MD 1861 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR SOUTHEASTERN MISSISSIPPI INTO CENTRAL AND SOUTHERN ALABAMA
Mesoscale Discussion 1861
NWS Storm Prediction Center Norman OK
0742 AM CDT Wed Oct 12 2022
Areas affected...southeastern Mississippi into central and southern
Alabama
Concerning...Severe potential...Watch unlikely
Valid 121242Z - 121445Z
Probability of Watch Issuance...5 percent
SUMMARY...Scattered strong thunderstorm development likely will
persist at least into mid to late morning, with isolated stronger
storms continuing to pose a risk for severe hail.
DISCUSSION...Weak southerly low-level return flow on the
southwestern periphery of surface ridging now shifting east of the
Atlantic Seaboard is contributing to plumes of low-level moistening
across the Gulf Coast. One such plume is ongoing near/east of the
southeast Louisiana coast into the southern Mississippi/Alabama
border vicinity, where the moisture return is still generally
elevated above a residual stable boundary layer. However, in the
presence of modestly steep lower/mid tropospheric lapse rates, this
appears to be contributing to most unstable CAPE up to around 1000
J/kg, which is supporting increasing scattered thunderstorm
development.
This is occurring near the southern periphery of a 40 kt
west-southwesterly 500 mb jet streak streak, which is gradually
propagating eastward into the southern Appalachians vicinity, in
advance of amplifying large-scale mid-level troughing across much of
the interior U.S. Associated deep-layer shear is enhancing ongoing
thunderstorm development, and may continue to support at least
isolated stronger storms posing a risk for severe hail into the
15-17Z time frame.
..Kerr/Grams.. 10/12/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BMX...MOB...JAN...
LAT...LON 33068847 33658744 33878604 32358543 31188699 31098807
31458900 32008917 32718878 33068847
