FXUS64 KAMA 250019
Area Forecast Discussion
National Weather Service Amarillo TX
719 PM CDT Thu May 24 2018
.UPDATE...Subsidence behind a shortwave trof now to our east,
height rises noted on mesoanalysis and an upper level ridge
building in are all contributing factors to the lack of
thunderstorms this afternoon. A line of thunderstorms in Kansas
could potentially clip Texas and Beaver counties in the Oklahoma
Panhandle as they propagate towards the southeast, but confidence
is low as this line may run into increasing CINH and subsidence in
that area. Have held with low end slight chance PoPs for now and
will monitor further. Otherwise, minor tweaks were made to the
rest of the forecast grids to adjust location of the dryline and
account for ongoing temperature and wind trends.
.PREV DISCUSSION... /Issued 623 PM CDT Thu May 24 2018/
AVIATION...00Z TAFs...VFR conditions will prevail at all
terminals through the TAF period. An area of high pressure will
develop that will push all precipitation chances out east, with
diurnal winds BTWN 10 to 20 kts (with higher gusts at KAMA)
expected through the period.
PREV DISCUSSION... /Issued 406 PM CDT Thu May 24 2018/
Can't totally rule out an isolated TSTM this aftn/evening in ERN
Panhandles along a moisture axis (SFC-H8 theta-e ridge) east of the
dryline. That said, moisture depth above that layer is lacking and
subsidence in wake of departing S/WV could prohibit convection all
together. CAMs are certainly not excited about prospects. If a storm
pops, there is a marginal risk for SVR storms given potential for 0-
6 km bulk shears around 30-35. Similar story extreme SE TX Panhandle
Mid-upr level ridging will build NE from Mexico into the Panhandles from
this weekend as troughs deepen either side near NV and across the
NRN GOMEX. This will lead to hot temps with at least upper 90s by
Saturday. Previous forecasts and models had some low 100s, but am
wondering if recent rainfall will temper those values just slightly,
esp in areas north of I-40.
Sun and Monday are interesting as the WRN trough approaches and
pushes the ridge a bit east and this leads to similar setup as the
last week with SW flow aloft and S/WVs embedded in the flow.
Models show a nice H7-H5 theta-e ridge pushing NNE from NRN Mexico
up into the region by Sunday and continuing into Monday. That
said, unlike the past few weeks, SFC-H8 moisture may be somewhat
lacking with dewpoints struggling to recover. That said, noted the
NAM is showing higher dewpoints by Sunday than the consensus
which indicates values in the low 40s west to mostly mid 50s east.
Any lack of low level moisture would be attributed to the GOMEX
trough and potential tropical system are disrupting low level
return flow. Think this will all add up to an uptick in POPs again
esp Sun-Mon based on the large scale pattern, but possibly with
less QPF potential (and possibly less coverage) than what we saw
in the past week or so if low level moisture is indeed lacking.
There is perhaps a little more wind shear currently shown for
Sun/Mon than what we saw in recent days, but inverted V soundings
would suggest very high based storms and a more significant
downburst threat with any convection we do get early next week.
This is of course assuming this all transpires as shown by med
range models and there is plenty of time to change the details.
Some lowish POPs linger in the east into mid week before moisture is
shunted further east as the western trough lifts with another one
ready to replace again for beyond the forecast period perhaps. Temps
are progged to remain well above normal with highs remaining in the
mid-upr 90s and possibly some lower 100s. Summer is here.
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