Area Forecast Discussion
Issued by NWS Amarillo, TX

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FXUS64 KAMA 201754
AFDAMA

Area Forecast Discussion
National Weather Service Amarillo TX
1254 PM CDT Fri Apr 20 2018

.AVIATION...
18Z Issuance...VFR conditions will degrade into IFR and perhaps
MVFR across the Panhandles after 01Z tonight. Showers and isolated
thunderstorms will affect all sites between 22Z and 03Z.
Confidence on fog is low so removed this round. Low cigs will not
ease until close to end of taf period if not after. Winds will be
southeasterly and breezy with strongest gusts in the southwest
where gusts could reach 40 to 45 kts. Winds should ease after
showers move away to the east and turn more northeasterly after
12Z due to a front.

Beat

&&

.PREV DISCUSSION... /Issued 1053 AM CDT Fri Apr 20 2018/

UPDATE...
Updated package to add Wind Advisory to the southwest TX
Panhandle. Winds off the deck are blowing at 50 kts and reaching
down into the Adrian mesonet. The HRRR is doing well right now
with precip location and is showing the winds in the southwest to
continue and increase through the afternoon with some spots
perhaps reaching high wind criteria.

Beat

PREV DISCUSSION... /Issued 619 AM CDT Fri Apr 20 2018/

AVIATION...

For the 12Z TAFs:

Conditions should go to MVFR late this morning or early this
afternoon as showers (and possibly thunderstorms) begin to
develop across the Panhandles. Ceilings will be the main category
in MVFR until the atmospheric column further saturates at which
time we will probably see some visibility restrictions as well.
Main concern will be the gusty wind speeds within showers or
thunderstorms that develop over the terminals, as well as IFR
conditions that could develop tonight. Confidence for IFR
conditions at KAMA was high enough to add into this TAF cycle,
but left KDHT and KGUY hovering right around MVFR/IFR (1000 foot
ceilings) conditions at this time.

Another small concern is low level wind shear (LLWS). The
termianls have some indication of a 50-60 knot jet from the south
(~180 degrees) while the surface wind speeds will be 140 degrees
this afternoon (~18Z) around 25 knots. The low level jet is around
3000 feet on forecast soundings. Given the height of the jet and
the strong wind speeds at the surface during this time, decided to
leave the LLWS out of the TAF cycle, but definitely something
worth mentioning in the event the jet actually becomes lower in
the atmpshere.

Guerrero

PREV DISCUSSION... /Issued 443 AM CDT Fri Apr 20 2018/

DISCUSSION...
A closed upper low near the Four Corners region will track slowly
east across the central and southern Rockies tonight and then
across the Panhandles and western Kansas Saturday before exiting
the forecast area late this weekend. A surface wave will pass
south of the Panhandles this weekend as abundant low level
moisture advects north and west across the Panhandles today
through Saturday. Chances for convection will increase today and
tonight before tapering off by late Saturday and Saturday night.
PWATs are forecast to approach an inch today and this evening
across the forecast area with the possibility for some locally
heavy rainfall today and early tonight.

Short wave ridging expected late this weekend into early next
week with drier conditions expected. A northern stream closed
upper low over the Central Plains states forecast to bring
additional chances for convection by Tuesday night and Wednesday
with a cold front pushing through the forecast area Tuesday. Cool
surface high to build in to the forecast the middle of next week
with warmer conditions by the end of next week. Another cold front
possibly by next Thursday night and Friday with another chance
for convection possible late next week with short wave trough
embedded in northwesterly upper flow.

Schneider

&&

.AMA Watches/Warnings/Advisories...
TX...Wind Advisory until 7 PM CDT this evening for the following
     zones: Deaf Smith...Oldham...Potter...Randall.

OK...None.

&&

$$

16/29



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