046
FXUS63 KMPX 151715
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1215 PM 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 1153 AM CDT Wed May 15 2024

A band of scattered to continuous rain showers will move into
western MN later this afternoon and slowly continue east-
northeast into eastern MN by late this evening, and western WI
by early Thursday morning. These showers should be light enough
for impacts to terminals not to be realized, except at RWF
where non-zero instability could lead to a thunderstorm or two
from 23-02Z. The main impact will be cigs lowering with the
building clouds, with large-scale low-end VFR to MVFR expected
at most terminals thru the end of the period. However, AXN has a
good chance of dropping to IFR overnight tonight into Thursday
morning with its proximity to the surface low. Cigs should
slowly improve towards the end of the period. Southeasterly
winds will eventually turn clockwise to west-northwesterly
overnight as the cold frontal passage occurs. Aside from western
MN where winds and gusts will be 3-5 knots greater this
afternoon, winds should be at or just below 10 knots the entire
period.

KMSP...The best timing for -SHRA continues to look like 03-08Z.
Forecast soundings also have kept with very low instability,
signaling a low likelihood of TS. Thus, have kept TS out of the
TAF. Periods of MVFR cigs (down to 1500 feet) also look
possible after 06Z but confidence is too low to include at this
time.

/OUTLOOK FOR KMSP/
FRI...VFR. Wind SE 10-15kts.
SAT...VFR, chc MVFR/-TSRA. Winds SE becmng W 15-20G30kts.
SUN...VFR. Wind W 10-15kts

&&

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

&&

$$

DISCUSSION...MPG
AVIATION...CTG