Special Weather Statement, NWS Twin Cities, MN

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1019 PM CDT Thu Jul 25 2019

.UPDATE...
Issued at 1019 PM CDT Thu Jul 25 2019

Updated to include 06Z aviation discussion below.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 245 PM CDT Thu Jul 25 2019

A pronounced circulation (noted by regional satellite imagery) over
southwest Minnesota early this afternoon, was associated with
convection that occurred in South Dakota overnight. There remains
enough energy with this circulation to continue high chance
percentages in south central Minnesota through the late afternoon.
However, instability is weak, and lapse rates are not conducive for
anything more than an isolated storm. Farther to the northwest
across far eastern North Dakota/northwest Minnesota, the combination
of modest instability along the surface front, and upper level
energy from a storm system in south central Canada, has led to a
line of showers and thunderstorms to form this afternoon. This area
of convection will likely move east/southeast during the late
afternoon/early evening before becoming weak and disorganized as it
runs into weaker instability. There is enough surface convergence
along the front to continue chance percentages in west
central/central Minnesota this evening. Slowly the area of
convection will move southeast across southwest, and into east
central Minnesota toward early Friday morning. Severe weather will
be limited to areas of west central Minnesota before 9 pm.

Precipitation will likely weaken Friday morning before reforming
late Friday afternoon along the slowly moving frontal boundary. This
boundary will likely washout in southern Minnesota Friday evening
setting the stage for isolated storms on Saturday. Temperatures will
be dependent on how much sunshine develops once the precipitation
stops/weakens Friday morning and skies become sunnier. The best
chance of 90s will occur in west central Minnesota, with 70s/80s in
west central Wisconsin where the cloud cover will likely hold. Due
to the proximity of the weakening frontal boundary Friday night, I
can't rule out isolated showers or storms. However, most of the
energy with the storm system moving across south central Canada
today, will have moved farther away to have little affect in our
region for large scale lift.

.LONG TERM...(Saturday through Thursday)
Issued at 245 PM CDT Thu Jul 25 2019

Forecast concern in the longer term remains convective potential
Saturday afternoon to the south, developing again later Saturday
night and continuing into Sunday Night. Trend is cooler early
next week with a warming trend late in the week.

Frontal boundary associated with Friday night convection is
forecast to exit to the southeast Saturday afternoon. This should
take the chance of thunder with it. Timing may still be an issue
with The GFS a bit slower and may continue at least a small threat
over the far southeast CWA in the afternoon. We continues the dry
trend for now.

This remains short lived however, as the deterministic models
drive another potent short wave trough over the upper ridge across
the CWA Saturday night into Sunday night. The GFS is a bit faster
and pretty much brings a rainy day for the region for Sunday.
This will likely affect overall instability and significant
thunder threat. If this system is slower, closer to the ECMWF, we
could see warmer temperatures, especially across the south with
some lower 90s a possibility Saturday afternoon.

Following the front, cooler and drier high pressure should
dominate the weather through Wednesday. We could see a threat of
showers/isolated thunder skirt mainly the southwest CWA Tuesday
night as a weaker short wave travels across that region, closer to
possible stationary boundary southwest of the state. The GFS is
drier with this system.

Both the GFS and ECMWF begin to build heights across the western
CONUS the second half of next week. The ECMWF is a bit warmer as
it builds in higher heights by Friday. The GFS continues to leave
the CWA in the transition zone with the stationary/warm front
remaining mainly west of the area with leaving us in weak
northwest flow and possible shower/thunder threat returning with
frontal passages.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1019 PM CDT Thu Jul 25 2019

Convection has had a tough time developing southward along the
instability axis to our west this evening, but there are some
indications that a few storms could develop over night (in the
HRRR and some other CAM solutions). However, don't have enough
confidence in development, particularly with the expecation that
coverage would be limited even if storms develop, to include too
much mention in the TAFs at this point. However, updates could
certainly occur if/when the atmosphere shows its hand. Still look
to have another chance later in the day on Friday when the frontal
boundary moves through the area, but most of the guidance suggests
limited coverage with that activity as well.

KMSP...Main concerns continue to be with chance for SHRA/TSRA late
tonight and again late Friday afternoon. Will need to keep an eye
on it and update if needed, but otherwise didn't see a need to be
too pessimistic at this point.

/OUTLOOK FOR KMSP/
Saturday...VFR. North to northwest wind 5 kt or less.
Saturday night...VFR. Variable wind less than 5 kt.
Sunday...MVFR possible with a chance of SHRA/TSRA. Southeast wind
5 to 15 kt becoming southwest.
Sunday night...MVFR possible with a chance of SHRA/TSRA. Southwest
wind 5 to 15 kt becoming northwest.
Monday...VFR. Northwest wind 10 to 15 kt.

&&

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

UPDATE...
SHORT TERM...JLT
LONG TERM...DWE
AVIATION...

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
1210 PM CDT Thu Jul 25 2019

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
261715-
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-
1210 PM CDT Thu Jul 25 2019

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

.DAY ONE...This Afternoon and Tonight

Isolated non-severe thunderstorms will occur in far southern
Minnesota this afternoon. Scattered thunderstorms will develop in
west central Minnesota late this evening. Some of these storms
could be locally severe.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

There is a chance of thunderstorms Friday into Friday evening
and again Saturday night into Sunday night. A few storms may be
severe Friday across east central Minnesota and western
Wisconsin.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
232 AM CDT Fri Jul 26 2019

MNZ054>056-260800-
Chippewa-Lac Qui Parle-Swift-
232 AM CDT Fri Jul 26 2019

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL LAC QUI PARLE...
NORTHWESTERN CHIPPEWA AND SOUTHWESTERN SWIFT COUNTIES...

At 232 AM CDT, a strong thunderstorm was located over Correll, or 17
miles east of Ortonville, moving east at 30 mph.

Nickel size hail is possible with this storm.

This storm will be near...
  Appleton around 240 AM CDT.
  Milan around 255 AM CDT.

Other locations impacted by this storm include Louisburg, Danvers,
Hagen, Big Bend City, Appleton Airport and Holloway.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4521 9621 4519 9612 4518 9610 4524 9610
      4524 9612 4533 9611 4527 9564 4501 9571
      4513 9623
TIME...MOT...LOC 0732Z 281DEG 26KT 4521 9611

BORGHOFF