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FXUS63 KMPX 050809
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
309 AM CDT Fri Jul 5 2024

.KEY MESSAGES...

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- Scattered showers continue this morning, with a morning break
before further scattered showers and weak storms return this
afternoon and evening.

- Diurnal showers and weak storms possible this weekend and into
  the beginning of next week.
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&&

.DISCUSSION...
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Issued at 308 AM CDT Fri Jul 5 2024

Our low pressure center is located in far eastern Minnesota and
western Wisconsin this morning evidenced by the slow moving rotating
showers that have persisted over the past few hours. These slowly
rotating showers will continue to churn near the surface low through
sunrise as the low begins to push eastwards. The showers tonight
have largely remained just north of our coverage area towards
central Minnesota and northern Wisconsin, covered by our neighboring
WFO Duluth, with the two main showers over our area affecting
portions of McLeod, Sibley, Dakota, and Scott counties. Isolated to
scattered showers are likely to continue throughout the day until
the system is fully out of the area, which looks to happen by later
this evening to early Saturday morning. Due to how scattered showers
are expected to be today versus yesterday, additional accumulations
resulting in 2 day totals above an inch will be locally isolated,
favoring the areas that have been seeing the rainfall overnight.
Outside of the showers this morning has been persistent fog as a
result of the weak winds under the surface low alongside lingering
moisture, with visibility dropping below 1/4 mile in spots favoring
western Wisconsin. Fog should also begin to dissipate as the surface
low tracks eastwards and winds strengthen just enough to mix us out.
High temperatures this afternoon in the mid 70s alongside lower
overall shower coverage should make for a nice day in many spots, as
long as you can avoid or tolerate the passing showers.

As the near-term system winds down, we do not truly see another
widespread synoptic scale event within the scope of the 7 day
forecast, with a diurnally driven pattern favoring isolated to
scattered showers and weak thunderstorms through the weekend and
into next week. Flow aloft stagnates as a trough spanning almost the
entire CONUS swings its apex south of the area, with weak upper
level flow as a result with a lack of significant shortwave energy
to help force stronger storms. Unlike the past few weeks, we also do
not see a strong low level jet influencing our pattern, with lower
overall moisture content to work with. Our main forcing will likely
be diurnal heating with a hint of shortwave perturbations, enough to
cause some nuisance showers and storms but not enough to produce any
significant wet signal or thunderstorms. Instability generally looks
meager with forecast soundings from the GFS peaking at around 1000-
1500 J/KG largely surface based with adiabatic lapse rates near the
surface becoming much less favorable aloft. Based on current
guidance, the best day to have a chance at more widespread showers
looks to be Monday as the upper level trough begins to occlude and
produces forcing that is a bit better compared to the weekend. After
Monday, our flow aloft turns northerly as a ridge builds over the
Rockies, setting up what looks to be a trend towards warmer weather
as we get into the middle of the month.
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&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1047 PM CDT Thu Jul 4 2024

We`ve moved off to phase 2 of this system and thats rain
associated with the upper low itself, which at 11pm, water
vapor imagery showed being not far from Litchfield (KLJF).
Rotating around this low as been a broad shield of light to
moderate rain with some embedded downpours. As the low slowly
track ESE through the night, these areas of showers are expected
to follow the upper low. Besides the rain, the expanding
IFR/MVFR obs we`re seeing with obs is supported by moist low
levels in RAP soundings and we expect extensive MVFR/IFR stratus
through the night near the surface low that is slowly taking
shape between MSP & MKT. CIGS will slowly improve through the
morning, with another round of diurnally driven scattered
shra/tsra expected Saturday afternoon. Have included PROB30s to
cover that threat. HREF is most bullish with activity Saturday
happening west of I-35, so kept MSP/EAU/RNH dry after the upper
and surface lows clear the area in the morning.

KMSP...We expect one more round of shra to move through MSP
overnight as the upper low passes nearby. 8z-12z looking to be
the window when -shra is most likely. For Saturday afternoon,
MSP looks to have enough influence in the subsidence region of
the departing upper low to suppress diurnal activity.

/OUTLOOK FOR KMSP/
SAT...Chance PM MVFR/SHRA/TSRA. Wind SW 5-10 kts.
SUN...VFR. Chc aftn SHRA/TSRA. Wind SW 10-20 kts.
MON...VFR. Chc aftn SHRA/TSRA. Wind WNW 5-10 kts.

&&

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

&&

$$

DISCUSSION...TDH
AVIATION...MPG