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 2 Tornado Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
5 %
58,792
117,144
Havre, MT...Miles City, MT...Lewistown, MT...
2 %
99,018
704,545
Billings, MT...Rapid City, SD...Great Falls, MT...Gillette, WY...Sheridan, WY...
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 2 Wind Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
15 %
163,954
846,798
Billings, MT...Bismarck, ND...Great Falls, MT...Grand Forks, ND...Minot, ND...
SPC AC 060536
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1236 AM CDT Mon Jul 06 2020
Valid 071200Z - 081200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
NORTHERN HIGH PLAINS...NORTHERN PLAINS...AND UPPER MIDWEST...
...SUMMARY...
Severe thunderstorms are possible across portions of the northern
High Plains, northern Plains, and Upper Midwest from Tuesday
afternoon through early Wednesday morning.
...Synopsis...
A belt of strong southwesterly/westerly flow aloft is forecast to
extend from central CA through the northern Plains/Canadian Prairie
Provinces into the Upper Midwest/Ontario. A shortwave trough is
expected to move within this enhanced flow aloft on Tuesday,
reaching the northern High Plains by Tuesday afternoon and the
northern Plains/Canadian Prairie Provinces by early Wednesday
morning. Elsewhere, upper ridging is expected to persist from the
Southwest into the southern/central Plains and a weak upper low will
drift northeastward over the Carolinas.
...Northern High Plains/Northern Plains into the Upper Midwest...
Lee troughing is expected to deepen across the northern High Plains
ahead of the approaching shortwave trough. Surface cyclogenesis is
anticipated by early Tuesday afternoon, with the resulting low
moving northeastward into southern Saskatchewan. Increase in the
surface pressure gradient will result in strengthening southeasterly
winds throughout the day and into the evening, helping to advect low
60s dewpoints into central MT. Additionally, the strong
southeasterly winds beneath the belt of enhanced
westerly/southwesterly flow aloft will result in moderate to strong
vertical shear.
Thunderstorms are expected to develop near the surface low/cold
front over central MT during the early afternoon. An initially
cellular mode is anticipated. The environment suggest these initial
storms will be high-based supercells with strong wind gusts as the
primary severe threat. Low-level moisture and instability will
increase with eastern extent, with subsequent increase in the
likelihood for large hail and a tornado or two. Given the steep
mid-level lapse rates in place, some very large hail is possible.
Storm coverage will also likely increase with eastern extent, with
upscale growth into an organized convective line possible. The
resulting convective line, aided by a dynamically strengthening
low-level jet, would likely pose a continued severe threat across
much of ND.
The strengthening low-level jet will also support warm-air advection
across the warm front ahead of the convective line, fostering
elevated thunderstorm development across portions of the Upper
Midwest. Steep mid-level lapse rates will support moderate buoyancy
amid the enhanced westerly flow aloft, resulting in conditions
favorable for a few severe storms.
..Mosier.. 07/06/2020
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
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