401
FXUS63 KMPX 191955
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
255 PM CDT Fri Jul 19 2024

.KEY MESSAGES...

- Multiple rounds of isolated showers & thunderstorms tonight
 through this weekend. Slow-moving storms mean localized
 rainfall amounts of a few inches are possible.

- Diurnally-driven afternoon showers and thunderstorms are
 likely through midweek, with the best chances for widespread
 rain coming Tuesday night into Wednesday morning.

- Drier conditions likely to end next week.

&&

.DISCUSSION...
Issued at 253 PM CDT Fri Jul 19 2024

More of the same this afternoon with light winds, seasonable
temperatures, & smoky skies aloft as weak northwest flow
continues over the region. The surface high pressure that has
led to the quiet weather this week will slide east of the region
tonight, with a slow moving vorticity lobe aloft & surface
pressure trough advancing in in its wake tonight through
tomorrow. Enough forcing will be present with this upper-level
feature for isolated showers and thunderstorms to develop late
this evening & continue into tomorrow morning. Models still
remain quite spread out with where these showers and
thunderstorms could develop, but overall look most likely along
the path of the upper-level feature across western & south-
central Minnesota. Better chances for rain across the whole area
come tomorrow afternoon through tomorrow night, as diurnal
heating lights up a slow-moving cold front descending southwards
out of northern Minnesota. Rain chances will likely hold off
until late in the afternoon or evening across our area, when the
front reaches central MN & WI, so most of the daytime tomorrow
looks to remain dry. Showers & thunderstorms will be scattered
along the front so not everyone will see rain. Storms will be
slow-moving as well which could result in very localized
rainfall amounts of a few inches in areas that see multiple
rounds of rain tonight & tomorrow. The front lingers over
southern MN & western WI Sunday, which will likely initiate
another round of showers and thunderstorms by the afternoon.
Similarly to Saturday, storms will be scattered & slow-moving
with a chance for very localized heavy rain.

The front will be out of the region by Monday, but a typically
stagnant summertime upper-air & surface pattern means diurnally-
driven scattered showers & thunderstorms are likely each
afternoon through mid-week. Our forecast shows a general 20-30%
chance of precipitation through this time, but chances will be
highest during the afternoon & early evening with most locations
likely staying dry. A chance for more widespread rain does look
likely Tuesday night into Wednesday morning when most models
bring a more-organized shortwave somewhere through the Upper
Midwest. Heavier rain & strong thunderstorms cant be ruled out
with this wave, if it happens to come through the region Tuesday
afternoon/evening, but otherwise just looks to result in a
better chance for more widespread showers and thunderstorms.
High pressure builds back into the area behind this system with
drier conditions expected to end the week.


&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1224 PM CDT Fri Jul 19 2024

VFR conditions will hold through this evening before some sites
see MVFR cigs/vis by early tomorrow morning. Expecting showers
to stay far enough to the south/west through this afternoon that
they won`t impact any of our terminals, but did throw in a VCSH
mention for KRWF. Morning fog will once again develop early
Saturday with MVFR/IFR cigs/vis for some. The biggest
uncertainty at this point are the chances for precip tomorrow
morning. Left most locales dry, but this will need to be
addressed in future forecasts.

KMSP...LAMP guidance is trying to take cigs MVFR by tomorrow
morning, but wanted to hold VFR until there`s more model
agreement. Otherwise, west/southwest winds 10kts or less. Also
opted to leave out mention of showers tomorrow afternoon, but
again, this will need to be looked at for the next set of TAFs.


/OUTLOOK FOR KMSP/
SUN...VFR. Chc PM TSRA/MVFR. Wind NE 5 kts.
MON...VFR. Chc PM TSRA/MVFR. Wind NW 5 kts.
TUE...VFR. Chc PM TSRA/MVFR. Wind NE 5 kts.

&&

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

&&

$$

DISCUSSION...ETA
AVIATION...Dye