663
FXUS63 KMPX 260801
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
301 AM CDT Wed Jun 26 2024

.KEY MESSAGES...

- Isolated showers possible this morning. Best chance for a few hundredths
  of rain will be across southwest Minnesota through 7 AM.

- Next periods of unsettled weather will be Thursday night into
  Friday and again Monday into Tuesday.&&

.DISCUSSION...
Issued at 258 AM CDT Wed Jun 26 2024

Early morning water vapor imagery captures a shortwave sliding to
the southeast from North Dakota into Minnesota. Showers have
developed ahead of this feature and can be seen moving through west
central Minnesota on KMPX imagery at this hour. The shortwave and
associated showers are forecast to drift southeast across southern
Minnesota and western Wisconsin through daybreak. We do not expect
much in the way of QPF from these showers given the sampled dry air
across the region, however hi-res guidance has displayed that the
best chance for a few hundredths of rain will be across southwestern
MN. Dry weather, sunshine, light northwest winds, and more
comfortable levels of humidity will win out for the remainder of
Wednesday, with highs in the mid 70s...enjoy!

The forecast will remain quiet for most of Thursday, with highs once
again forecast to climb into the mid 70s. A mid-level shortwave will
develop east of the Rockies during the day, in response to an upper-
level trough digging into the Pacific Northwest. The eastward
advance of the shortwave and associated warm air advection will be a
focus point for the return of precipitation chances by Thursday
afternoon across western Minnesota. Our latest forecast grids
reflect only chance PoPs (~30%) across western Minnesota until after
00z, as the initial wave of warm air advection driven precipitation
will likely struggle to hold together due dry air in place (captured
on forecast soundings). PoPs will quickly increase to the 60-80%
areawide overnight into Friday morning, as more widespread
precipitation develops in response to a strengthening low-level jet.
An initial glance at the forecast data depicts another airmass
capable of producing heavy rain due to PWATs in the 1.75"+
territory, however deeper inspection may help to quell those
concerns from a widespread perspective. As mentioned in previous
AFDs, there will likely be two focus points for heavy precip (along
the surface warm front near the US/Canada border & to the south
along the Iowa/Missouri border). The 00z guidance has captured this
idea once again, supporting the idea that a 0.25-0.5" can be
expected for most locations. The concern for locally heavier
rainfall would be tied to any convection that occurs, but that
potential appears isolated overnight due to a lack of forecast
instability. The morning batch of rainfall will likely be exiting to
the east by mid-morning, with a lull in the action expected. With
the cold front forecast to still be trailing to the west, we have
included chance PoPs (30-40%) for a showers and storms across
eastern MN/western WI through Friday afternoon/evening. The setup
for severe weather is not overly impressive following the morning
rain, but the combination of ~1000 j/kg of MLCAPE, sufficient shear,
and ample moisture will support the potential for a few stronger
storms capable of producing damaging winds and large hail. SPC has
introduced a Day 3 Marginal Risk to support this potential. The
latest LREF (Global Ensemble Suite comprised of the GEFS/EPS/CMC)
shows a 90% probability of less than 1.0" falling across south
central Minnesota and western Wisconsin, which includes any
additional rainfall from any storms that fire Friday.

Northwest winds on the backside of the departing system will bring
cooler and comfortable air for the weekend. Highs will reach the
upper 60s to low 70s on Saturday and warm a few degrees into the low
to mid 70s on Sunday. The pleasant weather will give way to our next
chance for widespread rain for the start of next week, as a deeper
trough digs into northern CONUS and spawns another round of rain and
thunderstorms. The trough is forecast to become negatively tilted
across the Upper Midwest by Monday evening, which may be the upper-
level support needed for a more pronounced severe weather threat,
though it will take a few days to better define the setup. LREF
PWAT`s climb towards to higher end of sounding climatology again,
which means that this storm system will reinforce the ongoing hydro
concerns regardless of any severe weather threat that develops. The
progressive nature of the upper-level pattern should support a quick
departure of this system and a drier trend looking towards
Independence Day.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1033 PM CDT Tue Jun 25 2024

Only larger changes to the forecast include: 1. The delayed
arrival of -SHRA to MKT by a couple of hours Wednesday morning.
2. Inclusion of a multi-hour period of MVFR cigs at AXN
Wednesday morning. Otherwise, only minor/non-impactful changes
occurred with VFR conditions expected at all other terminals.
10 knot north-northwesterly winds Wednesday afternoon will slow
to under 5 knots and become northeasterly Wednesday evening.

KMSP...Kept mention of -SHRA from 9-13Z Wednesday but impacts
should be minimal. North-northwesterly winds Wednesday afternoon
could gust to 20 knots.

/OUTLOOK FOR KMSP/
THU...VFR, MVFR/SHRA late. Wind S 5-10kts.
FRI...VFR/MVFR, chc -TSRA. Wind SE 10-15kts.
SAT...VFR. Wind NW 10-15kts.

&&

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

&&

$$

DISCUSSION...Strus
AVIATION...CTG