Sunday, July 5, 2020

SPC Jul 5, 2020 0730 UTC Day 3 Severe Thunderstorm Outlook

SPC 0730Z Day 3 Outlook
Day 3 Outlook Image
Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0216 AM CDT Sun Jul 05 2020

Valid 071200Z - 081200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN MT
AND FAR WESTERN ND...

...SUMMARY...
Severe thunderstorms are possible across portions of the northern
High Plains and northern Plains from Tuesday afternoon through early
Wednesday morning.

...Northern High Plains/Northern Plains...
A belt of strong southwesterly/westerly flow aloft is forecast to
extend from central CA through the northern Plains/Canadian Prairie
Province 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. Surface lee troughing is expected to deepen ahead of this
system, with the resulting increase in the pressure gradient
contributing to strong low-level moisture advection into
central/eastern MT. This low-level moisture beneath steep mid-level
lapse rates will result in moderate to strong instability, from
central MT into the western Dakotas, ahead of the approaching
shortwave trough and its attendant surface low. Additionally,
southeasterly surface winds beneath the aforementioned belt of
enhanced southwesterly flow aloft will contribute to strong vertical
shear.

Current expectation is for thunderstorms to develop along and ahead
of the surface low and cold front associated with the approaching
shortwave trough. Initial development currently looks most likely
across central MT Tuesday afternoon. The conditions previously
mentioned with result in an environment conducive to severe
thunderstorms, including the potential for an organized convective
line. A few discrete supercells are also likely. Greatest
probability for severe thunderstorm currently appears to be over
eastern MT and far western ND as the front moves through Tuesday
evening. A strong low-level jet will support severe thunderstorm
potential eastward across ND and northern SD Tuesday night into
Wednesday morning. All severe hazards are possible, with large hail
currently expected to be primary threat.

...Elsewhere...
Numerous thunderstorms are expected across the Southeast states, but
weak vertical shear will keep any severe threat very isolated.
Isolated to widely scattered thunderstorms are also possible over
the central and southern High Plains. Severe probabilities in these
areas are currently less than 5%.

..Mosier.. 07/05/2020

Read more

from SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day3otlk_0730.html

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