August 2020:

General Weather Discussions and Analysis
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tireman4
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000
FXUS64 KHGX 071708
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1208 PM CDT Fri Aug 7 2020

.AVIATION...
PW values are a bit lower than yesterday and convective temps are
a bit higher so showers will probably struggle to develop this
afternoon. Will not mention VCSH/VCTS today. Generally VFR
conditions are expected today and tonight although there could
once again be some patchy morning fog at the usual spots around
sunrise. Models diverge with rain chances on Saturday with the
CAMs looking more aggressive with rain chances. Will keep things
dry for now but a VCSH may be needed for Saturday afternoon if
models come into better agreement. 43

&&

.PREV DISCUSSION... /ISSUED 414 AM CDT Fri Aug 7 2020/

SHORT TERM [Today Through Saturday]...

While surface moisture today will be in place, the mid to upper
levels will be a little too dry for good chances of convection.
PWI`s will be roughly 1.75 in the area at the time of max heating,
and the temperatures are forecasted to be in the low to upper 90s.
This passes the low 90s convective temperatures across the area.
With that said, a few stray thunderstorms are possible in the area,
but not to the point of being able to say exactly where. Right now,
it looks like subsidence from the high will keep any build up from
happening. Lows will get down to the mid 70s across the are
overnight with mostly clear skies.

Tomorrow moisture returns to the mid to upper levels elevating
chances of precipitation. However, vicinity of the high will still
help keep chances somewhat low. Showers building over the coastal
waters could advect inland as the evening sea breeze kicks in and
further develops into thunderstorms, but coverage will be spotty.
PWIs will be higher, along with higher instability; the possibility
of a thunderstorm is possible. 35

LONG TERM [Saturday Night through Friday]...

Mid/upper level ridging across the state at the start of the
long term period will edge westward and will be centered in/
around the Arizona/New Mexico border for much of next week.
Our area will generally be positioned between this ridge off
to our west and ridging that will be off the SE U.S. coast.
A persistent onshore flow and our positioning between the two
ridges should allow for almost daily mainly diurnally driven
shower and/or thunderstorm chances.

Little change in temperatures can be expected, with lows in
the mid to upper 70s inland and in the lower 80s near the
coast, and highs in the mid to upper 90s inland and in the
lower 90s near the coast. We will need to keep an eye on
our max heat index values with current forecasts showing
some elevated readings Sunday through Wednesday. Even if
there is no heat advisory, always protect yourself and your
loved ones, including pets, if you plan to spend time
outdoors or in areas with poor ventilation. Always practice
heat safety! 42

MARINE...

No real changes from the previous marine discussion. Light winds and
low wave heights through the weekend. Early next week, stronger
onshore flow returns. So the typical summer pattern of stronger
winds at night and lighter winds during the day will be the pattern
in the coastal waters. Bay areas will see stronger day time winds
and lighter winds at night. 35

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 97 76 97 75 99 / 10 10 0 0 10
Houston (IAH) 96 76 94 77 95 / 10 10 20 0 20
Galveston (GLS) 92 83 90 82 93 / 10 10 20 0 20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$
Cpv17
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Enjoy this calm period for the next week or so. Things could get quite interesting later this month.
Cromagnum
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How's it looking for saturday?
davidiowx
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Cromagnum wrote: Fri Aug 07, 2020 9:19 pm How's it looking for saturday?
Mostly sunny with a high of boiling!
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tireman4
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000
FXUS64 KHGX 081527
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1027 AM CDT Sat Aug 8 2020

.UPDATE...

Have bumped up PoPs slightly as satellite derived PW imagery shows
an increase in moisture over the southern half of the CWA. Radar
is also showing an increase in coverage this morning. 12z morning
soundings show MaxT values a few degrees cooler than yesterday and
this seems plausible as increased cloud cover and precip should
keep values a shade cooler than yesterday. 43

&&

.PREV DISCUSSION... /ISSUED 429 AM CDT Sat Aug 8 2020/

SHORT TERM [Today Through Sunday Night]...

Some coastal showers near the Galveston Bay area will dissipate
early, along with some mist in the northern and western counties.
The rest of the day will be partly cloudy skies and a chance of
afternoon showers and a thunderstorm is possible along the I-10
corridor. Over night will be similar to last night with some mist in
the same areas leading to another partly cloudy day with some
slightly higher chances of thunderstorms and showers. Heat will be
the main impact this weekend. Today`s heat indices will be in the
low to mid 100s and tomorrow is looking high enough for a Heat
Advisory with indicies up to 110. 35

LONG TERM [Monday through Saturday]...

As we head into the end of the weekend, the prevailing upper ridge
that has dominated the synoptic pattern of late will push slightly
westward, with a robust surface high remaining in place over the
central Gulf of Mexico as we head into the beginning of next week.
With lower surface pressures over W Texas allowing for a continued
onshore flow, the coming week will continue to be characterized by
seasonably warm temperatures and the diurnal formation and northward
propagation of showers and thunderstorms. Onshore moisture transport
looks to slowly increase through mid-week, with most recent global
model runs showing a rise of surface PW values into the 1.75 to 2.0
in range by Wednesday afternoon. As a result, have continued to
maintain the increasing trend of PoPs as the week progresses, with
values in the 15-25% range on Monday ramping up to near 40% by
Wednesday. Low-level moisture transport will become even more
favorable by the weekend as a tightening of the surface pressure
gradient will create a stronger southeasterly fetch.

Expect the hot and humid conditions that have persisted across the
region for the past several days to continue in the long term.
Daytime highs should remain fairly steady in the mid 90s across the
Greater Houston Area, while locations further north are likely to
flirt with the triple digits. As the aforementioned onshore flow
pattern will keep surface dewpoints elevated, we`ll continue to see
maximum heat index values in the upper 100s and perhaps the low 110s
in some places through the duration of the week. As a result, may
need to consider the issuance of Heat Advisories as the week goes
on. For those planning to head outdoors, it will continue to be
important to practice heat safety. This includes remaining hydrated,
applying sunscreen, and avoiding strenuous activities during the
daytime hours.

Cady


MARINE...

Light onshore flow through the weekend and low seas. As the high
shifts to the northeastern Gulf, stronger winds over night will
prevail over the Gulf waters and lighter winds during the day and
stronger daytime winds over the bays and lighter winds at night.
Seas will be around 2 ft with some periods of 3 ft in the outer
coastal waters. 35

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 97 76 97 76 98 / 10 10 10 0 10
Houston (IAH) 95 78 94 77 95 / 20 10 40 0 20
Galveston (GLS) 92 83 93 83 91 / 20 20 30 10 20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

Discussion...43
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DoctorMu
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It's a good thing the Death Ridge doesn't exist...
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tireman4
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000
FXUS64 KHGX 091521
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1021 AM CDT Sun Aug 9 2020

.UPDATE...

CAMs remain aggressive with rain chances today and this seems
reasonable as PW values climb to almost 2.25 inches and SE TX
will lie on the east side of a weak inverted trough axis.
Convective temperatures range from about 88 degrees near the coast
to around 93 degrees well inland. Tweaked sky grids and lowered
MaxT a degree or so based on expected cloud cover and precip. 43

&&

.PREV DISCUSSION... /ISSUED 454 AM CDT Sun Aug 9 2020/

SHORT TERM [Today Through Tomorrow Night]...

Some coastal showers near the Galveston Bay area will slowly build
up and move inland through the morning. The rest of the day will be
partly cloudy skies and showers building and thunderstorms building
as afternoon heating reaches convective temperatures. Most storms
will be along the I-10 corridor as showers that move inland build.
This mixed with some sea breeze in the area will help build and
enhance these storms. After sunset, storms will dissipate or move out
of the area. Ambient temperatures are expected to reach the low 90s
along the coast and almost 100 further inland with heat indices in
the mid to upper 100s.

35

LONG TERM [Tuesday through Sunday]...

If you`ve enjoyed the warm and humid conditions with isolated
thunderstorms over the past few days...you`re in luck. As persistent
upper ridging remains the dominant synoptic feature across SE Texas,
seasonably warm conditions with diurnally driven precipitation will
remain the story through the upcoming work week. The presence of
surface high pressure over the central Gulf of Mexico will continue
to support a light but persistent onshore flow pattern through the
extended forecast period, with surface PW values rebounding to near
2.0 in by Wednesday as deepening pressure over western TX will
create a relatively stronger surface pressure gradient. While
forecast soundings show favorable instability for convective
development through mid-week, precipitation chances will be
moderated by upper-level subsidence associated with the
aforementioned ridge. Nonetheless, there are likely to be some
scattered to isolated thunderstorms driven by diurnal effects each
morning and afternoon as the sea breeze boundary propagates inland.
As a result, have continued to maintain 15-30% PoPs along the coast
and south of the I-10 corridor through the extended forecast period.

Heat remains a concern in the coming work week. Daily high
temperatures across the Houston metro remain on track to reach the
mid to upper 90s through the end of the week, with some areas north
of I-10 expected to rise above 100. As the persistent onshore flow
continues to keep dew points fairly high, elevated heat indicies
will be something to watch for closely in the coming days. Daily
maximum heat index values should reach 105-110 in most locations,
which raises the possibility of heat advisories. Practicing heat
safety will be especially important during this time, particularly
if you work outside or are planning any other outdoor activities.
Low temperatures should consistently remain in the upper 70s to low
80s...which could threaten to break some additional daily high
minimum temperature records in the coming days.

Cady

MARINE...

Light onshore flow will persist through the forecast period with
seas remaining at 1-2ft with some peak times of 3ft. Some higher
onshore flow can be expected early in the night. Some isolated
showers and thunderstorms can be seen in the early morning and
evening hours.

35

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 97 76 98 76 99 / 20 10 10 0 10
Houston (IAH) 94 77 95 78 95 / 50 30 20 0 20
Galveston (GLS) 92 83 90 83 91 / 40 10 10 10 20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$
TexasBreeze
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I have seen HGX mention the CAMs models more lately. What are those models short range I presume?
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DoctorMu
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Today's sea breeze might be our best chance at an isolated shower for at least a week...although I'm seeing a wall just north of Brenham where the ridge is lurking.

Not seeing much of a chance of rain on GFS, Euro, Canadian, Ensembles until at least the 18/19th up in the Brazos Valley.

Welcome to August!
Cpv17
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The tropics look to be pretty quiet for now. The EPAC is stealing the show.
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