352
FXUS63 KMPX 282016
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
316 PM CDT Sun Apr 28 2024

.KEY MESSAGES...

- Showers & thunderstorms return on Tuesday, with a few strong to
  severe storms possible across southern Minnesota.

- Active pattern continues with additional chances for rain
  Thursday & next weekend.

- Temperatures will remain Spring-like through the work week.

&&

.DISCUSSION...
Issued at 314 PM CDT Sun Apr 28 2024

It is a rather raw & soggy day across the Upper Mississippi Valley
today. Widespread rain has spread across the region and will persist
through this evening before tapering off overnight. Temperatures are
more similar to mid-March, in the mid 40s, with sustained E/NE winds
10-15mph adding additional insult to injury to end April. The
surface low located over NE Nebraska will track through southern
Minnesota into northern Wisconsin before exiting through the
northern Great Lakes. We`ll see steady showers through the afternoon
with an area of heavier rain setting up in the deformation axis
across western Minnesota and eastern Dakotas. We`re looking at 0.5
to 1.0" total rainfall by Monday morning with locally higher amounts
possible across portions of western and central Minnesota. The cold
& dry E/NE flow has limited any attempt to build instability into S
MN & latest CAMs fail to bring the warm front into Minnesota or
Wisconsin. This lines up with the SPC removing the Marginal risk of
severe across S MN for this afternoon. There could be a few
thunderstorms embedded in the precipitation that`ll produce heavier
rains & a few rumbles of thunder. Otherwise, we`ll "dry out"
overnight before the deformation zone pivots through Monday morning.

Monday will see shower chances return in the first half the of day,
especially across W WI, before we actually dry out. Cool flow &
overcast skies will limit our highs into the upper 40s and lower 50s
for the second straight day. Tuesday will be a stark contrast to
Monday. High temperatures will be in the 60s and lower 70s. A
thermal ridge will move through during the day, allowing ample WAA
to occur ahead of shortwave trough. That potent shortwave is
forecast to dig into northern Plains and become negatively tilted by
Tuesday afternoon. This will enhance flow and provide additional
ascent across Upper Midwest Tuesday afternoon/evening, which will
support shower and thunderstorm development across much of the area
along and ahead of a sfc front. Timing is favorable, at peak diurnal
heating, but our limiting factor will be the lack of CAPE (500 j/kg)
& weak lapse rates (6.0-6.5 deg/km). So this isn`t going to be a
widespread severe but low CAPE/high(er) shear setup. Hires guidance
brings a line of thunderstorms across Tuesday PM. A few strong to
severe thunderstorms will be possible, and SPC`s day 3 places us in
a Marginal risk. What`s more impressive is the trend in higher QPF
associated with this wave. We`ve seen QPF more or less double since
yesterday so another solid rain event is on tap for much of the
area. We`ve also opted for 3 hourly PoP grids to better
represent the passing line of thunderstorms on Tuesday.

Wednesday will be a brief return to drier, seasonal conditions with
highs in the 60s and lower 70s. Guidance has doubled down on an
another shortwave impacting the region Thursday into Friday. This
was hinted at yesterday by a few ensemble members, but was far from
the best signal. Fast forward a day and we`re looking at solid
chance for another widespread rain maker. Temperatures cool into the
50s and 60s with likely PoPs now appearing in the NBM. As this
system exits on Friday we`ll see our active pattern continue as yet
another system is possible this weekend before the pattern resets
after next weekend. While temperatures have trended cooler for the
first weekend of May appears to trending cooler, there is a signal
for warmer temperatures to return for the second week of May.
&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1235 PM CDT Sun Apr 28 2024

Showers are spreading north and increasing in coverage early
this afternoon. Conditions will deteriorate to IFR within the
first couple hours of the TAF and remain there for the rest of
the period. The steadier showers will end this evening, but
additional showers are likely to develop early Monday morning
across southwest and central MN.

KMSP...MVFR to start, but by 20Z MSP should be trending IFR as
steadier rain continues to move in.

/OUTLOOK FOR KMSP/
TUE...VFR through mid afternoon. MVFR or IFR with TSRA late
aftn/evng. Wind SE 10-15G30 kts.
WED...VFR. Wind light/variable.
THU...MVFR/-SHRA likely. Wind ENE 10-15G25kts.

&&

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

&&

$$

DISCUSSION...BPH
AVIATION...Borghoff