Special Weather Statement, NWS Twin Cities, MN

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
342 PM CDT Mon Aug 26 2019

.SHORT TERM...(This evening through Tuesday night)
Issued at 330 PM CDT Mon Aug 26 2019

Surface analysis this afternoon shows a nearly north-south
oriented cold front bisecting eastern and western MN, emanating
from a low pressure center over central Manitoba province, and
extending south southwest to the OK/TX panhandles. Expansive high
pressure occupies the northwestern CONUS. A fairly narrow swath of
rain continues to press eastward over the I-35 corridor into
western WI. No thunder has been evident within this rainfall but
there have been some rates of around 0.50"-0.75" per hour so the
rainfall production has been rather efficient. Mesonet
observations have shown some rainfall totals of over 1" thus far
today within an environment having PWATs of 1.25"-1.50".

The cold front will reach eastern Wisconsin around midnight and
cross Lake Superior by daybreak Tuesday. While the main swath of
rain will be well to the east by late this evening, isolated to
scattered showers now popping up over western Minnesota will
continue to drift eastward thru the rest of the evening into the
overnight hours so the threat of additional rainfall is certainly
not unreasonable although the coverage will not be nearly as
great. And, like during the day today, thunderstorms are by and
large not expected.

With the cold front now passed by for Tuesday, the upper level low
of the system will drop to near the Great Lakes while a secondary
weak trough slides southeast into northern Minnesota and northern
Wisconsin. The heating of the day looks to allow some instability
cold pool showers to develop mainly late morning thru early
evening Tuesday, and again mainly over central Minnesota into
western Wisconsin. Coverage will be rather sparse, so "scattered"
wording looks to work best here. Very few, if any, thunderstorms
are expected but with cold air aloft as a relatively shallow
depth, some showers containing small hail (or "graupel") cannot be
ruled out.

In addition, a strong pressure gradient will develop behind the
potent departing cold front and strong high pressure arriving from
the west. This will make for breezy conditions with sustained
winds in the 15-25mph range and gusts to around 30 mph. Winds are
expected to settle down going into Tuesday night and conditions
overall will improve Tuesday night with gradual clearing.

.LONG TERM...(Wednesday through Monday)
Issued at 330 PM CDT Mon Aug 26 2019

Overall long term trends remain rather consistent. The eastern
CONUS trough will remain through much of the week. Cyclonic flow
around the exiting upper trough will drive lingering threat of
showers into early Wednesday before drier air moves in. Otherwise,
cool and breezy conditions linger over at least the eastern CWA early
Wednesday. Fall-like high temperatures expected around 70.

Another short wave trough/spoke of energy moves quickly southeast
over the Dakotas Wednesday night and across the CWA Thursday.
Decent warming ahead of the incoming surface front should bump
highs into the 75-80 degree range Thursday afternoon. Moisture
will struggle to pool ahead of the fast moving front and most
deterministic models bring this front through dry across our CWA
Thursday afternoon. We will continue this trend for now. Timing of
the trough/front will determine any real convective threat. Winds
should increase with the cold frontal passage with gusts to
20-25kt likely.

The southern CWA may be clipped by some leftover moisture as a
weak wave moves south of the area Friday night into Saturday. We
retained the small chance PoP into south central MN. Otherwise,
dry trend with slow warming ahead of ridging aloft builds east
over the weekend as a result of a cutoff upper low builds into
the Pacific Northwest. Models diverge on overall precipitation
development along a developing stationary frontal boundary which
is progged over northern MN late Sunday/Monday. We left the
blended model small chance PoP over mainly the northern CWA then.
Temperatures should trend upward through the weekend, close to
normal by Monday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1226 PM CDT Mon Aug 26 2019

Swath of -RA approaching the I-35 corridor at initialization.
While there is a mix of VFR-MVFR visibilities due to the intensity
of the rain, virtually no thunder to speak of. So as to not
completely discount the potential for convection but convey a
lesser chance, have transitioned from TEMPO for TS to VCTS at KMSP
and eastward. Rainfall will gradually end from west to east with
conditions then improving to VFR. In addition, winds will swing
around to NW with the frontal passage and have some gustiness to
them, especially after daybreak Tuesday morning.

KMSP...Kept ceilings within VFR range at this point, but not by
much. Heavier rainfall looks to move into the terminal area by 19z
with good chance of some MVFR visibility. Conditions will then
improve mid-to-late afternoon as winds swing around. During the
evening push, conditions are expected to run as VFR throughout but
ceilings will be between 4-5 kft.

/OUTLOOK FOR KMSP/
Wed...VFR. Wind NW 10-20 kt.
Thu...VFR. Wind SW 5-10 kt.
Fri...VFR. Wind NW 5-10 kt.

&&

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

SHORT TERM...JPC
LONG TERM...DWE
AVIATION...JPC

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
1224 PM CDT Mon Aug 26 2019

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
270600-
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-
1224 PM CDT Mon Aug 26 2019

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

.DAY ONE...This Afternoon and Tonight

A few thunderstorms are possible into early evening. Some spots
may have heavy rain for a short while. Severe weather is not
expected.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

There is a slight chance of thunderstorms Tuesday. Severe weather
is not expected.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
359 PM CDT Mon Aug 26 2019

MNZ065-073-074-262215-
Brown-Renville-Redwood-
359 PM CDT Mon Aug 26 2019

...SHOWERS AND THUNDERSTORMS WITH THE POTENTIAL FOR FUNNEL CLOUDS
WILL AFFECT REDWOOD...BROWN AND RENVILLE COUNTIES...

At 357 PM CDT, a line of scattered showers and thunderstorms were
moving east at 20 mph. If you see a funnel cloud, please calmly move
inside to a sturdy structure.

Locations impacted include...
New Ulm, Redwood Falls, Sleepy Eye, Olivia, Springfield, Renville,
Fairfax, Hector, Bird Island, Morgan, Walnut Grove and Lamberton.

This includes the following highways...
 U.S. Highway 14 between mile markers 45 and 103, and near mile
marker 106.
 U.S. Highway 212 between mile markers 61 and 101.
 U.S. Highway 71 between mile markers 52 and 106.

LAT...LON 4454 9544 4455 9536 4470 9536 4489 9527
      4489 9450 4472 9450 4471 9463 4446 9463
      4445 9478 4443 9470 4439 9467 4435 9449
      4426 9437 4411 9437 4411 9509 4420 9512
      4420 9559 4421 9559
TIME...MOT...LOC 2057Z 290DEG 19KT 4466 9507

JRB