National Weather Service Raw Text Product

Displaying AFOS PIL: AFDSHV Received: 2018-05-21 17:01 UTC

FXUS64 KSHV 211701

Area Forecast Discussion
National Weather Service Shreveport LA
1201 PM CDT Mon May 21 2018

Cigs have become mostly vfr across area with isold brief mvfr 
cigs possible. Scattered convection across se TX advecting nwd 
and nearing the klfk terminal. Storms this aftn may contain brief
but stg wind gusts. With mstr axis splitting the cwa, terminals
most likely to be affected will be klfk, kshv, and possibly ktxk
and keld later this aftn, but should diminish with setting sun.
Winds to remain mostly lgt and vrbl thru period. Lack of southerly
flow and presence of mid/upper cloud decks will both make fog
development, and low cloud advection, too uncertain for any
mention in fcst attm./07/


.PREV DISCUSSION... /issued 1126 AM CDT Mon May 21 2018/ 

The morning visible satellite imagery indicates that the extensive
AC shield along a weak shear axis in place over SW AR/extreme Ern
TX/Wrn LA has begun to thin out, which has allowed for a sct cu
field to quickly develop with the onset of diurnal heating. The
vis imagery also depicts an MCV near this shear axis over Wrn AR 
just N of MEZ, which has allowed for the development of sct
convection near and E of the center. Meanwhile, sct convection has
quickly developed over SE TX along the tail end of the shear axis,
where moderate SBCapes have risen to 2000-2500 J/kg. 

Additional heating within the moist air mass in place through the
afternoon will allow for moderate SBCapes to become realized
across the region, contributing to the development of sct
convection near and E of the shear axis through the remainder of
the day. However, it should be noted that the CH. 9 and 10 of the
water vapor imagery indicates a fair amount of low and mid level
dry air over the Ern sections of Ncntrl LA, which is likely why we
are seeing the development of the cu field delayed over these
areas for the time being. The short term progs are in good
agreement with the shear axis drifting very slowly E across Scntrl
AR/Wrn LA this afternoon, with the strongest vorticity remaining
just NNE of the region over Cntrl and Ern AR, closer to the
primary shortwave trough over the Nrn Plains and Midwest. The 12Z
HREF and latest HRRR runs suggest that sct convection will remain
confined primarily to extreme Ern TX/SW AR/Wrn LA, with additional
convection being driven by outflow interactions within the weakly
sheared but moderately unstable air mass. 

Have maintained high chance pops for much of SW AR closer to the
MCV/stronger vorticity center near the shear axis, but lowered
pops to low chance across the Wrn sections of NE TX which will be
a bit farther removed from the overall forcing. Did not make much
of any changes to today's max temps, other than raising them 1-2
degrees over Ncntrl LA, which have already reached the mid 80s as
of 16Z. As was the case Sunday, the sct convection should begin to
diminish during the evening with the loss of heating. 

Zone update already out...grids will be available shortly. 



SHV  87  70  90  71 /  40  20  40  20 
MLU  91  69  90  70 /  30  20  40  20 
DEQ  85  66  88  66 /  50  20  30  20 
TXK  85  68  87  69 /  50  20  40  20 
ELD  87  67  88  68 /  40  20  40  20 
TYR  85  69  87  70 /  30  10  40  10 
GGG  85  69  88  69 /  40  20  40  10 
LFK  86  68  89  70 /  50  20  30  20