Scientific Forecaster Discussion
fxus64 klch 180532
Area forecast discussion
National Weather Service Lake Charles la
1132 PM CST sun Nov 17 2019
Aviation...VFR conditions are expected during the period. Winds
will be light and vrb tonight with light north winds veering west
during the afternoon.
Previous discussion... /issued 915 PM CST sun Nov 17 2019/
wx map shows weak pressure gradient as 1017mb surface high
pressure resides over East Texas/ la this evening, with generally calm
winds. Satellite shows scattered cirrus continuing to stream over
the region is now over the Gulf, with clear skies across inland
areas. Temperatures ranging in the mid to upper 40s this evening,
expected to drop into the upper 30s over central Louisiana, to
lower/mid 40s elsewhere. Ongoing forecast on track with no
updates needed at this time.
Previous discussion... /issued 526 PM CST sun Nov 17 2019/
Aviation...mostly VFR conditions are expected, however stratus
around 3kft may move into kbpt overnight causing periodic MVFR
ceilings. Winds will light and vrb but becoming more northerly
Previous discussion... /issued 352 PM CST sun Nov 17 2019/
mostly sunny and mild across the area this afternoon, with
temperatures generally in the mid/upper 60s and just some high
cirrus streaming overhead. High pressure is prevailing at the surface
underneath westerly flow aloft near the base of an upper trof
traversing the central Continental U.S..
Model guidance in the near term remains in good agreement, showing
the upper trof continuing to dig toward the eastern conus, and sending a
weakening surface front through the area late tonight into early Monday.
Not much in the way of return flow ahead of the front, but a
modest increase in surface dewpoints expected via west/SW flow will
result in warmer temperatures tonight, with lows ranging from the
upper 30s across east central la to the upper 40s over coastal southeast
Texas/SW la. Surface high pressure settling into southeast Texas behind the front
will continue to yield dry and warm weather on Mon, with highs in
the upper 60s.
Warm and dry weather will continue into Tuesday as a reinforcing surface
high slides into the region, with more robust warming Tuesday night
into Wednesday as this surface high slides off to the east and a deeper
return flow begins to establish. Temperatures Tuesday and Tuesday night
are expected to be near or just above seasonal normals.
Model guidance has come into a bit better agreement for the mid
to late week period. As an upper low currently west of the baja
fills and ejects out across the plains on Wed, this feature will
lay out a frontal boundary well to our west and NW, which is not
expected move much until a second upstream trof pushes east across
the central Continental U.S.. there remains a fair amount of spread in the
timing of when this will occur and when the front will eventually
push its way through the area, but it appears at this time that
warm and dry with increasing cloud cover can be expected on Wed,
with increasing rain chances on tap Thursday and especially on Friday.
Whether/how much rain lingers into Sat will depend on the
timing/evolution of the upper trof and any upstream infusions of
jet energy, and of course the passage of the associated surface
front. The GFS remains on the faster/more progressive end of the
spectrum and the European model (ecmwf) on the slower end, with support for the
latter coming from the CMC and more so the gefs.
light northwest to westerly flow will prevail into Tuesday, with
a light to modest onshore flow developing Tuesday afternoon and
continuing into Thursday. The timing of a cold front later this
week remains uncertain, but a modest offshore flow could develop
as early as Friday. Increasing rain chances are also expected in
association with the approaching front.
Preliminary point temps/pops...
aex 38 65 42 73 / 0 0 0 0
lch 45 68 47 73 / 0 0 0 0
lft 42 68 45 72 / 0 0 0 0
bpt 47 68 48 72 / 0 0 0 0