996
FXUS63 KMPX 150826
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
326 AM CDT Sun Jun 15 2025

.KEY MESSAGES...

- Scattered thunderstorms late this afternoon and evening across
  southern Minnesota.

- Enhanced Risk for severe thunderstorms across much of the
  area Mon day afternoon & evening. Tornadoes, large hail, and
  damaging wind are all possible.

- Active pattern continues through the week with a return to
  above- normal temperatures for the weekend.

&&

.DISCUSSION...
Issued at 216 AM CDT Sun Jun 15 2025

Two regions of precipitation are ongoing overnight across the
far-southern portion of Minnesota, lingering showers across
southeast Minnesota from this evening`s convection and a
cluster of elevated thunderstorms across southwest Minnesota.
This trend will continue through the day with mostly dry
conditions looking likely across east-central Minnesota &
western Wisconsin through the day, while another round of
showers and thunderstorms develops this afternoon and evening
across southern Minnesota. These storms will be generated by the
remnant MCV from a decaying cluster of storms across southern
SD, with MUCAPE values around 1000 J/kg by afternoon across
south-central & southeastern Minnesota but only paltry values
of deep shear. The threat for any severe weather looks to be
limited to eastern SD & northwest IA, but the strongest storms
could contain small hail & brief heavy downpours. Temperatures
will be warmer today some breaks in the cloud cover this
afternoon allowing most areas to warm into the 70s. Dew points
will also become notably muggier, as low-level southeasterly
flow raises dew points into the mid to upper 60s by this
evening.

Monday continues to look like the day with the greatest
potential for severe weather, as continued warm advection
overnight & through the day leads to a much warmer & humid
environment over the southern half of Minnesota and to a
lesser-extent, over western Wisconsin. Assuming we stay
relatively clear of morning precipitation and cloud cover
during the day, temperatures should be able to warm well into
the 80s during the afternoon, along with our muggiest air of the
season so far with dewpoints around 70. This juicy low-level
environment along with very steep mid-level lapse rates possibly
in excess of 8 C/km has the potential to generate MLCAPE values
of 2000-3000 J/kg, along with strengthening deep shear as a
shortwave moves over the area.

However, confidence is still quite low on the timing of this
shortwave along with the location of a surface cold front, which
ultimately will decide when, where, & how strong thunderstorms
can develop. If the shortwave moves through during the morning
and/or overnight convection from the Dakotas remains ongoing (as
a few solutions depict), then the environment will likely be
unable to destabilize enough by afternoon to realize the full
potential for severe weather during the afternoon and evening.
Despite that possible outcome, the general model consensus as
of this evening does suggest that any morning precipitation
should be waning as it moves through our area & thunderstorms
still able to initiate by the early evening, but we will have to
monitor these trends closely into Monday morning. Assuming the
atmosphere cooperates & the current consensus on an
afternoon/evening timing occurs, initially discrete
thunderstorms will likely initiate across western Minnesota
during the late afternoon along a surface cold front. These
initial storms have the potential to become supercellular given
the very unstable environment and deep shear values increasing
to 40-50 kts. All modes of severe weather are possible should
these supercells develop, primarily very large hail and damaging
wind gusts but also the chance for a few tornadoes. Convection-
allowing model trends suggest that these initial supercells
will congeal into bowing line segments after a few hours,
leading to more of a damaging wind threat later into the
evening over eastern Minnesota and western Wisconsin. Heavy
rainfall will also accompany these storms with precipitable
water values near 2", but the fact that they should be
progressing vs training should keep the rainfall rates over 1-2"
per hour from sitting over any one location for more than an
hour or so, mitigating the potential flash flooding threat.

The pattern remains active over the Upper Midwest through the
rest of the week, but we may see a break in the thunderstorms
midweek as the jet stream dips more southerly over the mid-
Mississippi valley. Multiple rounds of showers and thunderstorms
are still likely with this pattern, but models are showing a
trend towards the bulk of this activity mainly staying just
south of the area. A shortwave Tuesday night morning will
generate widespread thunderstorms and probably the best chance
for heavy rain & flooding this week, but most guidance keeps
this activity over Iowa with maybe the northern fringes of this
activity leading to some thunderstorms over far- southern
Minnesota. Otherwise, Wednesday & Thursday look notably drier
over our area aided by building ridging over the central plains.
This ridging will lead to much warmer temperatures by Friday &
especially over the weekend, with temperatures potentially
nearing 90 along with summer-like humidity. The building ridging
will also place the upper midwest under a potentially active
:ring of fire" pattern, where a number of shortwaves ride along
the northern periphery of the ridge. Pick a model & you`ll find
any number of potential heavy rain and severe thunderstorm
events, but models notoriously struggle with depicting these
shortwaves at this timescale. Confidence is high towards above-
normal temperatures and at least the potential for anther round
or two of thunderstorms, but low on where and when any of these
systems may develop.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1217 AM CDT Sun Jun 15 2025

Cigs will continue to lower to IFR (and even LIFR at RWF) this
evening as moisture increases from the south. Reduced
visibilities are also expected with southern MN and west-central
WI likely seeing 2-3sm with fog. Visibilities should improve
after 12Z while cigs will slowly rise to MVFR by Sunday
afternoon as daytime heating occurs. Have only kept PROB30s for
-TSRA at RWF and MKT as these terminals seem the most likely to
 have afternoon showers and storms due to their location to
 nearby synoptic lift. Forecast predictability really decreases
 Sunday evening of if cigs go to VFR, MVFR, or even IFR. Have
 opted to play it safe with most terminals staying MVFR thru the
 period. East-northeasterly winds under 5 knots tonight will
 become southeasterly and increase to 5-10 knots during the day
 Sunday. Winds will slow under 5 knots Sunday evening.

KMSP...Conditions should fall to IFR early this morning as cigs
drop below 1000 feet. Expect an improvement to MVFR by noon with
further improvements to near VFR by late afternoon. Kept a
PROB30 for -TSRA during Sunday night as that looks like the best
chance for convection.

/OUTLOOK FOR KMSP/
MON...VFR/MVFR chc IFR/-TSRA. Wind S 5-10kts.
TUE...VFR/MVFR chc IFR/-TSRA. Wind W 5-10kts.
WED...MVFR/-SHRA chc IFR/-TSRA. Wind N 5-10kts.

&&

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

&&

$$

DISCUSSION...ETA
AVIATION...CTG