Forecast
Discussion:
Now
that early morning showers and thunderstorms have pushed well east of the area…my
attention is going to be focused out to the west later this afternoon/evening.
The Storm Prediction Center (SPC) has placed south central Texas under the
SLIGHT RISK CATEGORY for severe weather today/tonight with an ENHANCED RISK for
severe weather for north central and north Texas, including Waco and DFW. The
atmosphere was temporarily stabilized after this morning’s activity, however,
as of the latest composite mesoanalysis issued by the Storm Prediction Center
for the southern plains, it shows that instability has now increased once again
across the area…simply, the juice for strong/severe storms has returned,
however, at the same time, there is a large area of convective (thunderstorm)
inhibition across the western Hill Country and west Texas where a strong cap,
or lid, is in place. That lid, simply a layer of warmer air aloft, effectively
works to inhibit storm development because it does not allow for air to
continue to rise high into the atmosphere. Another inhibiting factor to
thunderstorm development this afternoon is the thick cloud cover across the
area along and west of the I-35 corridor. If we can get some breaks in that
cloud cover out west, which I think is possible, those sun breaks will help to
destabilize the surface environment further and would in turn increase our risk
for storms. Surface heating is one of the ways in which the cap can be eroded.
High
Resolution forecast models continue to show a line of strong, potentially
severe storms moving through the area later this evening…now it is just a watch
and waiting game. The main threats form the storms that develop this
afternoon/evening would be large hail and damaging winds, however, an isolated
tornado can never be ruled out.
Current
Visible Satellite Imagery over south central Texas: (This is a black and white
image of what Texas looks like from space right now):
Today’s
Severe Weather Risk Areas:
Major
Weather Geek Stuff Here, but this is the SPC’s latest mesoanalysis…see that
shaded area of blue west of the Hill Country that is where the strongest cap is
in place right now…the red lines represent CAPE values (Convective Available
Potential Energy)…anytime CAPE values exceed 1500 joules per kilogram ALONG WITH the other factors necessary for storm development (moisture and
lift)…severe weather becomes more likely…CAPE values currently running 1500 to
2500 across the area which tells me that storms, if they are able to get going,
they have a good chance of becoming severe. As of the latest forecast model guidance, CAPE values look to continue to go up through the afternoon:
FYI: A thunderstorm is
considered severe if it produces thunderstorm winds of 58 mph or greater,
and/or one inch diameter hail or larger, and/or a tornado is
present…lightning/heavy rain are not considered in the official decision to
issue a severe thunderstorm/tornado warning…because those two things are always
found with thunderstorms.
Plus,
remember a WATCH
means conditions are favorable…be on the lookout…it’s a head’s up
A
WARNING means the
type of severe weather warning issued is occurring or imminent and is likely to
pose a risk to property and life
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