Severe Thunderstorm Warning 237, NWS Memphis, TN

Area Forecast Discussion
National Weather Service Memphis TN
311 AM CDT Fri May 16 2025

...New DISCUSSION...

.KEY MESSAGES...
Updated at 310 AM CDT Fri May 16 2025

- A regional outbreak of severe thunderstorms is likely this
  afternoon into tonight with strong tornadoes, perhaps long
  tracked, damaging winds and very large hail.

- An Enhanced (3 out of 5) to Moderate (4 out of 5) Risk for
  severe weather is in effect across the northern half of the Mid-
  South this afternoon into tonight.

- Saturday will be mostly dry and warm.

- Scattered showers and thunderstorms will persist from Saturday
  night through the middle of next week with chances for severe
  storms each day, especially Tuesday.

&&

.DISCUSSION...
(Today through Thursday)
Issued at 310 AM CDT Fri May 16 2025

The active spring continues across the Mid-South. Currently we are
monitoring a mid level jet moving across the region this morning
which will serve to enhance lift and weaken the cap in place
across the region. Convection has been struggling so far but the
latest CAMs indicate robust development over the next few hours.
The airmass is very unstable with MLCAPES of 2500-3500 J/kg. Shear
is plenty sufficient for organized storms with 0-6km bulk shear
values of 60-70 kts. The main threats will be large hail and
damaging winds but the low level thermodynamics could also support
a tornado. A Severe Thunderstorm Watch is in effect until 9 am
roughly north of I-40. This activity will push east in Middle TN
by mid morning as the upper support lifts out.

The airmass almost immediately recovers as gusty SSW winds
continue to advect warm, moist air into the Mid-South. The
airmass becomes very unstable by the afternoon with dewpoints in
the lower 70s and enormous MLCAPEs in excess of 3500 J/kg. A cold
front approaches the region this afternoon as a mid level jet
moves into the Mid-MS Valley. This feature will provide the lift
to trigger storms along and just ahead of the front late this
afternoon. 0-6km bulk shear values of 50-60 kts this afternoon
and evening with 0-1km helicity values increasing to well over 200
m2/s2 will support organized storms. These storms will likely be
discrete with all hazards expected including strong tornadoes,
perhaps long tracked, very large hail and damaging winds. The lift
across the Mid-South is not overwhelming strong which will serve
to keep the storms at least semi-discrete as they gradually form
into a line during the evening. This will keep the strong tornado
threat going well into the evening hours especially along and
north of the TN/MS border. The higher end severe threat will end
by about midnight as storms move into Middle TN. A lower end
severe threat will continue across north MS as convection lingers
there until about 4 am.

The front/boundary along with associated convection will push
well south of the region by Saturday. The Mid-South will be in
between systems and should squeak out a pretty nice, warm day with
highs in the mid to upper 80s Saturday afternoon.

The front/boundary will lift back north into the area starting
Saturday night and remain over the region into early next week.
This will result in unsettled weather and chances for showers and
thunderstorms each day with a low end severe threat. Expect a more
organized severe risk by Tuesday as a potent mid level trough
pushes across the region along with its associated cold front.

Dry and cool weather is expected in the wake of Tuesday's system
as a deep upper trough is carved out across the eastern US with NW
flow developing across the Mid-South.

&&

.AVIATION...
(06Z TAFS)
Issued at 1155 PM CDT Thu May 15 2025

Nailing down the timing of each window of precip is quite
difficult this period as CAMs have been handling the initiation
quite poorly thus far. Given the northward trend of overnight
convection through 12Z, opted to make some pretty drastic changes
to MEM and MKL's precip for the next several hours. The vast
majority of the day looks completely dry for most areas. Main
show looks to be Friday night after 00Z, and will likely also
pack a punch with gusty winds as the convection materializes along
a very strong cold front. In terms of ceilings, don't think there
will be more than a few hours of MVFR this (Fri) morning,
otherwise VFR looks to prevail for all sites. Gusty non-
thunderstorm winds from the SW will also prevail for the majority
of the day into the evening tomorrow, finally diminishing
overnight into Saturday.

CAD

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&

PUBLIC FORECAST...SJM
AVIATION...CAD