SPC AC 300720
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0220 AM CDT Sun Jun 30 2019
Valid 021200Z - 031200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
THE MID MISSOURI VALLEY EASTWARD INTO THE SOUTHERN GREAT LAKES AND
ACROSS THE NORTHERN HIGH PLAINS...
...SUMMARY...
Marginally severe thunderstorms with strong wind gusts and hail will
be possible on Tuesday from the Mid Missouri Valley into the
Southern Great Lakes and across parts of the northern High Plains.
...Mid Missouri Valley to Southern Great Lakes...
Westerly mid-level flow will be in place across the northern U.S. on
Tuesday. At the surface, a cold front is forecast to advance
southeastward into the mid Missouri Valley and western Great Lakes
region. Thunderstorm development should take place along the front
during the afternoon with storms moving east-southeastward across an
unstable airmass during the mid to late afternoon. Model consensus
places the strongest instability across northern Illinois and
southern Wisconsin where the GFS and NAM solutions show MLCAPE
values in the 2000 to 3000 J/kg range. In addition, model solutions
show steep low-level lapse rates and strong enough deep-layer shear
for a marginal wind-damage threat. This potential could extend
eastward across lower Michigan where deep-layer shear is forecast to
be a bit stronger. Once certainty decreases concerning the position
of the front and convective coverage, a slight risk could be added
in later outlooks.
...Northern High Plains...
An upper-level ridge is forecast to move across the central and
northern Rockies on Tuesday. At the surface, a cold front is
forecast to move southward into the northern High Plains. Along and
south of the front, model forecasts show an east-to-west corridor of
maximized low-level moisture. A pocket of instability should develop
along this corridor by mid to late afternoon. Thunderstorms that
form along the front could obtain a marginal severe threat mainly
due to moderate deep-layer shear and steep mid-level lapse rates.
However, the influence of the upper-level ridge is expected to keep
any severe threat isolated.
..Broyles.. 06/30/2019
CLICK TO GET WUUS03 PTSDY3 PRODUCT
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z
| 
)
