Hail and Damaging Wind in Wisconsin, July 6, 2017

Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
651 PM CDT Thu Jul 6 2017

.SHORT TERM...(This evening through Friday)
Issued at 315 PM CDT Thu Jul 6 2017

No significant changes to the previous forecast. There is still a
narrow window for convection later this afternoon and early this
evening ahead of a passing cold front. This frontal boundary will
usher in noticeably cooler and drier air across the Upper Midwest
with high temperatures about 10 degrees cooler tomorrow than they
were today, and dewpoints in the mid 50s, as opposed to upper 60s.
Expect northerly winds around 10 to 20 mph, with a few afternoon
showers or thunderstorms mainly east of I-35 and north of I-94.

Early afternoon preliminary 1-minute visible satellite imagery
together with surface obs identified the frontal boundary across
Minnesota moving southeast. Locations behind the boundary were in
the upper 70s with dewpoints in the 50s, while areas ahead of the
boundary were in the upper 80s to near 90 with dewpoints near 70.
This warm moist air mass together with mid-level lapse rates of 7 to
7.5 C/km led to around 2000 J/kg of MLCAPE along and ahead of the
frontal boundary. The limiting factor from producing widespread
convection along this frontal boundary was the lack of low level
convergence, and this will continue to be the limiting factor this
evening.

HiRes models do try to generate a few showers and thunderstorms
across eastern MN and western WI later this afternoon. Given the
location of the surface boundary, do think there is indeed a chance
of seeing a few storms develop around 5-6pm, and these storms could
be strong to severe given the aforementioned CAPE parameters and
deep layer shear values around 40 kts. The main threat would be
large hail and damaging wind.

Precip will exit the area later this evening, but a potent little
shortwave will bring a few showers across the arrowhead of MN, and
northern WI. Forecast soundings show a thin sliver of instability,
so included the thunder mention as well.  High temperatures will be
around 80, which is near the seasonal average for early July.

.LONG TERM...(Friday night through Thursday)
Issued at 315 PM CDT Thu Jul 6 2017

The longer term concerns are the increasing threat of
thunderstorms later Sunday into Monday and overall expected
warming trend into next week.

Initially we should see drier conditions across the area with
overall high pressure in control through most of Sunday.
Following this models trend a short wave lifting across the
western CONUS ridge into the CWA either Sunday night or Monday
night depending on the deterministic model of choice. The ECMWF is
the slower model at this point. In either event, this system has
the potential of severe weather along with heavy rainfall with an
MCS becoming more likely. PW's increase to near 2 inches by Monday
and with organized convection expected we should see a good
chance of widespread heavier rain.

The western CONUS ridge builds east during the week, and this
should help promote warmer conditions as the week wears on. We are
probably not warm enough at the moment. If the models continue
this trend we will likely see some 90's creep back into the much
of the Minnesota area later in the week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 651 PM CDT Thu Jul 6 2017

Storms should remain east of most of the TAF sites, with EAU
having the best chance of being impacted through 02Z. Otherwise,
mostly clear skies and no aviation concerns are expected through
the period.

KMSP...Storms are expected to remain east of MSP through the
evening.

/OUTLOOK FOR KMSP/
Sat...VFR. Wind W at 5 kts.
Sun...VFR. Chc TSRA. Wind S 5 kts.
Mon...VFR. Chc TSRA Early. Wind E-ESE 5-10 kts.

&&

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

SHORT TERM...JRB
LONG TERM...DWE
AVIATION...BORGHOFF

Hazardous Weather Outlook...UPDATED
National Weather Service Twin Cities/Chanhassen MN
729 PM CDT Thu Jul 6 2017

MNZ041>045-047>070-073>077-082>085-091>093-080030-
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-Watonwan-Blue Earth-Waseca-
Steele-Martin-Faribault-Freeborn-
729 PM CDT Thu Jul 6 2017

This Hazardous Weather Outlook is for portions of central
Minnesota...east central Minnesota...south central Minnesota...
southwest Minnesota and west central Minnesota.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

There is a chance of thunderstorms from Sunday through Wednesday,
with the best chance Sunday night. The risk of organized severe
thunderstorms is low at this time.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.

MNZ078-WIZ014>016-023>028-080030-
Goodhue-Polk-Barron-Rusk-St. Croix-Pierce-Dunn-Pepin-Chippewa-
Eau Claire-
729 PM CDT Thu Jul 6 2017

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

.DAY ONE...Tonight

Isolated strong or severe thunderstorms are possible this
evening. Large hail and gusty winds are the main threats.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

There is a chance of thunderstorms from Sunday through Wednesday,
with the best chance Sunday night. The risk of organized severe
thunderstorms is low at this time.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation may be needed this evening.

Borghoff