Area Forecast Discussion
Issued by NWS Shreveport, LA

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FXUS64 KSHV 181821

Area Forecast Discussion
National Weather Service Shreveport LA
121 PM CDT Sun Mar 18 2018

Cigs across the cwa range from mostly mvfr with ocnl ifr across ne
TX to vfr at kmlu and keld. Warm front from south of kmlu to near
just south of Red River Valley bordering TX and OK will be main
focus for tstm development later this aftn. Stg instability
partially dependent on an increase in breaks in ovc skies. Storms
could become supercellular in nature and very large hail
potential. Will leave mention as tstm vcnty in TAF`s and update as
rapid convection begins to develop. Low clouds may be producing
some lgt drizzle across nw half of area.
Overnight, storms to diminish around 19/03z or so, and low clouds
off and on overnight, with dry slotting only allowing brief low
clouds across ne TX. Fog is expected overnight at kmlu and
possibly keld. Skies becmg skc prior to dryline movg thru area.
The dryline will result in rapid mid morning mixing, and sw-w
winds to increase to 15 to 20 kts by 19/18z for ktxk, kshv, kggg,
and ktyr./07/


.PREV DISCUSSION... /issued 1106 AM CDT Sun Mar 18 2018/

Widespread rainfall that encompassed our southeast zones early
this morning has since exited our region to the east with just
some remnant showers and patchy light rain noted on radar mosaics
from in and around NW LA into the Middle Red River Valley of SE
OK, SW AR and NE TX. Looking at the latest sfc analysis, a cool
front continues to slowly backdoor into our region from the
northeast and as of 16z was located near or just south of a
TVR...TXK...PRX line. Latest 12z progs are very different in the
handling of this backdoor cold front with the 00z GFS holding it
up pretty much where it is now and the HRRR/NAM wanting to
continue pushing it southward along its eastward flank into EC LA.

For the morning update, had to lower temperatures just a degree or
two...especially across our northern zones where temperatures have
been nearly steady since 8 am and in some cases, has come down a
degree or two. Kept the I-20 Corridor and most locations south of
this line nearly unchanged or a degree lower. Also lowered high
chance pops across our eastern zones for the remainder of the day
and kept chance pops unchanged for the afternoon hours.

Speaking of the afternoon into this evening, severe thunderstorm
probabilities still highly dependent on the placement of the
frontal boundary spoken to above and convective initiation near or
to the west of the I-35 Corridor later this afternoon and we will
have to watch with how much instability these storms will have to
sustain themselves as they move into our area this evening. 12z
progs this morning are all over the place with some suggesting
convection will initiate closer to NE TX this evening, others
suggesting renewed convection will not initiate at all and still
others with the suggestion that we will be dealing with supercell
thunderstorms along or north of the I-20 Corridor this evening
with very large hail possible. There are arguments for each
scenario attm so will await on seeing just what happens to our
backdoor boundary this afternoon and keep our eyes out west for
convective initiation that should not influence us (if at all)
until this evening.

Update out shortly...13.


SHV  74  59  83  49 /  40  30  10  10
MLU  72  61  83  49 /  40  30  20  10
DEQ  65  49  75  46 /  40  40   0  20
TXK  67  53  78  48 /  40  40   0  10
ELD  66  57  79  48 /  40  40  10  20
TYR  76  55  78  47 /  40  30   0  10
GGG  75  56  80  49 /  40  30   0  10
LFK  81  61  82  49 /  40  30  10  10



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