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000
FXUS63 KMPX 211944
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
244 PM CDT Sun Apr 21 2024

.KEY MESSAGES...

- Chance of showers across eastern/southern MN and WI Monday
  afternoon/evening and again Tuesday.

- Widespread frost/freeze Tuesday night and early Wednesday.

- The pattern becomes very active with two systems passing
  through at the end of this week and beginning of next week.

&&

.DISCUSSION...
Issued at 244 PM CDT Sun Apr 21 2024

Elevated fire weather conditions are underway this afternoon
with RH values falling into the teens to mid 20s across the
area. Northwest winds occasionally gusting to 20 mph will ease
just before sunset. High pressure across the central Plains will
slide east this evening, resulting in winds shifting south
overnight with WAA beginning. Light winds across WI should
allow temps to drop into the low to mid 30s overnight, but the
dry air in place will largely prevent frost formation so no
frost or freeze headlines have been issued.

A weakening system tracking east across the southern provinces
of Canada will send a surface warm front through Tuesday. Gusty
southwest winds will develop mid to late morning with some gusts
as high as 35-40 mph in southern MN. Increasing moisture ahead
of a cold front could spark scattered showers over eastern MN
and WI in the afternoon, but PoPs have trended down a bit with
the deeper moisture not reaching this area in time for the
fropa. Cyclonic flow behind the system, a vort max rotating
southeast across the Upper Midwest and steep mid level lapse
rates will likely generate showers and some thunderstorms across
much of the region during peak heating Tuesday afternoon. Any
activity would diminish quickly around sunset.

Another high pressure arrives Tuesday night, bringing light
winds and clear skies. Lows will likely drop to subfreezing
levels again, except maybe across western MN where return flow
may begin late. Freeze warnings or frost advisories will be
needed again early Wednesday.

The longer term then becomes interesting as flow aloft shifts
southwest. Multiple waves will eject from the desert southwest
and track northeast to the Upper Midwest in the Friday to
Sunday/Monday timeframe. A prolonged period of return flow from
the Gulf will set up, and each subsequent system will have
deeper and deeper moisture to work with. In addition, at least
moderately steep mid level lapse rates atop this moist airmass
and strong deep layer shear will create an environment favorable
for severe thunderstorms. The predictability with each system
remains low at this range and the severe threat locally will
depend on the track of any given system, but it`s a possibility
the severe season could ramp up quickly next weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1256 PM CDT Sun Apr 21 2024

Clear skies through the evening with gusty northwest winds
easing late this afternoon. Mid level clouds will increase early
Monday with winds turning south and increasing with gusts of
25 kts after 15Z.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/
TUE...Chance MVFR/-SHRA, then VFR late. Wind NW 15-20G30-35kts.
WED...VFR. Wind SE 5-10kts.
THU...VFR. Chance MVFR/-SHRA late. Wind SE 10-15kts.

&&

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

&&

$$

DISCUSSION...Borghoff
AVIATION...Borghoff