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Area forecast discussion
National Weather Service Shreveport la
445 PM CST Sat Nov 16 2019

Aviation...

VFR conditions expected to prevail across our airspace through the
next 24 hours. Infrared imagery this evening showing thin cirrus
continues to invade our region from the west and northwest ahead
of a longwave trough that is currently moving out of the
intermountain west and expected to move into the Great Plains
overnight. Sfc ridge axis to remain in place through the overnight
hours which will result in near calm winds. There will be a
frontal boundary associated with the longwave trough axis that
will begin moving into our northwest airspace sun aftn and should
push through our entire airspace by Sunday night. Not much in the
way of a strong pressure gradient in the wake of this boundary for
Sunday into Sunday night so strong winds will not become a factor.
Cannot rule out a weak cu field along the frontal boundary with
cloud heights near 5kft or so sun aftn into the evening hours.

13

&&

Previous discussion... /issued 348 PM CST Sat Nov 16 2019/

Short term.../through Sunday night/

High clouds have been on the gradual increase (especially to our
west) this afternoon in response to lift from an approaching upper
level disturbance. But skies can generally be categorized as
"mostly sunny" in the region right now and any cloudier periods
will be transient and mainly confined to the arklatex. The high
pressure ridge in the lower levels over the area will ensure
moisture is far too low for surface precipitation as the trough
passes. In fact, radiational cooling conditions will remain decent
tonight since higher clouds will generally not be too thick and
the boundary layer will be dry with light winds. With that in
mind, expect at least patchy frost in all locations tonight in
conjunction with low temperatures ranging from 30 to 35 degrees.

Temperatures will moderate a bit tomorrow in comparison to today,
but still will remain a little below average (max temps ranging
from 60 to 65 degrees). Winds switching to the southwest to west
in the tropospheric lower levels will help drive the temperature
moderation tomorrow, but right before the northwest flow aloft on
the backside of the departing upper trough helps drive another,
albeit weak, cold front through the four state region Sunday
night. The mixing association with this fropa will inhibit great
radiational cooling and lows for early Monday morning should be
chilly, but probably entirely above freezing.

50

Long term.../Monday through Friday night/

The new work begins with a 1017mb sfc high pressure area expanding
over Texas and the midsouth, that will slowly modify it's chill;
while drifting eastward along the Gulf Coast by midweek. All this
while, we will be under cirrus with mostly clear to partly cloudy
skies to start and some increasing mid and lower clouds by midweek.
Our high temperatures will keep to the 60s again on Monday, but edge
into the low 70s by Tuesday with a few mid 70s by Thursday.
Likewise, our lows in the mid 40s to upper 40s to start the week and
will warm into the mid to upper 50s by Thursday with southerly winds
persisting.

Showers and isolated thunderstorms begin to return by late
Wednesday, overnight and into or through (depending on model
preference) Thursday as our next wet cold frontal boundary moves
across the region and settles across the northern Gulf Coast. The
northerly winds will return by late morning and all afternoon on
Thursday.

Temperatures on Thursday afternoon could range from the low to mid
60s north of the front across the I-30 corridor to the low to mid
70s south well ahead of the front. The European model (ecmwf) is a little faster on
the cold front and associated precip than the GFS, but both are
looking at a 1025mb air mass. The timing should come in better
agreement with subsequent model runs for this first cold front.

Behind this cold front we will be more seasonal readings and not an
Arctic chill again. Our low temperatures on Friday morning will to
fall into the 40s and 50s and cooler still into the weekend as a
secondary 1026mb arrives to settle into and over the area during
next weekend. The models also vary greatly on the second frontal
boundary and the associated quantitative precipitation forecast. The European model (ecmwf) takes this second system
slower and GFS is faster for a change of pace.

24

&&

Preliminary point temps/pops...
shv 32 63 39 65 / 0 0 0 0
mlu 32 62 38 64 / 0 0 0 0
deq 32 61 36 64 / 0 0 0 0
txk 32 61 37 64 / 0 0 0 0
eld 30 61 36 64 / 0 0 0 0
tyr 35 65 39 66 / 0 0 0 0
ggg 33 65 38 65 / 0 0 0 0
lfk 33 66 41 67 / 0 0 0 0

&&

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

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