Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Shreveport la
1158 am CDT Wednesday Sep 2 2015
middle level cloud decks across the area inhibiting cumulus development
in moister air underneath. Convection thus far today has remained
just offshore in Gulf and NE movement of cells could possibly traject
towards kmlu later this afternoon...so placed thunderstorm vicinity at that
terminal but none elsewhere. Fog and low clouds tonight limited in
lack of southerly flow or recent fog development across area...but
if so...klfk would be most likely terminal to see any tempo MVFR
conditions overnight. Light variable winds across area to remain until
at least 03/15z with only southeast winds around 5 kts after that./Vii/.
Previous discussion... /issued 1137 am CDT Wednesday Sep 2 2015/
a few minor changes to afternoon probability of precipitation/sky and high temperatures.
add 10 at 10 CST rule with observation ranging all through the 80s. A
dense middle deck is working over The Heart of the arklatex with low
80s and light or calm surface winds. Ruston and Monroe are in the
upper 80s with a good deal more sunshine this morning. Our radar
has a clean sweep and with limited heating and that may be
through the lunch hour.
Our sounding showed moisture into the middle levels...but very dry
above an inversion at 18kft. It is likely that the NE flow above
the inversion has worked down a bit looking at the water vapor.
Any thunderstorms today will be low topped and perhaps few and far
between. Middeck showers are more likely until we see better
heating this afternoon. The vapor shows the dry air spreading southeast
for the last few hours...but has slowed its motion. There is a
little vorticity working up across west la in over Toledo Bend country.
This may help with some chance probability of precipitation for I-20 corridor later with
more heating as the middle deck moves farther northwest.
The hrrr shows decent coverage and is why we left chance probability of precipitation.
Slight chance may be a more likely event if that little vorticity fails
to spread deeper tropical moisture back into that drier air. The
chance for rain still looks to decline into the next few days as
the main Gulf low moves eastward...taking the tropical connection
out of reach. /24/
Previous discussion... /issued 412 am CDT Wednesday Sep 2 2015/
water vapor imagery continues to depict a weak upper level low
near Galveston Bay this morning with a shear axis extending nwrd
across deep East Texas...north la...and southeast Arkansas. Middle and high clouds continue
to blanket these areas while points along and north of the I-30
corridor are sky clear. As moisture remains quite abundant over the southeast
half of the region today...expect showers and thunderstorms to increase as
we move into the afternoon hours with the added instability from
heating. Using persistence as a guide...do expect cloud cover to
hold down temperatures slightly much like yesterday with upper 80s
and lower 90s expected.
Rain chances will begin to drop off as we head into late week and
the Labor Day weekend as upper ridging becomes more influential in
our weather pattern...sending temperatures higher into the middle 90s
and possibly even upper 90s for some areas over the weekend. Some
diurnally driven convection cannot be completely ruled out but it
will be isolated at best with sea breeze activity across mainly
our southern zones.
Relief from the late Summer heat will likely have to wait until
Thursday of next week with an advancing cold front. This will also
provide our next best chance at seeing widespread showers and thunderstorms
across the region. Expect noticeably cooler and drier air in the
wake of this front...with temperatures likely a few degrees below
normal by the end of next week. /19/
Preliminary point temps/pops...
shv 73 95 74 96 / 20 20 10 10
mlu 72 96 73 97 / 20 20 10 20
deq 69 94 70 94 / 10 10 10 10
txk 71 94 73 96 / 20 10 10 10
eld 70 95 72 95 / 20 20 10 10
tyr 73 94 73 95 / 10 20 10 10
ggg 72 94 73 94 / 10 20 10 10
lfk 71 93 72 93 / 20 30 20 20