Severe Thunderstorm Warning 103, NWS Amarillo, TX

Area Forecast Discussion
National Weather Service Amarillo TX
355 PM CDT Tue May 16 2017

.DISCUSSION...
See below for details on today's setup with scattered to numerous
thunderstorms over eastern half of the Texas and Oklahoma
Panhandles through this evening.  Isolated tornadoes expected
across the eastern one-third.

Main trof passes overnight, with winds increasing with arrival of
Pacific cold front.  May see a few thunderstorms after midnight
in northwest part of forecast area, as steep lapse rates and mid-
level moisture accompany sharp shortwave trof.

Wednesday through Thursday morning expected to remain dry.  By
Thursday afternoon, next strong mid-level closed low sets up to
our northwest, with low pops warranted across most of area
Thursday afternoon through Saturday.

Followed blended guidance closely, with pops accepted Sunday night
through Tuesday.

Cockrell

&&

.PREV DISCUSSION... /Issued 128 PM CDT Tue May 16 2017/

MESOSCALE UPDATE...
..Severe weather outbreak likely today...

* Overview/Bottom Line: This has the makings of a pretty
  significant severe weather outbreak and as much we dug for a
  reason it may not happen, there are few to point to. Everyone
  stay safe and weather aware today!

* Synoptic Overview: A synoptically evident severe weather outbreak
  pattern has set up with pretty much all the boxes checked and also
  verified by observational data. In short, an upper low analyzed
  near Las Vegas this morning will open as it bottoms out over srn
  NM this afternoon before lifting and deepening again as it ejects
  over us tonight. Though the best height falls will occur this
  evening, modest height falls and the approach of a lead shortwave
  will be able to easily overcome a weak EML with storms all but
  guaranteed to form this afternoon.

* Mesoscale: A dryline is slowly mixing east early this afternoon
  and with the more significant synoptic forcing hanging back and
  fairly meridional flow aloft, think dryline progression will
  continue to be slow early this afternoon. Mid to upper 60s dewpts
  are present over the eastern half of the Panhandles and with the
  exception of the very western edge of the deep sfc moisture, these
  dewpts should not mix out much through the day. Unlike many severe
  weather days around here, this one won't require sunshine and
  strong daytime heating as forecast soundings indicate 76/68 will
  yield upwards of 3500 J/kg MLCAPE in the east. Even if
  temperatures rise to the mid 80s...mixing of dewpts into the low
  to mid 60s that would occur simultaneously would probably keep
  CAPE values in the same range as they would be with 76/68. These
  T/Td trends will be monitored closely though for tornado potential
  this afternoon as more limited mixing could actually somewhat
  counter-intuitively increase the tornado threat by keeping LCLs
  lower. In addition to expecting MLCAPE values to push 3500-4000
  J/kg, a good deal of 0-3km MLCAPE should be noted with values
  pushing 150 J/kg this afternoon. CAPE in the hail growth zone will
  be near or surpass 1000 J/kg as well, so thermodynamically this
  event is on point.  If that wasn't quite exciting (or scary)
  enough for you, kinematically this event may be better. After a
  period of veer-back-veer profiles early this afternoon (seen on
  the 18z KAMA special sounding), expected veering flow around h6
  will put the last piece of the puzzle in place to create uber-
  favorable shear profiles. These forecast profiles feature veering
  and mostly strengthening flow with height through the entire
  atmosphere and effective and 0-8km bulk shears of 60-70 kts.
  Initially weak low level shear/helicity will increase rapidly late
  this afternoon, especially in the eastern 2 tiers of Panhandle
  counties.

* Threats and Timing: Storms may struggle a bit initially due to
  the VBV profile and a bit of remaining CINH, but won't take long
  to get going in earnest and this is an "all-threats" kind of
  day, though fast storm motions could keep the flash flood threat
  on the lower side. The biggest concerns are tornadoes and large
  to giant hail given supercell storm mode and the aforementioned
  CAPE/shear combo. Some hail could get as big as softballs. The
  tornado threat is pretty concerning late this afternoon/early
  evening as 0- 1 SRH values increase to nearly 300 m2/s2 by 23Z
  in the southeast TX Panhandle and over 200 m2/s2 further north.
  Given this and expected discrete or quasi-discrete supercell
  storm mode, concern certainly exists for a strong tornado or
  two. The best tornado threat will be 20Z-01Z in the eastern half
  of the combined Panhandles with the first round of storms,
  though another tornado threat cannot be ruled out in the far
  east with a possible second round later this evening. This
  second round of storms will be conditional on the first round,
  but the stronger dynamics as the main upr wave crosses should
  help make up for any lacking thermodynamics in the wake of the
  first round.

* Location: As has been mentioned, the eastern half of the
  Panhandles looks the best.  Right now it looks like the western
  edge of the severe threat will be bounded by a Canyon to Amarillo
  to Stinnett to Spearman to Liberal line.  None of these
  aforementioned locations are free from a severe threat though the
  tornado threat on the western edge is certainly lower than it is
  further east.  If a second round materializes, it should occur
  after 9 PM and be confined to areas east of a Clarendon to Pampa
  to Perryton line.

Simpson

&&

.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX                55  81  54  82  50 /  20   0   5  10  20
Beaver OK                  55  84  52  83  52 /  30   0   5  20  50
Boise City OK              48  77  49  72  44 /  20   5   5  20  40
Borger TX                  58  82  56  84  52 /  20   0   5  10  20
Boys Ranch TX              54  81  53  81  49 /  10   0   5  10  20
Canyon TX                  53  80  52  83  51 /  20   0   5  10  20
Clarendon TX               54  81  55  87  57 /  30   0   5  10  20
Dalhart TX                 50  79  50  77  46 /  10   0   5  10  30
Guymon OK                  51  81  51  79  49 /  10   5   5  20  40
Hereford TX                53  80  52  82  50 /  10   0   5  10  20
Lipscomb TX                57  83  55  85  54 /  30   0   5  20  40
Pampa TX                   54  82  55  83  52 /  30   0   5  10  30
Shamrock TX                56  83  55  87  57 /  40   0   5  20  30
Wellington TX              56  85  56  89  59 /  50   0   5  20  30

&&

.AMA Watches/Warnings/Advisories...
TX...None.
OK...None.

&&

03/03

Hazardous Weather Outlook
National Weather Service Amarillo TX
338 PM CDT Tue May 16 2017

OKZ001>003-TXZ001>020-171100-
Cimarron-Texas-Beaver-Dallam-Sherman-Hansford-Ochiltree-Lipscomb-
Hartley-Moore-Hutchinson-Roberts-Hemphill-Oldham-Potter-Carson-
Gray-Wheeler-Deaf Smith-Randall-Armstrong-Donley-Collingsworth-
338 PM CDT Tue May 16 2017

This Hazardous Weather Outlook is for the Texas and Oklahoma
Panhandles.

.DAY ONE...Through Tonight.

Scattered to numerous thunderstorms are expected, mainly across
the eastern half of the Panhandles. Severe weather is likely to
occur, with very large hail, damaging winds, and isolated
tornadoes all possible into the early evening.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Thunderstorms are again possible Thursday afternoon through
Saturday, and again Sunday night and Monday. A few storms during
this time could become severe with large hail and damaging winds
being the main hazards.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed through this evening.

Cockrell

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AMARILLO TX
408 PM CDT TUE MAY 16 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0351 PM     HAIL             1 NNW BRYANS CORNER     36.64N 100.83W
05/16/2017  E2.75 INCH       BEAVER             OK   STORM CHASER

&&

EVENT NUMBER AMA1700526

BIEDA

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AMARILLO TX
416 PM CDT TUE MAY 16 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0413 PM     HAIL             3 N HOWARDWICK          35.08N 100.91W
05/16/2017  E1.50 INCH       DONLEY             TX   STORM CHASER

&&

EVENT NUMBER AMA1700527

BIEDA

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AMARILLO TX
433 PM CDT TUE MAY 16 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0429 PM     HAIL             3 SSW MCLEAN            35.19N 100.62W
05/16/2017  M1.50 INCH       GRAY               TX   STORM CHASER

&&

EVENT NUMBER AMA1700528

TLH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AMARILLO TX
434 PM CDT TUE MAY 16 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0430 PM     HAIL             7 S ALANREED            35.11N 100.73W
05/16/2017  M2.00 INCH       DONLEY             TX   STORM CHASER

&&

EVENT NUMBER AMA1700529

TLH

Special Weather Statement
National Weather Service Amarillo TX
434 PM CDT TUE MAY 16 2017

TXZ004-005-009-162200-
Ochiltree TX-Roberts TX-Lipscomb TX-
434 PM CDT TUE MAY 16 2017

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL LIPSCOMB...NORTH
CENTRAL ROBERTS AND EASTERN OCHILTREE COUNTIES UNTIL 500 PM CDT...

At 434 PM CDT, Doppler radar was tracking a strong thunderstorm 11
miles southwest of Wolf Creek Park, or 21 miles south of Perryton,
moving northeast at 40 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.

Locations impacted include...
Wolf Creek Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take shelter in a sturdy building if threatening weather approaches.

&&

A tornado watch remains in effect until 1000 PM CDT for the Panhandle
of Texas.

LAT...LON 3597 10069 3605 10089 3649 10068 3637 10038
TIME...MOT...LOC 2134Z 206DEG 36KT 3608 10075

Ward

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AMARILLO TX
437 PM CDT TUE MAY 16 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0434 PM     HAIL             3 SSW MCLEAN            35.19N 100.62W
05/16/2017  M2.00 INCH       GRAY               TX   STORM CHASER

&&

EVENT NUMBER AMA1700530

TLH