Heat Advisory 1, NWS Twin Cities, MN

Blue Earth County, MN, Brown County, MN, Chisago County, MN, Faribault County, MN, Freeborn County, MN, Goodhue County, MN, Isanti County, MN, Kanabec County, MN, Le Sueur County, MN, Martin County, MN, McLeod County, MN, Nicollet County, MN, Redwood County, MN, Rice County, MN, Sherburne County, MN, Sibley County, MN, Steele County, MN, Waseca County, MN, Watonwan County, MN, Wright County, MN, Yellow Medicine County, MN, Barron County, WI, Chippewa County, WI, Dunn County, WI, Eau Claire County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Rusk County, WI, Saint Croix County, WI

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1106 PM CDT Sun Jun 12 2022

.UPDATE...
Issued at 1056 PM CDT Sun Jun 12 2022

Updated for 06Z aviation discussion below.

&&

.DISCUSSION...(This evening through Sunday)
Issued at 242 PM CDT Sun Jun 12 2022

KEY MESSAGES:

- Sneaky severe weather possible if storms manage to develop in
  central/eastern MN this afternoon/evening.

- Confidence increasing on risk for severe thunderstorms overnight
  for parts of the region, but uncertainty remains in exact location.

- High temperatures Monday are highly dependent on the evolution of
  storms tonight. It could be much warmer across southern MN if the
  warm front can begin lifting north sooner.

- Heat remains on track for Tuesday with heat indices near 100 across
  eastern MN and WI.

- A cooldown mid to late week could be followed by a heat wave later
  next weekend.

Today...A narrow ribbon of severe weather potential exists across
central and eastern Minnesota. Morning clouds have allowed surface
winds to be out of the southeast ahead of a weak boundary, Meanwhile
clearing along the boundary has supported nearly 3000 J/kg of SBCAPE.
In addition, deep layer shear owing to a strong upper level northwest
jet is on the order of 40 to 50 kts. If storms manage to develop
across central Minnesota, a few could become supercellular and
produce severe weather later this afternoon and into the evening. The
main threat would be large hail, but damaging wind and even a tornado
or two is possible given the large curvature in the near-boundary
hodographs.

Tonight into Monday...Confidence remains fairly high that a complex
of severe thunderstorms will come out of the Dakotas overnight and
move into western Minnesota, and possibly eastern Wisconsin by Monday
morning. The instability is the primary concern as forecast soundings
along the CAPE gradient show a fat CAPE profile, which as mentioned
in the previous discussion should lead to a sufficient cold pool
developing. The SPC outlooks have a tough time conveying the
potential across the Twin Cities area because the storms will be
coming through right around 12Z, plus there is uncertainty in the
location. So those two variables led to the marginal risk, but the
potential certainly exists for a severe MCS to be on the metro's
doorstep by sunrise.

This complex of storms will keep the main warm front to the south,
and areas along it should see highs in the 90s, while areas to the
north remain cool and possibly overcast. That makes the temperature
forecast for Monday more of a challenge, and a lot will depend on how
the convection unfolds overnight.

Tuesday through Sunday...Temperatures for Tuesday still look hot,
especially along the I-35 corridor. Mid to upper 90s are realistic,
with the potential for heat indices near 100 degrees. Southerly winds
will increase as well on Tuesday.

On Wednesday a cold front will move through the region, and
showers/thunderstorms will develop along it as an upper level wave
lifts through the region. Instability is limited, and so is the
severe threat. Looking ahead. Thursday will have breezy westerly
winds, so lowered the humidity across the region. Temperatures will
start to rebound on Friday, with 90s appearing likely again over the
weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1056 PM CDT Sun Jun 12 2022

The main question continues to revolve around storms this morning
followed by the development of MVFR cigs. At this point, storms look
likely across portions of central and southern MN into WI, though
slightly further south of previous forecast. It does not look like a
solid line across the entire area. There are still too many
uncertainties and some areas may barely have any thunder, while other
areas could get severe impacts. High-res models have trended more
aggressive with convection entering the area after 09z and making
toward KMSP by 12z. I've tried to time -TSRA arrival with tempo
groups, but again timing is still uncertain.

KMSP...
Although there is not much clarity on where storms will be strongest
as they move through central/southern MN, there does appear to be a
delay of a couple hours. Thus have indicated 12z-15z for now, but it
is possible that could change a little depending on storm motion.
Storms would likely last up to two hours at the airfield. If storms
do occur, MVFR ceilings should develop during and in the wake of the
storms.

/OUTLOOK FOR KMSP/
Tue...VFR. Chc MVFR/SHRA/TSRA late. Wind S/SW 10-15g25 kts.
Wed...VFR. Chc MVFR/SHRA. Wind W 5-10 kts.
Thu...VFR. Wind W 15G25 kts.

&&

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

DISCUSSION...JRB
AVIATION...BPH

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
125 PM CDT Sun Jun 12 2022

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
131830-
Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns-
Benton-Sherburne-Isanti-Chisago-Lac Qui Parle-Swift-Chippewa-
Kandiyohi-Meeker-Wright-Hennepin-Anoka-Ramsey-Washington-
Yellow Medicine-Renville-McLeod-Sibley-Carver-Scott-Dakota-
Redwood-Brown-Nicollet-Le Sueur-Rice-Goodhue-Watonwan-Blue Earth-
Waseca-Steele-Martin-Faribault-Freeborn-Polk-Barron-Rusk-
St. Croix-Pierce-Dunn-Pepin-Eau Claire-
125 PM CDT Sun Jun 12 2022

This Hazardous Weather Outlook is for portions of central and
southern Minnesota, and west central Wisconsin.

.DAY ONE...This Afternoon and Tonight.

There is a chance of thunderstorms this afternoon/evening. A few
storms could produce large hail, damaging wind, or a tornado
mainly in central Minnesota.

Better chances for thunderstorms arrive after midnight. Damaging
winds, large hail, and heavy rainfall are possible with some of
the storms.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Hot and humid air will arrive Tuesday. Heat indices near 100
degrees are expected across southern and eastern Minnesota into
Wisconsin.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation may be needed.

jrb