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Area Forecast Discussion
Issued by NWS Amarillo, TX
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FXUS64 KAMA 031121
AFDAMA

Area Forecast Discussion
National Weather Service Amarillo TX
621 AM CDT Wed Jun 3 2020

.AVIATION...
VFR conditions expected for the 12Z TAF period. Winds will be
variable at 5-10 kts throughout the forecast period with mostly
clear skies. A thunderstorm is possible for KDHT/KAMA starting
after 18Z through 02-03Z Thursday. Confidence is low at this time,
but will be updated in the next TAF issuance.

Meccariello

&&

.PREV DISCUSSION... /Issued 332 AM CDT Wed Jun 3 2020/

SHORT TERM...through Thursday...
The heat really begins to build across the Panhandles later this
afternoon and through the short term period. On the eastern
periphery of a building H500 ridge into central New Mexico, light
winds and clear skies with H850 WAA of 26-29C into the Panhandles,
high temperatures today will get well into the mid and upper 90s
with Palo Duro Canyon at or just below 100 degrees this afternoon.
Latest 03/00Z model and numerical data does show a window later
this afternoon into the evening hours, where peak heating coupled
with H700 perturbation across the TX Panhandles & residual outflow
boundaries from precipitation earlier this morning will help to
generate additional thunderstorm chances. SBCAPE of 750-1000 J/kg
coupled with effective shear under 20 kts will generate pulse type
thunderstorms with gusty winds and lightning the main threat with
small hail also possible. With weak shear, outflows generated
from convection should race away from updraft with storms not
lasting too long with left over rain showers and low topped
convection by this evening and tonight. A second area of showers
and thunderstorms this afternoon is possible across the
northwestern Panhandles downstream of thunderstorms developing in
the Raton Mesa in the high terrain. These storms will also be high
based with gusty winds and lightning the main threat before
chances diminish later this evening. With slow storm motion and
PWAT values of + 2 S.D., locally heavy rainfall with slow moving
thunderstorms cannot be ruled out.

Northwest flow aloft will continue into the day on Thursday.
Residual outflow boundaries along with a more pronounced
perturbation in the mean 700-500 hPa flow moving ESE into the
Panhandles is beginning to increase chances for thunderstorms.
Mid level lapse rates along with a deep inverted-v profiles and
MLCAPE of 1500-2000 J/kg will support the potential of some
thunderstorms potentially reaching severe limits. H850-700 theta-e
advection also present in the central Panhandles thursday
afternoon. If severe storms develop, damaging wind gusts and some
large hail will be the main threats. With initial updraft along
boundaries Thursday afternoon and effective shear still limited
around 20 kts, multi-cell clusters could be main storm mode with
tallest updrafts providing a large hail threat initially with
damaging wind gusts as well. Thunderstorm chances expected to
continue into early portions of Thursday night as well. High
temperatures will continue to remain hot with values ranging from
the upper 90s to 100-103, with PDC topping out around 103-104.

Meccariello

LONG TERM...Thursday Night through Tuesday Night...
Shortwave will push through under northwest flow and help add some
lift in addition to the already buoyant parcels given the very
hot temperatures. Inverted V soundings indicate high based T
storms with enough CAPE and shear to at least give the storms a
chance to go severe. Right now max hail size looks to be half
dollar to ping pong ball. Wind gust potential looks to be around
60 mph. Even though the storms will be high based, the PWAT values
range from 1.00-1.50" and thus moderate to heavy rain can be
expected with these storms. Forecast soundings (onion) later in
the evening suggest the area might be primed for potential heat
bursts due to dry air in the lower levels that lingering moisture
in the mid levels may evaporate and accelerate towards the
surface. Right now it`s just something to watch, confidence is
still low.

Upper level trof expected to move into the Pac NW Friday evening
and through the weekend. Right now keeping NBM pops, but might
still have a pop up storm on Friday just due to the very hot
temperatures and that we might be able to get to the convective
temperature through heating alone. Dewpoints are going to be the
key, we have some models suggesting that dewpoints could be in
the upper 50s, providing a better chance for convection, and other
models suggesting mid 40s, which will probably not be quite
enough to get storms to trigger.

As the trof lingers over the Pac NW strong southwest flow will be
in play over the Panhandles. Normally this might be a favorable
pattern for continued showers storms, but we have a tropical
system that will linger over the Gulf. The setup would actually
support offshore flow, instead of advecting more low level
moisture to the area. So have continued the NBM dry pops through
the extended. Temperatures will be in the 90s to lower 100s for
the majority of the extended.

Weber

&&

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

&&

$$

29/89
National Weather Service Regional Headquarters
