Flash Flooding and Hail in Minnesota, June 23 to 24, 2022

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
258 PM CDT Thu Jun 23 2022

.SHORT TERM...(This evening through Friday night)
Issued at 255 PM CDT Thu Jun 23 2022

KEY POINT;

- Severe Weather Potential Tonight and Friday/Friday Night

Two shortwaves were noted in the afternoon water vapor imagery
across the Northern Plains, and Upper Midwest. The first was moving
across central Minnesota. The second was across southern North
Dakota. This second shortwave will have more impacts of convection
developing over west central Minnesota late this afternoon/evening.
In addition, MLCAPES are highest across South Dakota and far west
central Minnesota which extended northeast across the arrowhead of
Minnesota. This is also well noted in the GOES-16 Lifted Index
derived product which highlighted the lowest LIs. This correlated
well with the instability axis from the morning convection and will
be the main focus for afternoon/evening convection redeveloping.

There remains a weak surface trough across northern Minnesota which
could be the focus for initiation this afternoon in this region.
Farther to the west, very weak CIN and ample instability will also
be the focus where the cumulus field becomes more concentrated later
today. Based on the latest cumulus field and where the current
surface trough is located, areas north and east of Brainerd,
Minnesota will likely see some activity by late afternoon. After the
storms develop, the instability line will be the most activity with
redevelopment to the west (and associated with the second shortwave).
However, outflow boundaries from the storms this afternoon will
likely build southward and may affect areas as far south as the Twin
Cities, and Redwood Falls. However, these areas have a much lower
chance of widespread activity vs. central Minnesota. Later tonight,
and into Friday morning, the best chance of convection will remain
north and west of MPX CWA. I can't rule out a few morning storms
across central Minnesota where leftover convection overnight may
reside. The best chance of widespread showers and thunderstorms will
occur late Friday night as the main surface front and upper level
support moves across the region.

As for severe potential, wind shear is marginal tonight and Friday
as the main jet stream is north of our region. However, due to ample
instability and fairly strong lapse rates, a few stronger updrafts
could support a few large hailstones or damaging winds reports. But,
this is dependent on timing of the best instability, and the upper
level support of stronger wind shear. Currently, SPC has a slight
risk of severe thunderstorms tonight and Friday/Friday night where
the best of these two ingredients occur.

.LONG TERM...(Saturday through Thursday)
Issued at 227 PM CDT Thu Jun 23 2022

KEY POINTS;

- A chance for showers and thunderstorms along the cold front pushing
  through the area Saturday afternoon. Strong storms generally not
  expected.

- Quiet weather post-front that lingers for much of next week.

Saturday into Sunday...Saturday begins with a cold front pushing
into western MN from the Dakotas, reaching west-central Minnesota by
15-18z per GFS/NAM low level theta-E. Forecast soundings show meager
instability by the time the front swings through central and eastern
Minnesota by around 21z, with around 500-1000 J/KG MLCAPE and weak
but sufficient low level shear. We could get a few storms to pop
along the boundary that could produce transient low-end severe
weather, however widespread and significant severe weather is not
expected. The front will continue into western Wisconsin by the
evening, with scattered showers and weak storms continuing as it
pushes out of the region. Temperatures will cool behind the departing
front with overnight lows in the upper 50s to low 60s.

Sunday through Thursday...Sunday will remain cool behind the
departing front with highs in the 70s, with a return to 80s during
the week. Broad high pressure enters the plains on Monday and lingers
through most of Tuesday, resulting in plenty of sunshine, light
winds, and comfortable temperatures, so outdoor plans during the
first few days of the week are looking like a great idea! High
pressure begins to wane by the end of Tuesday, with subtle shift in
the upper level pattern that will introduce small chances for showers
by Wednesday. For now, the longer range deterministic models are not
too enthusiastic about widespread or strong precipitation, however
there is the potential for some shortwave activity on Wednesday and
Thursday which could produce some marginally more active weather. Our
coverage area still remains on the southern edge of the a jet streak
north of the US border, which will keep our forcing from becoming
all that strong. Expect to see a bit more in the way of coverage and
timing as we head into next week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1250 PM CDT Thu Jun 23 2022

Biggest forecast issue is timing and extent of thunderstorm
development over northern and central Minnesota this evening. Thinking
any development will be along instability axis roughly BRD-DLH area
aft 22z with further development west towards AXN and STC along the
north edge of LLJ later in the evening. A few models develop an
strong outflow from these storms which would push development further
south so trends will need to be monitored for an increased chance at
MSP and RWF after 06z - but low confidence in that occurrence at
this time.

KMSP...VFR conditions thru the period with increasing high cloudiness
on Friday. Not much change in S wind direction with diurnal weakening
towards sundown and increase Friday a.m. Conditions will be
monitored for any possible movement and development of thunderstorms
ahead of an outflow late tonight - but again, low confidence of any
encounter at the field.

/OUTLOOK FOR KMSP/
Fri...VFR. Chc TS/MVFR late. Wind S 10-15 kts.
Sat...Chc SHRA/MVFR early, then VFR. Wind WNW 10-15 kts.
Sun...VFR. Wind NW 15G25kts.

&&

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

SHORT TERM...JLT
LONG TERM...TH
AVIATION...WFO MPX

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
238 PM CDT Thu Jun 23 2022

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
241945-
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-
238 PM CDT Thu Jun 23 2022

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

.DAY ONE...Tonight.

There is a Slight Risk of severe thunderstorms (level 2 of 5)
across central Minnesota. Thunderstorms may develop this evening
and could contain large hail and damaging winds.

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

Scattered thunderstorms can be expected Friday afternoon through
Saturday. There is a Slight Risk of severe weather in western
Minnesota (level 2 of 5) with a Marginal Risk of severe weather
in eastern Minnesota through western Wisconsin (level 1 of 5)
Friday into Friday night. A few of the storms could be severe
with large hail and damaging winds.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation may be needed tonight across central
Minnesota.

Borghoff

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
520 PM CDT Thu Jun 23 2022

MNZ043-232245-
Morrison MN-
520 PM CDT Thu Jun 23 2022

...A strong thunderstorm will impact portions of northwestern
Morrison County through 545 PM CDT...

At 519 PM CDT, Doppler radar was tracking a strong thunderstorm 8
miles north of Randall, or 18 miles northwest of Little Falls, moving
east at 25 mph.

HAZARD...Winds in excess of 40 mph and nickel 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 storm will remain over mainly rural areas of northwestern
Morrison County, including the following locations... Cushing and
Crow Wing State Park.

This includes U.S. Highway 10 in Minnesota between mile markers 127
and 134.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4630 9436 4627 9434 4623 9440 4618 9437
      4616 9438 4616 9417 4611 9415 4609 9461
      4631 9463 4632 9458 4631 9451 4633 9444
TIME...MOT...LOC 2219Z 249DEG 21KT 4621 9455

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

JRB