298
FXUS63 KMPX 300807
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
307 AM CDT Mon Sep 30 2024

.KEY MESSAGES...

- Critical fire weather conditions expected this afternoon in
  western and central MN as gusty winds and dry air will arrive
  following a cold front. A Red Flag Warning has been issued.

- Cooler Tuesday with seasonable temperatures in the mid 60s.

- Dry weather for the rest of the period with temperatures
  fluctuating from normal to above-normal.

&&

.DISCUSSION...
Issued at 305 AM CDT Mon Sep 30 2024

By late September standards, temperatures tonight have stayed rather
balmy. Lows are mainly in the 50s but warmer air is present in
western MN where lows have only reached the low 60s. Southeasterly
winds in western MN have also remained steady with gusts reaching 20-
25 mph. Area winds are expected to increase throughout today,
turning more southerly this morning, as a trough arrives from the
west. Along the Buffalo Ridge, gusts this morning could reach 35 mph
as a strong southwesterly LLJ quickly passes overhead. Temperatures
will rise quickly into the low to mid 80s this afternoon before a
strong cold passes through from west to east. As the front passes,
winds will quickly rotate counter-clockwise to northwesterly and
increase in speed. Sustained values across western MN will be
between 17-23 mph this afternoon with gusts of 25 to in excess of 30
mph. As one goes east, wind strength should slowly decrease but
gusts of 30 mph are still possible at MSP and eastern MN.
Additionally, our already arid air will only dry out more following
the front. Relative humidity values across western and southwestern
MN will drop to 15-25% (lowest values in extreme western MN) by late
this afternoon. RH values in the mid to upper 20s are expected for
the rest of our MN counties while values improve to above 35% in WI.
With these factors in mind (and our prolonged recent dry spell),
have issued a Red Flag Warning for portions western and central MN
from late this morning until this evening. Critical fire weather
conditions will foster an environment for any sparks or flames to
quickly grow out of control. For most of the rest our MN counties to
the east, a Special Weather Statement has been issued for elevated
fire weather conditions. Some uncertainty does exist on the duration
and extent the strongest wind gusts will overlap with the driest air.

The northwesterly winds will spread east tonight and remain pretty
gusty through about 1 AM as cold air following the front will keep
the boundary layer mixed. Wind gusts could still reach 25-35 mph
around midnight. Eventually, the boundary layer will begin to
collapse as we cool, suppressing the flow to the surface. Lows by
Tuesday morning will be in the 40s. The northwesterly winds will
still be breezy thru most of Tuesday with gusts near 20 mph. Highs
are forecast to be much cooler in the low to mid 60s. The remainder
of the period continues to look dry as guidance shows us lacking any
southerly return flow moisture. Temperatures will fluctuate a bit,
though, as waves within zonal flow move through the Northern Plains.
Highs on Wednesday are forecast to reach the mid 70s to even lower
80s prior to the arrival of a shortwave. Southwesterly winds should
also be breezy and combined with the forecast dry air, another day
of elevated fire weather conditions looks probable. Once the wave
passes through, temperatures will dip back to near normal Thursday
and Friday. Morning lows these 2 days could actually be chilly in
the upper 30s in eastern MN and northwestern WI. Long-range ensemble
guidance favors another brief warmup for the early part of next
weekend before another wave arrives. This wave should return us back
to normal temperatures for early next week. However, the mild, dry
weather doesn`t appear to end as long-range guidance suggests
another upper-level ridge building over the northwest CONUS and
traveling east throughout next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1043 PM CDT Sun Sep 29 2024

VFR with clear sky or high clouds this TAF period. Visibility
reductions are unlikely tonight due to lower dew points, but
there is a small chance at usual low lying sites. This chance
was too low for inclusion in the TAFs. The biggest impact this
period will be the wind shifts as a front moves through. This
will include a period of atypical southwest winds which could
result in the use of crosswind runways at many airports.

KMSP...Main impact will be the changing winds creating a period
of gusty crosswinds in the afternoon and evening. If gusts
over-perform it will be around thresholds for the use of the
crosswind runway.

/OUTLOOK FOR KMSP/
TUE...VFR. Wind NW 10-15 kts.
WED...VFR. Wind S 10-15G25 kts.
THU...VFR. Wind NW 10-15 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Fire Weather Watch from 11 AM CDT this morning through this
     evening for Brown-Chippewa-Douglas-Kandiyohi-Lac Qui
     Parle-Martin-Meeker-Pope-Redwood-Renville-Stearns-Stevens-
     Swift-Todd-Watonwan-Yellow Medicine.
WI...None.

&&

$$

DISCUSSION...CTG
AVIATION...NDC