National Weather Service Raw Text Product

182 
FXUS64 KAMA 050002 AAA
AFDAMA

Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
702 PM CDT Tue Jun 4 2019

.AVIATION...
For the 00Z TAFs, the next round of showers and tstms organizing
over parts of eastern New Mexico is expected to move across the
area this evening and tonight. Have included VCTS at KGUY, KDHT,
and KAMA to account for this. The next crop of showers and tstms
is expected to begin developing mid to late Wednesday afternoon, 
and will likely need to be addressed in subsequent TAF forecasts.

02

&&

.PREV DISCUSSION... /Issued 359 PM CDT Tue Jun 4 2019/ 

SHORT TERM...Today through Noon Tomorrow... 
Current mid-level satellite water vapor shows a low pressure 
system riding the southern border of Arizona. Deep southwesterly 
flow resides over the Panhandles ahead of the upper level system. 
Plenty of moisture from the Pacific continues to be pumped into 
Texas, while storms have begun to fire along a line from western 
Mexico up to Colorado. Storms are firing off a surface trough that
will move east later this evening and bring a line of strong 
storms across the western half of the Panhandles. The timing of 
these storms have been pushed back as they will begin to enter the
Panhandles later this evening from 4 PM to 6 PM. A strong capping
inversion will need to be broken for storms to succeed in the 
Panhandles. The best environment will be in the southeast Texas 
Panhandle, but storms are not expected to make it to that area. 
MLCAPE values will range from 1000-1500 J/kg with limited 
effective bulk shear of 20-25 knots in the western half of the 
Panhandles. Large hail and strong winds will be the main threats 
as mid-level lapse rates will be around 8-9 C/km with enough 
buoyancy to support strong updrafts, while downdraft CAPE values 
suggest strong downdrafts that could produce gusty surface winds. 
Storms are expected to be high based with little to no shear, so 
the potential for any tornadoes is very small. The threat for 
flooding is low as storms are not expected to produce heavy 
rainfall with PWAT values of less than 1 inch. The precipitation 
will be ending by the early morning hours tomorrow, while overcast
skies will remain.

Rutt

LONG TERM...
Weak upper low over the Desert Southwest is expected to slowly
shift east across AZ into NM through Wednesday. The main center of
the 500mb low is expected to cross into west Texas late Wednesday
night, and slowly cross to the east by Thursday night. A weak
ridge will try to build into the southern plains Thursday into the
weekend while a vigorous Pac NW trough moves across the Great
Basin and northern plains into early next week. 

On Wednesday, modest synoptic lift associated with the low and 
embedded shortwaves ahead of the low will overspread the
Panhandles. Meanwhile, a weak surface boundary is progged to shift
south into the area during the morning, before retreating north
during the afternoon. There is some indication of a 700mb low
attempting to develop near the Raton Mesa during the day with 60s
dew points setting up across the eastern FA and 50s across the
western FA. Most guidance suggest fairly deep upslope flow will
setup across the Panhandles during the afternoon with ample
low level theta-E advection. PWATs are expected to rise back 
above the 90th percentile by afternoon as storms initiate with
ample lift from upper low, upslope flow and possibly a surface
trough in the western Panhandles. Weak mid and upper level flow 
will keep shear on the weak side, but storm motion will be slower
than usual. The combination of slower moving storms, possibly widespread
coverage, and efficient rain makers will lead to an increased 
flooding risk. A Flood Watch may need to be considered in the
upcoming shift. MLCAPE of around 1000 to 2000 J/kg (highest in the
east) may also support a few strong updrafts capable of producing
large hail (especially given cool mid level temperatures). Low
level lapse rate and DCAPE are high enough to also consider a
microburst potential, so strong winds can't be ruled out. Storm
mode will likely be multicellular as outflow boundaries produce
new updrafts. 

The slow eastward motion of the upper low will keep storm chances
high through Thursday. The severe risk should be mitigated due to
the lack of better instability and shear, but flooding will remain
a concern as storms form over the same areas. The 700mb low is 
expected to shift into western OK by Thursday night. Drier 700mb 
air is expected to transport south behind the low and should 
finally put an end to rain and storms for a couple days. 

The Pac NW trough is progged to send a cold front (strong for
June standards) into the area Sunday or Monday (model agreement
still low). Ahead of this, some semblance of a dryline does show
up Sunday. Trends will need to be watched here. Behind the cold
front, northwest flow is progged to setup as the upper trough
shifts over the Great Lakes. This could setup an active period for
storms as moisture looks to be present and a period of upslope 
flow looks possible for a day or two next week.

Ward 

&&

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

&&

$$