Area Forecast Discussion


989 
FXUS64 KSHV 220601
AFDSHV
Area Forecast Discussion
National Weather Service Shreveport LA
1201 AM CST Thu Feb 22 2018
.AVIATION...
For the 22/06z TAFs, convection continues along a quasi- 
stationary front from the South Texas Coast northeast to the 
Toledo Bend Country, and into North Louisiana and South Arkansas. 
Latest water vapor loops indicate indicate some mid-level dry air
moving across Central Texas, and this has resulted in a gradual 
diminishing of the precip west of a line from KDEQ to KJSO. 
However, the leading edge of a secondary plume of moisture is 
nearing the Rio Grande and will move over our area during the TAF 
period. This will likely result in redevelopment of convection 
farther west across Southeast Oklahoma, Southwest Arkansas, and 
East Texas by mid to late Thursday morning.
Flight conditions continue to vary widely, but most TAF sites will
generally remain MVFR or lower for much of the period. Showers and
thunderstorms should taper off across Southern Arkansas and
Northern Louisiana by 22/15z, but the precip is expected to 
become re-focused farther to the west around the same time, and 
will persist through the remainder of the period prevailing at all
sites except KELD and KMLU.
CN 
&&
.PREV DISCUSSION... /issued 837 PM CST Wed Feb 21 2018/ 
UPDATE...
Have made no changes to the current Flash Flood Watch which
remains in effect through 6 am Thursday Morning. Cold front which
has pulled up stationary late this evening was oriented from just
north of BPT to just north of ESF attm. Best upper level forcing
and overrunning frontal ascent will take place across our
southeast zones for the remainder of the night so for this reason,
have increased pops to high end categorical variety. Good
agreement from the HRRR and the latest 00z NAM output for a
decreasing trend in precip coverage and intensity across our
northwest zones. Pops were scaled back to low end chance variety
across our northwest after midnight so have left that pop grid
unchanged. 
Temperatures remain tricky overnight as hourly temperatures have
wavered back and forth in the colder airmass across NE TX and
portions of NW LA and SW AR over the past hour. The stationary
front to our south will not begin returning back northward until
the daytime hours on Thu so plan on keeping temperatures nearly
stationary for the remainder of the night and the currently fcst
hourly grid output reflects this trend well. 
No other changes are necessary attm...13.
PREV DISCUSSION... /issued 555 PM CST Wed Feb 21 2018/ 
AVIATION...
For the 22/00z TAFs, IFR/LIFR flight conditions are expected to
persist at most terminals for the entire TAF period. Widespread
convection will also continue without much of a break for the next
24 hours. The rain may be heavy at times. In fact, the initial
conditions are expected to change very little for the duration of
the period. The exceptions might be some portions of Southeast
Oklahoma, extreme Southwest Arkansas, and Northeast Texas,
including KTXK and KTYR. The convection may taper off a bit during
the early morning hours, but is still expected to prevail for much
of the daytime hours of Thursday.
CN
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV  52  65  60  74 / 100  70  80  50 
MLU  52  75  64  79 / 100  70  50  30 
DEQ  43  53  50  63 / 100  80  90  90 
TXK  45  55  54  66 / 100  70  90  90 
ELD  45  63  60  73 / 100  70  70  60 
TYR  44  56  52  69 /  90  70  90  70 
GGG  46  60  55  72 / 100  70  80  70 
LFK  55  70  60  79 / 100  60  60  40 
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Flash Flood Watch until 6 AM CST Thursday for ARZ050-051-059>061-
     070>073.
LA...Flash Flood Watch until 6 AM CST Thursday for LAZ001>006-010>014-
     017>022.
OK...Flash Flood Watch until 6 AM CST Thursday for OKZ077.
TX...Flash Flood Watch until 6 AM CST Thursday for TXZ096-097-108>112-
     124>126-136>138-149>153-165>167.
&&
$$
09/13