Area Forecast Discussion
Issued by NWS Shreveport, LA

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309
FXUS64 KSHV 210915
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
415 AM CDT Mon May 21 2018

.SHORT TERM.../Today through Tuesday Night/

Ongoing convection this morning is mainly limited to parts of SW
Arkansas as it continues drifting N/NE. Elsewhere, abundant mid
and high clouds blanket the much of the region with some spotty
low stratus across parts of E Texas where a weak frontal boundary
continues to linger this morning as it extends north into western
Arkansas. This boundary is expected to be the focus for additional
showers and thunderstorms later today as we begin to heat up and
destablize the atmosphere. Couple that with nearly 2 inch PWATS,
and you have a good recipe for more of what we saw yesterday over
much of the region. More rainfall is certainly welcome as May has
been an unusually dry month in our part of the country. The other
benefit, of course, is dampening our high temperatures just a bit
with max readings today mainly in the mid to upper 80s to near 90
degrees over sections of north central Louisiana where POPS are a
little lower today. Much like yesterday, expect to see convection
diminish after sunset with heating loss. Overnight lows will fall
into the mid and upper 60s to near 70 degrees on Tuesday morning.

Weak upper ridging will try to nudge eastward from the Plains on
Tuesday, but expect another day of scattered convection along the
southern periphery of the ridge axis. Temperatures will inch back
up a few degrees under the influence of the ridge but remain just
below 90 degrees for most areas due to the more extensive cloud
cover and scattered convection during the afternoon. The diurnal
trends will play a factor once again as convection will diminish
with the setting sun on Tuesday evening with overnight lows ending
up on either side of 70 degrees. /19/

.LONG TERM.../Wednesday through Monday/

By the middle portion of the work week, 500mb analysis shows weak
ridging across the Lower Miss Valley with an embedded inverted
trough centered across the Middle Red River Valley into Central La
and offshore the S LA coast. This general pattern will remain
virtually unchanged through much of the remainder of the work week
which will work with daytime heating and higher pwat content to
produce scattered showers and thunderstorms each day.

Differences begin to plague the medium range when it comes to the
development of a closed low in the 500mb height fields across the
Central Gulf. The 00z ECMWF wants to bring this feature northward
towards the south central LA Gulf Coast by Sat while the 00z GFS
just keeps a broad trough axis to the east of our region through the
upcoming weekend. The Canadian is more in line with the development
of this gulf trough into something more significant than the GFS
suggests but keeps the feature east of our region through the
weekend as well. Made an attempt to blend model pops for late in the
work week into the upcoming weekend which would keep the higher pops
across our eastern most zones but confidence is not there to go any
higher than chance pops attm.

Did not stray too far from MOS temps, especially during the
overnight hours through the extended but did shave MOS daytime highs
for late in the extended period due to the above mentioned
parameters.

13

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  87  70  90  71 /  50  20  40  20
MLU  90  69  90  70 /  30  20  40  20
DEQ  85  66  88  66 /  30  20  30  20
TXK  84  68  87  69 /  50  20  40  20
ELD  87  67  88  68 /  50  20  40  20
TYR  85  69  87  70 /  50  10  40  10
GGG  85  69  88  69 /  50  20  40  10
LFK  86  68  89  70 /  50  20  30  20

&&

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

$$

19/13



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