207
FXUS64 KAMA 290522
AFDAMA

Area Forecast Discussion
National Weather Service Amarillo TX
1222 AM CDT Wed May 29 2024

...New AVIATION...

.SHORT TERM ...
(This evening through Wednesday night)
Issued at 1232 PM CDT Tue May 28 2024

Multiple outflow boundaries are apparent via multiple means which
resulted from last night`s MCS and this morning`s elevated
convection. Much of the area is seeing either no clouds (western
Panhandles) or partly cloudy skies, but there are pockets of mostly
cloudy skies. Nonetheless, dew points are in the 50s to low 60s
across much of the area with temperatures already climbing into the
80s as of 12 PM. The quality of low-level moisture may wane some as
diurnal mixing occurs, but MLCAPE values between 1500-2500 J/kg
should be achievable by mid to late afternoon. By then, the
westward moving outflow should be over or just west of Amarillo as
a dryline pushes east into the southwestern TX Panhandle, and the
cap should be sufficiently eroded for thunderstorms to develop.
Forecast wind profiles are favorable for the development of
supercells (effective shear 40-50 kts, 180 degree turning of the
winds from surface to 500mb). However, weak low-level shear is
expected this afternoon which creates a straight hodograph,
suggesting splitting supercells would be favored. Given the
moderately unstable environment, steep lapse rates, and decent
shear within the hail growth zone, hail up to Tennis Balls (2.50")
will be possible. Given the steep lapse rates below mid-level
moisture which increasingly becomes drier and warmer toward the
surface, damaging winds will also be possible, with some wind
gusts between 70-80 mph possible. The tornado threat is certainly
mitigated by the previously mentioned weak low-level winds, but
can`t rule out a tornado with any right-moving supercell that can
latch onto a boundary. However, current thinking is that any
right-moving supercell would move out of the CWA given its motion
and the currently favored area of convective initiation (southwest
TX Panhandle).

A secondary round of strong to severe thunderstorms may begin in the
late afternoon hours. A shortwave trough will approach the
northwestern combined Panhandles, developing thunderstorms in
southeastern Colorado. These thunderstorms may be discrete/semi-
discrete initially but grow upscale once they move into the
northwestern combined Panhandles. These storms should also
strengthen owing to moving into greater instability. Here, very
large hail and damaging winds may be the initial threat but as the
storms grow upscale, damaging winds should become the primary threat
with large hail just below it. Can`t rule out a 70-80 mph wind gust
early on in the MCS`s life. The strong to severe thunderstorm threat
should wane past around 9-10 PM, but can`t rule out an additional
strong to severe thunderstorm before Midnight. Isolated areas of
flash flooding may be possible in urban areas, or with any slow
right-moving supercell, given the very moist environment.

Vanden Bosch

&&

.LONG TERM ...
(Tomorrow through next Monday)
Issued at 1232 PM CDT Tue May 28 2024

A temporary break in the activity going into the day on Wednesday
for most areas as a small amplitude ridge moves over the
Panhandles. Later Wednesday night, a disturbance moving over the
central Rockies may provide a chance for some showers and
thunderstorms, but this would favor the far northern combined
Panhandles.

Going into Thursday, our next chance for more widespread strong to
severe thunderstorms return. Will have to watch observational trends
closely, including cloud cover, LL moisture return, etc. Overall
setup appears to have a dryline setting up near the TX/NM stateline
with a good easterly sfc flow. Latest data indicate with this
that the dryline to help initiate thunderstorm chances should
first start in the western Panhandles before moving east
throughout the afternoon hours. The environment at this time
should support a high CAPE and relatively low shear environment,
which would favor severe weather parameters being large hail and
damaging winds as the primary threats. Boundary convergence may
enhance low level winds for a tornado threat as well. With PWAT
values nearing the 99th percentile, and not a strong of steering
flow, training and/or back building thunderstorms with heavy
rainfall rates may also cause localized flooding. We will also be
watching a cold front moving south the second half of Thursday
which can also be a local catalyst of lift for thunderstorm
development as well.

Thunderstorm chances continue Friday into the weekend as the main
southern CONUS synoptic pattern remains in place. Exact timing and
ingredients for how strong thunderstorm may get will be determined
as we get closer with time as more data is available. Temperatures
on Friday will be below average, but for the remainder of the
forecast period, temperatures will be above average.

Meccariello

&&

.AVIATION...
(06Z TAFS)
Issued at 1218 AM CDT Wed May 29 2024

VFR conditions are forecast to start this TAF cycle. Some gusty
winds may continue for a few hours but they should decrease to 15
kts or less in a few hours. Low clouds will move in at the TAF
sites near 12z through around 18z and MVFR ceilings are forecast.
Winds during the daytime hours will be out of the southeast.
Showers and thunderstorms are possible at the terminals late in
this TAF cycle, but confidence is not high enough to mention at
this time.

Muscha

&&

.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX                76  61  82  58 /  20  50  50  70
Beaver OK                  79  60  81  57 /  20  40  60  80
Boise City OK              78  57  83  54 /  40  40  60  60
Borger TX                  80  62  85  59 /  20  50  60  70
Boys Ranch TX              80  62  88  58 /  30  50  50  60
Canyon TX                  76  60  84  56 /  20  40  40  60
Clarendon TX               74  60  77  58 /  20  50  60  70
Dalhart TX                 79  58  84  54 /  30  40  50  60
Guymon OK                  79  58  81  55 /  30  50  60  70
Hereford TX                81  62  86  57 /  30  40  40  50
Lipscomb TX                78  61  78  58 /  20  50  60  80
Pampa TX                   76  61  78  58 /  20  50  50  70
Shamrock TX                77  62  77  59 /  30  50  60  80
Wellington TX              78  62  77  60 /  30  50  60  80

&&

.AMA WATCHES/WARNINGS/ADVISORIES...
TX...None.
OK...None.
&&

$$

SHORT TERM...52
LONG TERM....29
AVIATION...05