Special Weather Statement, NWS Twin Cities, MN

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
234 AM CDT Fri Aug 28 2020

.SHORT TERM...(Today through Saturday)
Issued at 234 AM CDT Fri Aug 28 2020

Focus this morning is with severe convection currently making its
way into west central Minnesota. Numerous severe wind gusts have
been observed with this activity over South Dakota overnight, and
we should see similar results for a while as it works into our
area. MUCAPE values ahead of the convection are AOA 2500 J/Kg,
although they do drop off a bit north/east of the Minnesota River
Valley. The best shear (deep layer and low-level) is north of the
best instability, but there is some overlap near the northern
portion of the linear MCS where several mesovortices have been
noted over the past hour or so. With 0-3 km shear of 30-35 kt
ahead of the north end of the MCS, things will still support the
possibility of mesovortices for a little while as things move
through west central Minnesota. Overall, expect some weakening of
the activity as it gets farther east, although that may not happen
until things are east of I-35 after 5 AM.

We could see some showers linger and/or develop into the afternoon
as forcing from the upper trough currently moving into northwest
North Dakota works through the area. Otherwise, high pressure will
build into the region tonight and Saturday, with cooler and drier
conditions expected across the area.

.LONG TERM...(Saturday night through Thursday)
Issued at 234 AM CDT Fri Aug 28 2020

Not a whole lot has changed in respect to the extended
forecast period. Sunday will be pleasant, sunny skies and
temperatures in the low/mid-70s, with increasing sky cover Sunday
evening. Model consistency remains high with a trough ejecting
eastward from the northern Rockies into the Upper Midwest. A cold
front will extend from the parent low pressure in northern Manitoba
through north central CONUS. Rain and thunderstorms will accompany
the passing boundary during the day on Monday with some remaining
across west-central WI Monday night.

After that system exits, a dry pattern sets up in part to a
northwestern flow aloft. This translates into more seasonable
temperatures through next Thursday. A few model solutions bring a
weak shortwave through Wednesday night/Thursday with low QPF over
the area. For now, no reason to adjust PoPs either way.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1100 PM CDT Thu Aug 27 2020

VFR conditions as the start of the taf period but storms have
developed out west in the Dakotas as expected and these will race
through Minnesota overnight and into Wisconsin early Friday
morning. Westerly wind gusts of greater than 40 kts are possible
with these storms. After the storms pass through, stratus and
northwest winds will develop and could linger into the afternoon,
so have delayed the transition to VFR conditions toward the
evening.

KMSP...
Storms are still on track to arrive early this morning. Winds
could easily exceed 35 kts if they hold together as expected, so
will have to watch for an AWW or severe TS warning. Northwest
winds will develop on Friday and clouds will scatter out during
the afternoon.

/OUTLOOK FOR KMSP/
SAT...VFR. Wind NW 10 kts.
SUN...VFR. Chance -TSRA/SHRA/MVFR late. Wind SSE 10G20 kts.
MON...MVFR with -TSRA/SHRA likely. Wind SSW 10 kts shifting to NW
10 kts

&&

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

SHORT TERM...
LONG TERM...BPH
AVIATION...JRB

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
739 PM CDT Thu Aug 27 2020

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
290045-
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-
739 PM CDT Thu Aug 27 2020

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

.DAY ONE...Tonight.

Confidence remains high in a line of thunderstorms moving from
west to east overnight, mainly after midnight. The primary threat
will be damaging wind, but large hail, and a tornado or two cannot
be ruled out.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Isolated thunderstorms linger on Friday, although the severe risk
is expected to have shifted southeast of the area.

Additional thunderstorms are expected Sunday night and Monday.
The threat for severe weather with these storms appears low at
this time.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will likely be needed later tonight as
the storms move in from the Dakotas.

jrb

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
346 AM CDT Fri Aug 28 2020

MNZ049-055-057>059-065-066-280930-
McLeod-Stearns-Kandiyohi-Renville-Meeker-Wright-Swift-
346 AM CDT Fri Aug 28 2020

...A LINE OF STORMS WILL AFFECT SOUTHWESTERN WRIGHT...MEEKER...
NORTHWESTERN MCLEOD...SOUTH CENTRAL STEARNS...SOUTHEASTERN SWIFT...
NORTHEASTERN RENVILLE AND KANDIYOHI COUNTIES...

At 346 AM CDT, radar indicated strong thunderstorms were located
along a line extending from near Murdock to 7 miles west of Willmar
to near Olivia. Movement was east at 60 mph.

Winds in excess of 40 mph are possible with these storms.

These storms will be near...
  Willmar around 350 AM CDT.
  Spicer and Cosmos around 400 AM CDT.
  Atwater around 405 AM CDT.
  New London and Grove City around 410 AM CDT.
  Hutchinson, Litchfield and Paynesville around 420 AM CDT.
  Watkins and Silver Lake around 425 AM CDT.
  Richmond and Kimball around 430 AM CDT.

Other locations impacted by these storms include Willmar Airport,
Blomkest, Lake Lillian, Darwin, Green Lake, Cedar Mills, Paynesville
Airport, Litchfield Airport, Kandiyohi and Strout.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4547 9455 4526 9424 4489 9414 4487 9511
      4511 9525 4515 9525 4515 9532 4530 9558
TIME...MOT...LOC 0846Z 260DEG 53KT 4527 9544 4512 9519 4486 9498

NDC