FXUS64 KSHV 200139

Area Forecast Discussion
National Weather Service Shreveport LA
839 PM CDT Mon Aug 19 2019


Wave of convection movg wwd, increased after crossing ms river
valley into sern cwa. One stg storm reqrd sps issuances over se
corner of area. Increased pops for remainder of eve to 30 percent
far east cwa and slgt chance to the west, where convection may
move into prior to dissipating by midnight./07/.


.PREV DISCUSSION... /issued 721 PM CDT Mon Aug 19 2019/


Mostly vfr skc except where isold convection still occurring
across mainly portions of nrn LA into extreme eastern TX, south of
I-20. These cells remaining just south of kmlu terminal and one
isold tstm recently developed near KOCH, with cells movg generally
slowly wwd. This direction of movement often produces brief very
heavy rainfall and stg gusty winds. Patchy late night fog possible
at mainly keld, kmlu, ktlx, and especially klfk where both low
clouds and fog expected. Klfk is also terminal most likely to see
vcnty tstms Tue aftn. Winds from south to east across area
generally remain near or below 5 kts thru 21/00z fcst period./07/.

PREV DISCUSSION... /issued 346 PM CDT Mon Aug 19 2019/

SHORT TERM.../through tomorrow night/

Heat index values are ranging from 104 to 112 degrees across the
Arklatex region this afternoon with absolute temperatures ranging
from 95 to 100. So far, pop-up shower and thunderstorm activity
has been almost entirely outside of the region - although our
eastern and southern borders are being skirted by varying coverage
levels of convection. In short, the Southern Plains subtropical
ridge is flexing its muscles a bit more today and the minor
disturbance rounding the ridge yesterday is no longer in much of
a position to positively impact our weather (e.g., bring
rain/clouds). That said, there is consolidated storm outflow
moving toward southern zones right now and this trigger will at
least get isolated showers/storms initiated over southern zones
over the next few hours. Unfortunately, low level shear vectors
are not conducive for working with the incoming outflow for the
purpose of very efficient convective initiation and propagation.
Expect some very isolated storms to form toward the heart of the
region through early this evening before all activity diminishes
by late evening. Lows tonight will be in the steamy 75 to 80
degree range.

Tomorrow looks to be a close repeat of today as the eastern
periphery of the nasty subtropical ridge does its best to keep
conditions oppressively hot and mostly dry. There will again be
low-end afternoon through early evening shower and storm chances,
but mainly toward central LA. Peak heat index values will again be
at least to 105 degrees so the heat advisory will be kept going
in all areas (and was actually extended in all locations through
Wednesday afternoon). Like today, some isolated spots could have
peak heat index values briefly tip over the 110 mark, but these
occurrences should be too much of the exception to consider
hoisting an excessive heat warning at this time. /50/

LONG TERM.../Wednesday Night through Tuesday/

Through Thursday afternoon, the upper level ridge that we've become
all too familiar with will continue to be the main weather story.
However, long range guidance continues to suggest that the ridge will
slightly weaken ahead of a weak low pressure, and associated trough,
headed into Friday. Because of this, expect shower and thunderstorm
potential to increase Thursday evening and into Friday morning as
additional forcing from the approaching trough interacts with the
plethora of moisture in the atmosphere.

Meanwhile, in the Gulf of Mexico, long range guidance has
consistently been developing a very weak disturbance, and moving it
towards the LA coast. However, it appears that just as this system
would move ashore with additional rain chances, that the trough
moving in grabs the system and ejects it eastward. Some of this
tropical activity may interact with our southern and eastern
parishes, so the PoPs over the weekend have been adjusted to
reflect this. Additionally, both the Euro and GFS are hinting at
some more energy with a minor disturbance coming through Sunday
into Monday, possibly associated with a weak front. This would
essentially carry increased shower and thunderstorm possibilities
through Monday evening and the end of this period

As for temperatures, the Heat Advisory that was set to expire
Tuesday evening has been extended through Wednesday evening. Heat
index values will continue to hover around the 105 degree mark
through then. Past Thursday and into the weekend, the increased
cloud cover and precipitation probabilities will allow for some
slight relief of the heat. Guidance suggests that we can expect
temperatures to drop just a few degrees by Saturday, and hang around
the low to mid-90's through the end of this forecast period.



SHV 78 99 78 97 / 10 20 10 20
MLU 75 96 75 95 / 30 30 10 30
DEQ 75 97 76 97 / 10 10 10 10
TXK 77 97 77 95 / 10 10 10 10
ELD 75 97 76 95 / 10 20 20 20
TYR 76 98 77 97 / 10 10 0 10
GGG 77 100 77 97 / 10 10 10 20
LFK 76 96 76 95 / 10 20 10 20


AR...Heat Advisory until 7 PM CDT Wednesday for ARZ050-051-059>061-

LA...Heat Advisory until 7 PM CDT Wednesday for LAZ001>006-010>014-

OK...Heat Advisory until 7 PM CDT Wednesday for OKZ077.

TX...Heat Advisory until 7 PM CDT Wednesday for TXZ096-097-108>112-


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