Blowing Dust Warning 2, NWS Memphis, TN

Area Forecast Discussion
National Weather Service Memphis TN
646 AM CDT Wed Apr 2 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 642 AM CDT Wed Apr 2 2025

-Severe weather and very heavy rainfall are expected this afternoon
through Saturday.

-Five day total rainfall amounts are in the 10 to 15 inch range
along and north of I-40. This is not your average flood risk.
Generational flooding with devastating impacts is possible.

-A High Risk of severe weather today, a Slight Risk is in effect
 Thursday,Friday and Saturday.

-A Moderate Risk of excessive rainfall is in effect today, Friday
 and Saturday with a High Risk on Thursday.

&&

.DISCUSSION...
(Today through Tuesday)
Issued at 354 AM CDT Wed Apr 2 2025

A dangerous weather pattern will unravel this afternoon as an upper
level low and attendant cold front will impinge on the area. As the
system inches closer, the pressure gradient will tighten and bring
strong sustained and gusty wind conditions. A Wind Advisory will go
into effect at 7 AM this morning due to these conditions. The
highest winds will be found across northeast Arkansas, the Missouri
Bootheel, and northwest Tennessee with gusts up to 50 mph possible.
Elsewhere, gusts around 40 mph and sustained winds between 20-30 mph
are expected.

Surface analysis as of 3 AM shows a warm front lifting north across
the Memphis metro. Surface observations behind the boundary show
dewpoints entering the 60s. This moisture will provide ample
instability combined with lift from the approaching cold front and a
70 kt LLJ; a High Risk for severe weather is in store for portions
of the Mid-South today. The upgrade in risk is tornado driven as SRH
values exceed 200 m2/s2 with curved and elongated hodographs. The
CAMs have also been more in favor of discrete cell development, and
given this prime environment, these cells could easily turn
supercellular and produce strong tornadoes. Discrete cell
development will be approaching from the west as early as 3 PM this
afternoon.

Strong tornadoes are not the only concern, lapse rates
are between 7-8C/km with almost 3,000 MUCAPE to work with,
significant hail is not out of the question; especially in any
supercells. The discrete cells eventually will congeal into a line
as the cold frontal boundary is anticipated to stall practically
along the I-4O corridor late tonight which will shift to a damaging
wind threat of 70+ mph gusts. Once the storm mode is more linear,
embedded supercells within the line could still produce a tornado.
The most likely timing for the severe weather is 3 PM- 12 AM as the
loss of daytime heating and rain cooled surfaces should help
stabilize the environment. It is so important to have multiple
ways to receive warnings especially as some of these tornadoes
could be strong and long tracked. All hazards could occur after
sunset, which is the most deadly time.

As mentioned above, the stalled frontal boundary will linger with at
least slight chances of severe weather through Saturday.
Instability to the south of the front is still favorable of a
strong to severe thunderstorm. As this front remains parked, it
will provide enough lift and bursts of energy to need to be
monitored for a few storms with all hazards at play. This pattern
will continue until the front clears the area. Saturday, the
severe weather threat could increase slightly across north
Mississippi as the front begins to move over a not as saturated
area.

While we continue to monitor the severe weather potential, a
historical rainfall event will commence. Generational flash, river,
and areal flooding are all possible. Maxed out precipitable water
values for four convective days, training storms extremely
likely, and any convective development increasing localized
amounts has QPF values forecast to be in the 10-15 inch range. The
area likely to see such high amounts will be along and north of
I-40. Considerable flash flooding, especially in urbanized areas,
is expected. Never drive through flooded waters, and flooded
roadways are significantly more difficult to see at night. The
axis of heavy rainfall could still very easily shift so be sure to
continue to monitor the forecast.

While our current forecast could break several rainfall records
across the area, it is a bit more optimistic for it to be more
spread out over four days, however, the culmination will put a
strain on the ground's ability to absorb. At some point, soils will
become supersaturated and leave no option but to reject all the
additional rain as runoff. Flash flooding will emerge as a primary
concern with this extremely active pattern. In addition, all of this
rainfall will make tree limbs very weak and easily breakable. It is
best to not only prepare for flooding, but power outages as well.
Moderate Risks and a High Risk of excessive rainfall are in effect
for portions of the Mid-South each day through the event.

Once the front is forced out of the area by a reinforcing cold
front, dry and cooler conditions return Monday morning. Until then,
stay safe.

DNM

&&

.AVIATION...
(12Z TAFS)
Issued at 642 AM CDT Wed Apr 2 2025

MVFR cigs this morning will improve this morning to VFR. Gusty
south winds will prevail today with gusts of 30-40 kts across the
areas. Showers and thunderstorms will push into the area this
afternoon and this evening impacting JBR, MKL and MEM mainly
between 02/23z and 03/06z. TUP should remain south of the activity
through the TAF period.

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Wind Advisory until midnight CDT tonight for ARZ009-018-026>028-
     035-036-048-049-058.

     Flood Watch from 1 PM CDT this afternoon through Sunday morning
     for ARZ009-018-026>028-035-036-048-049-058.

MO...Wind Advisory until midnight CDT tonight for MOZ113-115.

     Flood Watch from 1 PM CDT this afternoon through Sunday morning
     for MOZ113-115.

MS...Wind Advisory until midnight CDT tonight for MSZ001>017-020>024.

     Flood Watch from 1 PM CDT this afternoon through Sunday morning
     for MSZ001>005-007-008-010>014-020.

     Flood Watch from late Friday night through Sunday afternoon for
     MSZ006-009-015>017-021>024.

TN...Wind Advisory until midnight CDT tonight for TNZ001>004-019>022-
     048>055-088>092.

     Flood Watch from 1 PM CDT this afternoon through Sunday morning
     for TNZ001>004-019>022-048>055-088>092.

&&

PUBLIC FORECAST...DNM
AVIATION...SJM