Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
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 %
31,888
1,750,406
Cedar Rapids, IA...Rochester, MN...Waterloo, IA...Lakeville, MN...Cedar Falls, IA...
SPC AC 051252
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0752 AM CDT Sat Sep 05 2020
Valid 051300Z - 061200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE UPPER
MIDWEST...
...SUMMARY...
Scattered thunderstorms capable of large hail and isolated wind
damage are expected tonight across parts of the Upper Midwest.
...Upper Midwest...
A moderately strong belt of northern-tier northwesterlies will
undergo modest cyclonic amplification through late tonight.
Cyclogenesis across the Canadian Prairies and northern/central Great
Plains will support increasing moist advection northeastward across
the Middle Missouri Valley into the Upper Midwest later today and
especially tonight. After sunset, a strong (50+ kt) southwesterly
low-level jet will enhance warm/moist advection with parcels
isentropically reaching their LFC to the north of a warm front.
Current thinking is that storms will develop by mid/late evening
across far eastern South Dakota/southwest Minnesota, potentially as
early as around 9-11 pm CDT. These storms will be influenced by
ample elevated instability (2000+ J/kg MUCAPE) and robust shear
through the cloud-bearing layer, which will be well-supportive of
elevated supercells. Large hail, potentially including some
golfballs or significant-caliber hailstones (>2 inches), is expected
to be the primary risk as storms increase in coverage and develop
east-southeastward across southern Minnesota including the I-90
corridor. However, over time, storm aggregation into the overnight
could lead to upscale quasi-linear growth into a forward-propagating
MCS. Even while surface-layer inhibition will be considerable,
potential cold pool development and the possibility of lingering dry
air just above the surface could lead to at least some late-night
potential for strong to locally severe-caliber wind gusts across
south-central/southeast Minnesota into northern Iowa and far
west/southwest Wisconsin. Some severe storms could reach far eastern
Iowa/northwest Illinois in the pre-dawn hours of Sunday.
..Guyer/Mosier.. 09/05/2020
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
| 
)
