Area Forecast Discussion
Issued by NWS Shreveport, LA
FXUS64 KSHV 280315
Area Forecast Discussion
National Weather Service Shreveport LA
915 PM CST Mon Feb 27 2017
Interesting forecast for the remainder of the night as we have
several scenarios that could play out which leads to a complicated
Looking aloft...water vapor imagery and 500mb progs showing
continued west southwesterly flow with a disturbance in this flow
across the TX Hill Country. As this feature moves north and east
later this evening...PVA in advance of the disturbance should
result in a slight increase in shower/tstm coverage across the
Middle Red River Valley of NE TX/SE OK/SW AR. May be starting to
see the beginnings of this as regional radar mosaics showing some
developing convection currently just north of the Red River across
SE OK into portions of Central Arkansas and also Northeast Texas
just north of the I-20 corridor.
At the surface...we are still dealing with this pesky surface
boundary which at the moment remains stalled across EC LA into NW
LA and NE TX north of the I-20 corridor. North of this boundary
currently we are seeing some patchy fog developing which makes
sense in the slightly milder airmass. Progs are in pretty good
agreement with this boundary slowly lifting northward overnight
tonight which would suggest the likelihood of slowly rising
temperatures or temperatures remaining nearly steady overnight.
Progs are also indicating the possibility of some increased shower
activity developing late tonight across our eastern zones in an
area of increasing isentropic lift.
So for the update...have lowered pop forecast to slight chance
variety across most of the area with chance pops across our
eastern flank and northwest flank for the above reasons. Also
tried to adjust hourly temp fcst overnight to suggest temperatures
remaining nearly stationary or slowly rising overnight as the
boundary begins to slowly retreat northward.
Also adjusted cloud cover grids as areas along and south of the
I-20 corridor currently seeing partly cloudy skies but this region
should fill back in with widespread cloud cover later tonight.
Updated forecast package will be out shortly...13.
.PREV DISCUSSION... /issued 650 PM CST Mon Feb 27 2017/
For the 28/00Z TAFs, a wide range of ceilings covering our TAF
locations this evening with a stalled frontal boundary oriented
generally along the I-20 corridor and slowly drifting northward.
South of this front, cigs are VFR with dissipating CU for now
while widespread low stratus is found farther north at ELD/TXK.
Low cigs will gradually fill back in over our E TX/N LA terminals
later this evening along with patchy fog developing overnight so
expect MVFR/IFR conditions areawide throughout Tuesday morning.
Increasing southerly winds will occur as the warm front shifts
farther north through Tuesday so cigs will lift and scatter out
during the afternoon with VFR returning. Convection will likely
hold off until after this period ends at 01/00Z.
.PRELIMINARY POINT TEMPS/POPS...
SHV 65 82 63 71 / 20 30 50 30
MLU 63 82 69 73 / 30 30 60 50
DEQ 58 80 54 64 / 30 40 60 20
TXK 59 81 57 67 / 20 40 60 20
ELD 58 81 64 69 / 30 40 50 40
TYR 69 83 57 66 / 20 40 50 20
GGG 68 82 60 69 / 20 40 50 30
LFK 70 82 66 73 / 20 30 60 40