Area Forecast Discussion
Issued by NWS Shreveport, LA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 181136
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
536 AM CST Mon Dec 18 2017

.AVIATION...
All kinds of aviation concerns this morning with dense fog being
reported across most of our airspace. The only exception to this
is the TXK/ELD terminals but vsbys continue to bounce back and
forth from LIFR to MVFR vsbys at these locations with LIFR
ceilings. Elsewhere we are looking at prevailing VLIFR-LIFR
ceilings with the dense fog. Given the strength of a very stout
low level inversion this morning, very light winds and low sun
angle, not expecting much improvement today with these already bad
conditions but did try to show some slight improvement by late
morning or early afternoon across most areas, bringing most
locations to MVFR VSBYS and near IFR ceilings.

After dark, would not be surprised to see ceilings and vsbys
crater once again to LIFR-VLIFR conditions. Isentropic lift should
be increasing overnight as a warm front from the S LA/SE TX coast
begins lifting back northward. Thus we should begin to see
increasing coverage in showers from south to north which could
provide enough mixing to limit the lower vsby/ceiling
restrictions. Introduced vcsh across all but the TXK/ELD/MLU
terminals beginning as early as 03z with coverage likely increasing
in nature beyond 06z tonight.

13

&&

.PREV DISCUSSION... /issued 514 AM CST Mon Dec 18 2017/

DISCUSSION...
Dense fog continuing across most of the area along and south of
I-20. Low clouds and patchy fog will likely continue into the aftn
under a stg low lvl inversion. A warm front near the coast with
dewpoints in the lower 70s over the gulf waters will begin pulling
rich moisture onshore with pcpn water values nearing 2 inches,
very unseasonally high. This slow movg warm front will reach near
the interstate 20 corridor by Tue aftn with very heavy rain near
this frontal boundary. Two to four inches of rain may occur where
this boundary begins to stall. Very stg low lvl shear may also
cause a few tstm cells to become stg and produce gusty winds.
The vigorous upper low will pass east of the area durg the day
Wednesday with quiet wx expected under the approach of deep long
wave trough bringing continued southerly flow and fairly warm
temps. Convection will likely remain scattered in the warm sector.
Models still have not come into agreement with either the arrival
of the much colder arctic airmass, or the amount of moisture as
the colder air arrives. A wintry mix is possible across the
northern edge of the area in the stratiform rain behind the front
although will keep pops isold for now with no accumulations
expected. Finally, the GFS suggests a brief period of light snow
movg across OK well into the cold air mass with the entire column
of air sub freezing late Sat night into Sun mrng.

/07/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  62  58  68  57 /  10  50  90  90
MLU  62  58  71  60 /  10  20  70  90
DEQ  60  51  65  53 /   0  30  90  90
TXK  60  55  65  56 /  10  40  90  90
ELD  61  54  67  55 /  10  40  80  90
TYR  58  58  65  54 /  10  50 100  80
GGG  59  58  68  55 /  10  50 100  90
LFK  62  61  71  56 /  20  50  80  70

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...Dense Fog Advisory until 10 AM CST this morning for LAZ001>006-
     010>014-017>022.

OK...None.
TX...Dense Fog Advisory until 10 AM CST this morning for TXZ124>126-
     136>138-149>153-165>167.

&&

$$

07/13


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