A place to discuss upcoming severe weather setups. Unless otherwise noted, all posts of weather graphics are for informational purposes only, by non-meteorologists. All posted weather models should be taken with a grain of salt. Please refer to your local news or radio and other official sources for up-to-date weather information.
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SPC AC 270730
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 AM CDT Fri Sep 27 2019
Valid 291200Z - 301200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN/CENTRAL PLAINS AND UPPER MIDWEST...
At least isolated severe thunderstorms may develop Sunday into
Sunday night across parts of the northern/central Plains and the
...Northern/Central Plains into the Upper Midwest...
A large-scale upper trough/low will remain over a majority of the
western CONUS on Sunday. A strong mid/upper-level jet associated
with this feature will overspread the northern/central Plains
through the period. Even though large-scale forcing for ascent will
probably be delayed across much of the northern/central Plains
through at least Sunday evening, a pronounced low-level mass
response is expected across this region. A surface low is forecast
to deepen over the central High Plains through Sunday afternoon,
before developing northeastward over SD late. A warm front with rich
low-level moisture to its south is likewise expected to shift
northward across parts of the central into the northern Plains
through Sunday evening/night.
Main uncertainty regarding overall severe potential remains
initiation of storms across the warm sector, as a low-level
temperature inversion will probably limit development through most
of the day. Some guidance does show potential for surface-based
convection to develop from northeastern NE into eastern SD and
southwestern MN late Sunday afternoon and early evening. A low-level
jet will likely strengthen to around 40-50+ kt across this region in
the same time frame. A strongly veering wind profile with height
along with plentiful moisture suggests potential for rotating storms
capable of producing all severe hazards, including tornadoes.
Isolated large hail may also occur farther north across the Upper
Midwest Sunday night with mainly elevated convection, given the
presence of strong shear above a near-surface stable layer.