Tornado and Hail in Minnesota, July 11, 2020

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
407 AM CDT Sat Jul 11 2020

.SHORT TERM...(Today through Sunday)
Issued at 407 AM CDT Sat Jul 11 2020

Models continue to overestimate the amount of QPF/Pop across the
Upper Midwest early this morning. A complex of storms that
originated across South Dakota Friday evening moved southward into
Nebraska and kept better moisture advection across this region.

There still remains ample elevated instability across southern
Minnesota. However, the lack of any mid-upper level support/low
level jet, will limit any concentrated area of showers/thunderstorms
until later this morning as a stronger feature upstream across North
Dakota moves over the region.

The main feature (evident in the early morning water vapor imagery
over north central North Dakota) that will increase large scale
ascent later this morning over western Minnesota, should increase
the areal coverage of showers and thunderstorms. Most of the
convection early this morning is concentrated near the center of
circulation. However, there are isolated storms along the frontal
boundary in north central South Dakota which is the axis of
instability associated with this upper level feature.

Residual moisture from the decaying complex in Nebraska, and
southerly winds developing ahead of the North Dakota feature, should
be efficient enough to develop thunderstorms by mid morning across
west central Minnesota. Once this feature moves southeast this
afternoon, more activity will likely evolve across central/southern
Minnesota as this feature rotates southeast toward the Iowa border
by early evening. Severe weather will be concentrated across far
southern Minnesota where both ample instability and modest wind
shear will resides. The latest day 1 outlook from SPC supports a
marginal risk of severe storms across far southern Minnesota, mainly
south of the Minnesota River Valley. Once this feature exits
Minnesota, the precipitation will end with high pressure building
across the Upper Midwest on Sunday.

.LONG TERM...(Sunday night through Friday)
Issued at 407 AM CDT Sat Jul 11 2020

Next week will feature rounds of thunderstorms, some severe, and
temperatures near or slightly below normal.

A large trough over western Canada will dig southeast across the
northern Plains to the Upper Mississippi Valley Monday and Monday
night. Forcing will be decent, especially across North Dakota and
northern Minnesota as the trough becomes increasingly negatively
tilted while it swings through. Low level moisture advection will
be impressive ahead of the trough. Pwats increase to around 2
inches Monday night and a 35-40 kt low level jet will result in
decent moisture flux. A surface low over South Dakota will weaken
as it tracks east toward Minnesota. However, backed surface flow
Monday afternoon and early evening will enhance low level shear
for a time. Storms, possibly supercells, will develop Monday
afternoon over the Dakotas. All severe hazards will be possible,
including tornadoes until the low level flow veers more
southwesterly throughout Monday evening. Therefore, the best
potential for tornadoes will be where convection develops early on
(Dakotas eastward to possibly western Minnesota). These storms
should eventually grow upscale into clusters or multiple large
complexes as they advance eastward across MN and WI Monday night
due to the mid level flow. At that point, wind damage would become
the main threat. Locally heavy rainfall is also possible given the
pwats and strong forcing, especially if training occurs on the
south side of the clusters.

The cold front will slow Tuesday with the trough axis swinging
northeast back into Canada. Showers and thunderstorms will
continue along it and intensify during the afternoon across
southern MN into central WI. Some severe weather is possible but
should be more isolated than Monday night.

Models have been trending weaker and less impressive with the
ridging across the southern U.S. for the middle to latter parts of
next week. However, a belt of strong mid level westerly flow and
multiple disturbances tracking along it should bring rounds of
showers and thunderstorms. The increased cloud cover and
convective activity should keep temperatures subdued and actually
below normal at times. Periodic severe weather looks likely
across the Midwest, but much of this will depend on mid level
lapse rates, boundary layer moisture, and the character of the
waves. Such elements are not resolved well enough at this range
to get too specific and are subject to influences of prior
convection.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1022 PM CDT Fri Jul 10 2020

Confidence continues to decrease in chances for showers and
thunderstorms tonight into early Saturday morning. It does appear
that we will still have scattered showers and thunderstorms by
late morning into the afternoon. The highest chances are generally
along and south of the I-94 corridor. Winds will be northwest.

KMSP...
Still have thunderstorm chances in the late morning to afternoon
period at KMSP. Storms should move down from the northwest and
could produce some brief gusty winds. Otherwise VFR conditions
expected.

/OUTLOOK FOR KMSP/
Sun...VFR. Wind N 5 kts.
Mon...VFR. TSRA likely late. Wind SE 10 kts.
Tue...Mainly VFR. Chc SHRA/TSRA. Wind SW 5-10 kts.

&&

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

SHORT TERM...JLT
LONG TERM...Borghoff
AVIATION...JRB

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
330 AM CDT Sat Jul 11 2020

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
120830-
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-
330 AM CDT Sat Jul 11 2020

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

.DAY ONE...Today and Tonight.

Thunderstorms are likely later this morning through early evening,
especially across Minnesota. There is a Marginal Risk of severe
thunderstorms south of I-94. Large hail and damaging winds are
possible with the stronger storms.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Rounds of thunderstorms are expected through next week. Some
severe weather is possible at times. There is a Slight Risk of
severe thunderstorms Monday night west of I-35 and a Marginal Risk
east. Large hail, damaging winds, and heavy rainfall are the main
hazards, but a few tornadoes are also possible.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation may be needed this afternoon.

Borghoff