673
FXUS63 KMPX 211104
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
604 AM CDT Sat Sep 21 2024

.KEY MESSAGES...

- Isolated to scattered showers and storms in central Minnesota
  this morning shifting to southern Minnesota into western
  Wisconsin later today.

- A fall temperature roller coaster with another warm day today
  before temperatures fall substantially Sunday and warming back
  up through the rest of the week.

&&

.DISCUSSION...
Issued at 240 AM CDT Sat Sep 21 2024

This weekend...Scattered showers with some isolated
thunderstorms will continue this morning driven by a LLJ in the
warm sector of the advancing system. Another round of showers
and thunderstorms is expected today along and ahead of the cold
front. With a cap in place there should be a time gap in
precipitation later this morning once the LLJ driven convection
comes to an end. As the surface heating continues ahead of the
front thermal profiles will eventually allow for the cap to
break. This will most likely be in the afternoon. By that time
the front should get far enough that the most likely areas for
rain and thunder will be in the southeastern quarter of
Minnesota and into western Wisconsin. The heating under the cap
should allow for some instability to form with up to around 1000
J/kg of SBCAPE forecast. Not a great shear setup so the chances
for severe storms are low. Any chance for a stronger storm
would likely be pulse convection and would not be a long lived
strong to severe threat if even occurs. Temperatures will be
much cooler behind this front with temperatures across
northwestern Minnesota (behind the front) 20 to 25 degrees
cooler than southeastern Minnesota (ahead of the front) for
today`s forecast high temperatures. Behind this front Sunday
will be much cooler with high temperatures in the mid to upper
60s. Also with high pressure moving in, there should be
clearing skies during the day. Another system likely staying to
our south is unlikely to provide rain chances, but could keep
cloud cover longer across southern Minnesota into parts of
western Wisconsin.

Monday through Friday... The week ahead will be dominated by
surface high pressure with little chance for additional
rainfall. Also under mostly high pressure expect clear to mostly
clear skies. Winds at 850 mb trend back to a southerly or
westerly direction with more of a WAA regime in place. This will
help provide a warming trend through the week. Bringing
Monday`s highs of near 70 up into the upper 70s by the end of
the week. Normal high temperatures this time of year are in the
upper 60s. So near normal the start of the week warming back
above normal for the remainder of the week. Despite annual
precipitation numbers still well above normal September has
been dry for many, with MSP Airport currently on track for one
of the driest Septembers on record.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 604 AM CDT Sat Sep 21 2024

Overall VFR today with periods of showers and thunderstorms
possible. Isolated thunderstorms will continue this morning.
These will remain isolated and may not hit terminals, but it
could be close and the spots where it is most likely have a
PROB30. Another chance for showers and storms this afternoon.
This would be for eastern MN and western WI terminals. Some LLWS
will continue early this morning, but later this morning it
should wind down the LLWS. As the LLWS winds down winds will
pick up later this morning and remain gusty for much of the
period. Should overall be from the south or southeast before the
front comes through later today and shifts to the northwest.

KMSP...Isolated thunderstorms to the west could get near the
terminal between 14Z and 16Z this morning. Kept it as a PROB30
as uncertainty remains on if the storms will survive or
dissipate before reaching the terminal area. There is another
chance for rain this afternoon as well. Kept with SHRA for now,
but if we warm up enough today it might need to be changed to
TSRA.

/OUTLOOK FOR KMSP/
SUN PM...VFR. Wind N 5-10 kts.
MON...VFR. Wind E 5-10 kts.
TUE...VFR. Wind S 5-10 kts.

&&

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

&&

$$

DISCUSSION...NDC
AVIATION...NDC