Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX

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FXUS64 KEWX 031128

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
628 AM CDT Fri Jul 3 2020

The MVFR was little more widespread than expected with even AUS
getting into the mix. A mix of low and high clouds on satellite makes
it difficult to see the full extent of the stratocu but it has its
most coverage near the SAT area and along highway 90 out toward
Uvalde and into portions of the Hill Country. Am keeping the MVFR
cigs in SAT/SAT for the next few hours and then scattering out by
late morning. AUS has scattered out now but with some decks still in
the vicinity, elected to use a tempo group in case some more roll in.
DRT is still a wildcard in that satellite shows building ceiling
decks to their east and southeast. I brought in some scattered cu by
mid morning, but majority of model guidance shows the ceilings
should stay away for now. South winds currently...getting some
diurnal backing to SSE and SE by the late afternoon hours. Speeds
should remain below 15kt. With the building ridge...guidance does not
have any ceilings later tonight or Saturday morning so went with
that trend of VFR past late morning today into Saturday. Some high
clouds will still be lingering over the area.


.PREV DISCUSSION... /ISSUED 308 AM CDT Fri Jul 3 2020/

SHORT TERM (Today through Saturday)...
Plenty of mid and high clouds moving in from the north early this
morning as a mid/upper level ridge remains over Texas. This ridging
will dominate the middle part of the U.S. through the short term with
upper trofs holding strong over the Pacific NW and off the mid
Atlantic seaboard. As typical with an upper ridge, we will see an
increase in max temperatures the next few days with 4th of July being
the warmest, with most areas having forecast max temps of at least
100 degrees...the exception being a few areas in the Hill Country.
The large scale subsidence will also bring lower afternoon dewpoints,
making for lower PM humidities. So despite it getting warmer the
next 36 hours, heat indices should remain below heat advisory
criteria. Areas out west should see some dewpoints in the 50s during
the peak afternoon hours...and humidities as low as 20 percent. A
weakness in the upper levels develops near LA by Saturday, but it
will still be too far east to bring any significant impact to our
region in the short term.

Some morning clouds will still be prevalent today and Saturday, but
should burn off by late morning both days.  Today will continue to
see some mid-high clouds across the region, moving south due to the
center of the High pressure being off to our West. Models are
showing less in the way of cloudcover on Saturday...but hopefully a
few high clouds will remain to bring some brief relief from the
expected 100 degree heat.  Southerly surface winds are in the
forecast but speeds will be low due to the ridging. With a 700 mb
ridge centered on the Texas coast right now, expecting to drift west
today and Friday, some dust will still be visible although
concentrations look to be going down from the peak a few days ago.

LONG TERM (Saturday Night through Thursday)...
TX remains on the east periphery of a strong SWrn US upper ridge
through Sunday leaving another day of elevated temperatures at the
expense of humidities and heat indices. We could see some increased
high clouds drifting southwest into the area Sunday evening into
Monday, and this may lead to a couple degree drop in high temps. On
the other hand, the clouds leave a less favorable situation to mix
out low level moisture, and thus the slight bump in the heat index
will make each day feel roughly the same. There is also a slight
chance for convection as the GFS has been the more aggressive model
in dropping mid-level perturbations south into Central TX. The
features are poorly define with most of the past few runs, and with a
more conservative ECM model to consider, the forecast continues to
be a blend with only slight chance PoPs to consider as just some
daytime air-mass convection. The mid-level moisture pool begins to
retreat east Tuesday, and the rest of the week should be convection-
free, save for maybe a coastal shower over Lavaca county Wednesday.
The middle and latter part of next week shows the mid to upper level
ridge axes to be right over the TX coast, so this could lead to
lighter onshore winds and better mix-out days. The blended guidances
may not be picking up on this too well. We may see future forecasts
trend warmer on max temps and slightly lower on afternoon dewpoints
and heat indices.


Austin Camp Mabry              99  75 102  76 101 /   0   0   0  -    0
Austin Bergstrom Intl Airport  97  72 100  74  99 /   0   0   0  -    0
New Braunfels Muni Airport     98  72 101  74  99 /   0   0   0   0   0
Burnet Muni Airport            97  72 100  74  99 /   0   0   0   0   0
Del Rio Intl Airport          100  76 104  77 104 /   0   0   0   0   0
Georgetown Muni Airport        98  74 102  75  98 /   0   0   0  -    0
Hondo Muni Airport             99  73 102  73 100 /   0   0   0   0   0
San Marcos Muni Airport        98  71 102  74  99 /   0   0   0   0   0
La Grange - Fayette Regional   97  74 101  75  98 /   0   0   0   0  10
San Antonio Intl Airport       98  74 101  75 100 /   0   0   0   0   0
Stinson Muni Airport           97  73 101  75 101 /   0   0   0   0   0




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