Area Forecast Discussion
Issued by NWS Memphis, TN
FXUS64 KMEG 241811
Area Forecast Discussion
National Weather Service Memphis TN
111 PM CDT SUN JUL 24 2016
18z Aviation Discussion Update.
.PREV DISCUSSION... /issued 1021 AM CDT SUN JUL 24 2016/
Updated to cancel Heat Advisory.
Shear axis/remnant MCV is continuing to bring significant cloud
cover to the Midsouth this morning...with likely new scattered
convection expected by early this afternoon. Have lowered high
temperatures and thus heat indices for today accordingly. Though a
county or two may top out at 105F the majority of the region will
be lower to include the Memphis metro. Depending on how far this
feature tracks westward tomorrow...the heat may be able to build
back in across portions of the area for additional heat headlines.
.PREV DISCUSSION... /issued 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 CONUS. 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 AR/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.
18z TAF Set
VFR conditions will prevail through the forecast period. The
exception will be in thunderstorms where lower cigs and vsbys will
be possible. Highest storm coverage appears to exist this
afternoon over the east with tempos included at KMKL and KTUP.
Elsewhere more isolated coverage is anticipated with VCTS at KMEM
and KJBR today. Winds should remain light from the south
Tonight...convection should diminish across the east but may
continue in an isolated fashion at KMEM and KJBR in closest
proximity to lingering MCV. This continues into Monday morning at
KMEM and KJBR...but dry conditions expected at KMKL and KTUP.
Winds remain light tonight and Monday morning.