trough continues to dig into eastern MT and southern Canada
this afternoon, with strong southerly flow ahead of it pushing
through North Dakota. Winds aloft at the 800mb and 925mb level show
35-45kts. Lapse rates across the area are hovering around 7-7.5 C/km
and are needing to increase in order to mix down those higher winds.
The strongest winds aloft are currently situated over central North
Dakota into the Devils Lake Basin. Over the next 24 to 48 hours the
trough is expected to shift through southern Canada bringing windy
conditions to eastern North Dakota and the Red River Valley. A front
associated with the trough shifts through Friday into early
Saturday. Post frontal passage, we are looking at a zonal flow
developing for the weekend, before transitioning back to
southwesterly flow next week.

A few isolated showers will be possible (20% chance) in the Devils
Lake Basin this evening. Upper level smoke looks to continue through
the end of the week creating hazy conditions at times.

...Windy Conditions Today...

Pressure gradient force continues to increase across eastern North
Dakota this afternoon, with strong 800-925mb winds aloft. Winds
continue to be 35-45kts aloft, but the question remains on if we can
mix down the higher side of those winds. Over the past several
hours, we have struggled in increase our lapse rates across eastern
North Dakota. They continue to be around the 7-7.5 C/km rate. We are
needing to bump those up in the low levels to 8 C/km or higher to
start to mix down those higher winds. NBM and HREF do indicate some
of those winds making it to the surface as gusts, but have moved
back the timing a little. We currently are seeing 25-35mph gusts
across eastern North Dakota, but over the next several hours that
should start to increase up to 45mph. Since it has been hard to tap
into those stronger winds, confidence has decreased slightly on if
we can reach the 45mph winds in eastern North Dakota. This is shown
in the probabilities that have decreased from 60% to 40% over the
past 6 hours. None the less, there is still a 40% chance of seeing
up to 45mph wind gusts this afternoon and evening. Best potential
still remains in the Devils Lake Basin where the strongest part of
the LLJ looks to set up.

RH values are around the upper 30s to lower 40s across northern
Minnesota this afternoon and evening. This combined with winds up to
25mph may bring heightened concerns for fire weather. However,
chances for winds to gust up to 35mph are low in northern MN where
the lowest of RH values occur.

Once we start to loose the daytime heating factor an inversion
begins to develop aloft helping to cape the wind gusts from reaching
the surface. However, with the PGF being high across eastern North
Dakota we will hang onto the sustained winds being 15-20mph through
the overnight period. Some isolated gusts up to 30mph still remain
possible (40% chance) overnight. The LLJ sets up overnight bringing
LLWS to the region, but diminishes tomorrow morning. Chance of
precipitation increases tomorrow afternoon and evening as a frontal
boundary shifts west to east across the area. Instability is weak
(less than 1000 J/kg), but isolated thunderstorms remain possible
along the front as it moves through. Otherwise, periodic chances for
precipitation over the weekend and into early next week along with
above normal temperatures continuing.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1225 PM CDT Thu Sep 12 2024

Winds are starting to slowly increase out of the south southeast
this afternoon, with the highest gust potential in the DVL
region. Gusts in DVL reach up to 35kts this afternoon through
early evening. TVF, GFK, and FAR reach up to 30kts this
afternoon and evening. Wind gusts should diminish post 02-03z,
but sustained winds remain breezy as a Low Level Jet sets up.
This will keep sustained winds around 15-20kts overnight for
FAR, DVL, TVF, and GFK. BJI will see winds of 10-12kts
throughout the afternoon, evening, and overnight period.
Otherwise, LLWS will be another issue for all sites from 02z
through 15z tomorrow thanks to that Low Level Jet. We will
continue to see windy conditions at the end of the TAF period
and beyond.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Wind Advisory until 7 PM CDT this evening for NDZ006>008-
     014>016-024-026>030-038-039-049-052>054.
MN...None.

&&

$$

DISCUSSION...Spender
AVIATION...Spender