Area Forecast Discussion
Issued by NWS Shreveport, LA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KSHV 230906
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
406 AM CDT Thu Mar 23 2017

.DISCUSSION...
Yesterday`s backdoor cold front became quasi-stationary from
northwest to southeast across portions of east TX to central LA
since yesterday late aftn, where it is exhibited early this
morning. Similar to recent mornings, a stratus deck and patchy
fog has commenced to develop across portions of central LA and
deep east TX early this morning, where it is progged to spread
northeastward to near/across the Interstate 20 corridor near
sunrise. The stratus deck and fog is anticipated to scour out by
mid-morning. Concurrently, the cold front will be lifting north
and east and thereafter, east-southeast sfc winds will veer to
the south-southeast by the aftn. The warm front coupled with the
passage of an UA ridge will lead to temps warming into the 80s
CWA-wide. In addition to the above normal warmth, breezy
conditions will ensue this aftn particularly across east TX, deep
east TX and southeast OK, courtesy of a deepening sfc trough
across southern CO promoting a tightened pressure gradient. South-
southeast wind speeds of 15-20 mph with higher gusts equates Lake
Wind Advisory criteria and as such, will elect to issue the
advisory commencing at 23/17Z-24/00Z across east TX, deep east X
and southeast OK. Wind speeds will drop 20 mph shortly after
sunset, though it will be slightly breezy across the aforementioned
areas overnight.

The main focus in the extended period /and the reason for the
deepening sfc lee trough/ is the increased chances for widespread
rainfall and potential for severe storms tomorrow. The Pacific UA
trough is commencing to impinge on southern Cali/northern Baja
early this morning, and computer models continue to exhibit it
progressing east-northeast to south of the Four-Corners region
this evening, onto the Southern Plains tomorrow morning, during
which time it is progged to close off. Convection will initiate
along a dryline across the Red River Valley late tomorrow
morning/early aftn and progress to east TX and southeast OK by
late aftn, and to across the remaining ARKLATEX tomorrow evening
into the overnight hours. MUCAPE of 500-1000 j/kg coupled with 0-6
km bulk shear of 40-60 kts and steepened lapse rates suggests
storms could become organized and produce large hail and damaging
winds. Furthermore, low LCL`s and progged hodographs showing
curvature in the low levels raise concern for the additional
threat of isolated tornadoes. Will also need to consider the
issuance of another Lake Wind Advisory tomorrow across the entire
FA with the approaching system, as the pressure gradient tightens
quite a bit.

Saturday morning, precip will linger across portions of southwest AR
and central and northern LA while the UA disturbance and associated
precip start to exit the region late morning into the aftn.
During this time, the severe threat will be lowered substantially.
Thereafter, a progressive pattern will take place but long term
solutions still do not agree on the fine details. The ECMWF is
rather aggressive with the return low level moisture and speed of
several UA shortwaves thus resulting in precip potential Monday-
Thursday of next week. The GFS on the other-hand is a bit slower
with the passage of the disturbances and as such, shows instances
of dry conditions. Will opt to maintain slight chance/chance POPs
next week and while awaiting better model run consistency.

The above normal warmth today will be followed by a cool off in the
70s tomorrow, given the increased cloud cover and widespread
rainfall. Temps will rebound into the 70s and 80s late weekend-early
next week before the next wave of showery activity promote temps
dipping back down into the 60s and 70s by mid-late week. It is of
interest to note that Sunday morning temps will get off to a cool
start than what we have been experiencing of late /40s and 50s/,
because of a sfc ridge settling near the region.

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  85  64  77  60 /   0  10  60  80
MLU  85  64  79  63 /   0  10  20  80
DEQ  80  58  73  51 /  10  10  80  60
TXK  82  62  75  55 /  10  10  70  70
ELD  83  61  76  59 /   0  10  40  90
TYR  85  63  76  55 /  10  10  90  40
GGG  85  63  76  56 /  10  10  80  60
LFK  87  64  79  60 /  10  10  60  70

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...Lake Wind Advisory from noon today to 7 PM CDT this evening for
     OKZ077.

TX...Lake Wind Advisory from noon today to 7 PM CDT this evening for
     TXZ096-097-108>112-124>126-136>138-149>153-165>167.

&&

$$

29


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.