Area Forecast Discussion
Issued by NWS Shreveport, LA

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FXUS64 KSHV 240217

Area Forecast Discussion
National Weather Service Shreveport LA
917 PM CDT TUE AUG 23 2016

Isold convection has diminished with setting sun. Updated to
remove pops overnight./VII/.


.PREV DISCUSSION... /issued 830 PM CDT TUE AUG 23 2016/

For the 24/00Z terminal forecast...expecting mostly VFR flight
categories until the late night/early morning hours on
Wednesday. Current isolated showers and thunderstorms on the
decline and sky cover around 4 kft will slowly erode with
some lingering high clouds around 25 kft. Patchy mist/br and
areas of MVFR/IFR ceilings look to develop after 24/08-24/10Z
across parts of Deep East Texas and moving North Northeast
over East Texas near 24/12Z and may extend into Southwest Arkansas
and Northwest Louisiana between 24/12Z-24/16Z. Any ceilings into
the mid morning to late morning hours to return to VFR. A scattered
cumulus field developing in the early to mid afternoon hours
Wednesday around 4-5 kft. Surface winds will be light and variable
to light South 3-6 knots overnight night and South 5-10 knots on
Wednesday. /06/

PREV DISCUSSION... /issued 731 PM CDT TUE AUG 23 2016/

Very isold convection has continued into the early eve, mainly
south of I-20, thus updating fcst./VII/.

PREV DISCUSSION... /issued 411 PM CDT TUE AUG 23 2016/

A broad upper ridge centered over the Southeast U.S. has expanded
over the CWA today. Although most of the deep layer moisture plume
has been moved away by the ridge, southerly flow off the Gulf of
Mexico has aided in the development of isolated convection
associated with the sea breeze. This activity is primarily
diurnally driven and should dissipate by early this evening.
Conditions on Wednesday will likely be similar, expect the center
of the ridge should be in Mississippi, which will likely limit
convective development even more. Slight chance PoPs were
maintained for our far southern counties and parishes in Deep East
Texas eastward into Louisiana. The greater concern is the heat.
Relative humidity levels remain high due to the recent rains.
Combined with the temperatures in the mid 90s, this should result
in heat index values above 105 degrees F across all of Louisiana
and portions of Southern Arkansas and Deep East Texas for
Wednesday afternoon. It is worth noting that the models have been
too aggressive with mixing out dewpoints most of this summer.

Showers and thunderstorms should be more widespread Thursday
through Saturday as a shortwave trough moves northeast across
Oklahoma and Kansas and as a second weak upper wave rotates around
the southern and western periphery of the upper ridge. Current
thinking is that cloud cover and precipitation should be
sufficient to cool temperatures enough that heat index values
will be below advisory criteria for Thursday. However, the heat
headlines will be elevated one day at a time.

The flow aloft will transition to easterly on Sunday as the ridge
flattens, but expands to the west. There will be chances for
isolated to widely scattered diurnal convection each afternoon
Sunday through Tuesday as weak disturbances travel westward under
the ridge. Once rain chances begin to diminish, temperatures will
start to gradually warm.

Beyond Tuesday, the forecast is highly uncertain. It is worth
noting that the 12z ECMWF suggests a potential tropical system
affecting the Southeast U.S. by the middle of next week. However,
the GFS does not yet show this system. The impacts of this
potential system are still seven or more days in the future.



SHV  75  94  75  92 /  10  10  10  40
MLU  75  94  75  92 /  10  10  10  50
DEQ  73  92  72  92 /  10  10  10  30
TXK  75  92  75  92 /  10  10  10  40
ELD  75  93  75  91 /  10  10  10  50
TYR  75  91  74  91 /  10  10  10  30
GGG  75  92  75  91 /  10  10  10  40
LFK  75  92  75  92 /  10  20  10  40


.SHV Watches/Warnings/Advisories...
AR...Heat Advisory from noon to 7 PM CDT Wednesday for ARZ073.

LA...Heat Advisory from noon to 7 PM CDT Wednesday for LAZ001>006-

TX...Heat Advisory from noon to 7 PM CDT Wednesday for TXZ153-166-167.


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