Area Forecast Discussion
Issued by NWS San Angelo, TX
FXUS64 KSJT 271701
Area Forecast Discussion
National Weather Service San Angelo TX
1201 PM CDT Thu Apr 27 2017
Expect gusty south southwest winds of 15 to 20 knots to decrease
to 10 to 12 knots early this evening, except at KABI and KSJT
where winds will remain in the 15 to 18 knot range. Stratus is
forecast to develop at the southern 3 sites between 08z and 10z,
resulting in MVFR ceilings. For now, ceilings at KSJT were kept
VFR, but brief MVFR ceilings will be possible. VFR conditions are
forecast to return to all sites by mid to late morning.
.PREV DISCUSSION... /issued 655 AM CDT Thu Apr 27 2017/
VFR conditions expected through the next 24 hours. The only
aviation concern will be gusty southwest winds at all sites today.
Winds should increase to between 15 and 20 knots with gusts
between 25 and 30 knots at all sites by 15Z/10AM. Expect the gusty
conditions to linger into the overnight hours at both KABI and
KSJT, with gusts likely dropping off at the other sites between
00Z/7PM and 04Z/11PM. Only expecting some FEW to SCT upper level
clouds at times through tomorrow morning. 20
PREV DISCUSSION... /issued 408 AM CDT Thu Apr 27 2017/
(Today and Tonight)
Temperatures will quickly rebound for today from yesterday`s cool
northwest winds. Northwest flow across the western half of the
CONUS will carry another strong shortwave toward the area, which
will cause surface low development from southeastern Colorado into
the Texas Panhandle. This will quickly turn our winds to the
south and southwest today, while also being gusty at 20 to 30 mph.
Plenty of sunshine and downslope warming from the westerly
component of the winds will allow temperatures to warm into the
upper 80s to lower 90s.
Overnight, we will keep southerly flow across most of the
forecast area, which will bring Gulf of Mexico moisture into the
area. A cold front will approach Haskell County by early Friday
morning, but will not make significant progress into the area.
Lows will be fairly mild, ranging from around 60 far north to the
upper 60s from the Concho Valley south.
(Friday through Wednesday)
The most active part of the forecast is Friday into the weekend.
Within an upper trough over the Rockies, a closed low will develop
Friday and this low will be over the Four Corners region Friday
This upper low is forecast to drop southeast into New Mexico on
Saturday morning, and then lift northeast across the Texas Panhandle
on Saturday night. A weak cold front will sag south into our far
northern Counties on Friday morning before stalling. The front
should gradually lift back north to near or just north of Haskell
and Throckmorton Counties by late Friday afternoon. To the south of
this weak front, a dryline will mix east across much of our area and
sharpen during the afternoon. By late Friday afternoon, the dryline
should extend approximately from the eastern border of Throckmorton
County to Menard to just east of Sonora. Temperatures will be hot
Friday afternoon with a strengthened low-level thermal ridge south
of the aforementioned frontal boundary. Highs are expected to be in
the 90s across most of our area, with the warmest readings
expected in parts of the Concho Valley. A few thunderstorms will
be possible by late Friday afternoon and early evening across some
of our eastern counties from north of Brownwood to Throckmorton,
along and just ahead of the dryline. Strong instability and
favorable vertical shear will support a conditional severe weather
risk, especially for the far northeastern part of our area which
should be near the triple point.
The dryline will retreat to the west out of our area early Friday
night, and then a Pacific front should overtake the dryline west of
our area overnight. On Saturday, Pacific front/dryline will advance
east across West Central Texas, and should be east of our area by
mid-afternoon. Scattered showers and thunderstorms will be
possible Friday overnight into the day Saturday. A few strong
storms with hail will be possible, given the forecast steep mid-
level lapse rates over our area. A secondary cold front is progged
to move southeast across our area Saturday overnight. Scattered
showers and a few elevated thunderstorms will be possible
Saturday night. Despite the convergence/lift along the frontal
boundaries and increased large scale ascent with the incoming
upper trough, overall limited available moisture precludes our
carrying more than chance PoPs Friday night through Saturday
In the wake of the cold frontal passage, breezy and much cooler
conditions are expected for our area during the day Sunday, with
clearing skies as the upper low lifts northeast into Kansas.
Forecast lows Sunday night are in the mid to upper 40s, with
indications for good radiational cooling across much of our area
in the proximity of a surface ridge axis.
A rebound in temperatures is indicated again Monday-Tuesday of next
week, as south winds return Monday and increase across our area.
Highs on Monday are forecast to be in the mid to upper 80s across
much of our area, and in the mid 80s to around 90 on Tuesday.
A dry cold frontal passage is progged on Wednesday.
Warmer than normal temperatures, winds near 20 mph, and relative
humidity values from 15 to 25 percent will result in another near
critical fire weather day across the area. Vegetative greenness is
still higher than average however, and ERC percentiles are
running near normal between the 40th and 50th percentiles.
Considering the fuels, and winds being marginal for RFW criteria,
will again go with a Fire Danger Statement, as opposed to a RFW
for the area, mainly west of a Throckmorton, to Coleman, to Sonora
Hot temperatures, and low relative humidities on Friday will keep
conditions elevated, but slightly weaker winds are expected.
There is a chance for showers and thunderstorms for much of the
area from Friday night through Saturday night. However, aside from
briefly cooler temperatures Sunday, our temperatures will stay
warmer than normal, keeping fire weather conditions elevated
through next week.
.PRELIMINARY POINT TEMPS/POPS...
Abilene 65 92 66 79 / 0 10 30 30
San Angelo 67 97 68 85 / 0 5 30 20
Junction 66 95 69 87 / 0 5 10 20
Brownwood 65 92 69 81 / 0 10 20 30
Sweetwater 63 91 63 78 / 0 5 30 20
Ozona 64 94 68 86 / 0 5 20 10