Area Forecast Discussion
Issued by NWS Shreveport, LA

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FXUS64 KSHV 160409

Area Forecast Discussion
National Weather Service Shreveport LA
1009 PM CST Fri Feb 15 2019

.SHORT TERM.../Tonight through Saturday/

The evening sfc analysis indicates a cold front extending from
near a DKR, to just NW of OCH, to near 3F3, to just N of
a TVR line as of 04Z. 2-4hr/3hr pressure rises behind the front
over NE TX/SW AR will allow for the front to continue to shift
steadily SSE across the remainder of the region this evening,
exiting the Srn most parishes of Ncntrl LA shortly after 06Z.
Although the evening radar imagery has been void of any isolated
-SHRA, sfc obs indicate that some -DZ has been noted behind the
front across portions of SW AR, whereas vsbys have fallen to
2-4SM in BR, with cigs falling to LIFR as well. Believe that this
will be short-lived, with cigs to the N beginning to slowly
climb, which should translate S into far Srn AR later tonight.
Still can`t rule out very isolated -SHRA developing late tonight
near the front over the SE sections of Ncntrl LA, before ending
prior to daybreak Saturday.

Have scaled back pops to slight chance and maintained these pops
this evening for Srn AR and extreme Nrn LA where the -DZ may
persist for a while longer, before taking out pops for all but the
SE sections of Ncntrl LA after 06Z. The sfc obs depicts temps
falling some 10-15 degrees with the fropa this evening, but
upstream obs over SW AR have been fairly steady the last few hours
indicating that this air mass is shallow, and the higher terrain
of the Ouachitas has begin to dam this cold air, such that the
wedge of colder air will seep S and graze the far Wrn sections of
E TX overnight. However, farther E, the colder air is progged to
slowly backdoor SW into SW AR/portions of N LA overnight. Have had
to make some minor downward adjustments to min temps tonight given
this classing cold air damming regime, with the more noticeable
changes to temps noted across the Wrn sections of E TX, as well as
portions of SW AR.

With the front settling S to near the I-10 corridor of SE TX/SW LA
by or prior to daybreak Saturday, the colder air will remain
entrenched over much of the area, with overrunning expected to
gradually increase from late morning through the afternoon over
much of the area. Thus, max temps will struggle to reach
forecasted values, especially over portions of E TX/N LA. Have
lowered temps 1-2 categories over these areas into the lower/mid
50s, with very little of a diurnal swing expected farther N across
NE TX/SE OK/SW AR/extreme N LA. Have held off on slight chance
pops for the area for the afternoon, although the 18Z and new 00Z
runs of the NAM and the 12Z ECMWF depict that slight chance pops
may be needed for portions of the area where overrunning increases
atop the shallow cold dome in place. But will defer this decision to
the mid-shift once new model data is available.

Zone update already out...grids will be available shortly.



.PREV DISCUSSION... /issued 551 PM CST Fri Feb 15 2019/

As of 2330Z, the cold front has reached a CRS, to TYR/JXI, to
along the AR/LA line. VFR conditions will persist S of the front
through a portion of this evening across Lower E TX/N LA, but this
will change as the front quickly shifts SSE across the remainder
of E TX and into the Srn sections of Ncntrl LA by mid to late
evening. IFR/low MVFR cigs just N of the front over SW AR are
expected to spill S with the front this evening, with these lower
cigs reaching the SHV/MLU terminals by 03Z, but will take a bit
longer to affect the E TX terminals (TYR/GGG/LFK) until after 06Z
as these cigs will have to backdoor SW over these areas. The front
should reach the I-10 corridor of SE TX/SW LA by or shortly before
daybreak Saturday, although overrunning will quickly develop atop
this colder but shallow air mass by/after 12Z, resulting in IFR
cigs developing over Lower E TX throughout the morning and
lingering through the remainder of the 00Z TAF period. Elsewhere,
low MVFR cigs will persist through Saturday, with isolated areas
of -RA possible especially for the afternoon as the overrunning
spreads back NNE across the remainder of the region. However, low
confidence precludes mention in the TAFs attm, with little if any
impacts to vsbys. Look for NNW winds 8-12kts behind the front (SW
winds 4-7kts this evening over Lower E TX/N LA) to become more ENE
6-11kts after 12Z. However, SE winds 5-7kts will return to the W
and SW sections of E TX by mid to late afternoon Saturday. /15/


SHV  44  50  48  65 /  10  10  20  20
MLU  42  50  47  64 /  20  10  20  30
DEQ  39  45  40  60 /  10  10  20  10
TXK  39  46  42  60 /  20  10  20  20
ELD  38  49  44  62 /  20  10  20  30
TYR  40  49  49  62 /   0  10  20  10
GGG  46  50  49  63 /   0  10  20  10
LFK  51  54  54  68 /   0  10  20  20




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