Severe Thunderstorm Warning 304, NWS Memphis, TN

Area Forecast Discussion
National Weather Service Memphis TN
858 PM CDT Fri Jul 20 2018

.UPDATE...

Thunderstorms are starting to develop over Central Arkansas at
this time. The NAM Nest showed this development on the 18Z run.
This could be the start of the expected severe weather. Right
now if these storms continue to evolve, best chances for severe
storms may be along and south of I-40. Will leave forecast as is
for now.

KRM

&&

.DISCUSSION... /issued 303 PM CDT Fri Jul 20 2018/

Skies are mostly sunny across much of the forecast area this
afternoon with temperatures in the low to mid 90s. Current heat
index values are close to 110 degrees in areas where the excessive
heat warning is in effect. Currently, a cold front extends from
northern Indiana into central Missouri.

This cold front will continue to drop south tonight and move into
the forecast area overnight. Additional thunderstorms are expected
to develop ahead of the front tonight and move into the forecast
area. Some of these thunderstorms could become severe with
damaging winds as the main threat but large hail and isolated
tornadoes can't be ruled out especially over northwest Tennessee.
Temperatures will remain rather seasonable with lows Saturday
morning in the low to mid 70s.

The cold front will continue to move through the forecast area
Saturday with scattered thunderstorms expected ahead of the front
mainly over north Mississippi. Temperatures will be a little
cooler with highs in the lower 90s. Heat index values will be
lower on Saturday so no Heat Advisory should be needed. High
pressure will briefly build into the region for Saturday night
bringing dry weather and slightly cooler temperatures.

An upper level disturbance will drop south into Middle Tennessee
on Sunday with scattered thunderstorms possible over eastern
sections of the forecast area for Sunday and Sunday night. Monday
may see some scattered afternoon thunderstorms over eastern
sections of the forecast area.

Another cold front will approach the region on Tuesday and move
into the forecast area on Wednesday. This will mean more
thunderstorms both days. This front will die out across the
forecast area on Thursday but another front will start to approach
the region Thursday and next Friday so more thunderstorms are
expected to form.

ARS

&&

.AVIATION...

Expect SHRAs/TSRAs to develop in a very unstable atmosphere
across the Mid-South as an upper level disturbance moves through
in the strong NW flow aloft. Moved the timing for TSRAs up a
couple of hours given the ongoing trends and latest HRRR run.
Expect most of the activity to push south of the region by
sunrise. Saturday looks VFR with gusty NW winds.

SJM

&&

&&

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

Hazardous Weather Outlook
National Weather Service Memphis TN
808 PM CDT Fri Jul 20 2018

ARZ008-009-017-018-026>028-035-036-048-049-058-MOZ113-115-
MSZ001>017-020>024-TNZ001>004-019>022-048>055-088>092-220315-
Alcorn-Benton MS-Benton TN-Calhoun-Carroll-Chester-Chickasaw-Clay-
Coahoma-Craighead-Crittenden-Crockett-Cross-DeSoto-Decatur-
Dunklin-Dyer-Fayette-Gibson-Greene-Hardeman-Hardin-Haywood-
Henderson-Henry-Itawamba-Lafayette-Lake-Lauderdale-Lawrence-
Lee AR-Lee MS-Madison-Marshall-McNairy-Mississippi-Monroe-Obion-
Panola-Pemiscot-Phillips-Poinsett-Pontotoc-Prentiss-Quitman-
Randolph-Shelby-St. Francis-Tallahatchie-Tate-Tippah-Tipton-
Tishomingo-Tunica-Union-Weakley-Yalobusha-
808 PM CDT Fri Jul 20 2018

This hazardous weather outlook is for portions of East Arkansas...
the Missouri Bootheel...North Mississippi...and West Tennessee.

.DAY ONE...Tonight

An outbreak of severe thunderstorms is expected tonight. There is
a Moderate Risk for Severe Thunderstorms across northwest
Tennessee, with an Enhanced Risk of Severe Thunderstorms across
the remainder of the area. The potential will exist for very large
hail, some golfball size or larger, damaging winds, and a few
tornadoes. Please continue to monitor the weather through the
night and be prepared to take cover if warnings are issued for
your location.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed across the Mid-South
tonight.

KRM