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

FXUS64 KSHV 161557

Area Forecast Discussion
National Weather Service Shreveport LA
1057 AM CDT Fri Mar 16 2018

No changes needed to forecast package. Still expecting skies to
gradually move out from west to east today along with the
rainfall. But, a Marginal risk for severe storms remains in place
generally east of a line from Ruston Louisiana to Natchitoches
Louisiana to Hemphill Texas. The biggest threat will be damaging
winds and large hail, but an isolated tornado can`t be ruled out.


.PREV DISCUSSION... /issued 721 AM CDT Fri Mar 16 2018/

MVFR cigs have spread N across the region this morning, with the
potential for a brief duration of IFR cigs through mid-morning
across portions of E TX and possibly Wrn LA. Sct -SHRA have
developed over Scntrl AR/much of N LA this morning but continue to
quickly shift E, and will primarily affect the ELD and MLU
terminals through mid-morning before shifting E of the area. Thus,
have included VCSH for these terminals, and dropped mention of any
weather elements elsewhere as drier air aloft begins to entrain E
beneath a stout upper low and attendant trough entering the
Ozarks and MS Valley. The MVFR cigs will quickly lift and scatter
out between 15-18Z over E TX, and over extreme SW AR/NW LA by
early afternoon as the dry line mixes E into NE TX/SE OK/extreme
Wrn AR, with VFR cigs returning to Scntrl AR/Ncntrl LA by mid-
afternoon. The dry line is expected to become stationary by this
evening, with low MVFR/IFR cigs developing/returning back N across
Deep E TX and N LA by/after 06Z Saturday. These cigs will linger
over these areas through at least mid to late morning Saturday
before scattering out. SSW winds will increase to 9-14kts today,
with gusts to 22kts possible across E TX/SE OK/extreme SW AR.
However, SSW winds will diminish to 5kts or less after 00Z. /15/

PREV DISCUSSION... /issued 412 AM CDT Fri Mar 16 2018/

Showers have rapidly developed across the Southern Plains over the
last couple of hours, mainly east of the Interstate 35 corridor.
This activity has developed in an area of warm air advection
combined with a weak shortwave trough moving east across Arkansas,
Texas, and Louisiana. Farther to the northwest, a much stronger
shortwave trough over Eastern Colorado will eject across the
Central Plains today. A surface low pressure associated with the
Colorado trough will also move eastward across Northern Kansas. A
dryline/weak cold front trailing southward from the surface low
will surge eastward before stalling near a line from Mineola TX to
Nashville AR this afternoon, and finally moving back northward and
becoming stationary near the U.S. Highway 82 corridor.

The vertical ascent that is generating the ongoing showers should
move mostly out of the CWA by early afternoon. A couple of storms
are possible this morning, which could produce marginally severe
hail. Despite plenty of instability and deep layer shear,
convection is looking less likely after 18z this afternoon.
Subsidence behind the departing Texas trough, the lack of large
scale forcing for ascent, a rather stout capping inversion, and
weak convergence along the surface boundary are expected to
greatly limit thunderstorm development. However, model guidance
continues to suggest the cap make weaken enough for a couple of
isolated storms to develop this afternoon mainly east of a line
from Prescott AR to Toledo Bend Dam. Large hail and damaging winds
would be the main threats with any severe thunderstorms, but an
isolated tornado cannot be completely ruled out.

Skies are expected to rapidly clear this afternoon as mid level
dry air quickly invades. This large area of dry air can easily be
seen across Western Oklahoma and West Texas on water vapor loops.
The clearing skies and warm southwesterly surface winds should
result in very warm temperatures today. Most locations will likely
be near or above 80 degrees F, especially across the western half
of the forecast area.

A few showers or thunderstorms will be possible during the day
Saturday south of the stalled frontal boundary, but another very
warm day is expected areawide despite increasing cloud cover.
Convective development should increase Saturday night and into
Sunday as another strong shortwave trough and surface low develop
over the Southern High Plains. This system will track much farther
south than today`s. This should place the main region of large
scale forcing directly over the CWA on Sunday afternoon and
evening. The surface boundary will lift back northward during the
day Sunday as a warm front placing the entire CWA in the warm
sector. Convective coverage is expected to increase during the
late morning and into the afternoon Sunday as large scale forcing
and instability increases. The severe weather threat will increase
with storms that develop during this time frame. Large hail and
damaging winds will be the primary threats, but intersections with
the warm front and any mesoscale boundaries left over the earlier
convection could provide a localized enhancement of low-level
shear for isolated tornado development.

Rain chances will linger into Monday, but should decrease from
west to east as the Pacific cold front moves across the region and
dry and cool air quickly invade. No additional rain chances are
expected through the remainder of the work week. Temperatures will
be cooled back to near climo for Tuesday and Wednesday before a
gradual warming trend commences for the end of the week.



SHV  81  62  81  62 /  30  10  20  40
MLU  76  63  82  62 /  50  20  10  30
DEQ  81  51  78  55 /  30   0  10  20
TXK  82  57  79  58 /  30  10  10  40
ELD  77  58  81  57 /  30  20  10  30
TYR  84  61  81  62 /  20  10  20  30
GGG  83  61  80  62 /  30  10  20  30
LFK  84  65  84  65 /  30  10  20  30




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