863
FXUS63 KMPX 151143
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
643 AM CDT Wed May 15 2024

.KEY MESSAGES...

- Rainfall amounts are trending lower for this afternoon into
  tonight, with most areas seeing 0.25" of rain or less.

- Thursday and Friday should by dry for most locations.

- Next front and increased chances for rain comes Saturday.

&&

.DISCUSSION...
Issued at 237 AM CDT Wed May 15 2024

Water vapor imagery and RAP h5 analysis shows a rather broad and
disorganized positively tilted trough with multiple embedded
shortwaves from the Dakotas back down into the 4-corners.  There are
cloudy conditions across the northern half of MN and along the SD
border, though forecast soundings show lots of dry air below 10k
feet that will really impeded the progress of showers today.
Eventually, an inverted surface trough/front will move into western
MN this afternoon and into eastern MN and western WI this evening.
The heaviest precip looks to fall to the northwest of an h85 low
that develops over west central MN, with the HREF showing the
highest rainfall amounts up by Fargo. We still expect most locations
to pick up rain, but that rain looks to come in the form of a 3-6
hour period of scattered showers as a north to south oriented band
of moisture and forcing moves across any one location. 48 hour PMM
QPF from the HREF shows the vast majority of the MPX area receiving
less than 0.25" of rain, with a few streaks of QPF greater than
0.25" where one of the members happens to generate some stronger
convection. For the most part, this looks to be just showers, but
there will be a few lightning strikes, especially this
afternoon/evening in southwest MN. The previous discussion did bring
up the possibility of a weak tornado environment developing over
western MN with the surface low, but this is looking increasingly
unlikely as the potential for some stronger instability (FSD portion
of southwest MN) does not look match up with where the best low
level helicity will be (up by AXN).

By Thursday morning, the band of showers from Wednesday night will
largely be east of the MPX area, with dry weather expected Thursday
and Friday, as precip chances remain largely to our northwest,
closer to the better forcing associated with the h5 low over the
western Canadian Prairies/eastern Canadian Rockies. Precipitation
chances look to ramp up again on Saturday as we see a trough coming
across the Dakotas takes on an increasingly negative tilt as it
moves into MN. However, a very warm and dry low level airmass looks
to come in out ahead of the shortwave, so we may remain capped/dry,
with a better signal for precip across northern MN.

After Saturday, zonal flow looks to setup across the central CONUS,
though with the primary storm track to our south, with that not
really look to shift north until the end of next week. Still, given
the zonal flow, it`s the type of pattern where you get a dull roar
of low pops (generally 30% or less) as you can always find at least
a few ensemble members producing precip at any given time. Also with
the zonal flow, don`t look for much change in the airmass. Outside
of a quick hit of warmer air on Saturday, with highs making a run
into the 80s, we`ll highs near our climatological average in the
70s.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 632 AM CDT Wed May 15 2024

Not many changes to the going TAFs as dry air below 10k feet
will really check up the progress of moving -SHRA across the
area today. Trends in timing of rainfall in TAFs still looks
good, with a 3-5 hour window where scattered showers will be
possible at any one location. RWF is still the only field where
there`s any sort of mention of TS, with minimal levels of
instability expected to result in a limited amount of TS.
Confidence in MVFR or lower cigs remains highest at AXN/STC,
with a surface low passing over/near these sites. For everyone
else, MVFR cig probabilities look to pick up in the post
frontal, west wind environment.

KMSP...3z-8z continues to look like the best window for seeing
-shra. Some TS is possible, but that probability is under 20%,
 so continued to keep any sort of TS mention out of the TAF.
 Though by no means a certainty, MVFR cigs with levels as low as
 015 will be possible beyond 6z Thu in this TAF period.

/OUTLOOK FOR KMSP/
THU...VFR. Wind W 10-15kts.
FRI...VFR. Wind SE 10-15kts.
SAT...VFR, chc MVFR/-TSRA. Winds S bcmg NW 15-20G30 kts.

&&

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

&&

$$

DISCUSSION...MPG
AVIATION...MPG