Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Memphis Tennessee
419 am CDT sun Jul 24 2016
primary interrelated forecast challenges remains heat indices and
Early morning GOES water vapor imagery showed a broad upper level
height ridge across the southern half the Continental U.S.. this upper ridge
had deamplified from its position over the Central Plains several
days ago. In addition, a weak nearly stationary easterly wave and
extensive mid/upper level cloudiness was present over the lower
MS River Valley. This wave will drift slowly west into Arkansas/la by
this afternoon, likely initially focusing thunderstorm development
in this region. In the weakly-sheared environment, additional
thunderstorms will likely develop along eastward-expanding
outflow boundaries into the midsouth.
In areas not affected by thunderstorm outflow, heat indices could
quickly warm above 105f. The heat advisory has been carried over
today, but the initial presence of high clouds and low level
thunderstorm outflow later today limits forecast confidence.
Similar conditions expected for Monday. Given the limited forecast
confidence, and after collaborating with surrounding forecast
offices, have deferred extending the heat advisory into Monday.
Tuesday will see the arrival of weak westerly upper level flow
and additional destabilizing effects of a stationary sheer axis
near the arklamiss. Northwest upper level flow will gradually
increase in strength with height falls through late in the week,
leading to continued rain chances and daytime temperatures
moderating to near or slightly below normal as we close out July.
06z taf set
Isolated ts near mem is shifting to the south and should not be a
factor in the forecast by 06z. Winds will be light and variable
tonight...generally from the south around 5kt tomorrow. Additional
thunderstorms are expected to develop by midday tomorrow...likely
impacting all sites. Patchy MVFR br is possible at tup mem and mkl
tonight within a few hrs of sunrise.
Arkansas...heat advisory until 8 PM CDT this evening for Clay-Craighead-
MO...heat advisory until 8 PM CDT this evening for Dunklin-Pemiscot.
MS...heat advisory until 8 PM CDT this evening for Benton MS-Coahoma-
Tennessee...heat advisory until 8 PM CDT this evening for Benton Tennessee-Carroll-