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fxus64 kshv 161025 

Area forecast discussion
National Weather Service Shreveport la
425 am CST Sat Dec 16 2017

VFR conditions prevailing through the short term portion of the
terminal forecast with conditions deteriorating quickly this
evening through the overnight hours as an upper level disturbance
approaches from the west. Prevailing cirrus will become prevailing
Alto-cumulus by late morning through the afternoon with 4-6kft
VFR conditions prevailing at all but the eld/mlu terminals by 00z
with showers quickly overspreading our terminal airspace. After an
hour or two of quickly saturating the lower atmosphere, ceilings
will quickly fall to mfr/IFR conditions with taking vsbys in the
1-3sm range as well. Rain should end across all but our eld/mlu
terminal locations in the 08-11z timeframe. Cannot rule out some
embedded tsra with this activity through the overnight hours but
will not include in this taf package as it will be better handled
with amds if necessary.

Prevailing winds will be from the south near 10kts today with
variable winds in around the more showery weather overnight.



Previous discussion... /issued 354 am CST Sat Dec 16 2017/

upper low over Arizona/mex border closing off, providing a temporary
reduction of clouds streaming into area. Daytime temps will
rebound well from overnight lows around frzg, reaching the mid to
upper 50s across most of the area. Closing low will shift
southern stream further south, which will then curl back into area
later today in deep SW flow. Rapidly deepening mid lvl moisture
will begin to lower with showers beginning to develop in East Texas
lakes area by mid aftn today, and spreading north and east durg
the eve. Rainfall may be heavy at times overnight with increased
upper diffluence and saturating columns. A few embedded tstms
possible across southern portions of area as shear becomes quite
strong, especially in low lvls. This initial wave will move
quickly across the area Sunday. Models bringing next stg shortwave
in southern stream flow a little further north, and as a result
have increased pops for area late Monday into early Wed. Again,
embedded tstms possible across mainly southern portions of area.
Model solutions in extended in poor agreement and thus low
confidence in fcst. GFS indicating possible winter wx for at least
northern portions of the area, but European model (ecmwf) coming in warmer and
drier in upcoming wknd. Splitting difference and leaving mostly
chance pops. Have adjusted overnight lows slightly to keep temps
just above frzg where overrunning moisture is seen, as do not wish
to introduce winter wx just yet in extended, until models decide
to come into better agreement.



Preliminary point temps/pops...
shv 57 44 66 51 / 20 90 20 10
mlu 58 44 65 53 / 10 90 50 30
deq 58 43 58 45 / 10 80 10 10
txk 57 43 60 48 / 10 90 20 10
eld 58 42 64 49 / 10 90 30 10
tyr 56 45 65 51 / 30 90 10 10
ggg 58 45 65 51 / 20 90 10 10
lfk 56 45 67 55 / 30 90 20 20


Shv watches/warnings/advisories...

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