FXUS64 KAMA 111735 AAB

Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
1135 AM CST Mon Dec 11 2023

...New AVIATION...

(Today through Tuesday night)
Issued at 322 AM CST Mon Dec 11 2023

Mild northwest flow will keep conditions dry today with slightly
above normal temperatures. Highs will be in the mid 50s to near 60
in some areas. Partly cloudy skies with winds in the 5 to 10 mph
range should make for a pleasant day. Cooler air will be on the
way as a system approaches and we transition to a more zonal flow
aloft. Cloud cover will increase tonight and that will allow for
overnight lows to be a bit warmer, but still overall most areas
will be below freezing. With the cooler air in place on Tuesday
highs will only be in the upper 40s to mid 50s with mostly cloudy
skies. An upper level trough will begin to dig down over the Las
Vegas area and start to close off on Tuesday night. This along
with easterly flow at the surface will being to pump Gulf moisture
over the Panhandles and we'll begin to see chances of
precipitation starting over the southern Panhandles and gradually
transition north. The temperatures early Wednesday morning will be
close enough that a rain/snow mix could occur to portions of the
northern Panhandles. This will be the start of what looks to be a
three day weather event that could bring winter impacts to
portions of the Panhandles (See long term discussion for further



(Wednesday through Sunday)
Issued at 322 AM CST Mon Dec 11 2023

Main headline will continue to be the next system to bring
impactful precipitation to the region over multiple days this
upcoming work week. Confidence is very high that the Panhandles
will see precipitation during the Wednesday to Friday timeframe.
The exact amounts remain uncertain as well as the precipitation
types. It is not out of the realm of possibility that some
locations receive impactful snowfall from this system. Drier and
warmer conditions are favored going into next weekend.

An upper level H500 low pressure system should be located near the
southern tip of Nevada by sunrise on Wednesday morning. This would
leave the Panhandles underneath southwesterly flow aloft. At the
surface, southerly to southeasterly winds will continue to usher
in Gulf moisture across the Southern High Plains and this trend
will continue through Friday. Scattered rain showers may be
ongoing across portions of the Panhandles on Wednesday morning and
should become more widespread by Wednesday night as the low
pressure system continues to move east during the day. With the
system being well off to the west on Wednesday, temperatures
should remain warm enough so that the precip type should mainly be
rain. From midnight Wednesday to midnight Thursday there is
currently a 30 to 60 percent chance for the central and western
Panhandles to see a half inch of rainfall.

The upper level low will begin to become cutoff by early Thursday
morning near the Arizona/New Mexico state line. With the low
continuing to move slowly east, multiple rounds of precipitation
will continue to be possible from Thursday through at least mid
day Friday based on the latest 11/00z deterministic and ensemble
suite of guidance. Latest deterministic suite of guidance is in
fairly good agreement on the overall track of the low through
Thursday evening. The main area of concern will be where the
center of the low tracks from Thursday morning through mid day
Friday as this will play a large part in the precipitation types
during these days. Currently the GFS is the furthest south
solution, which takes the H500 low across southern New Mexico and
eventually across portions of west Texas. EC/CMC want to bring the
low a bit further north and eventually move the center of low
pressure across the Panhandles. If the later scenario comes to
fruition, more areas (mainly the central and west) would have the
potential to switch from rain to snow during this timeframe. Even
if the GFS solution wins out, winter impacts are still possible
for portions of the area, just not as much of the CWA. With the
low pressure system finally being onshore in time for the 00z
soundings this evening, hopefully models will begin to converge on
a track on Tuesday. Overall, the system should be east of the
Southern High Plains by Friday night.

The big question that everyone will be (and is probably already)
asking is, what amounts are to be expected with this system.
Based on the 11/01z NBM probabilities, a majority of the area has
around a 30 to 50 percent chance at receiving an inch or more of
liquid precip from this multiple day event. It should also be
noted that the typically dry biased GEFS mean is over an inch for
the entire area as well. In other words, there is very high
confidence in abnormal rainfall for December during these three
days. The main area of uncertainty is with regards to potential
snow amounts and unfortunately there is a lot of uncertainty. Even
though the GFS track of the low may be correct, am hesitant to
believe the very low snow accumulations given by the GEFS with the
known warm bias and model soundings suggesting snow potential at
some locations over multiple hours. Given all this, the potential
is certainly there for impactful snowfall from Thursday through
Friday, especially for the central and western Panhandles. Be sure
to continue to check back for forecast updates throughout the
week given the uncertainty with this system and its potential



(18Z TAFS)
Issued at 1134 AM CST Mon Dec 11 2023

Winds are expected to remain around 10 knots or less along with
VFR conditions.


Amarillo TX                29  54  39  47 /   0   0  50 100
Beaver OK                  26  51  33  47 /   0   0  30  90
Boise City OK              24  47  29  42 /   0   0  10  90
Borger TX                  29  56  40  50 /   0   0  40 100
Boys Ranch TX              27  54  37  48 /   0   0  40 100
Canyon TX                  28  54  38  47 /   0   0  50 100
Clarendon TX               31  54  42  47 /   0   0  50  90
Dalhart TX                 23  50  31  44 /   0   0  30 100
Guymon OK                  24  50  31  45 /   0   0  20  90
Hereford TX                28  55  38  48 /   0   0  60 100
Lipscomb TX                28  54  37  47 /   0   0  30  80
Pampa TX                   30  53  39  45 /   0   0  40  90
Shamrock TX                29  55  40  47 /   0   0  30  80
Wellington TX              30  55  40  48 /   0   0  40  80