640 
FXUS64 KAMA 222045
AFDAMA

Area Forecast Discussion
National Weather Service Amarillo TX
245 PM CST Fri Jan 22 2021

.SHORT TERM...Tonight through Tomorrow Night... 

Latest water vapor imagery shows next western NOAM upper trough 
digging southeast into northern CA and western NV. Mid/upper level
moisture is spreading northeast across the Four Corners region,
transitioning to drier mid level air over the southern plains. At
the surface, light easterly winds have slowly veered to the 
southeast through the morning in response to weak lee pressure
falls over Raton Mesa. This has resulted in low clouds in 
portions of the Texas Panhandle due to weak warm air advection and
some upslope flow. The latest RGB imagery indicated dissipation 
of clouds along outer periphery near Dalhart and Borger, but they 
are still holding strong over KAMA. Have lowered high temperatures
where clouds have held in the longest, and where temperatures 
were still in the 30s as of 19z. Clouds may finally get out of 
here by 21z or so, but that won't leave a lot of time to warm 
before the better sun angle is lost. 

For tonight, warm air advection regime continues as southwest flow
aloft increases ahead of western NOAM trough. Model sounding
profiles (even GFS to some extent) indicated a 50 to 100mb layer 
of saturation near the surface starting around 03z tonight in the
southern TX Panhandle, then spreading northwest to cover most of 
the combined Panhandles by 06z. Short term models including the 
HREF mean and NARRE indicated some dense fog potential, especially
after 06z tonight on the Caprock. Have thus included patchy and 
areas of fog/freezing fog depending on the temperatures (which 
will be right near freezing for southern zones). Fog headlines 
may be needed mainly between the hours of 06z Saturday and 18z 
Saturday, before surface winds become southwesterly and dry air 
invades. Otherwise, once the clouds and fog/drizzle clear out, 
temperatures should quickly climb. Current thinking is that the 
downslope effect will clear out the clouds in time to allow 
temperatures to rise into the 50s and 60s. However, high 
temperatures were lowered below NBM using blend of raw guidance 
and CAMS.

Ward

&&

.LONG TERM...
Water vapor analysis shows a mid to upper level low digging south
along the west coast of CONUS, located around northern California
as of this writing. The base of this trough is to move south just
off the coast of California with a positive tilt until the base 
of the trough is located just south of AZ Sunday morning. By 
Sunday evening this shortwave trough will be quickly positioned 
with a negative tilt as it starts to enter over the Panhandles. 
At least per the EC and CMC solution. The GFS keeps the trough 
oriented with more a positive tilt and speeds up the eastward 
progression. This system is looking to bring some PoPs to the 
combined Panhandles Sunday night into Monday. 

Sunday morning an associated surface front will move through the 
area but models show this cold front hanging up around the 
southern Texas Panhandle. This will create a nice gradient in 
daytime highs from the northern combined Panhandles to the 
southern Texas Panhandle. Winds will become more easterly in the 
afternoon as surface low continues its eastward progression. The 
aforementioned upper level trough will move into the area Sunday 
night with quite a bit of PVA according to the EC and CMC 
solutions with the negatively tilted trough. The NBM has been 
trending up with PoPs for the overnight period into Monday. The 
GFS has previously shown the FA getting dry slotted with this 
system. However, if the EC and CMC are correct the negatively 
tilted trough will make dry slotting less likely, but could also
keep warmer air in place. Have stuck with the NBM PoPs which do 
have 70 PoPs in the east and 40 PoPs in the west. 

Late afternoon Sunday into early evening some instability will be
present in the southeastern TX Panhandle and cannot rule out some
thunder. MUCAPE is limited to less than 200 J/Kg. Any 
precipitation going into the evening will most likely be rain. The
later it gets and temperatures start to drop, a brief period of 
freezing rain may be possible across mainly the northern half of 
the TX Panhandle before transitioning into snow. Eventually the 
northern combined Panhandles will turn to all snow.

Even though PoPs range from a chance to likely, this could be an 
event where the amount of liquid precip received will not do much
in the way of preventing degradations in drought for some areas. 
Further north in Kansas will be a different story as better 
moisture looks to be present. Therefore, not expecting much in the
way of snow accumulations in the north until you get to about the
KS state line. Generally less than an inch is expected at this 
time, with the exception of some isolated areas along the KS state
line. With that said, if the upper level system moves further 
south than what is forecasted at this time, higher snow amounts
along with its impacts will be of concern especially in the 
Oklahoma Panhandle and northern Texas Panhandle. Another thing to 
watch for will be the exact location of the cold front at the 
surface as temperatures will be playing an role in the rain snow 
line across the area. Model trends will have to be watched for 
southerly shifts in solutions leading up to Sunday night into 
Monday. In general, the ensemble members have been more generous
with precip compared to the drier GFS, especially across the
northern Panhandles. 

A second upper level system will move through Tue night into Wed
that will potentially bring precipitation to the FA. Confidence 
in the system Tue night is low and have lowered chance PoPs given 
by the NBM down to slight chance in the northern FA, primarily the
OK Panhandle. The low does look to be taking a northeast 
trajectory from the Four Corners Region up into IA at this time 
per deterministic solutions. Cool temperatures are expected 
through the week until Thursday when the area could see 
temperatures back in the 50s again. 

Hoffeditz

&&

.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX                31  59  33  55  30 /   0   0   0  20  50 
Beaver OK                  25  57  30  47  25 /   0   0   0   5  70 
Boise City OK              27  59  27  44  24 /   0   0   0  10  40 
Borger TX                  33  61  35  55  31 /   0   0   0  10  60 
Boys Ranch TX              30  63  30  55  28 /   0   0   0  20  40 
Canyon TX                  30  61  32  57  30 /   0   0   0  20  40 
Clarendon TX               32  57  37  57  34 /   0   0   0  20  60 
Dalhart TX                 27  60  27  49  24 /   0   0   0  20  40 
Guymon OK                  26  61  29  46  25 /   0   0   0  10  60 
Hereford TX                31  61  32  59  30 /   0   0   0  20  40 
Lipscomb TX                27  53  32  50  28 /   0   0   0  10  70 
Pampa TX                   30  57  34  53  30 /   0   0   0  10  60 
Shamrock TX                30  51  37  57  32 /   0   0   0  20  70 
Wellington TX              32  52  37  59  33 /   0   5   5  20  60 

&&

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

&&

$$

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