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000
FXUS63 KMPX 170840
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
340 AM CDT Wed Apr 17 2024

.KEY MESSAGES...

- Rain ends from west to east today, followed by additional rain
  in far southern MN tonight into early Thursday.

- Mainly dry Thursday through the weekend, with next best chance
  for rain coming Monday.

- Temperatures generally close to normal through early next
  week, though lows near to below freezing Friday-Sunday
  mornings may produce frost.

&&

.DISCUSSION...
Issued at 337 AM CDT Wed Apr 17 2024

Surface analysis early this morning shows a low pressure center
circulating over southern MN, which is also evident on KMPX
radar as bands of rain showers lift north over western WI, W
to NW over eastern MN and S to SE over southwestern MN. This low
is occurring under a compact sharp shortwave, stacked nearly
atop the surface feature. In the broader picture, a trailing
cold front is analyzed from southern Manitoba extending
southwest across the Dakotas into Wyoming with high pressure
building behind it over western Canada. Aloft, a more longwave
trough with its low centered over southwestern Canada is slowly
lumbering east-southeastward.

Both the surface low over MN and its reflection aloft will lift
east into the Great Lakes by late this afternoon, dragging the
rotating rain showers with it and allowing the precipitation to
end from west to east today. Little in the way of additional
rainfall is expected from daybreak onward, though the heaviest
rainfall looks to be confined to western WI as that part of the
WFO MPX will have the longest duration of remaining rainfall and
also the relatively highest instability and deepest moisture
available for producing some heavier showers. As the system
lifts away, a small bubble ridge aloft will traverse MN/WI,
making for a period of partial (if not mostly) clear skies late
this afternoon through this evening. However, clouds will fill
back in tonight into Thursday as the aforementioned cold front
to the west sweeps across the region. Deep moisture will
generally be lacking with this frontal passage, but sufficient
moisture will accompany the front near the MN/IA border late
tonight through Thursday morning such that additional rainfall
looks likely near the I-90 corridor. Instability, and hence
thunderstorms, will be very hard to come by with this cold
frontal passage so have omitted TS mention for the forecast for
that area`s rainfall.

From late Thursday on through the upcoming weekend, the western
Canadian area of high pressure will slowly slide east southeast,
moving across the Northern Plains and Upper Midwest. This will
promote several days of mainly clear skies with no precipitation.
However, there are indications of another frontal system
arriving early next week which may produce some rainfall.

Though no appreciable change in airmass is expected, generally
seasonable temperatures are expected with relatively large
diurnal spreads. After highs in the 50s both today and Thursday,
highs drop back to the 40s on Friday behind the cold front,
including low temperatures in the low-mid 30s Friday morning.
From Saturday onward, highs will increase to near 50 area-wide
on Saturday then near 60 area-wide Sunday-Tuesday and into the
low-mid 60s on Tuesday. The flip side is that lows will run in
the upper 20s to lower 30s Saturday and Sunday mornings,
potentially allowing for appreciable frost formation and hard
freezes (especially given the area-wide greening up of
vegetation with the widespread recent rainfall). Lows then
increase to the mid 30s to lower 40s early next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 133 AM CDT Wed Apr 17 2024

KMPX radar clearly shows the broad rotation of precipitation
bands around the low pressure centered over southern MN. Thus,
with the rain expected to continue spreading across much of
central-southern MN and western WI, periods of rain can be
expected at all sites, including some mod-heavy at times which
may well reduce visibility into MVFR range. Ceilings have
generally dropped into MVFR range at/near all sites, with
ceilings likely to drop into IFR range later this morning
through early afternoon. As the center of the circulation
slides east, this will allow winds to become more W to NW and
also increase in speed with a tightened pressure gradient and
deeper mixing aloft. Winds will diminish late tonight into
Thursday morning in conjunction with conditions improving to VFR
and clouds scattering out as the system exits to the east.

KMSP...MVFR to start but with additional bands of rain likely to
drift across MSP shortly after initialization time, ceilings may
well drop to IFR prior to sunrise and stay there through the
morning push, continuing through midday. Improvements will be
slow-to-come-by through the day today, including ceilings
potentially staying sub-1700ft through the afternoon push, with
improvement to VFR not coming until Wednesday evening. Breezy
winds will increase to around 20G30kt this afternoon and
evening, but are expected to have a 300 direction, right down
the 30s, thus any cross-wind component will be quite minimal.

/OUTLOOK FOR KMSP/
THU...VFR. Wind W 10-15 kts increasing to 15-20G25-30 kts.
FRI...VFR. Wind WNW 15-25G30-40 kts.
SAT...VFR. Wind NW 10-15G20-25 kts.

&&

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

&&

$$

DISCUSSION...JPC
AVIATION...JPC