937
FXUS63 KMPX 281735
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1235 PM CDT Sun Apr 28 2024

.KEY MESSAGES...

- Cool and rainy to close the weekend. Another half inch to inch of
  rain expected, with the highest amounts in western Minnesota.

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

- Unsettled pattern to swing another chance for rain Thursday
  into Friday. Temperatures will remain seasonal through the
  work week.

&&

.DISCUSSION...
Issued at 305 AM CDT Sun Apr 28 2024

All is quiet across the region early this morning, with temperatures
holding steady in the mid 40s to low 50s due to light northeast
winds and a cloudy skies. A well defined upper trough is driving
widespread convection for locations across the central and southern
Plains, as well as portions of the Midwest. Strong surface low
pressure located in central Nebraska will continue to lift northeast
towards southern Minnesota today, which will bring a broad region of
ascent and a expansive precipitation shield into the Upper Midwest.
The surface low continues to track slower than guidance had
advertised over the last few days, such that the arrival time of
higher PoPs has once again featured a slight delay. Also of note,
high temperatures were knocked down for this afternoon and Monday,
due to the expected cloudy, cool, and rainy weather conditions.
Early morning ACARS data from MSP reveals a stratus layer around
3kft, with notable mid-level dry air just above. This dry layer will
have to saturate before rain can begin and forecast soundings show
this occurring around mid-morning, likely in the form of scattered
showers. Greater coverage of rain (and higher rainfall rates) will
arrive this afternoon as the surface low draws near. The surface low
is forecast to occlude over southern Minnesota, with a deformation
axis setting up across western Minnesota. Not much change in
expected QPF, with a half inch to inch forecast for most of the
area, however the aforementioned deformation axis may result in
locally higher rainfall amounts (closer to 1.5") across western
Minnesota. We won`t rule out an isolated rumble of thunder here or
there, however the risk for strong thunderstorms appears low. A
Marginal Risk remains in place across southern Minnesota where the
best chance for an isolated strong storm or two will be possible,
owing to a few hundred joules of MUCAPE per the 00z HREF.

The heaviest rain will end before midnight, however some showers may
linger through the first part of Monday. Cooler flow out of the
northwest in tandem with cloudy skies will work to keep highs in the
mid 40s to low 50s Monday afternoon.

Our attention then turns to Tuesday, where warmer temepratures and
strong to severe thunderstorm chances make a return to the forecast.
A thermal ridge will move over the region heading into Tuesday
morning, with warm advection forecast to increase out of the
southwest in response. Highs are forecast to surge into the 60s and
low 70s for highs Tuesday afternoon. The eastward advance of the
thermal ridge will be driven by a potent shortwave trough that is
progged to dig through the Upper Midwest Tuesday afternoon and
evening. The shortwave trough will become negatively tilted by
Tuesday afternoon, which will increase lift and promote the
development of rain and thunderstorms across much of the area. The
environment appears conditionally supportive of strong thunderstorms
across southern Minnesota, given up to 500 J/kg of MLCAPE, ~40+
knots of 0-6km bulk shear, and veering in the low-level hodograph
captured on forecast soundings. Limiting factors for a more
extensive severe weather threat will be poor moisture return
(Guidance says you`ll have to go to central/southern Iowa to find
60s dew points!) and stable lapse rates aloft (6.0-6.5 deg/km).
SPC`s new Day 3 outlook highlights much of southern Minnesota in a
Marginal Risk for severe weather. The latest PoPs from the NBM
highlight a 70-80% chance for precipitation across western Minnesota
by midday, followed by an eastward push of the likely PoPs through
Minnesota and western Wisconsin by the evening hours.

Sure, the recent pattern has been active, but why stop now? It seems
Mother Nature would tend to agree. Another shortwave will rotate
through the northern CONUS Thursday, which will bring the
reintroduction of PoPs for those living in Minnesota and western
Wisconsin. Temperatures will remain mild ahead of the approach of
Thursday`s shortwave (60s/low 70s), however the passage of this
system will knock highs back down into the 50s to close the work
week and open next weekend. The unsettled extended period will
feature yet another chance for rain showers this weekend, before a
more defined upper-trough comes ashore in the Pacific Northwest and
"kicks" the current revolving door of weather systems every 2-3 days
off to the east. While the first weekend of May appears to trending
cooler, there is some hope for a revival of warmer Spring air heading
into the second week of the month.

&&

.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...Strus
AVIATION...Borghoff