Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/06/20
Area Forecast Discussion
National Weather Service Shreveport LA
649 PM CST Thu Nov 5 2020
For the 06/00Z TAF period, VFR conditions should largely prevail
this period despite the presence of an upper level trough/closed
low centered across the region. This upper low will slowly shift
more S/SW through Friday. Some cumulus present this evening will
likely persist overnight in some areas with the low still present.
In addition, some patchy fog may also develop closer to daybreak
at a few sites with MVFR vsbys possible for a few hours. Aside
from that, the low VFR cigs could occur intermittently overnight
into Friday morning with the cu that is currently present. Winds
will remain rather light from the E/SE with speeds generally near
5 kts or less.
.PREV DISCUSSION... /issued 126 PM CST Thu Nov 5 2020/
The latest RAP mid-level analysis indicates a 500mb trough axis
extends from northwestern Arkansas southwestward across the
ArkLaTex and into East Texas. While some vort energy is
coincident with the base of this weak trough, moisture is limited
to the 1000-925mb layer. At the surface, high pressure extends
from the Carolinas across the Mississippi Valley and into the
local area. Scattered diurnal cumulus clouds extend from Deep
East Texas across the ArkLaTex into southwestern Arkansas with
mostly sunny skies otherwise.
This evening, the relatively dry mid-level trough will slowly
slide southeastward across the ArkLaTex. Any lingering diurnal
cumulus this evening will mostly diminish after sunset. Southerly
winds at 5-10 mph will shift to more easterly this evening. Tonight,
the trough will begin to break southward and become a closed low
over the Texas coast and East Texas. Skies will mostly clear
overnight and patchy fog will develop by the pre-dawn hours.
Overnight lows side slightly closer to the cooler NAM/NBM guidance
with lows ranging from the mid 40s in southwestern Arkansas to the
mid 50s in portions of East Texas.
Friday into Friday night, the GFS/NAM/ECMWF all show the closed
lower meandering around East Texas and the southeast Texas coast.
While the ECMWF is hinting at some deep moisture advecting into
northern Louisiana and possibly a few showers moving into central
Louisiana and the ArkLaMiss Friday night into Saturday morning,
this is considered to be an outlier and the forecast remains dry.
For temperatures, a GFS/NAM blend is closest to the NBM with
highs in the mid 70s on Friday and lows ranging from the lower 50s
in SE Oklahoma/SW Arkansas to the upper 50s in central Louisiana.
At the start of this long-term period, a weak low-pressure will be
spinning off the SE Texas coast, allowing for increased moisture and
slight WAA to continue filtering into the region. However, this weak
low-pressure will degrade over the weekend, and be replaced with SW
flow aloft ahead of the next longwave trough expected to move east
into early next week. While this S/SW flow will increase the
moisture and cloud cover across the Four-States region,
precipitation is currently not expected due to lack of trigger.
However, some of the guidance at my disposal this morning did hint
at some spotty showers over the weekend, but my confidence was not
high enough to include them in this forecast. Afternoon high through
Monday should run in the mid to upper 70s, with overnight lows in
By Tuesday of next week, the next trough and cold front will begin
to work their way into the area. Shower and thunderstorm activity
will begin increasing in the morning, and expand east into the
afternoon and evening. At this time, due to limited instability, and
not the most favorable forcing, no severe weather is anticipated. By
the time the front passes on Wednesday, look for a slight swing in
temperatures with afternoon highs in the low-70s, and overnight lows
in the mid to upper-50s.
.PRELIMINARY POINT TEMPS/POPS...
SHV 50 75 56 76 / 0 0 0 10
MLU 48 76 58 75 / 0 0 0 20
DEQ 50 73 52 75 / 0 0 0 10
TXK 48 73 54 74 / 0 0 0 10
ELD 46 74 54 74 / 0 0 0 10
TYR 55 75 54 76 / 0 0 0 10
GGG 50 75 53 76 / 0 0 0 10
LFK 51 77 55 78 / 0 0 0 10