481 
FXUS64 KAMA 010838
AFDAMA

Area Forecast Discussion
National Weather Service Amarillo TX
338 AM CDT Thu Jul 1 2021

.SHORT TERM...

A wet couple of days are on tap for the Panhandles. Large amounts of 
moisture available in the atmosphere, a boundary pushing southwest 
into the Panhandles Thursday night, and slow shower and storm 
motion, all combined with our recent rainfall, will likely lead to 
flooding concerns in at least a few locations. As is typical, urban 
areas will be susceptible to flooding issues should a slow moving 
thunderstorm pass over, as peak rain rate potential of 2" per hour 
appears plausible. Severe thunderstorms appear highly unlikely. For 
more details, continue reading below.

07z WV satellite reveals an upper ridge to our south over TX with 
plenty of mid level moisture fetch on the west side of this feature 
from the eastern Pacific and western Gulf of Mexico and various 
perturbations in the southwesterly flow extending back to AZ/NM. WV 
also reveals an upper trough translating southeastward over the 
Midwest. Most recent RAOB at AMA and GOES wind retrievals show wind 
speeds through the troposphere of generally 20 knots or less. 
Additionally, the 00z AMA RAOB measured 1.55" of PWAT, a 
climatological maximum for 00z July 1st soundings at AMA.

After the aforementioned upper disturbances potentially kick off a 
few showers during the morning and early afternoon Thursday, the 
main round of potential precipitation arrives during the late 
afternoon and evening hours Thursday. The substantial moisture in 
place looks to be reinforced as the Midwestern upper trough and 
convective outflow push a surface boundary southwestward from KS, 
with a turn to upslope easterly winds aiding in low level saturation 
as well. Convergence along this boundary will aid in the development 
of showers and storms, particularly after 7pm when an upper 
disturbance translates southeastward from E CO. The relatively slow 
southwestward progression of this boundary, the weak flow regime 
suggesting storm motion will be to the east at around 10 knots, and 
pre-convective PWAT values of around 1.5"-1.75" - greater than their 
climatological maximum for the day just like our most recent RAOB - 
all suggest some locally heavy rainfall is possible. Chances for 
this to occur are increased a bit given the combination of the 
eastward storm motion and the southwestward moving boundary, which 
could lead to some training issues. When combined with our recent 
rainfall and the poor drainage of our urbanized areas, some flooding 
issues do appear possible tonight. Have thus issued a Flood Watch 
covering a majority of the forecast area starting Thursday evening, 
leaving out our southwest due to their continued drought conditions 
and our northeast due to collaboration concerns. On the subject of 
severe thunderstorms, given the aforementioned weak flow through the 
troposphere, 0-6km bulk shear values look to be around 20 knots. 
Additionally, while MLCAPE values of around 1000 J/kg are good 
enough to keep healthy mentions of thunder in the forecast, 
instability profiles remain quite tropical - in other words, skinny. 
Thus, severe thunderstorms appear unlikely.

Moving on to Friday, as showers and storms generate in our forecast 
area, outflow should continue to push the boundary southwestward 
with upslope easterlies dominant across the Panhandles. Thus, rain 
appears likely in our southwest. With progged thermodynamic profiles 
still depicting around 1.5" of PWAT, will keep the aforementioned 
Flood Watch running through the day, with adjustments to the area 
covered possible as details become clearer.

Ferguson

&&

.LONG TERM...Saturday through Wednesday...

The latest models and ensemble means continue to shift the 
anomalous upper high currently over central Canada east over
Ontario and Quebec through the weekend as the New England trough 
moves offshore. Meanwhile, the upper high over Texas will shift
west and setup near the Four Corners region. This high will 
foster periods of northwest flow aloft, although the flow should
stay fairly weak (<40 knots at 500mb). PWATs are expected to come
back down closer to normal this weekend into next week as the
main tropical moisture plume gets pushed south of our area. 
Forecast soundings continue to advertise CAPE with little in the 
way of CIN in the afternoons and evenings through Monday, so storm
chances will continue to be on the higher side as shortwave 
disturbances move down across the central/southern Rocky Mountains
and adjacent plains. Sunday (July 4th) is of particular note as 
this is when GFS soundings indicate MLCAPE approaching 2000 J/kg 
along with modest directional shear and slightly cooler mid level 
temperatures. The EC ensemble and GEFS also indicated a high 
probability of CAPE being 1000 J/kg or higher on Sunday (near 100%
in the eastern half of the combined Panhandles). Thus, will need 
to watch as conditions may be more favorable for severe 
convection in the afternoon and evening on the July 4th holiday.

The probability for storms comes down a little Monday through 
Wednesday, with some differences in the models with moisture and 
instability. The GFS is an outlier bringing an MCV type feature 
south out of KS on Monday, keeping PoPs high. Other models are 
not as interesting on Monday suggesting a cap may be in place. 
One thing that may put a damper on PoPs is if northeast flow at 
500mb is realized as a few models indicate going into Tuesday and 
Wednesday, as this would keep mountain convection in the 
mountains. 

As for temperatures, it appears that the area will stay mainly below
normal through the extended, yet some areas may be getting close 
to normal by Tuesday/Wednesday. The below normal temperatures are 
mainly due to the fact that low level moisture will stay up 
(afternoon surface dew points mainly in the low 60s) and enough 
subtropical mid level moisture hangs around to keep 850mb 
temperatures down. There is some concern that the NBM may be a  
little too cool for high temperatures Monday and beyond, as most
of the latest raw models, BC models, and statistical models are
warmer.

Ward

&&

.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX                84  65  77  65  80 /  20  80  70  50  40 
Beaver OK                  83  65  79  65  83 /  40  70  40  10  20 
Boise City OK              84  61  77  61  82 /  50  80  50  30  40 
Borger TX                  88  68  79  67  85 /  30  80  60  40  40 
Boys Ranch TX              87  67  80  65  84 /  20  70  70  50  40 
Canyon TX                  85  66  79  64  80 /  20  70  70  50  50 
Clarendon TX               87  67  78  67  80 /  30  80  70  50  40 
Dalhart TX                 85  63  78  62  82 /  30  80  60  40  40 
Guymon OK                  85  65  78  65  83 /  40  80  50  20  30 
Hereford TX                85  66  79  65  83 /  10  70  70  60  50 
Lipscomb TX                85  66  80  65  82 /  40  80  50  20  20 
Pampa TX                   85  65  76  65  80 /  30  80  60  40  40 
Shamrock TX                87  67  79  66  81 /  40  80  70  40  30 
Wellington TX              90  67  80  67  82 /  30  90  70  40  40 

&&

.AMA Watches/Warnings/Advisories...
TX...Flood Watch from this evening through Friday evening for the 
     following zones: Armstrong...Carson...Collingsworth...
     Dallam...Donley...Gray...Hansford...Hartley...Hemphill...
     Hutchinson...Moore...Ochiltree...Palo Duro Canyon...
     Potter...Randall...Roberts...Sherman...Wheeler.

OK...Flood Watch from this evening through Friday evening for the 
     following zones: Cimarron...Texas.


&&

$$

77/7