National Weather Service Raw Text Product

Displaying AFOS PIL: AFDSHV Received: 2018-11-13 18:16 UTC


846 
FXUS64 KSHV 131816
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
1216 PM CST Tue Nov 13 2018

.AVIATION...
Mostly mvfr cigs across area with skies becmg sct to skc by around
13/20z at ktxk, and later this aftn at ktyr,kggg, and keld with
drier air filtering from the north. Most areas bcmg vfr overnight
except for kmlu, which will remain mvfr and possible ocnl ifr cigs
overnight along with a possibly lgt wintry mix of pcpn thru the
14/18z fcst cycle. NW-n winds 10 to 15 kts gradually decreasing
thru the period as pressure gradient relaxes./07/.

&&

.PREV DISCUSSION... /issued 1059 AM CST Tue Nov 13 2018/ 

UPDATE...
Bright banding on radar showing up near Toledo Bend on TX side and 
movg e-ne into LA. Updating for a chance of rain/snow mix with
this feature, although it will probably be brief which may require
another early aftn update. Early morning pcpn has ended remainder
of area. Highs in upper 30s to near 40 still appear on track./07/.


PREV DISCUSSION... /issued 350 AM CST Tue Nov 13 2018/ 

SHORT TERM.../Today through Wednesday/

Vigorous upper trough continues to spin to our north and west 
early this morning, in the vicinity of SW TX, through the Upper 
Red River Valley of NW TX/SW OK into SE KS. Strong southwesterly 
flow aloft continues to be exhibited in advance of this trough 
across all of the Lower Miss Valley attm. Having said that, 
abundant mid level dry air has penetrated our entire region with 
moisture profiles showing low level moisture only about 5-6kft 
thick. With this moisture well below freezing across our western 
zones early this morning, we have been seeing some light 
snow/flurries reported across portions of NE TX and as this 
deeper/colder airmass continues to advance very slowly eastward 
this morning, would not be surprised to see a light rain/light 
snow mix as far east as portions of NW LA this morning. Further 
south and east across the Lower Toledo Bend and Sam Rayburn 
Country of Deep East Texas into North Central and Northeast 
Louisiana, any precipitation this morning should be in the form of
light drizzle or light rain. Have undercut temperatures today, 
closer to the colder NAM MOS output as strong cold air advection 
should continue to infiltrate the region from the northwest. 

By 00z tonight, the trough to our west will start to close itself
off and advance slowly to the east with the center of this trough
likely located across extreme SE OK into NE TX. A moist tongue of
700mb air will quickly swing NNE from SE TX late today, moving 
into Northern Louisiana and Southern Arkansas with 700-300mb 
Q-Vector Convergence becoming maximized along and north of the 
I-20 Corridor of Northern Louisiana including most of Southern 
Arkansas. There should be enough lift in this area of the 
atmosphere, just in advance of the upper trough to squeeze out 
some light snow late tonight near and east of a line from 
Natchitoches and Shreveport, Louisiana to Texarkana and 
Murfreesboro, Arkansas. Will only introduce slight chance pops for
now but this may need to be beefed up somewhat, especially across
our NE zones which would include the El Dorado, Arkansas area and
vicinity as it's this area that will be under the influence of 
this upper forcing for a longer period of time tonight into Wed. 
Despite the cloud cover, cold air advection should be strong 
enough to allow for most, if not all of our region to see freezing
temperatures tonight so will issue a Freeze Warning east of our 
current Freeze Warning for late tonight through early Wed. 

Will keep the slight chance of light snow mention through the
morning hours across NW LA and all day Wednesday across NC and NE
LA as well as S AR as this upper forcing will continue to be 
present through this period in these locations until we get the 
Upper low far enough north and east of our region, sometime late 
Wed aftn/evng. Needless to say, have undercut high temperatures 
quite a bit across the northeast half of or region on Wed, again 
closer the the colder NAM MOS output given the above scenario. 

Thanks for the coordination this morning FWD, LZK, JAN, HGX and
LCH. Prelims to follow...13.

LONG TERM.../Wednesday Night through Monday Night/

A deep upper trough will be lifting northeast towards the Ohio River 
Valley at the start of the period. Cold and dry air will quickly 
advect into the area from the northwest behind the departing trough, 
which quickly bring any chances for precip to an end. Clearing skies 
and diminishing winds during the overnight hours of Wednesday and 
into Thursday morning should lead to very cold temperatures. 
Overnight lows should be below 30 degrees F areawide. 

As the center of a surface high moves east along the Gulf coast, low-
level southerly flow will return by the end of the week. This will 
allow temperatures to quickly rebound and become much warmer for 
Friday and Saturday. Below freezing temperatures overnight 
Thursday/early Friday should be confined to areas north and east of 
a line from Clarksville TX, to Texarkana, to Peason Ridge LA. The 
entire area should remain above freezing Friday night/Saturday 
morning.

By early Sunday, another broad positively-tilted upper trough will 
dive southeast from the Rockies, across the Plains, and towards the 
Southeast CONUS. This will bring another cold front across the 
region on Sunday along with some scattered post-frontal rain. Some 
isolated instances of rain may linger through Monday night south of 
Interstate 20. 

CN

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  38  31  38  29 /  10  20  20  10 
MLU  39  32  36  29 /  20  20  20  10 
DEQ  38  23  38  25 /  10  10  10  10 
TXK  38  27  36  27 /  10  10  10  10 
ELD  38  27  36  27 /  10  20  20  10 
TYR  39  27  43  30 /  10  10  10  10 
GGG  38  29  43  28 /  10  10  10  10 
LFK  40  29  45  29 /  20  10  10   0 

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...Freeze Warning from midnight tonight to 9 AM CST Wednesday for 
     LAZ001>006-010>014-017>022.

OK...None.
TX...Freeze Warning from midnight tonight to 9 AM CST Wednesday for 
     TXZ151>153-165>167.

&&

$$