855
FXUS63 KMPX 012316
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
616 PM CDT Mon Jul 1 2024

.KEY MESSAGES...

- Widespread showers and thunderstorms this evening through Tuesday.
Locally heavy rainfall possible, primarily across southern Minnesota &
western Wisconsin.

- Thunderstorms and locally heavy rainfall likely for the 4th of
  July

&&

.DISCUSSION...
Issued at 355 PM CDT Mon Jul 1 2024

Current observations across much of our sites reporting breezy
conditions out of the south-southeast ranging between 25-35 mph.
Upper-level cirrus continues to spread in overhead out ahead of
our next system that is approaching from the west. As mentioned
in the previous discussion, a strengthening low level jet is a
likely culprit to the showery activity beginning to show up on
reflectivity early this afternoon across eastern SD and western
MN. So far though, most rainfall does not appear to be reaching
the ground likely due to dry air within the boundary layer.
Temperatures this afternoon will reach the low to mid 70s.

Tonight, upper-level troughing as well as a strengthening jet
streak will reach the northern plains where WAA is strongest.
Hi-Res forecast soundings showing PWATs of rich Gulf moisture
exceeding 1.8" well into MN and WI. The convergence of these
elements will create an environment able to provide widespread
showers and a few thunderstorms with locally heavy rainfall
possible. Current timing window for development occurs this
evening from west to east between 7-10 PM tonight. Although
storms are possible, the past few model runs bring the greatest
severe threat mainly across the Dakotas. However, a few storms
in western MN could produce isolated large hail and damaging
wind gusts. Latest forecasted QPF amounts through Tuesday
morning show southeastern MN and WI counties along and south of
the I-94 corridor having the greatest potential for observing
between 1 to 1.25 inches of rain. Farther north and west across
eastern MN and counties north of I-94 in WI could range between
0.75 inches to an 1 inch. Areas farther west can expect a half
an inch or less.

The system will be slow to exit Tuesday morning to our west as a
cold front becomes occluded over northwestern MN. Therefore
kept chance PoPs for much of Tuesday especially for both east
and southern MN and western WI. Skies will gradually clear to
where some sunshine peaks through for parts of western MN
tomorrow afternoon. Tuesday`s highs temperatures will reach the
lower 80s and then upper 70s across western WI where cloud cover
will be more prevalent. Another shortwave associated with the
larger troughing pattern ejects late Tuesday afternoon and could
provide enough support for more showers/storm across
southeastern MN and western WI.

Wednesday will be warmer and potentially the nicest day of the
entire week. Flow will become zonal above surface high
pressure. Skies are forecast to be mostly clear with highs
reaching the low to mid 80s. Thursday, a developing wave over
the PacNorthwest is progged to strengthen over the upper midwest
Thursday afternoon. We dont want to put any rain on the
firework fuses but ensemble guidance isn`t giving us many "oohs
or ahs" to marvel over in terms of dry conditions. NBM guidance
continuing to show likely PoPs across much of upper midwest
through the afternoon/evening hours. Ensemble guidance continues
to hint at heavy rain potential with QPF amounts nearing an
inch. Rain chances continue into the weekend however coverage
will not be as widespread and heavy rain threats look to
decrease.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 555 PM CDT Mon Jul 1 2024

All sites VFR to start but SHRA/TSRA still expected to move
across the region later this evening through the early morning
hours, bringing MVFR-IFR conditions to all terminals. Confidence
high enough to maintain prevailing -SHRA/-RA at all terminals,
not so much for TSRA so have maintained CB/TS generally in TEMPO
groups (western MN has the highest chances for TS so have
maintained prevailing mention there). Precip will move out of
the area prior to daybreak for the MN sites, lasting a little
longer for the WI sites, but ceilings will gradually drop
through the duration of the rainfall. MVFR ceilings are
virtually certain with IFR ceilings likely. Conditions will
gradually improve during the day tomorrow with VFR conditions
being realized mid-to-late day. Winds will remain breezy from
the SE through the overnight hours, then diminish and veer to SW
behind the swath of rainfall.

KMSP...Best timing for any TS into MSP still looks to be
04z-08z, with the overall timing for rainfall in the 02z-12z
timeframe, potentially ending earlier than advertised. Will
still expect ceilings under 2 kft for the Tuesday morning push,
potentially into IFR range after sunrise and through at least
midday. Ceilings may return to MVFR range for the afternoon push
but still likely below 2 kft. There is still a mentionable
chance for late afternoon SHRA/TSRA over southern-eastern MN so
it warrants keeping that PROB30 going late tomorrow afternoon.
Winds will still be breezy throughout the overnight hours and
beyond sunrise, generally in the 150-170 direction. Stronger
winds may be found at the 1-2 kft levels, not quite meeting the
LLWS definition but with a vector difference as those winds will
be more S to SW, there is a bit of low level turbulence that may
be experienced overnight through sunrise.

/OUTLOOK FOR KMSP/
WED...VFR.Wind WSW M10-15G20 kts.
THU...VFR. PM MVFR SHRA/TSRA.Wind SE 5-10 kts
FRI...MVFR SHRA/TSRA likely. Wind NE 5-10 G15-20

&&

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

&&

$$

DISCUSSION...Dunleavy
AVIATION...JPC