Area Forecast Discussion
Issued by NWS San Angelo, TX
FXUS64 KSJT 230432
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
1130 PM CDT TUE APR 22 2014
VFR conditions will continue through the night at all terminals.
There is a slight chance of late afternoon/evening thunderstorms
primarily over the northern sections of West central Texas
associated with a dryline that will move across the area. Have only
included a mention of storms over KABI for this evening at this
time. A stratus deck is expected to move over the southern terminals
by early morning resulting in MVFR conditions for several hours.
.PREV DISCUSSION... /ISSUED 615 PM CDT TUE APR 22 2014/
VFR conditions will continue over all terminals through tonight.
Stratus will move into the area from the south and lower the
southern terminal ceilings to MVFR by sunrise tomorrow. Ceilings
over the southern terminals will lift to VFR by mid-morning.
Surface winds will increase in speed from the south by mid-morning,
gusting from the south around 25 knots at the northern terminals
and around 20 knots at the southern terminals.
.PREV DISCUSSION... /ISSUED 340 PM CDT TUE APR 22 2014/
(Tonight and Wednesday)
The main concern in the short term is the potential for isolated to
scattered showers and thunderstorms Wednesday, some possibly severe.
A large upper level trough across the West Coast of the United
States, and will approach the Plains late Wednesday. Surface
moisture will be on the increase tonight ahead of this feature, with
dewpoints increasing into the upper 50s to lower 60s by daybreak. A
dryline will sharpen just west of our area by late afternoon, with
an increasingly unstable atmosphere ahead of the dryline. Steep
lapse rates, modest 0-6 KM bulk shear values, and SBCAPE values of
1000-2000 J/KG will be present across much of the area. I expect
isolated thunderstorms to initiate just west of our area by late
afternoon, then increase in coverage and slowly move east or
northeast. A few supercells will be possible, with large hail and
damaging winds being the main threats. For now I have kept PoPs in
the chance category, but these may need to be bumped up slightly if
coverage looks to be greater than what is currently anticipated.
Low temperatures overnight will remain above normal, generally in
the mid 50s to lower 60s. Highs on will once again be above seasonal
normals, in the upper 80s to lower 90s.
(Thursday through Tuesday)
Still looks like the chances for storms will expand across the area
during the Wednesday evening time frame, reaching towards San Angelo
and Abilene. The scattered storms already in the forecast looks
pretty good, but given the expected CAPE and shear, will go ahead
and mention the possibility of severe.
Weak cold front drops into the area for Thursday, bringing as much
as anything a slightly drier air mass to the area. However, front
doesnt make it very far and a return of south winds to the area will
quickly bring the low level moisture back into West Central Texas.
An approaching potent upper level low will drop into the southern
Rockies by early Saturday, with a negatively tilted trough axis
moving across the Southern Plains by Saturday afternoon. This upper
support combined with CAPE values well above 3000 j/kg will set up a
potential busy severe weather period late Saturday afternoon and
evening. Always a little hard to tell exactly how widespread it will
be on the southern edge where the cap usually is a factor. But have
increased the rain chances for the period. Saturday evening
certainly looks to the have the potential to be very active!
Rest of the forecast looks fairly quiet, as a much drier air mass
settles into the area.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 61 87 63 85 59 / 0 20 30 5 5
San Angelo 59 92 64 89 60 / 0 20 30 5 5
Junction 60 87 64 89 63 / 0 10 20 10 5