Area Forecast Discussion
Issued by NWS Shreveport, LA

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FXUS64 KSHV 251008

Area Forecast Discussion
National Weather Service Shreveport LA
508 AM CDT Sat Mar 25 2017

The morning MCS continues to weaken as it exits the region across the
MS River and Acadiana, with dry air aloft entraining E across E TX/NW
LA/SW AR ahead of the stacked upper low now centered over NE OK.
Meanwhile, the morning sfc analysis indicates that the dry line has
mixed E into McCurtain County OK S across Red River, Titus, Upshur and
Smith Counties in NE TX, before extending SW along a PSN to CLL line.
Wrly winds beneath the NE OK sfc low will allow for the dry line to
mix E into SW AR/NW LA/the remainder of E TX this morning, before
eventually mixing out of the rest of N LA into SE TX/Cntrl LA to the
MS River before pulling up stationary. Despite the dry slotting aloft,
still seeing weak isolated -SHRA developing across the warm sector
just E of the dry line, thus have maintained slight chance pops this
morning for the lower Toledo Bend Country NE across N LA/Scntrl AR
with low chance pops across the Ern zones where low level moisture
remains a bit deeper. Wrly winds will result in near to above normal
temps again this afternoon, although readings will be a bit cooler
with more tolerable RH`s. The short term progs indicate that the wrap-
around stratocu beneath the sfc low will fill in across the remainder
of SE OK into much of SW AR/possibly extreme NE TX today, which should
keep max temps a little cooler than previously forecast. Otherwise,
look for decreasing clouds later today in wake of the upper low
departure, giving way to a mostly clear and cool night with good
radiational cooling resulting in temps falling to near seasonal norms.

This will be short-lived however as a return srly low level flow
commences Sunday as the next upper trough now crossing Srn CA will
rapidly translate E across the Rockies Sunday morning before
amplifying a bit across the Srn Plains Sunday afternoon/evening. This
will induce low level cyclogenesis over the TX Panhandle which will
enhance moisture advection back N from the Gulf, with a warm front
progged to lift N across E TX/N LA Sunday evening before reaching the
Red River of SE OK/extreme NE TX into extreme SW AR around 06Z Monday.
Although deep lyr moisture will remain limited out ahead of this next
trough, lapse rates will steepen Sunday evening in VC of the warm
front and Ewd advancing dryline over portions of N TX/Srn OK. This
convection should progress ENE along the warm front into SE OK/extreme
NE TX late Sunday evening, sustained by strong swrly shear and
steepening lapse rates aloft and increasing CAPES near the sfc bndry.
Given the marginal moisture profile, still unsure how far E this
convection will build, thus have maintained chance pops across NE
TX/SE OK/adjacent SW AR. Also maintained chance pops Monday for SW
AR/N LA/portions of Deep E TX as a weak sfc front attendant to the
upper trough begins to shift SE into the region before eventually
pulling up stationary somewhere over N LA/E TX Monday night. Not quite
comfortable pulling pops out of the forecast just yet near this front
Monday night/Tuesday given the low level moisture pooling observed on
the 00Z GFS, with this bndry expected to slowly return N Tuesday as a
srly flow gradually resumes.

Our next storm system will be following the heels of the second upper
trough late Sunday night, as it quickly digs SE across Srn CA, before
undergoing amplification Monday and Tuesday as it crosses the Srn
Rockies. The ECMWF remains consistent with earlier runs in closing
this next trough off by Wednesday as it crosses into the TX
Panhandle, with the GFS also closing the trough off but quickly
opening it back up as it enters the Srn Plains. The end result will be
more widespread convection affecting the region Wednesday and
Wednesday night. Given the strengthening shear profiles and expanding
warm/moist sector, severe convection again is possible, while also
providing beneficial rainfall to the area. Given the consistency of
the GFS/ECMWF, have maintained high chance/likely pops over the area
Wednesday, before tapering pops from W to E Thursday. However, above
normal temps will continue through much of the forecast period.

Prelims to follow below...



SHV  76  52  85  65 /  10   0   0  30
MLU  79  51  82  65 /  30   0   0  20
DEQ  68  46  79  59 /  10   0  10  50
TXK  71  50  80  62 /   5   0   5  40
ELD  74  49  80  62 /  20   0   0  30
TYR  73  53  85  65 /   0   0   5  30
GGG  74  51  85  65 /   0   0   5  30
LFK  79  53  86  67 /  10   0   0  20




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