Tornado and Hail in Minnesota, June 11, 2017

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
430 AM CDT Sun Jun 11 2017

.SHORT TERM...(Today and tonight)
Issued at 430 AM CDT Sun Jun 11 2017

Long advertised severe weather was developing this morning on
schedule, maybe even an hour or so early compared to high-res models
from earlier tonight. Individual storms in central and east central
South Dakota do seem to be evolving into a wind complex, with an
eastward extension of new storms into southwest MN along a zone of
warm advection. Some of these will likely produce large hail in
southwest MN and eventually central and south central MN, prior to
the arrival of the developing bow and possible comma head.

High-res models do take the complex slightly farther north than
before, and have edged the higher pops a wee bit northward. Timing
of storms suggests they'll be into Wisconsin before Noon, so current
Severe Thunderstorm watch will likely be extended eastward by 7 am.
Damaging wind will continue to be the main threat, though some large
hail will also occur.

Main question is what happens to the atmosphere in the wake of the
morning storms. It will certainly take much of the day for that area
over which the storms traverse this morning. Models do disagree on
extent of redevelopment. The RAP seems to be the most bullish,
bringing storms southeastward from northern MN and then developing
more storms from southwest MN into east central MN, as low level
lapse rates recover. This seems overdone as the morning storms are
rather hefty and should stabilize the airmass pretty well. But with
so much precipitable water just to the south and southwest in an
area unaffected by storms, and another sort wave, it may be possible
for redevelopment late afternoon. So it's not automatic that the
morning activity will quash late afternoon storms.  Having said
that, the one area that seems most likely to see development mid-
late afternoon will be a little south of the metro into Wisconsin.
This will be an area that may not be worked over too much this
morning, and the low level jet does look to persist through the day
and shift eastward toward southeast MN by late afternoon. Warm front
will also be in the area, so any storms that do develop will have a
favorable environment for a tornado or two. The SPC tornado graphic
looks on target.

After storms exit this evening, some showers will still linger from
southern MN into WI.

.LONG TERM...(Monday through Saturday)
Issued at 430 AM CDT Sun Jun 11 2017

Hot and humid air remain in place as southwest mid level flow
persists ahead of the closed low to the west. The quasi-
stationary boundary lifts north from IA as a warm front on Monday
into Tuesday, and then the associated cold front passes across
the area on Wednesday. Periods of showers and thunderstorms
(possibly strong-severe) are possible as these transitions occur.

The threat for severe storms appears the highest on Tuesday as the
mid-level low ejects out of the Intermountain west and interacts
with the boundary. Temperatures will climb into the 90s south of
the front (generally along & south of I-94). With dewpoints well
into the upper 60s, heat indices in the 95 to 100 degree range
appear possible. Thankfully, breezy southerly winds will lessen
how hot it feels slightly.

Precipitable water values will be in the 2+ inch range again on
Tuesday, which illustrates we will still have plenty of boundary
layer moisture in place. With decent deep layer shear and
increasing low level shear, supercells will be possible, with all
types of severe weather threats including tornadoes. Heavy
rainfall will be a given with stronger/organized storms.

In the wake of the system temperatures return back closer to (but
still around 5 degrees above) seasonal normals. Dewpoints lower
into the 50s which will provide some relief from the recent humid
conditions.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1114 PM CDT Sat Jun 10 2017

VFR conditions are expected through tonight. Storms will fire
along the stalled front across southern MN late tonight and lift
north with the warm front around daybreak. Meanwhile, a severe
line of storms near the SD/MN border around 12Z (currently
developing over the Black Hills) will race eastward across
central/southern MN during the morning and into western WI by
early afternoon. Widespread damaging winds are possible.
Additional storms may develop a few hours after the passage of the
early round as the atmosphere becomes unstable again. MVFR cigs
are likely north of where the warm front ultimately sets up
following the morning activity.

KMSP...Storm chance appears to increase after 12Z as the warm
front approaches from the south. These cells should be scattered.
The main round with winds possibly exceeding 45 kt will arrive
around 15Z per many hi-res models.

/OUTLOOK FOR KMSP/
Mon...VFR/MVFR with TSRA possible. Wind SE at 10kt.
Tue...VFR/MVFR with TSRA likely late. WInd S at 10-15kt.
Wed...VFR/MVFR with TSRA possible. Wind SE 5-10kt becoming SW.

&&

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

SHORT TERM...TDK
LONG TERM...LS
AVIATION...BORGHOFF

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
424 AM CDT Sun Jun 11 2017

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
120930-
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-
424 AM CDT Sun Jun 11 2017

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

.DAY ONE...Today and Tonight

A line of severe thunderstorms over South Dakota will quickly
race eastward across the area this morning into early afternoon.
Widespread damaging winds and large hail are possible. Heavy
rainfall could lead to ponding of water on roads, especially in
urban areas. Redevelopment of thunderstorms is also possible this
afternoon. A few of the afternoon storms may also be severe with
damaging winds, large hail, and heavy rainfall.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Chances for thunderstorms continue Monday into Wednesday with the
severe weather looking the most possible on Tuesday afternoon and
Tuesday night. Peak heat indices in the mid to upper 90s are also
expected on Tuesday.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will likely be needed this morning, and
possibly again during the afternoon.