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Area forecast discussion...updated 
National Weather Service Amarillo Texas
1237 PM CST Tuesday Mar 3 2015

for the 18z tafs...deteriorating weather is expected at all terminal
sites during this forecast cycle. A strong cold front will move across the
taf sites later this afternoon and evening...with much colder air
invading the region tonight and Wednesday. In addition...a fast
moving upper level storm system will track through the southern High
Plains later tonight and Wednesday...and will bring a mixed bag of
precipitation...starting off as -ra...then transitioning to -fzra or
-rasn...and finally all snow. Ceilings will gradually lower to IFR and
visibilities will drop accordingly as well due to precipitation and br.



Previous discussion... /issued 541 am CST Tuesday Mar 3 2015/

12z taf cycle
VFR conditions to start the taf forecast package this morning with
only some patchy fog which expected to dissipate by 15z today. A cold
front will push across the three taf sites this evening around 23z
today to 03z Wednesday resulting in easterly to northeast winds 10 to
20 knots after the passage of the cold front. Ahead of the front this
morning through this afternoon...southwest to west winds 10 to 20
knots expected. An upper trough will approach the taf sites tonight
and Wednesday which will cause the VFR conditions to become MVFR
around 21z to 23z today...and then become IFR to vlifr after 01z to
03z Wednesday. Light rain by 01z Wednesday will become mixed with
and then change over to snow by 06z Wednesday and continue through
12z Wednesday.


Previous discussion... /issued 430 am CST Tuesday Mar 3 2015/

Short and tonight

Early morning water vapor satellite imagery indicates a deep upper
low near Baja California California with southwest upper flow over the Southern
Plains. Despite breezy southwest winds overnight...areas of fog have
persisted early this morning. Expect the fog to erode later this
morning as drier air moves into the area on southwest low-level flow.
Still expect to see considerable cloudiness today but also expect a
nice warm up for today with highs in the 50s to near 60 degrees in
the southern Texas Panhandle.

This warm up will be an Arctic front plunges
into the area later this afternoon/evening. Model guidance are in good
agreement in developing light wintry precipitation in the wake of
this forcing for ascent increases. Since temperatures will
start out well above freezing...precipitation type will start out as
rain particularly over the southern Texas Panhandle where the front is
not expected to push through until later this evening. However strong
cold air advection will quickly cause precipitation phase to
transition to snow across the Oklahoma Panhandle and the northern
half of the Texas Panhandle. However complicating the forecast is the
possibility for light freezing rain and/or drizzle as model soundings
indicate dry air in the snow growth zone this evening/tonight. Decided
to go with a rain/snow mix over the northern zones. However will have
to continue to keep a close eye on this. The passage of this cold
front will lead to a cold night...with lows in the teens to lower 20s.

Long term...Wednesday through Monday
snow event should be unfolding across the area Wednesday with the
upper low opening up over The Four Corners region. There may be a
small window of freezing rain/drizzle over the southern Texas
Panhandle early Wednesday morning...but the column will quickly
saturate indicating snow will be the main precipitation type during
the remainder of the event. Qg forcing and isentropic ascent has
raised confidence in a period of light snow especially in the
afternoon when the upper lift will be maximized. Of lower confidence
will be snowfall accumulations as this system is fairly progressive
which should limit total snowfall. Went with a general 1 to 2
inches...which fits in a potential Winter Weather Advisory. However
opted to not issue a Winter Weather Advisory with this package as
snowfall accumulations can be lower depending on if and how long
rain/freezing rain/freezing drizzle will precede the snowfall.

Any precipitation will shift off to the southeast Wednesday night
as isentropic downglide develops over the area. Skies will also
quickly clear Thursday morning. Downsloping southwest winds and
mainly clear skies will result in a noticeable warm up Thursday where
high temperatures will climb into the 40s as opposed to the 20s
Wednesday. Even warmer temperatures along with dry conditions are
expected late this week through early next week as an upper ridge
amplifies over the western Continental U.S.. several upper-level disturbances dropping
southeastward in the northwest upper flow can push a couple of weak
cold fronts through the area Friday and Sunday...although these will
have little impact on the sensible weather across the area. Overall
expect high temperatures in the 50s to low 60s through this period.



Ama watches/warnings/advisories...



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