Flash Flood Warning 1, NWS San Angelo, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
635 PM CDT FRI MAY 23 2014

.AVIATION...
/00Z TAFS/

Scattered showers and storms will continue near or over most of the
West Central Texas terminals for the next few hours, probably
dissipating around sunset. None of the activity at any one location
will last very long, but several storms may run across any
particular site more than once. General pattern really doesnt change
a whole lot, so MVFR ceilings will move back into the area late
tonight, with scattered storms developing again late in the
afternoon.

&&

.PREV DISCUSSION... /ISSUED 336 PM CDT FRI MAY 23 2014/

SHORT TERM...
(Tonight and Saturday)

Water vapor imagery shows the upper low situated over western
Arizona and is slowly continuing its eastward trek towards the
area. A ribbon of dry air is wrapping into the eastern flank of the
system. Further to the east, mid and high-level moisture continues
to stream into the region from the eastern Pacific.

The atmosphere is very moist, as mesoanalysis shows current PWAT
values of 1.5 inches and 850 mb dewpoints continuing to hold near
15 C. A differential heating/outflow boundary, currently located
along a line from near Midland to Wichita Falls, continues to make
a slow eastward progression. Showers and thunderstorms are
developing along this boundary, with more isolated development noted
near Junction. We expect this general trend to continue through
the evening hours. With the loss of diurnal heating, we expect
convection to begin a downward trend after sunset. However, given
an already moist environment, modest instability (MUCAPEs of 1000
to 2000 j/kg) progged to persist through the night, and the
possibility of additional weak ripples of energy crossing the
area, additional shower or thunderstorm development remains
possible through the overnight hours. 0-6 KM shear values of 20 kts
or less will keep the severe threat minimal, with cloud to ground
lightning and locally heavy rainfall this evening being the main
storm hazards. Overnight lows have been above guidance the last few
nights, so lows were raised to near 70 degrees.

For tomorrow, the upper low will move closer to the area. Mid
level lapse rates improve to 7.5 deg C/Km, with 0-6 KM shear
values near 30 kts. Given a slight eastward movement of the
dryline helping to improve low-level convergence, and the
likelihood of remnant outflow boundaries in the area, expect
showers and thunderstorms to develop. A few severe thunderstorms
will be possible, mainly west of a Haskell to San Angelo to Sonora
line. Large hail and damaging winds will be the main storm
hazards, in addition to locally heavy rainfall, especially in urban
areas. With a few more breaks expected in the cloud cover tomorrow
compared to today, have raised highs into the mid 80s.

LONG TERM...
/Saturday Night through Tuesday/
An active weather pattern is in store with a chance of showers and
thunderstorms with heavy rainfall likely and a few severe storms are
possible. Currently, a strong upper level low was located over the
Southwest U.S.(centered over western Arizona). The upper level low
will move slowly east across the southern Rockies during the next
few days and then into the southern Plains early next week. The
models are pretty consistent on the track of the upper low. However,
a hundred miles or less can make or break on the potential for heavy
rainfall, partially due to mesoscale details. The good news, all the
models are very wet across much of West Central Texas. The
ingredients for rainfall include: lots of moisture(PWATs of 1.5 to 2
inches), low level southerly flow and convergence (850 MB winds 30
to 40 knots especially Saturday night and Sunday), and significant
diffluence at 250 MB. Rainfall amounts of 1 to 3 inches are looking
pretty good across much of the area with amounts of 2 to 4 inches
across the Big Country with locally higher amounts possible. There
is the potential for urban and small stream flooding. Will hold off
on issuing a Flash Flood Watch, but the flooding potential will have
to be monitored over the weekend. In addition, severe weather may be
possible Sunday, especially during the afternoon and evening. The
combination of good instability(MLCAPES 1500 to 2000 J/KG) and bulk
0-6KM shear values of 30 to 35 knots will yield a few severe storms,
mainly west of a Abilene to San Angelo line. The main hazards will
be large hail and damaging winds. For now, have chance to likely
POPS going, with the highest POP numbers across the Big Country.
Would not be surprised to see POPS raised to categorical this
weekend, especially across the Big Country.

/Wednesday through Friday/
A quieter weather pattern for middle to late next week. The
combination of abundant low level moisture and weak upper level
northwest flow may result in isolated afternoon and evening showers
and thunderstorms. However, will keep the forecast dry for now.
Expect warmer temperatures, with highs in the upper 80s to lower 90s
and lows in the 60s.

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene 	 70  86  66  82  67 /  40  40  40  50  40
San Angelo 	 70  85  65  83  67 /  40  30  40  40  40
Junction 	 67  82  68  82  67 /  20  20  20  30  30

&&

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

07

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
300 PM CDT FRI MAY 23 2014

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-
140-154-155-168>170-242000-
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-
300 PM CDT FRI MAY 23 2014

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EVENING.
A FEW OF THESE STORMS MAY BECOME STRONG...PRODUCING HAIL AND GUSTY
WINDS...BUT THE MAIN CONCERNS WITH THIS ACTIVITY WILL BE LOCALLY
HEAVY RAINFALL AND DANGEROUS CLOUD TO GROUND LIGHTNING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THUNDERSTORMS WILL BE POSSIBLE SATURDAY THROUGH EARLY NEXT WEEK. A
FEW OF THE STORMS MAY BECOME STRONG TO SEVERE...WITH THE MAIN
CONCERNS BEING LARGE HAIL AND DAMAGING WINDS. THESE THUNDERSTORMS
WILL ALSO BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL AND
DANGEROUS CLOUD TO GROUND LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TONIGHT. HOWEVER...SPOTTER
ACTIVATION MAY BE NEEDED THIS WEEKEND.