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Area forecast discussion 
National Weather Service Shreveport la
1217 am CDT Thursday Sep 18 2014

Aviation...
for the 18/06z tafs...two areas of convection will affect the area
early in the taf period. A broken line of convection is moving southward
into southeast OK/extreme SW Arkansas. This line has shown a tendency to
back-build towards the west so believe these storms will remain west
of ktxk. These storms have been cycling but have shown some signs
of diminishing so current thinking is they will not persist S of
I-30 but cannot rule of convection affecting ktyr/kgg later this
morning. Farther S...the eastern edge of a large area of rain may
affect klfk for a couple of hours.

Otherwise...low clouds and fog are likely across much of the area
once again this morning leading to MVFR/IFR flight conditions.
Improvement back into the VFR range is expected by middle to late
morning. More convection is expected to develop and affect much of
the area during the day Thursday. Lingering frontal boundary and
increasing moisture/ascent from the remnants of Hurricane Odile
may allow convection to persist late into the taf period. /09/

&&

Previous discussion... /issued 900 PM CDT Wednesday Sep 17 2014/

Discussion...
local and regional radars continue to show a well defined
disturbance across east central Oklahoma into west central
Arkansas moving south southwest in weak northwest flow aloft. This
cluster of strong/severe thunderstorms has developed a cold pool
which is helping to initiate and sustain the convection even after
sunset. Latest mesoanalysis shows cape near 2000 j/kg in our
vicinity of southeast OK into SW Arkansas which suggests that the convection
should continue to come south at least into our far northwest zones later
this evening. Latest hrrr supports this scenario with the
convection weakening quickly just before it make it to txk. For
this reason...have raised probability of precipitation to chance category across our northwest
zones this evening.

Elsewhere...convection is more isolated in nature across NE Texas
despite increasing moisture across our SW zones. Precipitable waters near 2
inches exist mainly to the west of a line from tyr to the lower
Toledo Bend Reservoir and this is where we will continue to
advertise low end chance probability of precipitation overnight. Convection across central
Texas at this time showing no tendency to want to move towards our region
from the west so low end chance probability of precipitation across this region should
suffice.

Dewpoint temperatures are quite a few degrees higher tonight
compared to 24 hours ago given and given the increasing moisture
from the southwest...this will likely have an effect on our
temperatures across a few locations. Bumped overnight lows up
across our eastern most zones mainly. Elsewhere...lower 70s should
suffice except for upper 60s across our extreme northwest zones where
convection could allow temperatures to fall below 70 degrees.

Otherwise...all other forecast parameters are in pretty good shape
with no other changes necessary at this time.

13

&&

Preliminary point temps/pops...
shv 68 92 70 91 72 / 10 10 10 10 10
mlu 67 92 68 92 69 / 10 10 10 10 10
deq 66 88 67 89 68 / 10 10 10 10 30
txk 67 89 69 90 70 / 10 10 10 10 20
eld 67 89 67 90 69 / 10 10 10 10 10
tyr 68 89 70 90 72 / 20 10 10 20 20
ggg 67 90 69 91 71 / 20 10 10 10 10
lfk 69 91 70 91 71 / 20 20 10 20 10

&&

Shv watches/warnings/advisories...
Arkansas...none.
La...none.
OK...none.
Texas...none.
&&

$$

09

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