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000
FXUS64 KAMA 182307
AFDAMA

Area Forecast Discussion
National Weather Service Amarillo TX
607 PM CDT Sun Jul 18 2021

.AVIATION...00Z TAFs...

Summer thunderstorms will continue to threaten the combined
Panhandles this evening and in to the overnight hours. Categorical
degradation will be possible if a terminal is directly impacted
by a storm. KDHT will be next in line to be impacted by at least
VCTS in the first 2 hours or so of the 00Z TAF period. KAMA will
have a better chance for TS impacts after 03Z. Have kept TAFs as
optimistic as possible right now, but amendments may be needed at
times. Wind gusts up to 40 kts and torrential downpours will be
possible with thunderstorms. VFR conditions with light southerly
winds will be prevalent outside of thunderstorms.

Hoffeditz

&&

.PREV DISCUSSION... /Issued 244 PM CDT Sun Jul 18 2021/

SHORT TERM (Today through tomorrow night)...

Overview:
Somewhat tricky forecast today as we start shifting away from the
northwest flow aloft, yet continue to have the tropical airmass in
place across the Panhandles. It doesn`t take much with this type
of airmass to get convection going, but we have signals that could
inhibit thunderstorms today. With that said, any thunderstorms
that happen to develop could become strong to severe, especially
central and eastern parts of the combined Panhandles. Main
threats for any thunderstorms will be localized flooding,
lightning, and damaging wind gusts.

Further Details:
H5 center of high pressure residing over the Four Corners region
will slowly push northward today. By 00Z (7pm), the center could
be over eastern parts of the Great Basin. During this transition,
we are going to go from the northwest flow we have been
experiencing for several days to a more northerly flow. We still
have the tropical airmass in place across the area, but the
northerly flow pattern isn`t the best for convection. That said,
we have a convective complex pushing in from Nebraska and western
parts of Kansas. As of 2pm, a noticeable outflow boundary is
heading our way ahead of the complex, and could reach the Oklahoma
Panhandle by 3-4pm as storms are already starting to fire up. If
this trend continues, we could have thunderstorm activity through
about midnight. We need this boundary as we are lacking energy
aloft. In fact, forecast soundings from the HRRR and RAP indicate
subsidence aloft as seen from an elevated mix layer (EML) around
500mb-400mb. This EML will inhibit storms, but with the boundary
pushing in and some subtle semblance of energy aloft, this could
help initiate storms this afternoon and evening. If the convective
complex doesn`t make it this far south, we may end up dry across
most of the area besides maybe a few pop-up thunderstorms from
convective temperatures. Also, hodographs are small and there
isn`t much shear, so widespread severe weather is unlikely
today/tonight even with the outflow boundary from the complex.
Localized flooding, lightning, and isolated damaging wind gusts
will be the main threats. Weak lapse rates are not allowing for
much instability, but there could be enough MLCAPE to trigger a
couple rogue storms producing hail around an inch in diameter.

For tomorrow, its another one of the situations where today`s
convection--or lack thereof--will impact our thunderstorm
potential for tomorrow. Currently thinking if the outflow
boundary doesn`t make it into our area today/tonight, it may make
an entrance tomorrow morning and afternoon, increasing our threat
for thunderstorms during this time. For now, we will have to wait
and see what happens today, but any storms that form tomorrow
could become strong to perhaps severe with similar threats as
today. Only change with tomorrow is the lapse rates are steeper,
so we could have a greater threat for large hail tomorrow.

Guerrero

LONG TERM...Tuesday through Saturday...

Cooler temperatures are expected through the beginning of the
long term period before temperatures rise back to near normal for
this time of year. After Tuesday morning, drier conditions will
hold through Saturday.

A H500 ridge will extend across the central CONUS on Tuesday,
with the center of high pressure located near the four corners
region. The NBM is suggesting a stray shower or storm may remain
in the far southwestern Texas Panhandle after 12z on Tuesday.
However, latest guidance has most of this activity south of the
CWA, so have reduced POPs across the southwest after 12z.
Otherwise, the cooler than normal pattern continues through
Wednesday, as the main axis of the upper level ridge remains off
to the west.

Looking towards Thursday and beyond, the ridge will begin to
slowly drift towards the east. A weak low pressure system with
associated trough attempts to undercut the ridge across central
and west Texas. With the upper level high pressure centered over
the central Rockies near Colorado and a possible weak upper level
center of low pressure to our south, northeasterly to easterly
flow aloft is expected. This type of flow is not favorable for
precipitation, so drier and warmer conditions are expected through
the rest of the extended.

Muscha/Ward

&&

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

&&

$$

36/89