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Area forecast discussion 
National Weather Service San Angelo Texas
1227 PM CDT Monday may 25 2015

/18z tafs/

Flight conditions will improve as we head through the afternoon.
Showers and thunderstorms will depart all terminals to the east,
with ceilings rising above 3000 feet. With this clearing southwest
to west winds will gust to near 20 knots through sunset. Overnight
ceilings will drop into the 1000 to 2000 feet range at all terminals
except kabi. Here, numerical guidance suggests some of this stratus
may approach Abilene. For now we've added a scattered cloud group to
account for this possibility, and will monitor trends in the data
this afternoon.


Previous discussion... /issued 622 am CDT Mon may 25 2015/

/12z tafs/

Isolated to scattered showers and thunderstorms will develop and
move over west central Texas taf sites this morning. The best
potential is over kabi 15-18z. Have thunderstorms in the vicinity at most sites this
morning...with kabi down to 2 miles in moderate rain 15-18z. MVFR
stratus should rise to VFR at most sites by 18z, persisting until
21z at kabi. MVFR stratus otherwise returns after 6z tonight from
south to north.

Previous discussion... /issued 432 am CDT Mon may 25 2015/

Short term...
(today and tonight )

Heavy rainfall and severe storms possible today beginning early
this morning...

A strong upper trough will pass trough west central Texas this
morning, with strong lift associated with it. The atmosphere was
already unstable with Storm Prediction Center rap most unstable convective available potential energy of 2000-3000 j/kg.
0-6km bulk shears were 40-50 kts. Large hail and damaging winds are
possible, even the potential for a tornado. The main threat, however
will be locally heavy rainfall of 1 to 3 inches, as precipitable
water increases to 1.0-1.5 inches. Heavy rainfall on already
saturated soils will have the potential for flash flooding. A Flash
Flood Watch is in effect through 4 PM CDT.

Most of the high resolution models develop a band of thunderstorms
over I-20 corridor...from Sterling City to Brownwood this morning,
mainly after 7 am. Another second area of storms may develop east
off the mountains of Mexico... possibly affecting the Junction to
Mason to San Saba areas. Scattered showers and thunderstorms may
continue in the Big Country in the afternoon with more isolated
storms farther south. While the Big Country and southeast sections
will likely have highest potential for thunderstorms, just about
anywhere in west central Texas will be at risk for severe storms
today with the strong instabilities present.

Kept a slight chance of showers and thunderstorms over eastern
sections tonight. Most of this will be in the evening hours.


Long term...
dryline thunderstorms will be possible Tuesday and Wednesday during
the late afternoon and evening as temperatures climb into the 90s.
Moderate to high cape values and a low shear storm environment will
provide the threat for isolated strong updrafts that could result in
a few storms producing large hail and damaging winds.

as a broad upper level trough of low pressure moves into northern
Mexico, it will result in dryline afternoon and evening
thunderstorms each day. A cold front moving south through the
Central Plains could send an outflow boundary into west central
Texas on Friday, providing another focus for thunderstorm
development. Max temperatures will be a little lower because of
more cloud cover.

the previously mentioned cold front meandering across the region
could bring another threat for storms over the weekend with
temperatures in the lower 80s.



Preliminary point temps/pops...
Abilene 80 63 90 69 89 / 70 10 20 10 20
San Angelo 85 63 93 69 91 / 50 10 20 10 20
Junction 84 65 91 70 89 / 70 20 20 10 20


Sjt watches/warnings/advisories...
Flash Flood Watch until 4 PM CDT this afternoon for the
following zones: Brown...Callahan...Coke...Coleman...Concho...
McCulloch...Menard...Nolan...Runnels...San Saba...Schleicher...



Aviation: doll

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