Special Weather Statement, NWS Twin Cities, MN

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
345 PM CDT Fri Jul 28 2023

.DISCUSSION...(This evening through Friday)
Issued at 339 PM CDT Fri Jul 28 2023

KEY MESSAGES:

- Scattered showers and thunderstorms possible in southern Minnesota
  through this evening. A few severe storms are possible.

- Quiet pattern sets up starting this weekend, with cooler
  temperatures and no significant chances for precipitation through
  the middle of next week.

Still a rather highly uncertain setup for this afternoon's convection
with multiple but weak ingredients at play that could still produce a
few strong/severe thunderstorms over southern MN. KMPX radar this
afternoon shows a few showers and thunderstorms north of the US212
corridor in MN. These storms are running through an environment that
is rather moist in the lower levels (evidenced by dewpoints around 70
degrees) but with still an appreciable dry layer up through the mid-
levels. There is a jet exit region punching from NW MN into central
MN, in the vicinity of a southeastward moving cold front. There is
also a secondary front sitting over northern IA which will be the
better focusing mechanism for more robust thunderstorm development
through the rest of this afternoon and evening. Thus, while the
coverage will be rather meager and many areas will see little/no
rain within the WFO MPX coverage area, there is still the thinking
that any storms that do develop through this evening may so do in
clusters that could develop fairly quickly and rise to the level of
being strong-severe. With regards to the SWODY1, the latest update
has nudged the Marginal Risk portion over eastern portions of our
area farther north just into the WFO DLH area, thus now encompassing
the entire Twin Cities metro. No changes were made to the Slight Risk
area over southern MN. The primary hazards for any strong-severe
thunderstorms thru this evening will be large hail (owing to steep
lapse rates) and damaging wind gusts (with 40-50kt midlevel winds),
but the biggest mitigating factor will be the expected poor coverage
of storms, especially as they traverse eastward.

Once we get to midnight, any and all storms should be to the east of
the WFO MPX coverage area and have dissipated, with the cold frontal
passage not far behind. The frontal passage will allow for much drier
air and slightly cooler air to slide into the Upper Midwest for the
weekend into early next week. This will make for a very comfortable
summer weekend across MN/WI as highs in the upper 80s to near 90 with
dewpoints around 70 dropping to highs in the upper 70s to lower 80s
and dewpoints in the 50s both Saturday and Sunday.

Continuing into next week, high pressure at the surface along with
rather benign northwest flow aloft will be the prevailing features
which will drive a mainly dry forecast across our coverage area. The
few and far between rain chances will not amount to much, thus no
improvements to the drought conditions are anticipated. There does
look to be a cold frontal passage Wednesday into Thursday, as
temperatures warm through Wednesday (potentially reaching the lower
90s) then drop back for the end of the week. Blended model guidance
also has a few periods of slight chance PoPs in that Wednesday-
Thursday timeframe, but overall guidance is not impressed with the
prospects for appreciable precipitation.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1240 PM CDT Fri Jul 28 2023

Able to start out all TAF sites as VFR for the 28/18z TAFs but the
question again is where/when will convection develop later this
afternoon evening. Still plenty of low-level moisture available along
with an approaching cold front from the NW. However, multiple runs of
CAMs still show widely varying solutions of the development of TSRA
this afternoon-evening. Aside from scattered -SHRA at the start near
AXN, confidence is too low to include SHRA/TSRA at any of the TAF
sites for later this afternoon-evening. The best placement of
convection looks to be near KMKT-KMSP-KRNH-KEAU, so have at least
steered those TAFs in that direction by adding in a mid-level deck
(likely cumulus clouds) along with an upper level ceiling. The timing
of that window generally coincides of when convection could occur, so
that should at least make for relatively simple AMDs should that come
to fruition.

KMSP...Have kept the TAF dry at this time due to low confidence in
the placement of any isolated/scattered TSRA development later this
afternoon-evening. That said, the best timing of any development
impacting MSP looks to be in the 23z-04z window later today, hence
the addition of the mid-level clouds and the upper level ceiling.
Once reaching midnight, tranquil conditions are expected thereafter
through tomorrow and the rest of the weekend.

/OUTLOOK FOR KMSP/
Sun...VFR. Wind N 10-15 kts.
Mon...VFR. Wind SE 5-10 kts.
Tue...VFR. Wind S 5-10 kts.

&&

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

DISCUSSION...JPC
AVIATION...JPC

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
459 PM CDT Fri Jul 28 2023

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
291400-
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-
459 PM CDT Fri Jul 28 2023

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

.DAY ONE...Tonight.

Thunderstorms will be likely through this evening mainly in
eastern and southern Minnesota into western Wisconsin. A few
storms could be strong to severe, mainly along and south of a line
from Redwood Falls MN to the southern Twin Cities metro to Eau
Claire WI. The main hazards are large hail and damaging winds,
though a tornado cannot be ruled out, especially near the Iowa
border.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will likely be needed through this
evening in east central through southeastern Minnesota into
western Wisconsin.

Preliminary Local Storm Report
National Weather Service Twin Cities/Chanhassen MN
533 PM CDT Fri Jul 28 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0444 PM     Tstm Wnd Dmg     3 SW Eagan              44.82N 93.20W
07/28/2023                   Dakota             MN   Trained Spotter

            Multiple trees uprooted along Ballantrae Rd.
            Report from Twitter with photos.

&&

BPH

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
540 PM CDT Fri Jul 28 2023

WIZ015-027-282330-
Chippewa WI-Barron WI-
540 PM CDT Fri Jul 28 2023

...A strong thunderstorm will impact portions of northwestern
Chippewa and southeastern Barron Counties through 630 PM CDT...

At 540 PM CDT, Doppler radar was tracking a strong thunderstorm over
New Auburn, or 20 miles southeast of Rice Lake, moving east at 20
mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This strong thunderstorm will be near...
  Bloomer around 550 PM CDT.

This includes U.S. Highway 53 between mile markers 112 and 123.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
northwestern and west central Wisconsin.

&&

LAT...LON 4504 9133 4517 9167 4521 9167 4530 9159
      4526 9117
TIME...MOT...LOC 2240Z 291DEG 19KT 4523 9153

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

CTG

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
602 PM CDT Fri Jul 28 2023

WIZ023-025-282345-
St. Croix WI-Dunn WI-
602 PM CDT Fri Jul 28 2023

...A strong thunderstorm will impact portions of central Dunn and
southeastern St. Croix Counties through 645 PM CDT...

At 602 PM CDT, Doppler radar was tracking a strong thunderstorm near
Knapp, or 9 miles west of Menomonie, moving east at 35 mph.

HAZARD...Winds in excess of 30 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This strong thunderstorm will be near...
  Menomonie around 615 PM CDT.

Other locations in the path of this storm include Elk Mound.

This includes Interstate 94 in Wisconsin between mile markers 27 and
56.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
west central Wisconsin.

&&

LAT...LON 4471 9168 4481 9214 4485 9215 4486 9226
      4504 9219 4505 9165 4488 9165
TIME...MOT...LOC 2302Z 280DEG 28KT 4491 9210

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...30 MPH

CTG

Preliminary Local Storm Report
National Weather Service Twin Cities/Chanhassen MN
615 PM CDT Fri Jul 28 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0611 PM     Hail             3 NE Bloomer            45.13N 91.45W
07/28/2023  M1.75 inch       Chippewa           WI   Trained Spotter

&&

tdk

Preliminary Local Storm Report
National Weather Service Twin Cities/Chanhassen MN
632 PM CDT Fri Jul 28 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0612 PM     Hail             3 NE Bloomer            45.13N 91.45W
07/28/2023  M3.00 inch       Chippewa           WI   Trained Spotter

            Spiky hail. Most hail stones were 2 in
            diameter but the largest was 3 in from spike
            to spike.

&&

BPH

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
637 PM CDT Fri Jul 28 2023

WIZ025>028-290100-
Chippewa WI-Dunn WI-Eau Claire WI-Pepin WI-
637 PM CDT Fri Jul 28 2023

...A strong thunderstorm will impact portions of northeastern Pepin,
eastern Dunn, Chippewa and Eau Claire Counties through 800 PM CDT...

At 637 PM CDT, Doppler radar was tracking a strong thunderstorm 7
miles south of Altoona, or 9 miles south of Eau Claire, moving east
at 30 mph.

HAZARD...Winds in excess of 30 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
  Fall Creek and Augusta.

This includes the following highways...
 Interstate 94 in Wisconsin between mile markers 48 and 86.
 U.S. Highway 53 between mile markers 86 and 119.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
northwestern and west central Wisconsin.

&&

LAT...LON 4460 9183 4521 9181 4521 9155 4529 9153
      4529 9093 4460 9093
TIME...MOT...LOC 2337Z 265DEG 26KT 4469 9147

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...30 MPH

CTG