tropiKal wrote: βFri Jul 03, 2020 7:48 pm
Rip76 wrote: βFri Jul 03, 2020 4:23 pm
I bet that area of weather coming from the east dies out before it gets to Houston.
It defies logic how dry Texas is during summer relative to both the humidity seen across the state during summer, as well as how much rain places JUST to the east receive.
Thanks to the high pressure ridge at the mid to upper levels. The dreaded Death Ridge.
After today, we'll see a respite for a few days...but it won't last.
PREV DISCUSSION... /ISSUED 422 AM CDT Sat Jul 4 2020/
DISCUSSION...
Friday gave us our first signs of transitioning to a more active
weather pattern as a handful of thunderstorms scraped across the
far eastern parts of the area. We may see some isolated to
scattered activity again today, though heat will again be the
driving weather story this afternoon. Expect another day of above
normal temperatures and a heat index maxing out in triple digits.
Some of the hottest spots may even threaten the heat advisory
threshold.
Fortunately, we`ll begin to slowly back down from that heat
to...well...more seasonable heat levels, which is still rather
hot and could still be dangerous for those who spend long
stretches outdoors. You know it`s summertime in Southeast Texas
when the break from the heat means a peak heat index that might
not make it to 100 degrees rather than definitely making it to 100
degrees. The price of this "respite" is more shower and
thunderstorm activity, which we should see ramp up early next
week, and persist through at least mid-week.
By that time, we`ll
see a ridge return and whittle down rain chances and slowly allow
temperatures to drift upwards again.
SHORT TERM [Through Sunday]...
As we mark our nation`s 244th birthday, we enter into what is
shaping up be one of the hottest days of the year thus far across SE
Texas, with the seasonably warm and humid conditions of late
continuing as upper ridging continues to maintain itself over the
central CONUS. There will be
no shortage of low-level moisture to
keep heat indicies high once again this afternoon, as south to
southwest flow continues to transport moist Gulf air to the region.
With global models in good agreement showing an uptick in surface PW
values to near 2.0 in by this afternoon in areas east of I-45,
apparent temperatures will approach (but likely not reach) the
advisory threshold of 108. Given the expected conditions, it will be
imperative to take proper heat safety precautions if you have any
outdoor plans today. Remember to stay hydrated by drinking plenty of
water, apply sunscreen regularly, and avoid strenuous activity during
the daytime hours.
With the aforementioned moisture in place and late afternoon
convective temperatures of around 95-97 well within reach, another
round of thunderstorms is poised to develop around the Arklatex
region before sunset and push southward. While the bulk of activity
looks to remain to our east again, recent runs of the HRRR, TTU-WRF,
and WRF-ARW have indicated the potential for storm development
further into the northeastern zones compared to yesterday. While the
extent and magnitude of any storm development further south is
likely to hinge on the interaction of any developing convection with
mesoscale boundaries,
have maintained 30-50% PoPs across the metro
and east of I-45 given the favorable environmental conditions.
Yet another hot and humid day is in store across the area on Sunday
to close out the holiday weekend, with afternoon highs expected to
once again break into the upper 90s and heat indices reaching the
mid 100s. While a slight "cooling" trend looks likely heading into
the work week (see Long Term section below), onshore winds and
thereby the 70s dew points won`t be going away anytime soon and
proper heat safety precautions should still be taken.
LONG TERM [Sunday Night Through Saturday]...
By Sunday night, the western ridge aloft is expected to retreat
back towards the Pacific Coast, and we`ll come more under the
influence of the
retrograding upper trough. This will allow the
shower and thunderstorm development that has been happening to our
east to slowly expand across our area through the early part of
next week, particularly as precipitable water values are progged
to rise to around or above two inches for Monday and Tuesday. This
is likely why, even though the upper trough will begin pulling
away to the east on Tuesday, that rain chances are still fairly
high as late as Tuesday afternoon. Indeed, the consensus of model
guidance is the highest of the week on Tuesday. I`ve undercut that
consensus some, given the worsening environment aloft, but it`s
not *that* much worse, so I didn`t shave too much off.
Ridging aloft is back in charge as that trough moves off and
fills, so our good friend subsidence will be back to gradually
choke off rain chances and help temperatures drift back upwards
towards the mid 90s for the latter part of next week. Along with
this, our surface pattern continues to be dominated by high
pressure over the Gulf, keeping generally southerly flow in place,
pumping in moist Gulf air. The moisture on the one hand will
likely keep the daytime heating from getting too out of
control...but it will also keep overnight temps high, and make for
a pretty high daytime heat index. Triple digit peaks in the
afternoon will probably become the norm again late in the week. I
can`t say that I`m seeing much of a signal in the guidance for a
heat index that will exceed the advisory threshold, but it`s also
probably too early to take it off the table, either.
AVIATION [06Z TAF Issuance]...
VFR conditions overnight with light winds through tomorrow morning.
Indications for convection tomorrow afternoon starting at UTS/CXO
around 22z and potentially lasting around 03z. IAH is expecting to
have convection in the area starting at 23z until around 04z. At
this time, the exact timing of the thunderstorms is still uncertain.
Conditions are favorable for the support of thunderstorm activity
but is dependent on the initial development and if the storms
organize in the evening.
MARINE...
Calm conditions continue across the coastal waters with lighter
onshore winds and seas of around 2 feet expected through the
beginning of next week. Scattered showers and thunderstorms that
push southward late this afternoon and into the evening could reach
the coastal waters, and some gusty winds may occur once again as a
result. An increase in onshore winds by the middle of the week will
being seas back into the 3 to 5 foot range and potentially require
caution flags.
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 99 75 98 76 95 / 10 20 10 20 20
Houston (IAH) 97 78 96 78 93 / 10 30 20 20 40
Galveston (GLS) 93 81 92 82 89 / 10 20 20 10 30
&&