Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
15 %
61,035
2,966,537
Omaha, NE...Lincoln, NE...Sioux City, IA...Council Bluffs, IA...Ames, IA...
5 %
180,343
19,518,697
Charlotte, NC...Kansas City, MO...Minneapolis, MN...Raleigh, NC...St. Paul, MN...
Probabilistic Large Hail Graphic
Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
15 %
76,206
3,217,393
Omaha, NE...Lincoln, NE...Sioux Falls, SD...Sioux City, IA...Council Bluffs, IA...
5 %
149,051
9,907,856
Kansas City, MO...Minneapolis, MN...St. Paul, MN...Des Moines, IA...Overland Park, KS...
SPC AC 110540
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1240 AM CDT Sun Oct 11 2020
Valid 111200Z - 121200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN
MINNESOTA INTO NORTHERN KANSAS...
...SUMMARY...
Isolated strong to severe thunderstorms are expected late this
afternoon and evening across parts of the northern/central Plains
into the Upper Midwest, with marginally severe thunderstorms also
possible across parts of the Southeast and Mid-Atlantic.
...Northern/Central Plains...
00z models are in general agreement regarding the progression of a
short-wave trough over the northwestern US. This feature is forecast
to advance into the High Plains, extending from the western Dakotas
into eastern CO by 12/00z, then shifting to near 97W longitude by
the end of the period. Low-level moisture is currently a bit scant
across the northern/central Plains where surface dew points are in
the 30s/40s. However, strengthening LLJ across this region should
allow moisture across KS to begin advancing north. Latest
indications are this modified air mass will likely be drawn north
across the mid-MO Valley into portions of southwestern MN prior to
frontal passage.
Latest guidance suggests a narrow corridor of strong boundary-layer
heating will extend across the central Plains into southwestern MN
by mid afternoon. While surface parcels may struggle to reach their
convective temperatures, frontal convergence should easily assist
parcels to their LFC, and scattered thunderstorms are expected to
develop along the strongly forced high-latitude portions of the
boundary by 21z. Forecast soundings suggest adequate deep-layer
shear for potential supercells; however, strong forcing should
result in a squall line quickly. Greatest threat with this initial
activity will be hail/wind, evolving into more of a wind threat as
the squall line matures. Have extended severe probabilities
southwest along the front into portions of northern KS where
forecast soundings suggest inhibition will be very weak with MUCAPE
in excess of 2000 J/kg. Southern extent of large-scale forcing
should extend into this region which should be adequate for
scattered convection along the wind shift.
...Southeast/Mid-Atlantic...
Remnants of TC Delta are quickly ejecting east-northeast across the
TN Valley/northern Gulf States. Substantial mid-level drying is
spreading across AL/GA early this morning and this drying should
progress downstream into the western Carolinas early in the period.
Overall, this system is gradually weakening with forecast soundings
across the southeastern US/Carolinas exhibiting substantially weaker
shear than the eastern Gulf States Saturday. Even so, adequate flow
and moistening profiles suggest there is some risk for organized
robust convection. The greatest risk is for locally damaging wind
gusts, or perhaps a few brief/weak tornadoes.
..Darrow/Moore.. 10/11/2020
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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