Severe Thunderstorm Warning 233, NWS Memphis, TN

Area Forecast Discussion
National Weather Service Memphis TN
634 PM CDT Tue Jun 26 2018

.DISCUSSION...

Updated for aviation discussion

&&

.PREV DISCUSSION... /issued 356 PM CDT Tue Jun 26 2018/

Hot and very humid conditions remain in place across a large
portion of the Mid South where heat index values have exceeded 105
degrees. This will keep dangerous heat conditions in place
through at least this evening where a heat advisory remains until
8 pm cdt. Dangerous heat will expand across southern sections of
the area and the heat advisory has been extended and expanded into
Wednesday evening for some locations.

The next concern this evening will be the potential for severe
storms. A complex of strong to severe storms have formed ahead of
a shortwave rotating around the southern periphery of an upper
level low pressure system over eastern Iowa this afternoon. This
complex of storms will continue to advance southeast as and push
into an unstable airmass, where MLCAPES should remain greater than
2500 j/kg. In addition, deep layer shear across the northern
counties of the CWA will range from 30-40 kts. This will support a
continuation of convection into our northern half of the forecast
area tonight. A few of these storms may be severe with damaging
winds the primary threat with any bowing line segments. An
enhanced risk for severe storms is now in effect for portions of
northeast Arkansas and the Missouri Bootheel. A slight risk for
severe storms remains to the south of the enhanced risk for the
remainder of northeast Arkansas into much of west Tennessee.

Further south towards the I-40 corridor, mid level capping
inversion should remain stronger with upper level ridging holding.
Should see a gradual weakening and DISSIPATION of storms as they
reach this far south. Tapered pops and severe threat with
southward extent across the Mid South tonight.

Residual convection will continue into Wednesday across northeast
portions of the Mid South with either reintensification or
redevelopment along old outflow boundaries.

Upper level ridging then strengthens and centers across the Mid
South for Thursday and Friday. This will result in a reduction of
convection and the expansion of very hot and humid conditions.
Heat advisories or even excessive heat warnings may be needed for
most if not all of the Mid South.

The upper ridge breaks down over the weekend as deep tropical
moisture advects into the region from the southeast. This will
increase storm coverage some over portions of the area but will
keep dangerous heat over western portions of the area. Heat
advisories may continue over these portions of the area. Storm
coverage will continue to increase into early next week with a
return to seasonable temperatures for early July.

JLH

&&

.AVIATION...

Mainly VFR conditions expected through the period outside of
TSRAs. A complex over southern Missouri will drop SE into the
region this evening. KJBR stands the best chance of seeing TSRAs
on station as the line should hold together at least that long.
Line will probably remain north of KMEM and weaken before reaching
KMKL so stuck with VCTS at those locations. More convection is
possible Wednesday afternoon. Added a VCTS at KMEM after 18z
though confidence in that timing is low.

Expect winds to remain SSW around 10 kts at KMEM
overnight...slightly lower elsewhere. Gusty southwest winds
expected again tomorrow by late morning.

SJM

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Heat Advisory until 8 PM CDT this evening for Clay-Greene-
     Lawrence-Randolph.

     Heat Advisory until 8 PM CDT Wednesday for Craighead-Crittenden-
     Cross-Lee AR-Mississippi-Phillips-Poinsett-St. Francis.

MO...Heat Advisory until 8 PM CDT this evening for Dunklin-Pemiscot.

MS...Heat Advisory until 8 PM CDT Wednesday for Coahoma-DeSoto-
     Marshall-Panola-Quitman-Tallahatchie-Tate-Tunica.

     Heat Advisory from 10 AM to 8 PM CDT Wednesday for Calhoun-
     Chickasaw-Itawamba-Lafayette-Lee MS-Monroe-Pontotoc-Union-
     Yalobusha.

TN...Heat Advisory until 8 PM CDT this evening for Crockett-Dyer-
     Fayette-Gibson-Hardeman-Haywood-Lake-Lauderdale-Madison-
     Obion-Weakley.

     Heat Advisory until 8 PM CDT Wednesday for Shelby-Tipton.

&&

Hazardous Weather Outlook
National Weather Service Memphis TN
403 PM CDT Tue Jun 26 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>092-272315-
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-
403 PM CDT Tue Jun 26 2018

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

.DAY ONE...Tonight

There is an Enhanced Risk for Severe Thunderstorms across portions
of northeast Arkansas and the Missouri Bootheel tonight. A slight
risk to the south of the enhanced risk will cover the remainder of
northeast Arkansas and much of west Tennessee. Damaging winds will
be the primary severe weather threat.

A heat advisory remains in effect through this evening for a
large portion of the Mid South. Heat index values will remain
above 105 degrees resulting in dangerous heat conditions.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

A few strong to severe thunderstorms will be possible near the
Tennessee River on Wednesday.

Afternoon heat indices likely will exceed 105 degrees over the
Mid-South from Thursday through the first half of the weekend. A
heat advisory remains in effect on Wednesday for the southern
half of the Mid South.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed tonight across northern portions
of the Mid South.

JLH