-- Discussion containing changed information from previous version are highlighted. --
788
FXUS64 KAMA 222248
AFDAMA

Area Forecast Discussion
National Weather Service Amarillo TX
548 PM CDT Sat Jun 22 2024

...New AVIATION...

.SHORT TERM...
(This evening through Sunday night)
Issued at 232 PM CDT Sat Jun 22 2024

The large scale pattern consists of an upper-level ridge over the
Southern US with zonal flow and embedded shortwave troughs across
the northern half of the US. Southwesterly low-level winds over the
Panhandles have brought in very warm 850mb temperatures which will
help bring temperatures into the 90s across the area. At the surface
this morning, a boundary has been moving south through Western
Kansas and has begun to move into the northern combined Panhandles.
Expect northerly winds and drier air behind this boundary.
Otherwise, a moist environment remains in place as the moisture from
former Tropical Storm Alberto lingers. Expecting the aforementioned
boundary to settle somewhere in the northern TX Panhandle this
afternoon as convective temperatures are expected to be reached. The
higher chance for showers and thunderstorms will be along the
boundary from mid-afternoon to early evening, at which point
convection should weaken from the loss to daytime heating. Forecast
soundings suggest there will be weak instability (MLCAPE between 250-
750 J/kg) and very weak wind shear, suggesting pulse storms are
favored with almost no threat for a severe thunderstorm. However...
high freezing levels above 12,000 feet and seasonable PWATs will
favor the potential for moderate to heavy rain. Some locations may
receive a quick tenth of an inch or two of rain, but with the lack
of a more robust forcing mechanism and the general lack of
meaningful wind shear, thinking that the longevity of heavy rain
should remain limited. Will have to watch if heavy rain falls over
the same area that received extensive rainfall earlier this week as
that may exacerbate ongoing flooding to some degree, but overall,
the threat for additional flash flooding appears low at this time
for today. Some showers may move into the western Panhandles tonight
from northeastern New Mexico.

Going into Sunday, an upper-level trough dips down into the Great
Lakes which causes the southern ridge to move westward and become
more centered on the area from the Southwestern US to the Southern
Plains. Temperatures generally warm a degree or two from Saturday`s
highs as very warm 850mb temperatures remain. The 22/12z CAMs
suggest a boundary may be leftover from Saturday`s convection that
could start to mix out through the morning and afternoon. Convective
evolution looks rather uncertain right now with CAMs in a state of
disagreement given the weak forcing. The development of some showers
and isolated thunderstorms could occur as early as the early
afternoon hours if aggressive daytime heating occurs along a remnant
boundary, but could be later in the afternoon as a result of storms
moving in from northeastern New Mexico. Instability looks even
weaker than today, and PWATs look more on par with late June.
Regardless, some heavy rain could occur with this activity. Again,
there are hints that some showers could linger into the night as
well.

Vanden Bosch

&&

.LONG TERM...
(Monday through next Friday)
Issued at 232 PM CDT Sat Jun 22 2024

Even hotter temperatures are expected Monday as very warm 850mb
temperatures... 30-32C... move into the area which will encourage
highs in the mid-90s to low-100s for much of the CWA. With as much
as a 10% chance for rain in the Oklahoma Panhandle, much if not all
of the Panhandles should stay dry Monday.

Tuesday looks to be the hottest day of the next week. 850mb
temperatures between 32C to 34C are expected in the western 2/3 of
the Panhandles which will encourage widespread temperatures in the
100s. In addition to the widespread 100s, dew points in the upper-
50s to mid-60s are possible across much of the area, with the upper
end of that range being off the Caprock. This has the potential to
bring heat indices at or above 105 degrees for a portion of the
area. Therefore, a Heat Advisory will certainly be in the realm of
possibilities for Palo Duro Canyon... but barring a significant
change in the guidance, one or more Heat Advisories may also be
needed for some of the eastern OK Panhandle/northeastern TX
Panhandle counties. Later in the afternoon and into the evening, a
weak shortwave trough may round the upper-level ridge which could
trigger some thunderstorms.

There is consensus that the upper-level ridge sticks around into
Wednesday, but 100 degree highs won`t be as widespread as Tuesday.
Diurnal thunderstorms could develop again in the late afternoon
hours as temperatures reach the convective temperature.

Models diverge some after Wednesday regarding what happens with the
upper-level ridge. The 22/12z GFS and GEFS ensemble mean wants to
weaken the ridge as an upper-level trough moves into the Pacific
Northwest on Thursday while the 22/00z ECMWF/EPS holds on to the
ridge. As a result, ECMWF brings the trough northeastward into
Canada which allows the ridge to strengthen over the Southern
Plains. Meanwhile, GFS/GEFS wants to flatten the ridge and have more
of a zonal flow over the central Plains as the trough moves east-
northeast. The 22/00z ECMWF/EPS solution would result in hot and dry
weather, while the 12z GFS/GEFS would result in either average to
slightly above average temperatures and nearly daily chances for
thunderstorms. Therefore... confidence is quite low regarding the
pattern later in the week.

Vanden Bosch

&&

.AVIATION...
-- Changed Discussion --
(00Z TAFS)
Issued at 547 PM CDT Sat Jun 22 2024

Some showers, possibly with isolated thunder, will be possible
between KAMA and KDHT/KGUY over the next few hours. However,
impacts to the terminals are not anticipated. VFR conditions are
expected to prevail through the 00Z TAF period, with the exception
of possible showers and thunderstorms for KDHT towards the end of
the period. Winds should remain light around 10 kts or less with
a southerly component through the period.

36
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Amarillo TX                71  96  69  98 /  10  10  10   0
Beaver OK                  71  97  72 100 /  10   0  10   0
Boise City OK              67  94  64  97 /  20  30  10  10
Borger TX                  73 102  74 103 /  20  10  10   0
Boys Ranch TX              71  97  70 100 /  20  20  10   0
Canyon TX                  69  94  69  96 /  10  10  10   0
Clarendon TX               71  95  71  96 /   0  10   0   0
Dalhart TX                 67  95  65  98 /  30  30  10   0
Guymon OK                  69  96  66 100 /  10  10  10   0
Hereford TX                69  96  69  99 /  10  10  10   0
Lipscomb TX                72  99  74 101 /  10  10  10   0
Pampa TX                   72  98  71  99 /  10  10  10   0
Shamrock TX                71 100  72 100 /   0  10   0   0
Wellington TX              72 100  72 100 /   0  10   0   0
-- End Changed Discussion --

&&

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

$$

SHORT TERM...52
LONG TERM....52
AVIATION...36