Hail and Damaging Winds in Minnesota, August 9 to 10, 2020

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
205 PM CDT Sun Aug 9 2020

.SHORT TERM...(This evening through Monday night)
Issued at 204 PM CDT Sun Aug 9 2020

Visible imagery shows clearing skies across the western and
southern portion of the area in the wake of the convectively
enhanced shortwave trough moving into northwest Wisconsin.
Convection continues to develop with that feature, but will be out
of the area before the start of the forecast period. However, the
cold frontal boundary remains to our northwest, and the mid/upper
shortwave trough helping to push that through the region won't
arrive until tonight. Widespread convection is ongoing in
association with these features, but it may have difficulty
persisting too far into our area tonight. The guidance is mixed on
how well convection will survive/develop as the system moves
through tonight. We still have plenty of elevated CAPE in place
(MUCAPE values AOA 2500 J/Kg across much of the area), but things
are capped with respect to activity that would be rooted in the
boundary layer and MLCAPE across the northwest forecast area is
AOB 1000 J/Kg. This may recover a bit, and should the activity to
the northwest grow upscale sufficiently it may not matter.
However, we're seeing some height rises in the wake of the MCV,
and we also have some low-level ridging and lack of convergence
progged ahead of the frontal boundary as it moves through the
area. Kept chance PoPs given the uncertainty, but wouldn't be
surprised if most of the activity stays to our north.

Any lingering precipitation should quickly exit the area Monday
morning, with high pressure building in from the west through the
day. Ridging will remain in place through Monday night, with
seasonably dry weather across the area.

.LONG TERM...(Tuesday through Sunday)
Issued at 204 PM CDT Sun Aug 9 2020

The upper trough over the region will shift northeast by the
middle of the week, and large scale pattern looks to evolve toward
western troughing/eastern ridging by the end of the week.
Return flow looks to setup across the region for the latter part
of the week, increasing precipitation chances for us from Thursday
into the weekend. The deterministic and ensemble guidance is in
good agreement on this overall large scale pattern, but there is
understandably still plenty of spread in the details. As a result,
we will still have chance PoPs for much of the time from Thursday
into the weekend. That being said, late Thursday and Saturday
currently look to have the best chance for widespread activity
with decent consensus on synoptic scale forcing during those
periods. Temperatures look to be a bit above normal through most
of the period.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1217 PM CDT Sun Aug 9 2020

MCV will move east-northeast across the remainder of the forecast
area through early afternoon, with SHRA/TSRA impacting the
north/east portion of the area. Ceilings will mainly be VFR, with
some brief MVFR and possible IFR with heavier convection. After
this activity we should see fairly benign conditions through the
period, except for the possibility of additional convection with
FROPA tonight. The guidance has been inconsistent on whether we'll
see much activity with the front this far south, and there has
been a trend to keep things north of us. However, did include some
mention in main the northern sites to include SHRA/TSRA
possibility during the late evening. Winds will be a bit variable
as the MCV moves through this afternoon, but should then settle
into the south or southwest until the shift west and northwest
with the FROPA tonight.

KMSP...First hour or so looks to be the main window of concern
with convection coming through the area. Could see some gusts
above 30 kt from the west during that time, with winds variable
for a bit thereafter until settling back to southerly. Possibility
and potential timing of any additional convection tonight remains
highly uncertain, so stuck fairly close to the previous forecast
and consensus of guidance that still produces SHRA/TSRA in the
area.

/OUTLOOK FOR KMSP/
Monday night...VFR. West wind less than 5 kt becoming southwest.
Tuesday...VFR. Southwest wind less than 10 kt.
Tuesday night...VFR. South wind less than 10 kt.
Wednesday...VFR. Southeast wind around 10 kt.
Wednesday night...MVFR possible late. Southeast wind 10 to 15 kt.
Thursday...MVFR possible with a chance of SHRA/TSRA. Southeast
wind 10 to 20 kt.

&&

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

SHORT TERM...
LONG TERM...
AVIATION...

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
1033 AM CDT Sun Aug 9 2020

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
101545-
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-
1033 AM CDT Sun Aug 9 2020

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

.DAY ONE...Today and Tonight.

There is a Slight Risk of severe thunderstorms today and tonight.
The primary threats are damaging winds, large hail, and heavy
rainfall.

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

Periodic thunderstorms are possible Wednesday through Saturday.
Severe storms are not expected at this time.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation may be needed today and tonight.