Special Weather Statement, NWS Twin Cities, MN

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1232 PM CDT Tue Aug 7 2018

.SHORT TERM...(Today and tonight)
Issued at 408 AM CDT Tue Aug 7 2018

Fog has developed again this morning across much of Central MN and
Western WI as there is rich low-level moisture in place below a
subsidence inversion. Cloud cover from an area of thunderstorms that
have progressed eastward into Southwestern MN has prevented fog from
developing across Western MN.

Instability continues to decrease this morning, and without a low-
level jet, storms will continue to weaken. Convection will likely
initiate again once there is sufficient destabilization. The cloud
cover from the morning convection will limit the amount of
instability, but both the mean HREF and GFS indicate near 1000 J/Kg
by 18Z across Southern MN and Western WI. By that time, the mid-
level trough axis is expected to be located from East Central MN to
South Central MN. Thus, the best chances for thunderstorm
development will be across Southeastern MN and West Central WI. The
HRRR and HopWRF members are in agreement of this general area of
thunderstorm development. Bulk shear and mid level lapse rates will
be low -- 10-15 kts and 6-7 degrees C/km, respectively. Thus,
organized thunderstorm activity is not expected Tuesday. Storms are
anticipated to weaken shortly after sundown due to loss of daytime
heating and the trough forcing to the east.

.LONG TERM...(Wednesday through Monday)
Issued at 408 AM CDT Tue Aug 7 2018

The polar jet to our north will remain active this week, with
occasional short waves moving across Canada, dropping southeast
over the western Great Lakes, and helping to maintain the broad
eastern trough. Thus, MN and WI will be in upper northwest flow
through the rest of this week, with occasional short waves
bringing low precipitation chances to eastern MN and western WI.
Meanwhile, the western ridge will move east, and a detached upper
low off the Washington coast will get picked up by a trough moving
across southern Alaska later this week. Sometimes a western upper
low or trough is moved onshore too quickly, but in this case,
models are in decent agreement that it will move onshore. So it
appears that the western ridge will move into our area this
weekend and take on a southwest to northeast orientation. But as
this next trough continues to move east, the ridge looks like it
will be suppressed on Monday, and upper southwest flow should
begin to affect our area, with a return of storm chances.

The various short waves in northwest flow result in small
precipitation chances Wednesday night, Thursday night, and again
Friday night into Saturday. The potential will be typically less
than 25 percent, and confined to eastern MN and western WI. By
Monday night and Tuesday, the upper flow from the southwest
suggests that thunderstorms will return over much of the area.

Temperatures look to be slightly above average, with highs mostly
in the 80s through the period. Some 90 degree readings appear
possible on Wednesday as a thermal ridge over the northern high
plains extends eastward into MN, and somewhat into WI.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1230 PM CDT Tue Aug 7 2018

Widely scattered tsra over southern mn associated with upper
trough should exit to the east this afternoon. Will carry temp
tsra over WI taf sites with KMSP on the edge. Clouds lingering to
the east this evening with some fog possible later tonight with
light winds and where sky clears. Continued to mention fog chance
over eastern areas Wednesday morning. Surface winds light
generally less than 7 KTS.

KMSP...On the edge of the thunder threat through about 20z. more
scattered activity to the southeast. Should see vfr trend during
the period with the small chance of fog late tonight along the
river. WIll have to monitor trends into the night. Lit w-sw winds
less than 07kts becoming sw and increasing into Wednesday
afternoon.

/OUTLOOK FOR KMSP/
Wednesday night... VFR. West wind 5 to 10 kt.
Wednesday night... VFR. West wind less than 5 kt.
Thursday and Thursday night... VFR. Northwest wind less than 10 kt.
Friday...VFR. Variable wind 5 kt or less.

&&

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

SHORT TERM...AMK
LONG TERM...TDK
AVIATION...DWE

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
1210 PM CDT Tue Aug 7 2018

MNZ051>053-059>063-065>070-073>078-082>085-091>093-WIZ014>016-
023>028-081715-
Sherburne-Isanti-Chisago-Wright-Hennepin-Anoka-Ramsey-Washington-
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-
Chippewa-Eau Claire-
1210 PM CDT Tue Aug 7 2018

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

.DAY ONE...This Afternoon and Tonight

Scattered showers and thunderstorms will spread from west to east
across southern Minnesota and western Wisconsin. Severe weather
is not expected.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

No hazardous weather is expected.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.

MNZ041>045-047>050-054>058-064-081715-
Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns-
Benton-Lac Qui Parle-Swift-Chippewa-Kandiyohi-Meeker-
Yellow Medicine-
1210 PM CDT Tue Aug 7 2018

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

.DAY ONE...This Afternoon and Tonight

No hazardous weather is expected.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

No hazardous weather is expected.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
246 PM CDT TUE AUG 7 2018

WIZ014-072030-
Polk-
246 PM CDT TUE AUG 7 2018

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL POLK COUNTY THROUGH
330 PM CDT...

At 245 PM CDT, a strong thunderstorm was located over Centuria, or 31
miles east of Cambridge, moving east at 10 mph.

Dime size hail is possible with this storm.

Locations impacted include...
St. Croix Falls, Balsam Lake, Taylors Falls, Centuria and Wanderoos.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

To report severe weather, contact your nearest law enforcement
agency. They can relay your report to the National Weather Service
office in The Twin Cities.

LAT...LON 4550 9230 4529 9248 4541 9266 4543 9265
      4551 9263
TIME...MOT...LOC 1945Z 288DEG 11KT 4544 9260

JPC