Area Forecast Discussion
Issued by NWS Shreveport, LA

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054
FXUS64 KSHV 220855
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
355 AM CDT Wed Mar 22 2017

.DISCUSSION...
The backdoor cold front was starting to move in across portions of
southwest AR and southeast OK early this morning, brining with it
increasing cloud cover and perhaps initially some drizzle/very
light rain. The main shower and thunderstorm activity was noted
across northern AR and western TN, with model solutions hinting at
this precipitation struggling to get into southwest AR and
southeast OK. Considered removing slight chance POPs but latest
radar analysis did indeed show very light radar echoes across the
aforementioned areas. Have elected to insert slight chance of
rainfall with isolated thunderstorms versus slight chance of
thunderstorms, but will continue to monitor and if warranted will
remove the weather later this morning. In addition, A stratus deck
with patchy fog has been spreading northward from southern LA to
across central LA and deep east TX early this morning. The HRRR
solution show this stratus deck and fog continuing to move
northward to near the Interstate 20 corridor before scouring out
by mid- morning. This weather package reflects this trend.

The cold front will make it to south of Interstate 20 before
becoming diffused by late morning/early aftn. This front albeit
weak, will still be capable of resulting in an obvious temp gradient
of upper 60s to lower 70s across southwest AR, northeast TX and
southeast OK, to the lower to middle 80s across deep east TX and
central LA. As such, any chances for record breaking warmth will be
moot today. Tomorrow however, above normal temps will make a return
/80s/ courtesy of the weak cold front retreating as a warm front,
coupled with an UA ridge passing overhead.

Main focus in the extended forecast continues to be the widespread
showers and thunderstorms anticipated for Friday, as well as the
potential for some of the storms to become strong to severe.
Model solutions are in pretty good agreement in showing a Pacific
UA trough progressing east-northeast across southern Cali to
across the Four-corners region and onto the Plains, during which
time it is progged to close off before affecting the Four-State
region. Convection will ignite along the dryline across the Red
River Valley Friday late morning/early aftn and gradually push
east where it will impinge on east TX and southeast OK by late
aftn, and progress from west to east across the remaining
ARKLATEX during the evening and overnight hours. The Weather
Prediction Center has progged rainfall amounts of 1.00-2.00 inches
just during the 24-hour period of 12Z Friday to 12Z Saturday,
thus suggesting periods of moderate to heavy rainfall.
Furthermore, steepened lapse rates combined with 0-6 km bulk
shear of 40-60 kts and MUCAPE of 500-1000 j/kg raises concern for
some of the storms being capable of becoming organized and produce
damaging wind gusts, hail and isolated tornadoes. The severe
threat will start to diminish by late Saturday morning/early aftn
when the UA disturbance and associated precip commence exiting the
region.

We will see a brief reprieve from wet weather conditions on Sunday
as a short-amplitude UA ridge moves across the region. Thereafter, a
progressive synoptic flow will take place, though long term
solutions disagree a bit wrt how progressive the pattern will be.
The ECMWF is rather progressive in showing chances for rainfall
Monday-Wednesday, versus the slower evolving GFS hence resulting
in breaks from precip Tuesday-Wednesday. Have elected to show
slight chance/low end chance pops next week in order to account
for a bit of uncertainty.

Temperatures will cool into the 70s Friday and Saturday due to the
widespread showers and thunderstorms, but will rebound into the
70s and 80s next week /though next week temps could be overdone if
we receive more rainfall and cloud cover than expected/.

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  79  59  85  63 /  10  10  10  10
MLU  77  56  85  63 /  10  10  10  10
DEQ  69  52  81  57 /  20  10  10  10
TXK  73  54  83  61 /  20  10  10  10
ELD  73  54  82  61 /  10  10  10  10
TYR  80  60  85  63 /  10  10  10  20
GGG  79  59  85  62 /  10  10  10  10
LFK  85  61  88  64 /  10   0  10  10

&&

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

$$

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