Drought in Texas, April 1 to 30, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
1150 PM CDT MON MAR 31 2014

.AVIATION...
/06Z TAFS/

VFR conditions with mostly light and variable winds will continue
at all terminals through the most of the remainder of the night.
Stratus will move north into the area before sunrise degrading
ceilings to MVFR between 11Z and 12Z at the southern terminals.
Ceilings at the southern terminals will return to VFR just before
noon accompanied by southerly winds gusting to around 20 knots at
all terminals. There is a slight chance of convective activity
developing tomorrow evening primarily near KABI with even a lesser
chance at the remaining terminals. Due to the isolated nature of
any expected thunderstorm development and its occurrence at the
end of this TAF cycle, have not included any mention at this TAF
issuance.

15

PREV DISCUSSION... /ISSUED 615 PM CDT MON MAR 31 2014/

AVIATION...
/00Z TAFS/

VFR conditions with mostly light and variable winds will continue
at all terminals through the night. Gulf moisture will return to
the area overnight which will result in the degradation of
ceilings to MVFR at the southern terminals between 12Z and 13Z.
Ceilings will return to VFR just before noon accompanied by
southerly winds gusting to 20-25 knots.

15

PREV DISCUSSION... /ISSUED 346 PM CDT MON MAR 31 2014/

SHORT TERM...
(Tonight and tomorrow)

The water vapor is impressive this afternoon, showing a trio of
potent shortwave troughs lined up in the vicinity of the 40Th
Parallel, from the West Coast to the East Coast. South of these
cyclones, a strong subtropical jet is propagating across the
Southwest CONUS. Temperatures have warmed into the mid/upper 80s
across most of the area this afternoon, with a few locations topping
90 degrees. Winds have diminished this afternoon but remain from a
general westerly direction. Dewpoints have crashed across the
western portion of the CWA and will be slow to recover this evening.
Temps will fall into the low/mid 50s across the CWA tonight with low
clouds developing late along the I-10 corridor, spreading north
before eroding by mid morning.

The dryline will mix east tomorrow, but is expected to stall in the
vicinity of a Haskell, to Ballinger, to Sonora line. Isolated
thunderstorms will be possible along and east of the dryline, mainly
across the Big Country and Heartland counties where the cap will be
weakest. I think the cap will hold across most of the area but I do
expect a few updrafts to breach the lid by mid afternoon, generally
east of Sweetwater and north of the Colorado River. Coverage should
remain quite limited and most areas will likely remain dry. That
said, any storms that develop will have the potential to become
severe.

Both the NAM and GFS depict 0-6km bulk shear values exceeding 50 kts
and MLCAPE values in the neighborhood of 1500-2500 J/kg. Surface
temperatures near 90 degrees will promote deep mixing and an
inverted-V profile, with storm bases around 8000 ft. The primary
concern will be damaging winds and large hail as storm organization
is expected given the aforementioned forecast parameters. If the
dryline is a bit more aggressive than currently forecast,
thunderstorms will be pushed east. However, backing-low level winds
are expected due to the deepening lee cyclone. This will help keep
the dryline's eastward propagation in check.

Johnson

LONG TERM...
/Tuesday Night through Thursday/
The combination of a dryline and upper level disturbances moving
northeast in southwest flow aloft will bring possible thunderstorms
to mainly the eastern 2/3 of West Central Texas. The coverage will
be isolated and time frame mainly during the late afternoon and
evening hours. Any storms that do develop will rapidly become
severe(main storm type supercells) due to strong instability(MLCAPES
2000 to 3000 J/KG) and 0-6KM bulk shear values of 45 to 55 knots.
The main threats will be large hail and damaging winds. Temperatures
will be above normal with highs in the 80s to around 90 and lows 60
to 65.

/Thursday Night through Saturday/
The weather looks quiet and cooler behind a cold front. Highs will
be in the 60s and 70s with lows in the 40s.

/Saturday Night and Sunday/
Another upper level trough will move across the area with some
potential for mainly elevated convection. The ECWMF is much wetter
and deeper with the trough than the GFS. There are differences in
the two models, so for now will go with slgt chance POPS. Highs will
be in the 60s to lower 70s with lows in the 40s to around 50.

21

FIRE WEATHER...
Wind speeds have diminished this afternoon, limiting fire weather
concerns, despite temperatures largely in the 80s and relative
humidities falling into the teens across the west. Light winds will
prevail through the overnight period with relative humidities
increasing to greater than 70% across much of the area (the Big
Country will be more in the 40-60% range). South winds will increase
to 12-16 mph on Tuesday, especially during the afternoon hours. The
dryline will mix east, resulting in minimum relative humidities less
than 25% west of a Sweetwater to Ozona line. The result will be
elevated fire weather conditions. The dryline is forecast to mix
slightly farther east on Wednesday, but winds will remain generally
15 mph or less. Thunderstorms will be possible each day Tuesday
through Thursday, especially during the afternoon and evening.

Johnson

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene 	 56  89  66  90  60 /   0  20  20  20  20
San Angelo 	 54  91  67  89  60 /   0  10  10  20  20
Junction 	 54  89  67  87  64 /   0  10  10  20  20

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
321 PM CDT MON MAR 31 2014

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-
140-154-155-168>170-011100-
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-
321 PM CDT MON MAR 31 2014

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS PORTIONS OF WEST
CENTRAL TEXAS TUESDAY THROUGH THURSDAY...MAINLY DURING THE
AFTERNOON AND EVENING HOURS. IF STORMS DEVELOP...THEY WILL HAVE
THE POTENTIAL TO BECOME SEVERE. THE PRIMARY HAZARDS WILL BE LARGE
HAIL AND DAMAGING WINDS. ADDITIONAL THUNDERSTORMS WILL BE POSSIBLE
SATURDAY NIGHT AND SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUESTED TUESDAY AFTERNOON ACROSS THE
BIG COUNTRY AND HEARTLAND COUNTIES.

JOHNSON