Area Forecast Discussion
Issued by NWS Shreveport, LA

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000
FXUS64 KSHV 230453
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
1153 PM CDT Thu Jun 22 2017

.AVIATION...
For the ArkLaTex, range of flight categories from VFR TX to IFR
LA/AR as Cindy`s remnant move into SE AR. Sfc winds are S/SW
prevailing in the wake of the system, still gusty in NE LA/SE AR.
Aloft, our climb winds are SW and back quickly to W/NW 20-40KTS
in the profile. The low will eject NE overnight and the rain with,
but IFR/MVFr cigs and vsby remain. An approaching cold front will
arrive tomorrow late into Sat a.m. with more shwrs/TSTMS. /24/

&&

.PREV DISCUSSION... /issued 1020 PM CDT Thu Jun 22 2017/

DISCUSSION...
The center of TD Cindy continues to weaken as it shifts NE into
extreme Srn AR this evening, with sfc obs depicting the center
between TXK and ELD as of 03Z. Much of the convection containing
heavy rainfall remains localized near and just S of the center,
from near SHV E to RSN, with the continued dry air entrainment
having limited convection development across much of Ncntrl LA.
However, believe this will change overnight as Cindy continues to
open up into an elongated upper trough as she continues to lift NE
into Scntrl AR, with the trailing H850 trough expected to linger
across Scntrl AR into extre.DISCUSSION...


&&

me Nrn LA near the I-20 corridor. S of
this bndry, a 40-50kt Swrly LLJ will continue S of the ejecting
low center, resulting in a period of continued convergence along
the H850 trough and thus renewed development. In addition, 0-6km
winds are expected to remain unidirectional overnight, with the
potential for training across much of Ncntrl LA as evident from
the ongoing convection over extreme SE TX/SW LA over the last
couple of hours. PW`s remain near or in excess of 2.5 inches, with
the strong low level shear expected to maintain/aid in additional
redevelopment overnight. Despite little rainfall having already
fallen over this area, the HRRR and 00Z NAM suggest that
additional rainfall amounts of 1-3+ inches are possible, with
isolated higher amounts of 5+ inches, which could result in
localized flash flooding.

Given this, have cancelled the Flash Flood Watch for all of E TX
as well as Lafayette and Columbia Counties in SW AR W of the
center, but will allow the existing watch to continue for Union
County AR and all of N LA. Should the HRRR/NAM indeed verify, it`s
possible the watch may need to be extended for much of Friday
morning for portions of Ncntrl LA until the heavy rain threat
diminishes by midday. Winds have been struggling across much of
the earlier Lake Wind Advisory, thus have cancelled the Advisory
early. Have also adjusted pops, mainly to drop pops for SE OK and lower
them across E TX/portions of SW AR. Did maintain
likely/categorical pops for N LA/Scntrl AR with the expectation of
renewed development overnight. Did have to make some changes to
pops Friday as well, as the highest pops will remain concentrated
during the morning over N L.DISCUSSION...


&&

A. Did lower them elsewhere to low/mid
chance, with diurnal heating contributing to increased instability
ahead of a weak sfc front that will approach SE OK/SW AR Friday
afternoon, resulting in the potential for sct convection. Did make
some minor tweaks to min temps tonight, as only little change is
expected.

Zone update/FFA/NPW cancellation already out...grids will be
available shortly.

15

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  76  88  74  83 /  80  50  60  60
MLU  76  86  74  83 /  90  80  60  70
DEQ  73  89  70  84 /  20  40  60  40
TXK  74  87  72  82 /  50  40  60  60
ELD  75  85  72  82 /  90  80  60  60
TYR  76  91  74  84 /  20  20  60  60
GGG  76  89  74  83 /  40  20  60  70
LFK  76  90  76  86 /  50  20  40  70

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Flash Flood Watch until 7 AM CDT Friday for ARZ073.

LA...Flash Flood Watch until 7 AM CDT Friday for LAZ001>006-010>014-
     017>022.

OK...None.
TX...None.
&&

$$

24/15



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