261
FXUS63 KFGF 061458
AFDFGF

Area Forecast Discussion
National Weather Service Grand Forks ND
958 AM CDT Sun Oct 6 2024

.KEY MESSAGES...

- Near critical fire weather conditions are expected this
  afternoon across northwest and west central MN.

&&

.UPDATE...
Issued at 958 AM CDT Sun Oct 6 2024

Clouds are clearing west to east this morning. Winds should be
calmer today, with gusts around 30 MPH in the morning. These
should lessen as we move into the afternoon and evening as the
pressure gradient becomes looser over the area. Forecast remains
on track.

UPDATE Issued at 630 AM CDT Sun Oct 6 2024

Winds have continues to diminish with the majority of locations
having dropped well below advisory criteria. A few locations
near Lake of the Woods continue to gust near 40 mph, but the
trend there has also been decreasing and it has been almost an
hour since the last report of 45 mph. Considering these trends
and the fact that it has been 2-3 hours since advisory impacts
were reported for most locations I felt comfortable cancelling
the Wind Advisory for our area. The only other adjustment was to
sky cover to better reflect timing/position of stratus in our
east and clearing in the west.

&&

.DISCUSSION...
Issued at 337 AM CDT Sun Oct 6 2024

...Synopsis...

The strong mid/upper low responsible for this last wind event is
continuing east over Ontario with NW flow over our region behind it.
Broad ridging is already building over the Northern Rockies and is
shown to shift east over the Northern Plains through early next week.
It does eventually flatten with a return to westerly/zonal flow,
however the active jet stream remains well north of the region. This
maintains higher heights. deeper dry air, and anomalous/unseasonable
warmth through next weekend. NAEFS anomalies are generally +1.5-2.0
through Friday resulting in 15-20F departures from climate averages
(generally 70s and lower 80s). As flow transitions there may be a
few weaker shortwaves that pass our region late next week into the
weekend, but energy/moisture advection will be limited (probs for
0.01" are 15% or less). This shift does allow for some lowering of
heights aloft and shifts the warmest airmass to the south, but the
coldest air mass remains well to the north. Temperatures would trend
lower than midweek 60s) but still 10F above average considering how
quickly climate averages drop in October.

...Strong Winds This Morning...

Unidirectional flow in a dry adiabatic mixed layer remains in place,
with strong surface gradient supporting continued windy conditions.
Gusts 40 mph are still common, with occasional gusts 45mph+. The
general trend in obs is for an end to advisory impacts west to east,
which matches the trends in guidance for surface gradient and peak
winds aloft. Advisory impacts should end at all locations based on
these trends by 7 AM (current time for advisories expiring).

...Near Critical Fire Weather This Afternoon...

As clouds clear this afternoon a deep dry adiabatic mixed layer
remains in place allowing for mixed layer Tds to drop into the 20-
30F range this afternoon in MN as temperatures approach the upper
50s/low 60s. RH values below 30% will be common, with lower values
near 22% at some locations in northwest MN. Surface gradient will
continue to decrease west to east, but peak winds in the mixed layer
may still be high enough in MN during the period of lower RH values
to support periodic gusts 25-30 mph. How long this crossover of
gusty winds/lower RH lasts is hard to anticipate, but there should
be a period of near critical fire weather conditions in our
northwest/west central MN counties. In ND the window for lingering
higher gusts (25 mph+) is earlier, mixed layer Tds will trend
higher, and the chance for a crossover is lower. This lowers
confidence in fire weather impacts over eastern ND at this time. .

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 630 AM CDT Sun Oct 6 2024

MVFR stratus is still lingering near the ND/MN border but is
quickly eroding and should continue to clear west to east across
NW MN early in the TAF period (by 15Z). Northwest winds remain
gusty with the stronger gusts now in northwest MN this morning
(as high as 38kt at times). These winds will continue to
gradually diminish this morning through the afternoon as high
pressure builds west to east, with light and variable winds
returning this evening across eastern ND/northwest MN.

&&

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

&&

$$

UPDATE...AH/DJR
DISCUSSION...DJR
AVIATION...DJR