735
FXUS63 KMPX 040036
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
736 PM CDT Wed Jul 3 2024

.KEY MESSAGES...

- Thunderstorms and locally heavy rainfall likely for tomorrow
  and tomorrow night.

- Chances for showers and a few thunderstorms will linger into
  next week with temperatures remaining below normal.

&&

.DISCUSSION...
Issued at 312 PM CDT Wed Jul 3 2024

If you`re a fan of fair weather days... enjoy this one while it
lasts! Temperatures will drop into the mid-low 70s around sunset,
and cloud cover will begin to increase from the southwest overnight.

The upper trough over the northern Rockies is still on track to
deepen and develop a closed low as it moves east into the Upper
Mississippi Valley early tomorrow. A band of showers and few storms
will likely develop along the warm front across western MN shortly
after midnight, eventually expanding north and east throughout the
morning. Outside of some isolated precip, most locations will likely
see a few hours of dry conditions before more scattered to widespread
showers and storms develop during the afternoon. CAMS continue to
favor less of a widespread heavy rain event, and more of a localized
concern depending on what areas see the strongest and most numerous
storms. In other words, a broad swath of 1+ inches of rain is
still expected across southern and central MN, but CAMS suggest
that only a county or so will see values in excess of 2-3
inches. The area of focus looks to be somewhere within south-
central MN (just west of the TC metro) where the deformation
zone is expected to set up (northwest of the surface low). HREF
probabilities have a line of 40-60% chance for greater than 2
inches of rain (in 24 hours) extending from Redwood Falls up
towards Rogers, MN. As we head into the evening, precip should
become more isolated across southern MN while showers and storms
closer to the low should be favored with the continued synoptic
lift.

A few strong to severe storms are possible during the afternoon and
evening, however a few factors could limit things. 1) Lapse rates
will be modestly steep at best (about 6-7 C/km); 2) Extensive cloud
cover could limit instability, with only 500-1500 J/kg of CAPE
expected (greatest over southeast MN); 3) elongated/straight
hodos suggest splitting cells could interact/interfere with one
another; and 4) vertical wind shear will also be somewhat modest
(25-35 kts), potentially limiting storm organization. That
said, all hazards will be on the table for any storm that is
able to develop and become organized. Given the relatively
cooler temperatures aloft and the hodo signatures, hail
development would be favored, with a few instances of large hail
possible. This hail threat was noted as the main reasoning for
our upgrade to a Slight risk (level 2 of 5) on the SPC Day 2
Convective Outlook. Non-supercell tornadoes/funnels will also be
possible, especially near the surface low as it tracks through
southeastern MN. Bursts of heavy rain and strong winds will be
likely with any organized storms as well.

Several more chances for rain will be possible through the middle of
next week as the upper level heights remain in a western ridge,
central trough pattern. QPF amounts continue to look meager from
event to event, but could total up to an additional 1-2 inches for
some through this period. Temperatures will stay near or below
normal into next week, before potentially climbing as we head into
mid-July. Both the GEFS and EPS suggest a few days in the 90s will
be possible, but this will largely be dependent on how/if the ridge
over the western CONUS builds eastward.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 632 PM CDT Wed Jul 3 2024

A very unsettled period is expected as we see a mid-level low
track across southern MN on Thursday. Looking at the path of
850mb & 700mb low, the HREF shows these features tracking from
roughly Montevideo to Wabasha, along/north of this track will be
a favorable zone of forcing for seeing multiple rounds of
precipitation and thats what`s expected for most of the MPX
terminals. A continuous rain is not expected, but it will be on
& off activity for a good 12-20 hours. TS potential looks
greatest from the afternoon into evening. Surface pressure
pattern will be very baggy through the day on Thursday, so wind
directions will be tough to pin down, but speeds will be under
10 kts. Finally, RAP soundings show low levels moistening up
enough late in the afternoon to start bringing in MVFR cigs for
locations that area expected to be north & west of the
developing surface low.

KMSP...Models are absolutely all over the place with when/where
clusters of SHRA/TSRA will be through the day on Thursday and
into Thursday night, hence why precip mentions in the TAF are
VCs or PROB30. Current thinking is that the band of showers
along the eastern Neb/SoDak border will send an initial round of
showers through the metro during the morning, with a brief lull
in activity during the afternoon, before thunderstorms quickly
redevelop. As mentioned above, winds could be coming from just
about any direction on Thursday, though speeds will be generally
5 kts or less.

/OUTLOOK FOR KMSP/
FRI...MVFR SHRA/TSRA likely. Wind N 10G20 kts.
SAT...Chance PM MVFR SHRA/TSRA. Wind SW 5-10 kts.
SUN...MVFR/SHRA/TSRA likely. Wind SW 10G20 kts.

&&

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

&&

$$

DISCUSSION...BED
AVIATION...MPG