Area Forecast Discussion
Issued by NWS Shreveport, LA

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FXUS64 KSHV 061251
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
651 AM CST Tue Dec 6 2016

.AVIATION...
For the ArkLaTex, LIFR/IFR cigs and some vsby may get to MVFR at
a few terminals, especially this afternoon with some heating to
lift the decks. Sfc winds will keep W/NW early and veer N/NE later
today. Aloft...our winds are NW/W slowly increasing speeds to
50-90KTS into flight levels. Even more speed and backing to SW
above FL300. Outlook is slow improvement until Arctic fropa 08/06z.
/24/

&&

.PREV DISCUSSION... /issued 325 AM CST Tue Dec 6 2016/

DISCUSSION...
The stubborn ua low that has been west of the Four-State Region for
the last several days has finally shifted northeast of the area,
though wrap around moisture has allowed for lingering showers across
portions of northeast LA and southwest AR early this morning. Model
solutions exhibit the shower activity exiting the aforementioned
areas by daybreak, however drizzle will be prevalent as a
stubborn stratus deck remains. Despite the cloud cover, the recent
rainfall have resulted in moist grounds which raises concern for
fog. Several locations across the rain-free areas have already
reported VIS obstructions developed per 09Z metars, and both the
NAM and the HRRR hinting at dense fog particularly across Deep
east TX has led to adding that potential with this forecast
package. If it becomes more widespread later this morning, the
consideration of a Dense Fog Advisory will be warranted. The
patchy fog will scour out by mid-morning, but the stratus deck and
hence patchy drizzle will remain throughout the day, and into
tonight /especially across the southwest zones/ as winds veer to
an upslope sfc regime.

A northwest Pacific longwave trough was commencing to move across
the Great Basin early this morning, and poised to shift east
southeast onto the Rockies and the Plains by mid-late week. A cold
front associated with the ua trough will impinge on the region
Wednesday evening/night, with breezy northerly winds expected /10-20
mph which nears Lake Wind Advisory conditions/ as a 1040 mb sfc
ridge promote pressure rises on the order of 5-7 mb per 3 hrs. The
tightest gradient and subsequently breeziest conditions is
observed to be across east TX. However the main weather feature
associated with this fropa continues to be the rather CAA it will
usher in by Thursday night/Friday morning, as 850 mb temps drop to
between 0C and -5C. This will result in overnight temps plummeting
into the upper teens across the northwest zones to lower to
middle 20s elsewhere. This nears Hard Freeze criteria so we will
keep a close eye on this plausibility as the event draws near.
Thereafter, sfc winds will return to a southerly flow for the
weekend as well as another chance for precip, due to a shortwave
trough quickly progressing east across the Central Plains and
middle Mississippi Valley.

Below normal temps are expected through early weekend as an Arctic
front encompasses the region, but will moderate to seasonal avg. by
early next week /60s/ with the return of a srly sfc flow.

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  54  45  56  36 /  10  10  10  30
MLU  55  44  56  38 /  10  10  10  30
DEQ  52  39  47  29 /  10  10  20  20
TXK  52  41  50  31 /  10  10  10  30
ELD  52  40  51  33 /  10  10  10  30
TYR  54  46  56  31 /  10  10  20  30
GGG  56  45  57  33 /  10  10  20  30
LFK  60  47  61  39 /  10  10  20  30

&&

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

$$

24/29



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