Flash Flood Warning 45, NWS San Angelo, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
600 AM CDT THU OCT 22 2015

.AVIATION...
/12Z TAFS/

A line of showers and thunderstorms extends from McAmey, to Garden
City, to Snyder and continues to slowly advance east northeast.
Uncertainty remains in the eventual evolution of this line of
storms, but the current thinking is that KSJT and KABI have the
best chance of being affected this morning. Still, at least
scattered showers and thunderstorms will be possible at all sites
by this afternoon. For now, VCTS was included in the TAFs given
the continued uncertainty. MVFR conditions are currently being
experienced at all sites due to stratus. MVFR ceilings are
forecast to persist into this afternoon, with a brief return to
VFR conditions possible later this afternoon. Overnight, MVFR
conditions are expected to return with another chance of showers
and thunderstorms.

&&

.PREV DISCUSSION... /ISSUED 416 AM CDT THU OCT 22 2015/

SHORT TERM...
(Today and tonight)

..Locally heavy rainfall along with a few strong to severe
thunderstorms possible today and tonight...

A line of thunderstorms currently stretches from the Trans Pecos
north into the Permian Basin then into the South Plains. This line
of thunderstorms is slowly advancing east and should approach
our western counties between 5 AM and 7 AM. A moderately unstable
environment remains across West Central Texas, along with 0-6 KM
bulk shear values of 30 to 40 knots. A few strong to severe
thunderstorms will be possible this morning, mainly across our far
western counties, with the main threats being damaging winds and
an isolated tornado. A Tornado Watch is in effect for Irion,
Crockett, and Sterling Counties until 9 AM. Still, the main threat
will be the potential for locally heavy rainfall which could
result in flash flooding. High resolution models continue to
indicate convection across our western counties this morning, then
shifting mainly north of a Sterling City, to Robert Lee, to
Brownwood line this afternoon. Uncertainty remains on the exact
evolution of this line of thunderstorms this morning, but the
highest PoPs today were kept across the Big Country and western
counties, with PoPs decreasing as you head southeast. Highs today
will mainly be in the mid 70s to low 80s.

Overnight, the first upper level shortwave trough will swing
northeast across the Southern Plains, with the next shortwave
trough beginning to dig south across New Mexico/Arizona.
Additional shower and thunderstorm development is expected
overnight. Several of the high resolution models, including the
Texas Tech 3 KM WRF, develop convection along a general area from
the Big Country/Heartland then southwest into the Concho Valley.
Uncertainty remain on the extent and exactly where the convection
will set up, but PoPs were geared toward the high resolution model
solutions. Again, locally heavy rainfall will be possible
overnight with flash flooding a concern.

Exact rainfall totals through the next 24 hours are a bit hard to
pinpoint. We expect generally 1 to 3 inches north of an Ozona, to
San Angelo, to Brownwood line, although some higher amounts will be
possible. South of this line, rainfall totals of less than one inch
are generally expected, with isolated higher amounts possible.

Daniels

LONG TERM...
(Friday through Wednesday)

A weak surface trough will move into the western zones on Friday,
concomitant with strong forcing for ascent downstream of the
next shortwave trough. Precipitable water is progged to be at or
above 1.50 inches area-wide on Friday, remaining so over the
southeast half of the CWA on Saturday. This anomalously high
moisture, coupled with strong lift will promote widespread showers
and thunderstorms across the area, resulting in heavy rainfall for
west central TX. The highest PoPs by this time will be focused
over the Heartland and northwest Hill Country; roughly along and
southeast of a line from Brownwood to Sonora.

Categorical PoPs were included in this area Friday and Saturday,
and the mention of heavy rainfall was retained. Slightly lower
PoPs were included elsewhere, generally between 40-70 percent.
There could be a bit of a lull in the heavier rainfall Friday
afternoon as we'll be between systems, but rainfall is expected
to ramp up again Friday night into Saturday as the next system
approaches the area. This second wave is progged to clear the CWA
by Sunday morning, taking rain chances off to the east. These
showers and thunderstorms should be efficient rain producers,
capable of dropping 1-2 inches in a short amount of time.

Storm total rainfall amounts are expected to fall into the 2-4
inch range for most of the CWA, but locations to the east of a
Brownwood- Junction line could be closer to 4-6 inches. Even with
these significant rainfall totals, localized higher amounts are
likely. The Flash Flood Watch was expanded to include the
remainder of the CWA, with the watch for the new counties
beginning at 7 PM this evening (as opposed to 7 AM for the
original counties). This watch may very well need to be extended
in time into Friday, depending on what occurs over the next 12-24
hours.

Dry and cooler weather is in the forecast beginning on Sunday and
continuing through the middle of next week. Both the GFS and ECMWF
are showing a third shortwave trough moving across the area early
next week, but much of the moisture will be shunted off to the
east by this time. This may preclude the development of showers
and thunderstorms altogether. Will continue to watch this
potential for now. Otherwise, expect low temperatures in the
low/mid 50s with afternoon highs generally between 70-75 degrees.

The medium range models continue to advertise a more substantial
cold front by the middle of next week. The latest model runs
indicate this front arriving on Wednesday, potentially knocking high
temperatures back into the 60s.

Johnson

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene 	 77  65  80  62 /  90  80  60  60
San Angelo 	 79  65  79  62 /  80  80  60  60
Junction 	 81  69  79  65 /  60  70  80  80

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through Friday morning for Brown-Callahan-Coke-
Coleman-Concho-Crockett-Fisher-Haskell-Irion-Jones-Nolan-Runnels-
Shackelford-Sterling-Taylor-Throckmorton-Tom Green.

FLASH FLOOD WATCH from this evening through Friday morning for
Kimble-Mason-McCulloch-Menard-San Saba-Schleicher-Sutton.

&&

Daniels

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
431 AM CDT THU OCT 22 2015

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-
140-154-155-168>170-230945-
FISHER-NOLAN-STERLING-COKE-RUNNELS-IRION-TOM GREEN-CONCHO-
CROCKETT-SCHLEICHER-SUTTON-HASKELL-THROCKMORTON-JONES-SHACKELFORD-
TAYLOR-CALLAHAN-COLEMAN-BROWN-MCCULLOCH-SAN SABA-MENARD-KIMBLE-
MASON-
431 AM CDT THU OCT 22 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF WEST CENTRAL
TEXAS.

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY. LOCALLY HEAVY
RAINFALL IS EXPECTED WITH ANY THUNDERSTORMS THAT DEVELOP...WHICH
MAY RESULT IN FLASH FLOODING...ESPECIALLY AT LOW WATER
CROSSINGS...IN URBAN AREAS...AND AT OTHER FLOOD PRONE LOCATIONS. IN
ADDITION...A FEW STORMS MAY BECOME STRONG TO SEVERE WITH DAMAGING
WINDS AND DANGEROUS LIGHTNING BEING THE MAIN HAZARDS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS ALL OF WEST CENTRAL
TEXAS FRIDAY THROUGH SATURDAY NIGHT. THE MAIN HAZARD WILL BE
LOCALLY HEAVY RAINFALL THAT MAY RESULT IN FLASH
FLOODING...ESPECIALLY AT LOW WATER CROSSINGS...IN URBAN
AREAS...AND AT OTHER FLOOD PRONE LOCATIONS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TODAY.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN ANGELO TX
649 AM CDT THU OCT 22 2015

TXZ049-054-113-127-221245-
JONES TX-FISHER TX-NOLAN TX-TAYLOR TX-
649 AM CDT THU OCT 22 2015

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN JONES...FISHER...
NOLAN AND NORTHWESTERN TAYLOR COUNTIES UNTIL 745 AM CDT...

AT 649 AM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM OVER
CHAMPION...OR 8 MILES SOUTHWEST OF ROSCOE...MOVING NORTHEAST AT 35
MPH.

WIND GUSTS OF 50 TO 55 MPH WILL BE POSSIBLE WITH THIS STORM.

THIS STRONG THUNDERSTORM WILL BE NEAR...
  ROSCOE AROUND 705 AM CDT.
  SWEETWATER AROUND 720 AM CDT.
  LONGWORTH AROUND 735 AM CDT.
  SYLVESTER AROUND 745 AM CDT.

OTHER LOCATIONS IMPACTED BY THIS STORM INCLUDE LAKE SWEETWATER...
CAPITOLA...THE INTERSECTION OF HIGHWAY 70 AND RANCH ROAD 53...
GANNON...BUSBY...CAMP BOOTHE OAKS...CAMP BUTMAN...THE INTERSECTION OF
RANCH ROAD 608 AND HIGHWAY 147...US-180 NEAR THE FISHER-SCURRY COUNTY
LINE AND I-20 NEAR THE NOLAN-MITCHELL COUNTY LINE.

LAT...LON 3226 10001 3218 10066 3278 10066 3295 10023
TIME...MOT...LOC 1149Z 231DEG 28KT 3235 10063

DANIELS