Memphis NWS is onboard for an Outbreak:
Area Forecast Discussion
National Weather Service Memphis TN
413 PM CST Wed Feb 15 2023
...New SYNOPSIS, DISCUSSION, AVIATION...
.SYNOPSIS...
Issued at 313 PM CST Wed Feb 15 2023
A
nocturnal severe weather outbreak is setting up over the Mid
South this evening. Showers and storms will develop later on this
evening and last through Thursday morning. This will be a long
duration severe event with the possibility of multiple waves of
storms. Dry and cooler conditions return Friday as surface high
pressure shifts across the area. Expect some sub freezing morning
lows Friday and through the weekend. High temperatures will trend
warmer through the weekend, back to near 60 by Sunday and in the
70s early next week. Warm conditions are expected to continue into
next week as showers and thunderstorms return to the forecast.
&&
.DISCUSSION...
(This evening through next Tuesday)
Issued at 313 PM CST Wed Feb 15 2023
A long duration severe weather outbreak looks poised to occur
tonight into Thursday for the Mid South. Now is the time to prepare
for adverse weather. Nighttime severe weather can be particularly
dangerous. All the ingredients are in place
shear,
moisture,
instability, and lift will all be in place over the region for an
extended period of time. Dewpoints across the region range from
the mid 60s across north MS to the upper 50s and lower 60s across
E AR and W TN. Dewpoints should continue to
surge into the region
ahead of the
front tonight. Temperatures will remain mild and
winds will remain elevated keeping the area prime for storm
development.
Shear will not be an issue either as we will be in a
favorable position under a
jet streak as well as 0-3 KM
SRH
values will be anywhere between 300-500
m2/s2 over the region
tonight. We have been capped for the most part today, and that is
why we have been mostly quiet on the
radar. Looking at the current
vis sat there is a large area of cloud streaks across the Lower
Mississippi Valley. This is indicative of horizontal
shear and
the
atmosphere starting to uncap and destabilize. Latest guidance
suggests that we could have between 1000-2000
J/KG of
CAPE over
the Mid South tonight...this is concerning as this event we should
have the
instability in place. This has been the missing link
over the last few systems. With all of that being said the Storm
Prediction Center has a large portion of the forecast area in an
Enhanced Risk of Severe weather tonight. All modes of severe
weather will be on the table. Tornadoes will be possible...some of
those tornadoes could be strong meaning EF2 or better. I am
concerned with this aspect of the threat. Large
hail and damaging
winds will be possible.
Storm mode will also be important as this event should start out
as supercells, and possibly congealing into a QLCS or cluster of
storms. The supercells pose the greatest threat for the stronger
tornadoes early in the event. The best time for that is from 7PM
tonight through about 2AM tonight. The mode should congeal to a
large area of storms and tornadoes could be embedded in that, but
the heavy rain and damaging wind threat then increases during that
timeframe.
Rainfall totals through tomorrow should mostly stay
just under 2 inches, but any locally higher amounts could result
in localized flooding issues. The WPC has included most of the
Midsouth in a marginal risk for Excessive
Rainfall for tonight.
Portions of northeast MS and west TN near the TN river are also
included in a
Slight Risk for Day 2.
The severe threat continues into Thursday as the
front finally
starts to really push through the region. Storms should develop
along the
front again on Thursday. Strong to severe storms will
continue and may redevelop especially across NE Mississippi. This
would be the reason why the enhanced risk remains in the area
through Thursday. Storms should be completely out of the region
by Thursday afternoon. Needless to say this is a formidable system
and everyone should stay weather aware overnight and Thursday.
Cooler and dry air will filter across the Midsouth Friday and
remain in place through the weekend. Some sub-freezing
temperatures are expected Friday, Saturday and Sunday mornings.
Highs will trend warmer; from the 40s on Friday, to the 50s on
Saturday and near 60 by Sunday.
Warm conditions are expected early next week but showers and maybe
a few thunderstorms are expected to return to the area.
&&