Area Forecast Discussion
Issued by NWS Shreveport, LA

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FXUS64 KSHV 202013
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
313 PM CDT Fri Apr 20 2018

.DISCUSSION...
Benign weather occurring late this aftn as cirrus clouds have
thinned and/or shifted east of the Four-State Region late this aftn,
giving way to mostly clear skies. Despite plentiful insolation,
temps remain below normal /60s/ due to the influence of the
nearby sfc ridge. Attention will quickly turn to a closed UA low
noted across the Four-Corners Region late this aftn that is
progged to continue its eastward propagation to across the South
Plains by tonight, thus leading to 500 mb height falls. Progged
model soundings indicated the return of mid-upper level
cloudiness enveloping the region after midnight tonight but
despite the cloud cover, overnight temps will still manage to fall
into the 40s and 50s due to the sfc albeit with a fleeting grip.
At daybreak, the sfc ridge will be exiting the region and sfc
troughing will follow on its heels hence causing sfc winds to veer
to southeast. This will aid in promoting the gradual return of
low level moisture/a weak warm front as indicated by PWATS of
1.00-1.50 inches initially across southeast OK, east TX and deep
east TX. Model solutions are in pretty good agreement in showing
light precip impinging on the aforementioned areas late tomorrow
morning/early aftn as a 500 mb 50+ kt jet max ejects from the base
of the UA low. Extensive cloudiness will temper daytime
destabilization and by late aftn, precip will continue to shift
eastward to across the remainder of the FA whilst the warm front
struggles to make a northward jog to near northern LA
east/northeast TX and close to southwest AR. It will be of great
importance to know the exact position of the warm front because
if some clearing can occur and a bit more daytime destabilization
can become realized, it will be within this limited warm sector
that strong to severe storms will be possible as plentiful 0-6 km
bulk shear will exist /hail and gusty winds the main threats/.
Tomorrow evening-night as the UA low nears the Four-State Region,
a cold front will commence to impact the region from northwest to
southeast, but its slow movement and a slight PWAT improvement
will raise concern for a period of moderate to heavy rainfall. The
Weather Prediction is holding steady in showing widespread 1-3
inch rainfall amounts. It is noteworthy to mention that although
3 inches is moderately high, the last beneficial rainfall event
took place exactly one week ago, which is more than enough time
for soils to recuperate and thus be able to handle several inches
of rainfall /keep in mind low-lying or poor drainage roadways may
still be prone to flood/.

By late tomorrow night/early Sunday morning, dry-slotting will take
shape from west to east and will therefore see rainfall diminish
also from west to east. Only exception may be lingering wrap-
around precip that will affect portions of southwest AR and
north/northeast LA through Monday aftn before the UA low finally
pushes east-northeastward towards the Appalachians. Dry northwest
flow aloft will ensue on Tuesday but on Wednesday a shortwave
trough staying north of the region will send down a cold front
either Wednesday morning or aftn /time discrepancies still exist
amongst long term models/ and adequate frontogenetical forcing may
exist to generate showers and perhaps a few isolated
thunderstorms. Thereafter depending on which model is of
preference, region will either have a glancing blow from a
shortwave trough just to our east, but it will still promote a
fropa /with light precip/ on Friday, or a longwave trough will
progress across the region causing scattered precip to develop
along the fropa. Will elect to insert low end chance POPs area-
wide Thursday night attm, as confidence is not high enough to go
much above that for now.

Daytime temps tomorrow will be tricky as some clearing could occur
across parts of the region. With that said, will see a range of
middle to upper 60s west to lower to middle 70s east. By Tuesday it
will be in the 70s CWA-wide as CIGS scatter out.

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  51  72  58  69 /   0  60  90  30
MLU  48  75  61  74 /   0  20  90  60
DEQ  49  66  52  68 /  10  90  90  30
TXK  48  68  53  67 /   0  70  90  30
ELD  48  73  58  71 /   0  30  90  60
TYR  51  65  52  68 /  10  80  90  10
GGG  50  68  54  68 /   0  70  90  20
LFK  53  73  59  72 /   0  50  90  10

&&

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

$$

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