521 
FXUS64 KAMA 250908
AFDAMA

Area Forecast Discussion
National Weather Service Amarillo TX
408 AM CDT Sun Apr 25 2021

.SHORT TERM...Today through Tomorrow Night...

Synopsis: Very warm and breezy to windy conditions will lead to 
fire weather concerns today and tomorrow. 

Details: Latest WV imagery reveals an upper level low moving 
towards the northern CA coast as a low amplitude ridge over the 
Great Plains was helping maintain zonal flow over the Panhandles.
A large area of upper level moisture was moving out ahead of the 
upper low across the Great Basin, but a few high clouds were 
moving off the higher terrain in NM and CO. Closer to the surface,
VAD winds indicated a strong low level jet of 50 to 60 knots in
place over KAMA which has lead to some wind gusts over 20 knots 
at times this morning despite nocturnal inversion in place. 
Temperatures were very mild as of 0800z, with most locations
in the 50s. 

Through the day today, the 500mb westerlies will stay in the 30 to
40 knot range with an increasing southerly component starting this
evening as the upper low moves inland over CA/OR. The cross
barrier flow will help induce lee pressure falls with a surface low
pressure center of around 991 mb in eastern CO by 00z Monday. 
This will result in breezy to windy conditions today across the 
combined Panhandles, east of a diffuse dryline near the western 
OK state line. The winds may ramp up pretty quickly this morning 
as mixing takes place, however Bufkit profiles suggest max winds 
at the top of the BL never exceed 38 knots as the nocturnal jet 
kinematically decreases. Thus, we may get a little influence early
on from the low level jet, but not the full effect before the 
surface pressure gradient becomes the main driver and sustained 
winds of 20 to 25 knots become dominant with gusts near 30 to 35 
knots. The increasing downslope winds will help mix very warm 
850mb temperatures down to the surface beneath a low level thermal
ridge (LLTR). Upper 80s to low 90s look to be common by mid 
afternoon, which is about 15 degrees above normal. The airmass is 
also quite dry which will lead to critical fire weather concerns 
(see more below). 

Tomorrow will be very similar to today with two exceptions. First
is the increase in upper level cloud cover as the subtropical
moisture plume shifts east into the area ahead of the upper low.
Second is the increase in 700mb to 500mb winds as a mid level jet
streak of 50 to 60 knots moves out of NM ahead of the main wave
which should be centered over NV by 00z Tuesday. These two items
introduce a bit more uncertainty for high temperatures and peak
wind speeds, as mixing may not be as efficient due to reduced
insolation. Sustained winds should be at least as strong as Sunday
given similar pressure gradient in place, but max gusts may be
higher with stronger winds in upper half of BL, but will depend on
mixing. For now, keeping max gusts a bit higher than Sunday with a
peak of around 45 mph. Temperatures may be a degree or two lower
in some places based on clouds as well, but the stronger downslope
winds could help temperatures over achieve in some places. The
irony is that record highs are lower Monday, so temperatures won't
have to get as warm to break records. For instance, 92 is the 
record high for AMA on Monday (1927), but it is 99 on Sunday 
(2012). All of this will lead to critical fire weather for most
locations (see more below). 

Ward

&&

.FIRE WEATHER...

Critical fire weather is expected today in the western and central
Texas Panhandle, and across all of the Oklahoma Panhandle where
Red Flag Warnings have been issued. This will occur as southwest 
winds increase in response to a pressure gradient across the 
area. Twenty foot winds of 20 to 25 mph with gusts near 35 mph are
expected from mid morning through the evening. Relative humidity 
values will fall into the single digits across the western and 
central zones, with teens in the east as temperatures rise into 
the upper 80s to low 90s with strong mixing. These very warm 
temperatures are due to a notable low level thermal ridge which 
will expand across the Panhandles into western OK. Given the lack 
of any strong low level jets after the morning hours, IA fires are
most favored. Fire activity may be mitigated in the eastern zones
where areas saw some rainfall recently, but will still see 
elevated fire weather with RFTIs around 2. Areas in the central 
and western zones could see RFTI values around 4 to 6, with some 
7s in the far western Panhandles. TFS ERC percentiles seem to be 
the most reasonable right now and better reflect the areas of 
transitional green and recent rains / overnight RH recovery. 

Conditions should be very similar tomorrow with the addition of
slightly stronger jet level winds and more high level clouds. The
increasing jet level winds suggest higher gust potential 
tomorrow, but the high clouds suggest slightly cooler and less 
efficient mixing, so maybe gusts will be tempered some. Models do
hint at drier air with RH values falling a point or two lower 
than Sunday, so overall Monday has RFTIs of 4 to 7 with isolated 
8sand more receptive fuels. Fire Weather Watch will continue for 
all but far eastern Texas Panhandle. 

Ward

&&

.LONG TERM...Tuesday through Saturday...

There is the potential for a prolonged chance of precipitation 
for a good amount of the Panhandles. Although global model data
does diverge further out, current 25/00Z data shows that we still
have a chance for a few days of precipitation. 

Starting on Tuesday, latest 25/00Z model data are already not in
an accord. GFS/NAM/CMC is showing an upper level low moving ESE 
along The AZ/Mexico border throughout the day on Tuesday. ECMWF is
slower and has the center of the low further northwest near Las 
Vegas moving into western AZ throughout the day. Downstream of 
this well defined upper level low pressure, H500-250 UL divergence
is well pronounced over the Panhandles with a developing jet over
far west Texas extending into the Texas South Plains within all 
of the model data. The majority of the data given the further SE 
center of the H500 low will have much stronger H850-700 southwest
flow advecting into the Panhandles into the day on Tuesday. As a 
result, strong SW winds will likely push the main dryline well 
into western Oklahoma by Tuesday afternoon with the co-located 
moisture transport remaining across western/central Oklahoma. With
the exception of the far SE Panhandles of a chance of 
thunderstorms, the remainder of the Panhandles will have strong SW
winds and potential fire weather conditions continuing from 
earlier in the week. In the solution with less precipitation 
chances, especially in the western Panhandles, winds will be quite
strong as a deep mixing profile develops in the wake of the 
dryline moving east. Winds could be strong enough to warrant some 
headlines. However, the further west centered H500 low pressure 
solution Tuesday afternoon for the ECMWF and NBM data counteracts
the SW flow shifting the dryline with a good S/SE surface wind 
across the east with good moisture transport. This will help to 
develop thunderstorms across the eastern and portions of the 
central Panhandles by Tuesday afternoon. The more favorable 
precipitation solution shows 1000-2000 J/kg of MLCAPE for the 
eastern Panhandles and with very well defined shear throughout 
column, supercell development with large hail and damaging wind 
gusts will be possible for areas along and east of the dryline. 
Going from Tuesday night into Wednesday morning, a cold front will
move SE into the Panhandles, and with a more moist profile as it 
hits the dryline in the more favorable precipitation model, a 
second round of thunderstorms will be possible.

Going into Wednesday, perturbations around the main H500 low for
the 25/00Z GFS/NAM/CMC will bring additional chances of
thunderstorms for the Panhandles. Starting Wednesday night, as a
deepening British Columbia UL low enhances the main ageostrophic 
flow, a ridge downstream will build northeast into the Sierra 
Nevada. This will displace the now cut off low further south into 
Mexico bringing precipitation to an end by Thursday morning for 
the Panhandles in the latest GFS/NAM/CMC solutions. This same 
feature is also illustrated in the higher total QPF run of the 
ECMWF, however, the timing is around 24-36 hours delayed along 
with a lower amplitude ridge. This results in precipitation 
chances for the Panhandles continuing through at least Friday 
morning before the center of the ECMWF shifts south into Mexico 
and its moisture transport shuts off for the region. 

Temperatures throughout the forecast period, even with the cold
front passing through Tuesday night, should remain at or above
average. Dry conditions will most likely return for all of the
Panhandles as we go into the start of the coming weekend. 

Meccariello

&&

.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX                89  57  90  56  81 /   0   0   0   0   5 
Beaver OK                  89  60  91  55  84 /   0   0   0   0   5 
Boise City OK              87  47  84  49  75 /   0   0   0   0   5 
Borger TX                  90  61  93  59  85 /   0   0   0   0   5 
Boys Ranch TX              90  55  90  55  81 /   0   0   0   0   5 
Canyon TX                  89  55  90  54  82 /   0   0   0   0   5 
Clarendon TX               89  60  88  58  83 /   0   0   0   0  10 
Dalhart TX                 90  45  85  49  76 /   0   0   0   0   5 
Guymon OK                  89  54  90  53  81 /   0   0   0   0   5 
Hereford TX                89  53  89  53  81 /   0   0   0   0   5 
Lipscomb TX                88  60  88  56  85 /   0   0   0   0   5 
Pampa TX                   87  60  89  57  83 /   0   0   0   0   5 
Shamrock TX                88  57  87  57  86 /   0   0   0   0  10 
Wellington TX              89  57  88  58  86 /   0   0   0   0  20 

&&

.AMA Watches/Warnings/Advisories...
TX...Fire Weather Watch from Monday afternoon through Monday evening 
     for the following zones: Armstrong...Carson...Dallam...Deaf 
     Smith...Donley...Gray...Hansford...Hartley...Hutchinson...
     Moore...Ochiltree...Oldham...Palo Duro Canyon...Potter...
     Randall...Roberts...Sherman.

     Red Flag Warning from 11 AM this morning to 9 PM CDT this 
     evening for the following zones: Armstrong...Carson...
     Dallam...Deaf Smith...Hansford...Hartley...Hutchinson...
     Moore...Oldham...Palo Duro Canyon...Potter...Randall...
     Sherman.

OK...Fire Weather Watch from Monday afternoon through Monday evening 
     for the following zones: Beaver...Cimarron...Texas.

     Red Flag Warning from 11 AM this morning to 9 PM CDT this 
     evening for the following zones: Beaver...Cimarron...Texas.


&&

$$

7/29