213
FXUS64 KSHV 190235
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
935 PM CDT Wed Sep 18 2024

...New UPDATE...

.UPDATE...
Issued at 928 PM CDT Wed Sep 18 2024

Upper-level ridge extending from south Texas through the Red
River Valley into the Midwest to maintain stable conditions across
the region tonight. Under mostly clear skies and light winds,
temperatures are forecast to fall to saturation near 70 degrees
by daybreak. Accordingly, a weak surface boundary extending from
southeast Texas into central Louisiana could allow for patchy fog
to develop across much of Deep East Texas, north Louisiana, and
south Arkansas overnight. Ongoing forecast is on track no update
needed at this time. /05/

&&

.SHORT TERM...
(This evening through Thursday Night)
Issued at 205 PM CDT Wed Sep 18 2024

Water vapor imagery this afternoon nicely depicts a longwave
trough over the Western half of the CONUS, with a closed low over
the Northern Rockies and the Central CA Coast, while downstream of
this longwave feature extends a ridge of high pressure from the
Southern Plains N/NE into the Great Lakes region and Ontario.
A closed area of low pressure then exists downstream of the ridge
over the Carolinas and SE. In the lower levels, an expansive area
of high pressure extends influence across the NE, the Midwest and
towards the Central and Southern Great Plains. Weak troughing
continues over the SE, with an area of low pressure off the NC
Coast and Delmarva vicinity, with a cold front near the front
range of the Rockies associated with an organized cyclone over MT.

Quiet conditions are the rule across the Four State region this
afternoon provided the influence of high pressure both at the
surface and aloft described above. After some patchy morning fog,
a nice cumulus field has developed this afternoon. Clouds will
continue into the evening before dissipating and possibly
yielding the SE advection of some cirrus clouds into the overnight
period. Given increasing subsidence aloft and generally better
solar insolation, high temps will top off a few degrees warmer
than the previous few days for most locations.

Patchy fog will then redevelop overnight tonight into early
Thursday given limited scouring of low level moisture underneath
of the upper level ridge. The overall pattern will feature a
slight amplification of the upper level ridge over the Southern
Plains and ArkLaTex regions as the aforementioned closed low off
the central CA Coast digs SE towards the Great Basin. The increase
in subsidence aloft resulting from this will yield partly to
mostly sunny skies and another slight increase in afternoon
temperatures into the lower 90s.

Another round of patchy fog is likely again Thursday night into
Friday morning, however, expect coverage to decrease as compared
to previous mornings.

Kovacik

&&

.LONG TERM...
(Friday through next Tuesday)
Issued at 205 PM CDT Wed Sep 18 2024

The long term forecast period will feature a continued ridge of
high pressure over the Southern Plains and Midwest, with an open
wave trough along the Eastern Seaboard and a closed low
progressing towards the desert SW from S CA. With the continued
upper level ridge influence over the ArkLaTex, afternoon
temperatures will remain hot, with Friday afternoon likely to be
the hottest day of the week for many given the ridge will likely
be at its maximum intensity and have its best influence over the
region.

By the weekend, the large scale pattern will become more
progressive, with the previously mentioned closed low over S CA
finally moving into the desert SW, causing a slight eastward shift
in the downstream ridge axis. This shift will not be not be enough
to cause a marked change in expected weather conditions, with yet
another hot afternoon in the low 90s expected under mostly sunny
skies.

On Sunday, ensemble means and WPC cluster solutions continue to
agree upon the NE lift of the desert SW trough towards the
Southern and Central Rockies. This is likely to induce sfc
cyclogenesis on the leeward side of the Rockies near the OK
panhandle or across Eastern CO/Western KS. An associated frontal
boundary will then develop to the S of the sfc low and attempt to
approach northern zones by the end of the weekend/early next week.
Given the projected eastward track of the sfc low, it currently
seems reasonable to assume to at least a partial fropa can be
anticipated across the area. Currently not seeing a distinct
change in the airmass in the NBM guidance at present time, but
this will be monitored in future model runs. With the presence of
at least a weak boundary in the vicinity, low-end rain chances
are likely to materialize near the end of the forecast period.

Kovacik

&&

.AVIATION...
(00Z TAFS)
Issued at 518 PM CDT Wed Sep 18 2024

For the 19/00Z TAF update, light winds will dictate a familiar
pattern under surface ridging with MVFR/IFR vis/cigs likely
airspace-wide at 19/09-17Z due to low cloud/FG development. VFR
vis/cigs are likely before and after this timeframe with light
easterly winds returning by the end of the period. /16/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  73  92  73  95 /   0   0   0   0
MLU  69  91  68  93 /   0   0   0   0
DEQ  66  93  68  95 /   0   0   0   0
TXK  70  94  71  95 /   0   0   0   0
ELD  66  92  68  94 /   0   0   0   0
TYR  73  95  73  96 /   0   0   0   0
GGG  71  93  72  95 /   0   0   0   0
LFK  73  92  73  94 /   0   0   0   0

&&

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

$$

SHORT TERM...05
LONG TERM....23
AVIATION...16