797
FXUS64 KAMA 141848
AFDAMA

Area Forecast Discussion
National Weather Service Amarillo TX
148 PM CDT Tue May 14 2024

...New SHORT TERM/LONG TERM...

.DISCUSSION...
(This evening through Wednesday night)
Issued at 147 PM CDT Tue May 14 2024

Current satellite observations depict a mid to upper level low over
MO with a positively tilted ridge to the west over the leeside of
the Rockies. A couple of shortwaves/small areas of low pressure can
be seen over WY up into western MT and ID. Further down stream off
the coast of CA is a closed H5 low and shortwave trough that is
expected to impact the combined Panhandles tomorrow into Thu. The
areas of low pressure mentioned above over ID, MT, and WY are all
associated with a positively tilted parent trough that will
combined with the low off the coast of CA.

Tonight perturbations between the trough and ridge will move into CO
creating showers and thunderstorms over much of CO, with some of
this activity bleeding into the northern combined Panhandles
tonight. Based on forecast soundings any showers or storms that
develop will have high bases with a large inverted V sounding. DCAPE
values are progged to be 1200 and 1800 J/Kg. Overall confidence is
low in any one place measuring rainfall. However, there is moderate
confidence that high based storms could produce virga bombs leading
to a concern in severe wind gusts. If a storm can get going and gain
structure with potentially 1000 to 1200 J/kg, some large hail cannot
be ruled out entirely. Again overall confidence is low for getting a
healthy rain/hail producer at this time. Further south in the area,
depending on if some smaller perturbations come across the southern
TX Panhandle, isolated thunderstorms may form late this afternoon
and in evening over the south as well. Overall confidence in this
happening is low with only a 10 PoP mentioned in the forecast at
this time. A severe storm cannot be ruled out here. However, storms
are expected to be short live and unable to get very strong before
collapsing at this time.

As the areas of H5 low pressure over ID/MT/WY push south and merges
with the low coming off the southern coast of CA tomorrow, severe
thunderstorms are anticipated. PoPs will increase to around 40 by
the late afternoon evening and increase to 50-60 going into the
overnight hours. Not only will there be better upper level support
with the arrival of the upper level trough, but there will also be
an influx of better moisture. Surface high pressure over the Gulf of
Mexico should help pump up some better low level moisture up through
southern and western Texas into the Panhandles. A cold front will
also be arriving with the upper level trough and help bring some
higher Tds in at the surface behind the front, especially across the
northern third to half of the FA. The big question is how soon will
this moisture arrive and how soon will the front come in from the
north. Ahead of the front some mid level moisture may be present for
high based storms to get going especially if convective temperatures
are reached even before the main upper level support comes in. Just
liked today much of the southeastern half of the combined Panhandles
are expected to see daytime highs in the 80s before the front or
storms hamper the heating. Timing of the front is hard to see in the
models due to some convective feedback. However, it appears to stall
across the area by mid afternoon, dividing the northern and southern
combined Panhandles.

Tomorrow, some easterly winds may feed higher Tds into the
southeastern TX Panhandle enhancing the overall CAPE values.
Depending on which model one were to look at there is likely to be
1500-3000 J/Kg. Even areas behind the front could still have 1500 to
2000 J/Kg of CAPE, even surfaced based behind the front. Overall
bulk shear of 35 to 50 kts and lapse rates around 8 to 10 C/km will
liekly contribute to golfball size hail, and a potential wind
threat. Surface to 1 km helicity and surface to 1 km bulk shear do
not support tors. Hodographs are pretty straight as well suggesting
left and right moving cells are possible. However, with a frontal
boundary in play, cannot completely rule out a landspout or a hybrid
of sorts especially if some outflow boundaries interact with the
front. Going later into the evening and overnight hours, some of the
forecast sounding become slightly more tropical in nature with large
hail becoming less of a threat and isolated flooding becoming more
of a concern with some efficient rain producing storms as available
moisture continues to increase overnight into tomorrow.

Thu morning a break in storms could potentially occur with
thunderstorms picking up in the late afternoon/evening again. This
time across the southern TX Panhandle and south. Models seem to keep
much of the storm activity along the cold front. But, this could
also just be where the best PVA occurs when the center of the H5 low
comes across late Thu into Thu night. The track of the H5 low will
most likely determine who gets storms Thu night. Severe storms
cannot be entirely ruled out for Thu especially in the southeastern
TX Panhandle.

Showers and thunderstorms should come to an end by sunrise Fri with
drier and warmer temperatures expected Fri through the rest of the
extended period. Expecting an H5 ridge to build going into the
weekend with temperatures in the upper 80s and lower 90s. Some
perturbations in the flow aloft could spark some showers and
thunderstorms across the OK Panhandle Sunday into Sun night.
However, with only the GFS suggesting this, have stuck with the NBM
PoPs that are less than 10 but not zero.

36

&&

.AVIATION...
(18Z TAFS)
Issued at 1222 PM CDT Tue May 14 2024

VFR conditions are expected to prevail through the 18Z TAF period.
Winds will be relatively light for Panhandle standards. However,
KGUY has a chance to see some showers in the area that may cause
some gusty or erratic winds mainly between 21Z and 03Z Wed. There
is a low chance of a thunderstorm developing near or east of KAMA
at this time. Again confidence is low in any impacts to the
terminal and have left out of the TAFs for now.

36

&&

.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX                87  56  86  54 /  10  10  40  60
Beaver OK                  87  54  85  54 /   0  20  40  60
Boise City OK              87  50  78  49 /  20  20  60  50
Borger TX                  92  57  89  57 /   0  10  50  60
Boys Ranch TX              91  52  89  54 /   0  10  40  50
Canyon TX                  88  55  88  54 /  10  10  40  50
Clarendon TX               84  57  88  56 /  10  10  40  60
Dalhart TX                 86  49  83  50 /  10  10  40  50
Guymon OK                  88  52  82  52 /  10  20  50  60
Hereford TX                89  54  89  54 /   0  10  30  50
Lipscomb TX                86  56  87  56 /   0  10  40  70
Pampa TX                   86  56  85  54 /  10  10  40  60
Shamrock TX                84  56  89  57 /  10  10  40  70
Wellington TX              85  56  90  57 /  10  10  40  70

&&

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

$$

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