410
FXUS63 KMPX 160523
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1223 AM CDT Mon Sep 16 2024

.KEY MESSAGES...

- Highs in the mid-upper 80s to continue through Wednesday.

- A more active pattern is expected for the second half of next
  week into next weekend with the best chances for rain right
  now coming Thursday/Thursday night and Friday night into
  Saturday.

- Heavy rain is currently the greatest potential hazard, though
  a severe potential is slowly starting to emerge for the two
  active periods as well.

&&

.DISCUSSION...
Issued at 308 PM CDT Sun Sep 15 2024

We`re back to the unseasonably mild and mostly quiet weather today
as a blocking high over the Great Lakes continues to shunt any
significant forcing west and north of the upper MS Valley. However,
continued south winds have slowly pushed dewpoints back up into the
mid/upper 60s, which has pushed mlCAPE back up to near 2000 j/kg.
However, the last two MPX soundings showed a stout warm nose in
place just below h7 and that cap is still in place, so we`re not
anticipating any convective initiation. The atmosphere has been
giving it a valiant effort southwest of Redwood Falls, where some
differential heating along the Buffalo Ridge has resulted some brief
successes at deep convection, but none of this activity has survived
once it leaves this source of differential heating. For the rest of
tonight, the shower potential is expected to remain north of the
area, so we have maintained a dry forecast. We`re not seeing the
forcing to support all the QPF that the 15.12 GFS spits out over the
MPX area tonight.

For Monday through Wednesday, it`s more of the same, with the active
storm track remaining west and north of the MPX area as ridging to
our east continues to force rainfall around us. To go along with the
dry weather, it`s three more days of summer, with highs continuing
to run around 10-20 degrees above normal as they comfortably rise
into the 80s with dewpoints remaining in the 60s.

Change finally starts to happen mid-week as the h5 ridge to our east
begins to break down. This will finally allow a cold front to enter
the region on Thursday, which is when our first widespread rain
chances of the month finally arrive. For our first chance of rain, a
surface low will be tracking east across southern Canada, with a
cold front coming across the Dakotas during the day on Thursday.
Storms should fire along this front and work east across the MPX
area Thursday night. Where storms initiate during the afternoon,
there should be sufficient moisture, instability, and shear to at
least support a small threat for severe weather, nothing
significant, but something we`ll have to watch over the coming days.

We`re trending toward a drier scenario on Friday as a weak high
pressure moves in behind the Thursday night front. As this high is
moving in, a wave will be coming out of the 4-corners region,
heading for the upper MS Valley next weekend. There`s still quite a
bit of spread with exactly where this feature and its associated
surface low will track, but a threat for heavy rain and possibly
some severe weather will follow it depending on where it tracks. The
one trend seen over the last 24 hours with the models is a shift to
the east in where these two rounds rain fall, with the 2-4+ inch
rain swaths yesterday placed across the eastern Dakotas into western
MN now shifted east to be centered over MN. There`s still lots of
time for details to change, but it looks like normal precip for the
month of September will be within reach for MSP, despite only
getting 0.02" of rain in what is supposed to be the wetter half of
the month.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1218 AM CDT Mon Sep 16 2024

A quiet period is ahead of us with mainly high clouds at
FEW/SCT 150 to 250. Winds begin around 140-160 below 5kts,
increasing to 10-12kts at 160-180 this afternoon with a few
gusts to 20-23kts before falling back again by 00z. EAU has a
fog concern this morning but confidence was too low to include
for now and will be handled with AMDs if needed.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/
WED...VFR, chc MVFR/-TSRA late. Wind SE 10-15kts.
THU...VFR/MVFR, -SHRA likely. Wind SE 5-10kts.
FRI...VFR/MVFR, chc -TSRA. Wind S 5-10kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

$$

DISCUSSION...MPG
AVIATION...TDH