Phoenix, AZ...Denver, CO...Mesa, AZ...Colorado Springs, CO...Aurora, CO...
Probabilistic Tornado Graphic
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
5 %
284,769
10,227,134
Phoenix, AZ...Denver, CO...Mesa, AZ...Colorado Springs, CO...Aurora, CO...
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
5 %
8,032
19,144
No Major Population Center in Risk Area
SPC AC 190531
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1231 AM CDT Wed Aug 19 2020
Valid 191200Z - 201200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE WESTERN UNITED STATES AND THE ARROWHEAD OF MINNESOTA...
...SUMMARY...
Isolated strong/locally severe wind gusts will be possible within a
large, arc-shaped area from portions of Idaho and southwestern
Montana eastward into parts of South Dakota and Nebraska, southward
across the central and southern High Plains, and westward to
southeastern Arizona. A few strong storms may also spread across the
Arrowhead of Minnesota.
...Western US...
Dominant upper ridge over the Great Basin is forecast to sag south
over the next few days as mid-level heights fall across the Pacific
Northwest into the northern Rockies. Latest model guidance suggests
a weak short-wave trough will top the ridge over southern MT early
in the period which will allow a corridor of stronger 500mb flow to
arc from southern ID into northern WY. Stronger mid-level flow will
also extend along the front side of the ridge across the
central/southern Great Plains, enhancing the prospect for
potentially organized high-based convection. As the upper high
settles south toward the UT/AZ border, mid-level easterly flow
should lessen across the Mogollon Rim in AZ. Even so, isolated
thunderstorms should once again develop over the higher terrain.
Some of this convection could produce gusty winds. Otherwise, gusty
winds may accompany convection that develops along the periphery of
the anticyclone where subsidence will be notably absent/weak, and
the presence of mid-level flow will be adequate for some
organization. Even so, relatively low PW-values across these regions
will lead to high-based convection that could produce more gusty
winds than beneficial rain cores.
...Arrowhead of Minnesota...
Weak mid-level short-wave trough will dig southeast across western
ON with the southwestern flank of this feature expected to clip the
arrowhead of MN around 18z. By 20/00z, this short wave will advance
into the eastern UP of MI. While large-scale forcing for ascent will
spread downstream early, synoptic front is expected to drape itself
across Lake Superior, northwest across the arrowhead into extreme
southern MB. Modest boundary-layer heating will be noted south of
this wind shift and there is some concern that convection may try to
develop in the wake of the aforementioned short wave near the
boundary. Several CAMs solutions suggest potentially strong
convection will evolve near the international border, then spread
southeast across northeastern MN. If this occurs there will be some
low threat for wind/hail with this activity. For these reasons, will
add MRGL risk to account for this scenario.
..Darrow/Bentley.. 08/19/2020
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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