Special Weather Statement, NWS Twin Cities, MN

Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
728 PM CDT Thu Jul 7 2022

.SHORT TERM...(This evening through Friday night)
Issued at 159 PM CDT Thu Jul 7 2022

KEY MESSAGES:

- Scattered showers and thunderstorms will linger into tonight, with
  locally heavy downpours being the primary impact.

- Isolated showers and thunderstorms are expected Friday, mainly
  over the southern portion of the forecast area.

- Temperatures on Friday will be similar to today, but dewpoints
  will be a bit lower.

Synopsis...
Visible satellite imagery this afternoon shows plenty of
cu across the area, with the most vigorous build-ups over the
central portion of the area where a weak frontal boundary/wind shift
remains in place. We've seen some lightning with this activity, and
should see more as we move into the evening hours. MLCAPE values of
around 1000 J/Kg are in place (with MUCAPE in excess of 2000 J/Kg).
Shear is minimal, with deep layer (0-6 km) shear of 15 to 20 kt, and
low level (0-1 km) shear of 5 kt or less. Deep layer mean winds are
also light, so showers and storms are showing slow and inconsistent
movement. The activity should generally shift south over time,
mainly as a result of new development along outflow boundaries and a
slow southward sinking of the synoptic scale wind shift.

Tonight through Friday Night... Scattered showers and thunderstorms
will slowly shift south this evening, and weaken/dissipate later
tonight as instability wanes. Surface ridging will make a more
assertive push into the area on Friday, but we'll continue to have
some lingering instability across the southern portion of the area,
with dewpoint in the upper 60s. As a result, some redevelopment of
showers and thunderstorms seems like a good best across the south on
Friday. A better push of cooler/drier air from the northeast looks
to arrive Friday night, helping to scour out any lingering diurnal
convection. Convection which develops in the return flow over the
High Plains Friday afternoon/evening could bring some precipitation
back into the far west/northwest portion of the area late Friday
night, but doesn't look to deserve anything more than chance PoPs at
this point.

.LONG TERM...(Saturday through Thursday)
Issued at 159 PM CDT Thu Jul 7 2022

KEY MESSAGES:

- Severe Thunderstorms possible overnight Saturday into Sunday.

A shortwave and attendant cold front will pass through the region
sometime on Sunday, which will lead to the best chance for
thunderstorms and precipitation this week. Warm advection ahead of
the front will begin overnight Saturday and continue until the
frontal passage, meaning the return of warmer and more humid weather
on Sunday. Temperatures near 90 and dew points around 70 mean plenty
of instability will build ahead of the front, with shear values
increasing through the day as the shortwave approaches. However, the
overall severe threat will depend greatly on the timing of the front
with guidance still depicting the frontal passage spread across a 24
hour period from early Sunday morning into early Monday morning. A
faster frontal passage means the main thunderstorm threat would
mainly occur late Saturday night into Sunday morning, with a lower
threat Sunday afternoon and evening. Meanwhile, a slower passage
means the main thunderstorm threat would come late Sunday afternoon
and overnight into Monday. This scenario would bring the greatest
potential for widespread severe weather as instability and shear
values will be at their greatest Sunday evening. It’s still too
early to have an idea on the coverage of thunderstorms, and thus
rainfall amounts, but ensemble PW anomalies of 0.5-1” above normal
suggests healthy rainfall amounts wherever thunderstorms do occur.

Drier weather is expected beyond Monday and through most of the rest
of the week as high pressure moves over the region. Cooler
temperatures are expected midweek along with lower dew points as
cooler canadian air advects into the region under the high pressure.
Most guidance points to strong ridging aloft building back late in
the week, with an extended period of temperatures in the 90s looking
possible.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 728 PM CDT Thu Jul 7 2022

A large area of showers and embedded thunderstorms is ongoing across
west central and southwest MN with an arm extending east to east
central MN. This complex will evolve slowly and generally track
southeast through the evening. Locally heavy rainfall and IFR
visibilities are possible, but generally cigs will remain VFR.

KMSP...A few light showers may impact the area through much of the
night, but the heaviest activity should remain well south.

/OUTLOOK FOR KMSP/
Sat...VFR. Wind SE 5-10 kts.
Sun...VFR. Possible MVFR/TSRA. S 10-15G20 kts.
Mon...VFR. Possible MVFR/SHRA. NW 10-15 kts.

&&

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

SHORT TERM...WFO MPX
LONG TERM...ETA
AVIATION...Borghoff

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
843 PM CDT Thu Jul 7 2022

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
090145-
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-
843 PM CDT Thu Jul 7 2022

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

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

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

More chances for thunderstorms return Sunday. Some of these
storms may be severe.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.

Borghoff

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
1040 PM CDT Thu Jul 7 2022

MNC103-080645-
Nicollet-
1040 PM CDT Thu Jul 7 2022

...MINOR FLOODING EXPECTED...

Thunderstorms with heavy rain will cause minor flooding in the
following counties...

Nicollet...

* Until 145 AM CDT.

* At 1039 PM CDT, Doppler radar indicated heavy rain due to
  thunderstorms. This will cause minor flooding in the area. Two to
  four inches of rain have already fallen.

Additional rainfall of 1 to 2 inches are expected over the area.
This additional rain will result in minor flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

&&

LAT...LON 4445 9411 4439 9410 4441 9439 4445 9440

Borghoff