Area Forecast Discussion
Issued by NWS Amarillo, TX

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000
FXUS64 KAMA 171143
AFDAMA

Area Forecast Discussion
National Weather Service Amarillo TX
643 AM CDT Sun Sep 17 2017

.AVIATION...
For the 12z TAFs...
Short broken line of thunderstorms currently north of AMA moving
east at 10 to 15 kt.  These will move east of AMA shortly.
Remaining terminals expected to not be threatened by thunder this
morning.

IFR and MVFR ceilings moving into northern terminals at this time
expected to persist through much, if not all, of the morning as
moist northeast low-level winds continue.

Scattered thunderstorms expected to redevelop this afternoon and
evening, with a good chance for all terminals to receive a direct
impact.

Another round of low clouds could materialize late tonight and
early Monday morning, but certainty of extent and timing is too
low to include in forecasts at this time.

Cockrell

&&

.PREV DISCUSSION... /Issued 535 AM CDT Sun Sep 17 2017/

DISCUSSION...
With another day of southwest flow aloft, another shortwave is
progged to cross the area this afternoon. This shortwave will
bring added instability to the already moisture-rich profile
thanks to Hurricane Norma off the coast of the Baja Peninsula.
Short term models and CAMs are not in full agreement on just how
the day will evolve; however, all models are indicating storms
will likely form just to our south or west between 3pm and 6pm
and move through the Panhandles. Storm mode will likely be
supercells due to 35 to 50kts of bulk shear. CAPE profiles vary
between the models with the NAM being the most aggressive with
between 2000 and 3000 J/kg. With large amounts of CAPE in the hail
growth zone, large hail, up to golf ball size, will be possible.
Decent amounts of DCAPE and fast storm motions will mean damaging
winds could be possible for collapsing storms. Low level helicity
and hodographs show that a brief tornado could not be ruled out.
Storms should generally clear out of the area between 3am and 6am.

Meanwhile, the storms firing right now have been pulse
thunderstorms and should die off later this morning. Monday will
see a transition in the upper levels to zonal flow which will cut
off moisture from Norma as well as limit shortwaves from coming
across. This will also allow for downsloping winds on Tuesday
which will bring warm temps and strong winds, leading to elevated
fire weather conditions. Wednesday will see a frontal passage that
will bring temps back to seasonal norms. The end of the work week
and beginning of the weekend will see a return of southwest flow
as a positively tilted longwave trough pushes across the Rockies.
This will allow the return of shortwaves and thus thunderstorm
chances.

Beat

FIRE WEATHER...
Moisture-rich air will keep humidity values above 20 percent
through Monday. With RH values dropping into the teens and strong
winds on Tuesday, short-lived elevated fire weather conditions
for the northwest half of the combined Panhandles will be likely.
RH values will return above 20 percent by Wednesday along with
lighter winds.

Beat

&&

.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX                82  62  91  64  92 /  40  50  10  10   5
Beaver OK                  76  61  93  66  97 /  40  50  10  10   5
Boise City OK              72  57  89  57  89 /  30  40  10   5   0
Borger TX                  82  65  93  67  94 /  40  40  10  10   5
Boys Ranch TX              83  61  92  63  93 /  40  40  10  10   5
Canyon TX                  84  61  91  63  92 /  40  50  10  10   5
Clarendon TX               86  64  92  64  95 /  30  50  10  20   5
Dalhart TX                 78  57  90  58  91 /  30  40  10  10   0
Guymon OK                  74  61  92  62  94 /  30  40  10  10   0
Hereford TX                84  60  91  62  91 /  40  50  10  10   5
Lipscomb TX                79  63  92  67  96 /  40  50  10  20   5
Pampa TX                   82  62  90  66  92 /  40  50  10  10   5
Shamrock TX                87  65  94  67  95 /  30  40  10  20   5
Wellington TX              90  67  95  67  97 /  30  30  10  20  10

&&

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

&&

$$

03/16



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