Area Forecast Discussion
Issued by NWS Amarillo, TX

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FXUS64 KAMA 272315

Area Forecast Discussion
National Weather Service Amarillo TX
615 PM CDT Mon Mar 27 2017

The 00Z TAF period will start with VFR conditions, but as we go
just after 12Z, MVFR conditions are possible as well. Latest
forecast models indicate that precipitation may initiate as early
as 12Z-14Z Tuesday. These showers and thunderstorms will be
scattered in nature. Localized heavy rainfall, and some hail is
possible, which in-conjunction with ceilings below 4 kft at
times, MVFR conditions are possible in the most persistent showers
and storms. As the main system departs, wrap around moisture may
prolong chances of precipitation and low ceilings with periods of
MVFR conditions at all sites, especially at KDHT/KGUY as we work
our way toward the end of the TAF period. Going into Tuesday
afternoon, winds will pick up out of the southeast between 15-20
kts with gusts near 25 kts at times.



.PREV DISCUSSION... /Issued 508 PM CDT Mon Mar 27 2017/


This forecast is as filled with rain chances as it is uncertainty as
models continue their weak agreement and relatively poor
performance.  We`ve got one model showing mid teens dewpts in Deaf
Smith County tomorrow afternoon while others have low to mid 50s at
the same time. This weekend, the GFS pummels us with 2 inches of
rain while the ECMWF and GEM say, "What rain?"  So bear with us as
we try to figure these and other things out like: is the high on
Wednesday going to be 65 (GFS) or 45 (ECMWF) and things like will we
have accumulating snow around Boise City Wednesday night (NAM) or
just rain (all other models).

Tonight through Tuesday night... Rain chances will start to increase
very late tonight but especially Tuesday morning as an upper low
approaches from the west. Tuesday morning will present a threat for
a few elevated organized multicells and possibly some brief
supercell structures for maybe some marginally severe hail in the
eastern half of the area. This threat should exist generally east
of a Guymon to Amarillo line. Parcels originating from around
775mb should have over 2000 J/kg uninhibited MUCAPE to work with
and effective shear values of around 40-50kts so some storm
organization is likely. Think hail will be pretty much the only
severe threat outside of a slight chance for heavy rain with
morning convection. In spite of low freezing and -20C levels,
predominately speed shear above the sfc inversion should keep the
"spin" to a minimum, meaning hail may be big enough to make change
but probably not big enough to tee up at the local golf course.
There could be another conditional threat of severe weather
tomorrow afternoon, but again most of the area looks to be in an
elevated regime with marginal hail the main threat. The 12Z NAM
did have a pretty nice triple point that could light up NW of
Amarillo in the perfect scenario with other threats possible, but
this scenario would require an amount of "just-in- time" moisture
that probably won`t quite make it that far NW.

Wednesday through Sunday... Wednesday`s forecast is brutally
difficult as the ECMWF is really giving us some wrap-around precip
while most other models are more humble.  Have gone with a blend for
now, which puts highs on the low side of guidance as well. We`ll
have to watch to make sure we don`t get accumulating snows in the NW
corner of the CWA Wed night, but for now have held off on mentioning.

Thursday through Friday should be dry with rain chances returning
this weekend. As mentioned earlier, tons of uncertainty exists as
well this weekend with possible upper low tracks as far north as KS
to as far south as Mexico.  Stay tuned as we try to get a better
handle on this weekend.

Sorry we can`t offer a more confident forecast, but at least we have
some rain possibilities to talk about.



.AMA Watches/Warnings/Advisories...



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