Area Forecast Discussion
Issued by NWS Shreveport, LA

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FXUS64 KSHV 060256 AAA

Area Forecast Discussion...UPDATED
National Weather Service Shreveport LA
956 PM CDT Mon Jun 5 2023

...New UPDATE...

Issued at 934 PM CDT Mon Jun 5 2023

A broken line of thunderstorms continues from Deep East Texas
northeast into Northwest Louisiana and Southern Arkansas. Behind
it, a more robust cluster is moving west into Monroe and our
Northeast Louisiana parishes. All of the convection is generally
occurring along an instability gradient. Latest mesoanalysis
indicates these storms are moving into an environment where there
is still 1500-2000 J/kg of CAPE. Therefore, I expected the storms
to persist for several more hours, especially the strongest and
more organized storms near Monroe and northwest of Nacogdoches.
While model guidance has struggled somewhat this evening, nearly
all of the models agree that the convection should gradually
diminish especially near and after midnight.

Based on latest radar trends, I made significant tweaks to the
PoPs for tonight. Rain chances were increased significantly
through 06z tonight to account for the Deep East Texas and
Northeast Louisiana convection currently ongoing.



(This evening through Tuesday Night)
Issued at 200 PM CDT Mon Jun 5 2023

The latest mid-level analysis indicates that an omega block is in
place over the US. This block is thanks to a closed low located
over southern California, another low off of the coast of Maine
and a ridge between the two features across the northern Plains.
This blocking pattern puts the local area in a fairly stagnant air
mass with little change expected through Tuesday night.

In an environment with strong instability (approx 3000 J/KG
SBCAPE) and very little shear, isolated showers and single cell
pulse thunderstorms will continue to develop across the area and
increase in coverage, becoming more scattered by late afternoon
into the early evening. With PWAT values in the 1.25-1.5" range,
we could see some locally heavy downpours. Similar to yesterday,
would not be surprised to see a couple of strong thunderstorms
with gusty winds and small hail, but coverage is anticipated to be
more limited this evening. Showers and thunderstorms will mostly
end by midnight across the area with some patchy fog possible
during the pre-dawn hours.

On Tuesday, the GFS is hinting at a weak mid-level disturbance
sliding southward into the ArkLaTex and providing forcing for
initial showers and thunderstorms to develop north of the I-30
corridor and then working southward across the remainder of the
forecast area by the late afternoon and early evening hours.
Instability looks to be moderate around 2000 J/KG with weak shear
again in place. Thus, thunderstorms are again expected to remain
mostly sub-severe across the area. Showers and thunderstorms will
begin to diminish Tuesday evening with the loss of heating with a
dry forecast in place Tuesday night.

For temperatures, the forecast is closest to the National Blend of
Models (NBM) with highs in the upper 80s to lower 90s each day and
lows in the mid to upper 60s. /04-Woodrum/


(Wednesday through next Sunday)
Issued at 200 PM CDT Mon Jun 5 2023

The period begins as the upper-level setup showcases two closed
lows, one situated across the western coast of the CONUS while the
other is centered across the northeast coast near New Brunswick and
Nova Scotia. Meanwhile, upper-level ridging continues to remain
stalled and amplified across the central CONUS. The synoptic pattern
will remain rather stagnate with little to no change through the
first half of the long term period. With this in mind, continued NW
flow aloft is to be expected. At the surface, the summertime theme
continues to prevail as afternoon highs into the lower to mid 90s
appear favorable. Diurnal convection associated with weak
perturbations in the mid-level flow and daytime heating will
continue to be expected ahead of some slight frontal based forcing
by the end of the week in the form of another back door front with
high pressure development across the Great Lakes. Current guidance
suggests the front turns stalled Saturday AM across SW/AR and N/LA.

Into the weekend, we pick back up where we left off as the stalled
boundary begins to lift northward as the sfc ridge across the
Appalachians works offshore. Brief zonal flow aloft will be in place
Saturday into Sunday before a return to NW flow Sunday night. At the
same time, forcing aloft across the Rockies will support surface
cyclogenesis across the Upper Midwest that will work southward
across the Plains, approaching the Four State Region late Sunday,
early Monday AM. This will help to drive a cold front southward with
it, as another surface ridge evolves across the Midwest with a
cutoff across the Mid-Atlantic states. This should help support
frontal based forcing for showers and storms to start next week,
with drier air building in for Tuesday as ridging traverses directly
overhead, supporting a drier column aloft.

While still deep in the period, early model guidance showcases some
conducive parameters for stronger storms associated with the passing
front Sunday evening. Something that will need to be monitored in
upcoming model packages. Regardless, given the progged scattered
diurnal theme through the period, some thunderstorms may be on the
stronger side as already seen in recent weeks. Primary concerns
being for small hail, gusty winds and some heavier downpours
resulting in localized flooding/ponding.

Looking at the overnight lows, trends through the period expected to
remain the same with values in the 60s and low 70s.


(00Z TAFS)
Issued at 644 PM CDT Mon Jun 5 2023

Scattered showers and thunderstorms will persist across portions
of the area, especially portions of Louisiana south of Interstate
20 and possibly Deep East Texas, for at least the first few hours
of the period. Some of the model guidance suggests some of the
storms south of Interstate 20 may congeal into more a solid
complex and trek west-northwest until just after midnight. KTYR,
KGGG, and KLFK could be affected if this occurs. Another round of
widely scattered convection is expected again late in the period,
which could develop just about anywhere. Thus, VCTS was mentioned
at all sites after 06/18z. Patchy fog and some instances of MVFR
visibilities may occur after 06/06z, especially in areas that have
recently received rainfall. However, VFR flight conditions should
prevail at most terminals by 06/15z with the exception of any
impacts from precip.



SHV  68  90  69  90 /  30  40  10  30
MLU  67  90  68  90 /  50  40  20  20
DEQ  65  90  63  91 /  20  30  10  20
TXK  67  91  67  92 /  20  30  10  20
ELD  65  89  64  90 /  30  40  10  20
TYR  67  89  68  90 /  40  30  10  20
GGG  66  89  67  91 /  40  40  10  30
LFK  66  89  66  90 /  40  40  20  30




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