Severe Thunderstorm Warning 154, NWS San Angelo, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN ANGELO TX
618 PM CDT MON JUN 23 2014

.AVIATION...
/00Z TAFS/
Expect VFR conditions at the terminals this evening into the early
morning hours. Stratus will develop along the I-10 corridor during
the morning hours Tuesday, going with MVFR CIGS at the KSOA and KJCT
terminals after 10Z Tuesday. VFR conditions will return by 15Z
Tuesday. Isolated thunderstorms will be possible around the KSJT
terminal through mid evening and carrying VCTS through 03Z. A
complex or two of storms will develop well west of the terminals
later tonight and some of this activity may make it east into West
Central Texas by Tuesday morning. Confidence is not high enough to
put in the terminals and will watch radar and satellite trends this
evening.

&&

.PREV DISCUSSION... /ISSUED 344 PM CDT MON JUN 23 2014/

SHORT TERM...
(Tonight and Tuesday)

Showers and thunderstorms moved out of the area early this
afternoon, leaving partly to mostly cloudy skies and a very humid
air mass along with leftover outflow boundaries from the overnight
into early morning thunderstorms. Aloft, a shortwave trough is
moving east into New Mexico this afternoon helping to set off
thunderstorms across the mountains of New Mexico. Thunderstorms
were also developing across the mountains near and west of the Big
Bend area in Texas. A few isolated thunderstorms could develop
by late this afternoon or evening along some of the previously
mentioned boundaries.

For tonight, expect another cluster of thunderstorms to get
organized to our west or northwest and move into our area
overnight. Thunderstorms are already developing across the
mountains of New Mexico, and upscale growth into a cluster of
thunderstorms is expected as the shortwave moving into the area
approaches. Several models indicate an MCS moving east through the
Permian Basin overnight, and into our area by early tomorrow
morning. Timing the arrival of these thunderstorms is difficult,
but expect the bulk of the activity to be after midnight rather
than before. Locally heavy rainfall, and dangerous lightning would
be the primary concerns with these thunderstorms.

Additional thunderstorm activity is possible tomorrow afternoon,
especially if the atmosphere can destabilize during the afternoon
hours. The favored area for redevelopment tomorrow appears to be
northwest of the area near the Texas panhandle region where
another approaching shortwave will interact with persistent moist
upslope flow.

Temperatures will remain near normal with lows near 70 tonight,
highs around 90 tomorrow.

20

LONG TERM...
(Tuesday night through next Monday)

Weak northwest flow aloft will continue over our area Tuesday night
and Wednesday. Could have a leftover disturbance (possibly a MCV)
over our eastern counties Tuesday evening and early Tuesday night.
The NAM brings a weak upper level disturbance southeast across the
TX Panhandle and toward our far northern counties by early
Wednesday morning. Showers and thunderstorms would be possible
with both of these features. With this in mind, carrying 30 PoPs
across our eastern and far northern counties Tuesday night, with
20 PoPs elsewhere. Have a lingering low PoP for the eastern part
of our area on Wednesday, which will be on the eastern periphery
of the upper level high.

On Thursday and Friday, the upper high will remain positioned
over Mexico and the U.S. Desert Southwest, with an eastward
extension to near the Big Bend region. An upper shear axis is
progged to set up to the east of our area. Cannot rule out a low
possibility of showers/thunderstorms in some of our northern or
eastern counties Thursday and Friday. However, with lack of
confidence in placement of weak disturbances aloft or surface
boundaries, prefer to leave PoPs out for now.

For the weekend into the first part of next week, the 12Z GFS and
ECMWF are in better agreement in gradually building the heights
aloft over our area. While specific differences still exist, both
models show an overall shift with the upper high to the north
across the Southwestern states, while expanding it to the east
into Texas and the Southern Plains. This would effectively shut
off rain chances for our area, and lead to a warming trend in
temperatures. However, with fairly moist ground conditions and
evapotranspirative effects, along with south-southeasterly low-
level flow keeping an influx of Gulf moisture into our area,
believe the warming trend will be tempered. In addition, the GFS
keeps the low-level thermal ridge to our west, with only a limited
eastward expansion. With these indications, going with highs below
the GFS MOS guidance for our area.

19

&&

.PRELIMINARY POINT TEMPS/POPS...
Abilene 	 71  90  72  92  72 /  40  40  20  20  10
San Angelo 	 70  90  71  92  72 /  50  30  20  10   5
Junction 	 71  89  71  91  72 /  30  30  20  20   5

&&

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

21

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN ANGELO TX
309 PM CDT MON JUN 23 2014

TXZ049-054-064>066-071>073-076>078-098-099-113-114-127-128-139-
140-154-155-168>170-242015-
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-
309 PM CDT MON JUN 23 2014

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS WILL BE POSSIBLE TONIGHT ACROSS MOST OF
WEST CENTRAL TEXAS. THE PRIMARY HAZARDS WILL BE DANGEROUS
LIGHTNING...BRIEF HEAVY RAINFALL...AND GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE TUESDAY
THROUGH WEDNESDAY EVENING ACROSS WEST CENTRAL TEXAS. THE MAIN
HAZARDS WILL BE DANGEROUS CLOUD TO GROUND LIGHTNING...GUSTY
WINDS...AND LOCALLY HEAVY RAINFALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN ANGELO TX
632 PM CDT MON JUN 23 2014

TXZ170-240000-
MASON TX-
632 PM CDT MON JUN 23 2014

...SIGNIFICANT WEATHER ADVISORY EFFECTIVE UNTIL 700 PM CDT FOR MASON
COUNTY...

POTENTIAL STORM HAZARDS INCLUDE...
  HEAVY RAINFALL
  GUSTY WINDS AND HAIL

AT 627 PM CDT...A STRONG THUNDERSTORM WAS LOCATED 7 MILES SOUTHWEST
OF HILDA...OR ABOUT 16 MILES SOUTH OF MASON...MOVING EAST AT 15 MPH.

VERY HEAVY RAINFALL IS OCCURRING AND A FLASH FLOOD WARNING MAY BE
REQUIRED IF THIS HEAVY RAINFALL CONTINUES.

POTENTIAL STORM IMPACTS INCLUDE...
  DANGEROUS DRIVING CONDITIONS...POTENTIAL VEHICLE HYDROPLANING...
  ACCUMULATION OF WATER AT LOW WATER CROSSINGS...AVOID THESE AREAS...
  SOME BROKEN TREE BRANCHES AND A FEW WEAK TREES TOPPLED...
  SCATTERED POWER OUTAGES LIKELY...
  LIGHT LOOSE OBJECTS TOPPLED...
  DANGEROUS DRIVING CONDITIONS...
  MINOR SHINGLE DAMAGE...
  ISOLATED SMALL DENTS TO VEHICLES...

THE STRONG THUNDERSTORM WILL BE NEAR...
  HILDA BY 645 PM CDT
  US-87 NEAR THE MASON-GILLESPIE COUNTY LINE AND LOYAL VALLEY BY 700
  PM CDT

THIS INCLUDES THE LOW WATER CROSSINGS...
  SIMONSVILLE CROSSING BADER CREEK...
  RANCH ROAD 783 CROSSING DEER CREEK...
  SIMONSVILLE CROSSING BEAVER CREEK...
  LOEFFLER CROSSING BEAVER CREEK...
AND OTHER LOW LYING AND FLOOD PRONE PORTIONS OF MASON COUNTY.

LAT...LON 3050 9932 3061 9932 3063 9896 3061 9895
      3050 9896 3049 9897 3050 9930
TIME...MOT...LOC 2332Z 271DEG 15KT 3052 9918

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN ANGELO TX
645 PM CDT MON JUN 23 2014

TXZ168-240015-
MENARD TX-
645 PM CDT MON JUN 23 2014

...SIGNIFICANT WEATHER ADVISORY EFFECTIVE UNTIL 715 PM CDT FOR MENARD
COUNTY...

POTENTIAL STORM HAZARDS INCLUDE...
  GUSTY WINDS AND HAIL

AT 640 PM CDT...A STRONG THUNDERSTORM WAS LOCATED 3 MILES NORTHWEST
OF MENARD...MOVING SOUTHEAST AT 10 MPH.

POTENTIAL STORM IMPACTS INCLUDE...
  SOME BROKEN TREE BRANCHES AND A FEW WEAK TREES TOPPLED...
  SCATTERED POWER OUTAGES LIKELY...
  LIGHT LOOSE OBJECTS TOPPLED...
  DANGEROUS DRIVING CONDITIONS...
  MINOR SHINGLE DAMAGE...
  ISOLATED SMALL DENTS TO VEHICLES...

THE STRONG THUNDERSTORM WILL BE NEAR...
  MENARD BY 655 PM CDT
  THE INTERSECTION OF US-83 AND HIGHWAY 29 BY 710 PM CDT
  THE INTERSECTION OF US-83 AND RANCH ROAD 1773 BY 715 PM CDT

LAT...LON 3092 10000 3107 9982 3099 9960 3094 9960
      3094 9949 3092 9949 3071 9970 3071 9971
      3071 9977
TIME...MOT...LOC 2345Z 310DEG 9KT 3093 9982