Area Forecast Discussion
Issued by NWS Amarillo, TX
FXUS64 KAMA 300509 AAB
Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
1209 AM CDT Thu Mar 30 2017
Will leave the mention of fog out of this forecast for this
morning. Am a little concerned with the light winds and saturated
ground that some fog may be possible, but confidence is not high
enough to mention at this time. West to northwest winds will
gradually back to the southeast by this evening. Speeds should
remain around 10 knots or less. Skies are expected to remain VFR
with only an increase in high clouds.
.PREV DISCUSSION... /Issued 652 PM CDT Wed Mar 29 2017/
For the 00Z TAFs, the upper level storm system responsible for the
inclement weather yesterday and today is moving northeast into
scntrl KS and will continue moving further away from the fcst
area. All precipitation has ended, and expect decreasing clouds
tonight along with diminishing winds. VFR conditions are
anticipated at all terminal sites beginning late tonight into
early Thursday morning and continuing through Thursday afternoon.
PREV DISCUSSION... /Issued 515 PM CDT Wed Mar 29 2017/
Some clearing is on the way to the south as radar reflectivity is
on the decline across the Panhandles. The low centered over
southern Kansas will continue to pull away to the northeast
tonight. The northern TX and OK Panhandle will likely clear out
last as the center of the low will still remain fairly close in
Drier air will be in store for the Panhandles Thursday and into
early Friday. Winds will be out of the south and will draw up
warmer air. NAM model is not as aggressive with the the warmer
air, and in fact, keeps the OK Panhandle quite cool on Friday.
If NAM comes in line with the other models, temperatures will need
to be tweaked up a bit, as some models have 850H temperatures
across the southeast Panhandle at 20C. Current forecast does not
support warm enough temperatures for this scenario.
Friday and Saturday...The next upper level low is progged to
generally move over the four corners region Friday morning. Dry
southerly flow will be associated ahead of this system. The track
of this low will play a significant role in thunderstorm
development and the severity of the storms. Models seem to be
favoring the northern portion of the Panhandles for storms,
mainly north of I-40. Although, there are some limiting factors
for storm development. One model has better instability over the
TX Panhandle, and the other favors the OK Panhandle. Both models
have a lot of favorable ingredients for possible severe weather,
but sufficient instability could be lacking. NAM 0-6km bulk shear
is upwards of nearly 90kts, with 1000-1300 J/kg of CAPE and a good
veering profile. But this may be too much shear and might tear
the storms apart before they can mature. GFS is more focused on
the OK Panhandle Friday and Saturday. The shear again looks to
strong on Friday as the instability is even less than the NAM, but
there is a little less shear on Saturday with CAPE values around
1000 J/kg, which might be just enough to keep the storms from
shearing apart. All in all, it`s going to take more monitoring to
determine where the best chances of showers/thunderstorm and the
severity for this weekend. For now the lowest POPS are to the
south and will increase northward, peaking at the OK Panhandle.
Have just left the thunderstorms in the slight chance to chance
category as we continue to iron out the details of this weekend.
Saturday night into Sunday, models have the low splitting off
into two open wave troughs, one tracking through the Dodge City
area, and another tracking south towards San Angelo. Cooler drier
northerly flow behind is expected. This will quickly transition to
a westerly then southwesterly flow by Monday afternoon and
evening. As a result Mondays highs are expected to be 10 to 15
degrees warmer than Sunday.
Models diverge significantly on Tuesday, although it should be
noted that Tuesday has the next potential for active weather after
the weekend system. The next upper low is progged to impact the
Panhandles as early as Monday night to as late as Tuesday
evening. All three extended models, ECMWF, GFS, and Canadian,
have different solutions with signficantly different outcomes.
From a dry slot wind event, to showers and maybe thunderstorms
over the northern Panhandle areas, to a possible Panhandle severe
weather set up. Stay tuned for updates on the weekend system and
the system mid next week.
18Z Issuance...MVFR conditions will continue until around 00Z
when clouds look to start rising and breaking up. VFR conditions
should persist afterwards through the end of the period. Northwest
winds will be gusty while clouds persist then ease.