980
FXUS63 KMPX 262319
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
619 PM CDT Fri Jul 26 2024

.KEY MESSAGES...

- Hot and humid weekend on deck, with heat indices in the 90s. The
  heat aims to stick around into the start of August.

- Chances for thunderstorms and locally heavy rain return Sunday
  through Sunday night. Another chance for storms will arrive
  for the middle of next week.

&&

.DISCUSSION...
Issued at 208 PM CDT Fri Jul 26 2024

Early afternoon visible satellite loop illustrates that much of the
widespread stratus from this morning has mixed out. That said, the
skies are not exactly "clear" given the combination of diurnal Cu
and hazy skies from wildfire smoke aloft. Fortunately, much of this
smoke remains well above the surface, limiting air quality concerns.
The main weather hazard for the remainder of the day is the evolving
heat scenario in western Minnesota. The combination of air
temperatures in the 80s and dew points in the low to mid 70s has
pushed heat indices into the upper 90s/low 100s from Stevens to
Yellow Medicine counties, with multiple hours of warming ahead. We
have collaborated with neighboring offices to issue a Heat Advisory
for Stevens, Swift, Lac Qui Parle, Chippewa, and Yellow Medicine
counties through 8 PM. Skies will run mostly clear tonight, but it
will still be quite mild. Overnight lows are forecast to range
between the mid 70s in western Minnesota to the upper 60s in western
Wisconsin, setting the stage for a hot Saturday ahead.

Most locations across in central Minnesota, including most of the
Twin Cities Metro, are forecast to climb into the low 90s Saturday
afternoon. Locations in southeast Minnesota and western Wisconsin
may top out a few degrees cooler, in the upper 80s. Still, given the
expected upper 60s/low 70s dew points, all locations should have no
problem reaching the 90s for peak heat index values. Breezy
southerly winds will gust up to 25 mph through the afternoon, which
should help to provide some relief from the heat. While there was
discussion about heat headlines with neighboring offices, the
marginal nature of the temperatures combined with the surface winds
presented enough uncertainty to hold off at this time.

Warm air aloft and a lack of forcing will work against precipitation
chances for much of Saturday, however the eastward advance of the
low-level jet will be the focus for convection Saturday night. We
have included slight chance PoPs in west central Minnesota to
capture this potential. The majority of south central Minnesota and
western Wisconsin aim to stay dry until the second portion of
Sunday, when more clusters of storms are forecast to develop in
response to the eastward advance of a shortwave. Support from the
low-level jet should aid in a greater coverage of showers and storms
into late Sunday evening/early Monday, so the 60-70% PoPs from NBM
seem reasonable. The threat for widespread severe weather is limited
due to moderate instability (~1500-2000 J/kg of MLCAPE) and weak
shear, though the strongest cells will be capable of damaging winds
and small hail. This is reflected by SPC`s Day 3 Marginal Risk
across much of south central Minnesota. The threat for locally heavy
rain will be of greater concern, given forecast PWATs exceeding 1.5"
and the potential for slow-moving, perhaps training thunderstorms.

Convective activity will shift east during the first half of Monday,
followed by dry weather through Tuesday. Temperatures are forecast
to run a few degrees "cooler" Monday afternoon, though highs will
still reach the mid 80s. Temperatures and heat indices will then
warm back to more uncomfortable levels for Tuesday and Wednesday.
Another shortwave aims to track through the northern Great Plains in
the Wednesday/Thursday timeframe, which will bring the next chance
for scattered to widespread thunderstorms across the Upper Midwest.
Significant ridging builds out west for the middle to end of next
week, shifting the active jet and storm track north into southern
Canada. This coincides with CPC`s latest 8-14 day outlook, which
advertises above average temperatures/below normal precipitation to
through the first stretch of August.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 610 PM CDT Fri Jul 26 2024

MVFR cigs at MKT should eventually lift to VFR this evening. A
few models are also hinting at the possibility of IFR cigs at
STC overnight from pooling moisture. Have included a SCT008 from
06Z to 15Z to have mention of this possibility but keeping
conditions VFR. Low-end VFR will persist elsewhere through
tonight before skies lift and improve Saturday afternoon.
Southerly winds will slow slightly overnight but increase late
Saturday morning with MN terminals having the strongest winds.
Sustained values will range from 10-15 knots with gusts to 25
knots.

KMSP...Southerly winds will increase late tomorrow morning with
sustained values of 10-15 knots and gusts of 20-25 knots.

/OUTLOOK FOR KMSP/
SUN...VFR, MVFR/-TSRA likely late. Wind S 15G25 kts.
MON...Chc morning MVFR, chc -TSRA. Wind SW/W 10-15kts.
TUE...VFR. Wind VRB 5 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Heat Advisory until 8 PM CDT this evening for Chippewa-Lac Qui
     Parle-Stevens-Swift-Yellow Medicine.
WI...None.

&&

$$

DISCUSSION...Strus
AVIATION...CTG