Wind Advisory 18, NWS Sioux Falls, SD

Buena Vista County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Ida County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Dakota County, NE, Dixon County, NE, Brookings County, SD, Clay County, SD, Lake County, SD, Lincoln County, SD, Minnehaha County, SD, Moody County, SD, Turner County, SD, Union County, SD

AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
1152 AM CDT Sun Oct 11 2020

.SHORT TERM...(Today and Tonight)
Issued at 404 AM CDT Sun Oct 11 2020

Last warm/well above normal day for a while today, aided by gusty
southerly wind gusts which could briefly approach advisory criteria,
but like to remain just below. Not really seeing any significant
changes from recent forecasts, with cold front just pushing into the
western Dakotas early this morning. Not yet seeing extensive stratus
development which had previously been indicated by some models,
though some spotty development beginning in western Iowa, more
widespread farther to the east. Unless this dramatically increases
in coverage over the next few hours, not expected to have much of a
negative impact on temperatures today.

Much of the daytime hours will be dominated by some increase in mid
level clouds, the gusty south winds, and moderately humid air which
should prevent critical fire behavior. However, the strong winds and
dry fuels will still be enough to push grassland fire danger into
the very high range most areas. Expect highs to reach the upper 70s
to mid 80s, with far western areas dropping off through the mid to
late afternoon in the wake of the cold front.

This boundary, and associated dynamic upper level trough pushing out
of the northern Rockies will be the focus from mid afternoon through
this evening. Ample moisture streaming northward ahead of the front,
though warm temperatures aloft with expansive EML lifting northeast
ahead of the trough should inhibit initiation until the latter half
of the afternoon, when lead wave swings out of the base of the
trough into areas along/east of the I-29 corridor 21Z-00Z. Though we
could see some spotty high-based showers/storms along the boundary
prior to this time, this window is expected to be the period of
rapid development as the wave interacts with eastward-moving surface
boundary. With CAPE values around 1000J/kg, and 30-35kt effective
shear, should be able to organize rather quickly, with at least a
brief window of large hail threat with initial discrete cells,
before transitioning to damaging wind as storms congeal into linear
segments.

Consensus on timing among the various models has come in line, with
main development 21Z-23Z, and line largely pushing east of the CWA
by 03Z, though could see some trailing showers linger a bit longer
into the overnight hours. West-northwest post-frontal winds will be
gusty for a few hours right after FROPA, but should settle through
the night, with clearing skies and temperatures falling into the 40s.

.LONG TERM...(Monday through Saturday)
Issued at 404 AM CDT Sun Oct 11 2020

The week ahead will feature more seasonable temperatures to start,
briefly cooler Tuesday as a dry wave slides through the region.
Readings fall off further late week, in the wake of a broad trough
will drops into the late Wednesday/Wednesday night. Very little
consensus among models regarding how far south light precipitation
chances may slide as the wave moves through, though even if we do
see rain, most solutions indicate it would be spotty and light. Will
stick with dry forecast for now and monitor trends in the coming
days.

With dominant fast westerly flow over the area, diurnal mixing will
lead to breezy afternoons. With dry fuels and afternoon humidity
levels generally 25-40 percent, the breezier days will result in
continued elevated fire danger, though this may be abated somewhat
on Monday in areas which receive substantial rainfall tonight.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1149 AM CDT Sun Oct 11 2020

Strong southerly gusts around 35 knots will continue through the
afternoon, gradually decreasing from west to east as a cold front
approaches. Northwest winds behind the front will also be strong
for a couple of hours into the evening. Scattered strong to
possibly severe thunderstorms are possible across southwest MN,
northwest IA and extreme eastern SD from roughly 22z through 4z.
Seom lingering showers and isolated less strong thunderstorms will
be possible behind the front but should be short lived if they
develop. VFR conditions after about 5z.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&

SHORT TERM...JH
LONG TERM...JH
AVIATION...08

Hazardous Weather Outlook
National Weather Service Sioux Falls SD
611 AM CDT Sun Oct 11 2020

SDZ038-039-050-052>055-057>061-063>066-068-069-121200-
Beadle-Kingsbury-Gregory-Jerauld-Sanborn-Miner-Lake-Brule-Aurora-
Davison-Hanson-McCook-Charles Mix-Douglas-Hutchinson-Turner-
Bon Homme-Yankton-
611 AM CDT Sun Oct 11 2020

This Hazardous Weather Outlook is for central South Dakota, east
central South Dakota, south central South Dakota and southeast
South Dakota.

.DAY ONE...Today and tonight.

Gusty winds today, south initially, then turning to the west-
northwest this afternoon, will result in high to very high fire
danger.

There is a small chance of thunderstorm development 3pm-6pm toward
the Highway 81 corridor. If storms develop, an isolated strong to
severe storm could produce hail to quarter size.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Breezy afternoons and a return to dry conditions will lead to
periods of elevated fire danger through the week ahead, even as
temperatures cool to near or below seasonal normals.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ040-056-062-067-070-071-121200-
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Brookings-Moody-Minnehaha-Union-
611 AM CDT Sun Oct 11 2020

This Hazardous Weather Outlook is for northwest Iowa, west central
Iowa, southwest Minnesota, northeast Nebraska, east central South
Dakota and southeast South Dakota.

.DAY ONE...Today and tonight.

Strong southerly winds, gusting as high as 40 to 45 mph at times,
will result in very high fire danger today.

Scattered thunderstorms are expected to develop near the I-29
corridor late this afternoon, between 4 pm and 6 pm, expanding into
a line as the storms move east into southwest Minnesota and
northwest Iowa this evening. Large hail will be possible with
initial storm development, but the primary threat will transition to
damaging winds in excess of 60 mph as the storms move east. Storms
are expected to move east of the area by around 10 pm.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Breezy afternoons and a return to dry conditions will lead to
periods of elevated fire danger through the week ahead, even as
temperatures cool to near or below seasonal normals.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed between 4 pm and 10 pm.