Area Forecast Discussion
Issued by NWS Shreveport, LA

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FXUS64 KSHV 222319
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
619 PM CDT Tue Aug 22 2017

.AVIATION...
Isolated to scattered -SHRA/-TSRA noted south of kmlu and well
north of ktxk, the former likely being driven by daytime heating
thus will diminish shortly after sunset, but the latter is caused
by a cold frontal boundary. This quasi-stationary boundary is
expected to slowly push south tonight through tomorrow, and serve
as a focus for storm development. This TAF cycle will show
southerly winds shifting to the north due to the front, with
confidence high enough to insert a TEMPO group for -TSRA at ktxk
and keld at this time. Some computer models show this
precipitation breaking apart throughout the afternoon tomorrow,
hence struggling to reach the farther south terminals such as
klfk. However, a VCTS during the afternoon hours seem appropriate
for the remainder sites, but will of course amend necessary.
Otherwise, FEW-SKC VFR CIGS will scatter out to become SKC-FEW
overnight whilst sfc winds become light and variable. Clear skies
and light winds may set the stage for patchy fog, particularly at
klfk overnight.

&&

.PREV DISCUSSION... /issued 342 PM CDT Tue Aug 22 2017/

DISCUSSION...
Cold front draped across nrn AR/OK, associated with the upper
trof over SE Canada, continues to make its way swd this aftn.
Line of storms has developed along a swd-moving outflow boundary,
ahead of the cold front. Outflow storms will likely dissipate
with the loss of daytime heating this evening, but additional
storms will be possible as the front moves swd into our region
tonight/Wed. Front will move s of the region by Thursday, leaving
us with only slight chances for aftn convection for the latter
half of the work week. Cold front will bring cooler temps to the
region, only topping out in the 80s for Thursday/Friday.

Big story of the fcst for the next few days will be what happens
with the remnants of Harvey, which are currently over the Yucatan
Peninsula of Mexico. The remnants are fcst to move into the srn
Gulf of Mexico Wednesday and continue nnwwd onto the TX Coastal
Bend. Much uncertainty with the track of Harvey. Models have
adjusted the track nwd each run for at least the last 24 hours of
runs. Latest GFS/Euro/Canadian runs have the storm stalling/wobbling
just onshore /or even back into open waters/ before making an ewd
push along the TX coast. This is new to the most recent model
runs, so it will be interesting to see what happens in future
runs. Additional upper air soundings will be incorporated into the
models beginning with the 18Z runs today, so hopefully some
improved run-to-run consistency will be realized over the next
couple of days. Our very best first guess of what Harvey will mean
to our region places us seeing two to four inches of rainfall
areawide, with isolated higher amounts likely, beginning Saturday
and continuing through midweek next week. PoP/QPF grids lean to
the conservative side of things, considering that we are four or
five days out from these impacts. One thing is certain, one can
expect a lot of adjustments to the forecast over the next several
days. /12/


&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  76  93  72  88 /  20  40  30  20
MLU  75  90  70  85 /  10  40  30  20
DEQ  73  86  66  85 /  50  40  20  10
TXK  74  87  68  85 /  30  40  30  10
ELD  74  87  68  85 /  20  40  20  10
TYR  75  91  73  87 /  20  40  30  20
GGG  75  92  72  88 /  20  40  30  20
LFK  75  94  74  89 /  10  40  30  30

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&

$$

29/12



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