Red Flag Warning 4, NWS San Angelo, TX

REA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
542 PM CST Thu Feb 27 2014

.AVIATION...
/00Z TAFS/

VFR conditions will prevail at all the TAF sites over the next 24
hours. Winds will increase through the overnight hours as a low
level jet of 40 KTS develops, and the boundary layer remains
mixed. South to Southwest winds of 15 to 25 KTS can be expected
tonight. Model soundings hint at the possibility of low stratus
developing across southern terminals overnight. I'll leave this out
of the forecast for now and continue to monitor. During the day
tomorrow, a trough will develop to our west, helping maintain
southwesterly winds of 15 to 30 KTS.

Doll

&&

.PREV DISCUSSION... /ISSUED 311 PM CST THU FEB 27 2014/

SHORT TERM...
(Tonight and Friday)

..Warmer weather in store for Friday...

Currently, temperatures have warmed into the 50s to lower 60s
across most of the area, on their way into the lower to mid 60s.
Stubborn low clouds across Crockett, Schleicher, and Sutton
Counties through the early afternoon have limited warming for
southwestern areas, keeping temperatures in the 40s at Ozona and
Sonora through 130 PM. Once these clouds clear in these locations,
temperatures will likely shoot up into the 50s, and possibly low
60s for highs.

Tonight, a fast moving upper level shortwave will move toward and
across the area. This will cause low level troughing to occur
across the area during the overnight hours, resulting in a
tightening surface pressure gradient as well as height gradients
at 925mb and 850mb. Thus, winds will likely remain breezy
overnight at many locations, especially along the I-20 corridor.
This will help keep the boundary layer mixed, and temperatures
much warmer tonight than last night. Lows will drop into the mid
40s to lower 50s, with a few locations as cool as 40 degrees.

On Friday, we will see the breezy conditions continue across the
area. As the upper level trough moves east into the plains
tomorrow, the surface pressure gradient will be roughly parallel
with the geopotential height lines through 700mb. This will
encourage more efficient mixing of stronger winds aloft to the
surface from the late morning through early afternoon as the
trough axis moves east and downward momentum moves into the area.
So, winds will increase to 20 to 30 mph by late morning through
early afternoon. As the trough moves east, winds will diminish
aloft, and the surface pressure gradient will also relax, allowing
winds to diminish by late in the afternoon. The strongest winds
will be generally north of a Sterling City to Brownwood line.

20

LONG TERM...
(Friday Night through Thursday)

Unseasonably warm temperatures are forecast on Saturday, followed
by below normal temperatures for the first part of next week. A
large upper level trough will move ashore California Saturday,
then approach the Southern Plains Sunday. Ahead of the trough
Saturday, south winds will increase to 12 to 16 mph, with well
above normal temperatures. Highs will be in the lower to mid 80s
across the region, with some upper 80s possible. In the meantime a
cold arctic airmass will reside across much of the Plains, with a
cold front near the Red River Sunday morning.

The forecast on Sunday will be dependent on the exact timing of the
aforementioned cold front. A disturbance in the southwest flow aloft
will help to spark at least a few showers or a thunderstorms Sunday,
along and ahead of the front. I think the best chance will be across
the eastern Big Country and Heartland, and this is where I have
indicated the best PoPs. The current forecast indicates highs
ranging from near 40 across the northern Big Country, to the upper
70s across the Interstate 10 corridor. The cold front will move
through the day, approaching the Interstate 10 corridor by evening,
with falling temperatures behind the front. Of course, a faster
frontal passage would result in a quicker onset of the colder
temperatures. Much colder temperatures can be expected on Monday,
with dry conditions. Highs will range from the upper 30s north, to
near 50 south. Lows will generally be in the 20s, although some
teens will be possible across mainly the Big Country. A slow warm up
is forecast through the middle of the week, with highs 5 to 10
degrees warmer on Tuesday, and another 5 to 10 degrees warmer on
Wednesday.

Daniels

FIRE WEATHER...

..Fire Weather Watch in effect for Friday...

The Fire Weather Watch will remain in effect for areas generally
north of a Mertzon to Brownwood line. An upper level trough will
move across the area tonight. Behind this trough tomorrow, and
dryline will move east into the forecast area tomorrow. West of
the trough axis, and behind the dryline, the surface pressure
gradient and upper level heights will align allowing for strong
winds to mix to the surface. Expect winds to increase to 20 to 25
mph with higher gusts by late morning, and continuing through the
early afternoon hours. At the same time, temperatures will warm
well into the 70s by early afternoon, allowing relative humidity
values to drop below 20 percent by Noon or shortly after. While
winds will be diminishing during the afternoon hours, there is
still expected to be a few hours during the late morning and early
afternoon that Red Flag conditions are likely. While the longest
duration of Red Flag conditions are expected north of a Sterling
City to Brownwood line, it is possible that areas farther south
near San Angelo will also briefly hit Red Flag conditions.

Saturday will be very warm as well, but moisture moving into the
area from the south is expected to moderate relative humidity
values, and winds are expected to be below Red Flag criteria. A
wind shift will impact the area Sunday as a cold front moves
through, and colder weather will be in place through the first
half of next week.

20

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene 	 65  49  81  47  86 /   0   0   0   0   0
San Angelo 	 66  47  82  48  86 /   0   0   0   0   0
Junction 	 65  41  83  45  84 /   0   0   0   0   5

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH from Friday morning through Friday afternoon
FOR THE FOLLOWING ZONES: Brown...Callahan...Coke...Coleman...
Concho...Fisher...Haskell...Irion...Jones...Nolan...Runnels...
Shackelford...Sterling...Taylor...Throckmorton...Tom Green.

&&

Doll

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
346 PM CST THU FEB 27 2014

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-
140-154-155-168>170-282145-
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-
346 PM CST THU FEB 27 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...FRIDAY THROUGH WEDNESDAY

A FIRE WEATHER WATCH IS IN EFFECT FOR CRITICAL FIRE WEATHER
CONDITIONS FRIDAY FROM 11 AM TO 5 PM DUE TO STRONG WINDS AND LOW
RELATIVE HUMIDITIES ACROSS AN AREA NORTH OF A LINE FROM
MERTZON...TO EDEN...TO BROWNWOOD.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.