Area Forecast Discussion
Issued by NWS Memphis, TN

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FXUS64 KMEG 252036

Area Forecast Discussion
National Weather Service Memphis TN
336 PM CDT Tue Jul 25 2017

Dangerous heat continues to be the primary weather story across
the Mid-South today. Temperatures are running a few degrees above
climo this afternoon with 3 PM readings generally in the low to
mid 90s. Dewpoints remain in the mid/upper 70s across the
Mississippi Delta region, resulting in heat indices well over 105
degrees in some areas. Strong surface heating has resulted in
substantial instability across the region, supporting scattered
diurnal showers and thunderstorms. A few strong storms will be
possible this afternoon with the main hazard being damaging wind.
In addition, very slow storm motions will allow storms to produce
very heavy rainfall in localized areas. Isolated convection will
persist into the evening hours but should dissipate by 03z. Patchy
fog will be a concern late tonight, mainly in low areas and river
valleys in west TN and northeast MS.

Similar conditions are anticipated across the Mid-South tomorrow
with temperatures again warming into the mid 90s. In fact, a few
locations may be a degree or so warmer on Wednesday. Dewpoints are
forecast to be a bit lower, likely a response to the subsidence
associated with the building upper-level ridge. That said, my gut
says the models are overdoing the "drying" tomorrow afternoon
across the western half of the CWA as has been the case the past
few days. This may be do to the abundance of rice fields across
the AR delta counties. Either way, heat indices are likely to
reach 105 degrees, roughly along and west of a Martin, to Jackson,
to Somerville, to Clarksdale line. A Heat Advisory is in effect
for these areas through 8 PM Wednesday. It`s not out of the
question that a few areas could top 110 degrees again, primarily
from Jonesboro into the MO Bootheel. Convection will be possible
again tomorrow afternoon, but shouldn`t be as widespread and
generally confined to north MS and west TN.

We`ll see one more hot day across the region on Thursday. Again,
heat indices are likely to top 105 degrees in many areas. Will let
today`s heat headline expire before considering another for Day
3, but a Heat Advisory is appearing likely. Showers and
thunderstorms will be a bit more widespread to our north on
Thursday, but there is some indication that storms may develop
across the Mid-South in the warm sector during the afternoon
hours. This cold front is projected to move into the CWA
overnight and Friday, bringing with it a good chance for showers
and thunderstorms. A few strong to severe storms aren`t out of the
question as this system comes through late Thursday and Friday,
in addition to the potential for heavy rainfall. Rain chances will
gradually come to an end late Friday as cooler and drier air
advects into the Mid-South.

Expect pleasant late July weather across the region this weekend.
High temperatures are forecast to remain in the mid to upper 80s
with afternoon dewpoints in the lower 60s. This will yield heat
indices below 90 degrees, providing an opportunity to finally get
the lawn mowed. Overnight low temperatures will likely dip into
the low to mid 60s across much of the CWA during this period with
mostly clear skies over the weekend.

The synoptic pattern is quite amplified next week with a nearly
600 dam ridge over the western CONUS and a relatively deep trough
over the east. Northerly flow aloft will be present over our neck
of the woods, keeping temperatures at bay. Rain chances return to
the forecast early next week, but temperatures remain seasonably
cool with highs generally at or below 90 degrees.



/18z TAFs/

Isolated to scattered thunderstorms are expected this afternoon
but dissipate after sunset. Mainly VFR conditions outside of
thunderstorms. Winds will be from the SSW generally 5-8kt,
decreasing to 5kt of less overnight, then 5-8kt again Wednesday.



AR...Heat Advisory until 8 PM CDT Wednesday for Crittenden-Cross-
     Lawrence-Lee AR-Phillips-Randolph-St. Francis.

     Excessive Heat Warning until 7 PM CDT this evening for Clay-

     Heat Advisory from 7 PM this evening to 8 PM CDT Wednesday for

MO...Heat Advisory until 8 PM CDT Wednesday for Pemiscot.

     Excessive Heat Warning until 7 PM CDT this evening for Dunklin.

     Heat Advisory from 7 PM this evening to 8 PM CDT Wednesday for

MS...Heat Advisory until 8 PM CDT Wednesday for Coahoma-DeSoto-Tunica.

TN...Heat Advisory until 8 PM CDT Wednesday for Lauderdale-Shelby-

     Heat Advisory from noon to 8 PM CDT Wednesday for Crockett-Dyer-


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