July 2019: Warming Trend/Slight Chances For Rain

[tireman4]

I remember the Aug 2004 front well. I think our high was 84 and low of 61 with pure sunshine. Multiple nights of 60's.

Happened during my wedding...15 years ago....

[tireman4]

946
FXUS64 KHGX 252019
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
319 PM CDT Thu Jul 25 2019

.DISCUSSION...

- One more night of "cool" conditions and then temperatures will
slowly increase through the weekend into next week.
- Rain chances increase over the weekend as moisture returns from
the Gulf. Mainly scattered showers and a few storms.
- Overall synoptic pattern does not change much over the next 8-10
days.

.SHORT TERM [Tonight Through Friday]...

Another relatively cool night upcoming with inland min temps
generally falling into the 60s. Moisture levels will be returning
on Friday as high pressure moves off to the east and winds become
east-southeast. As Gulf moisture makes its return we will see
cloud cover increase tomorrow, especially near the coast.
Scattered convection will mainly be confined to the offshore
waters tomorrow, however, we could see a few late afternoon
showers as far north as I-10. 33


.LONG TERM [Saturday Through Thursday]...

Really there is not much change in the overall synoptic pattern
for the next 8 to 10 days. There is a ridge that remains centered
over the southern Rockies and 4 Corners. A mean trough remains
over the Midwest through Miss River Valley. There are some subtle
fluctuations in the ridge both in position and strength but really
not much change. The trough does become better defined again
Tuesday into Thursday next week as a stronger trough moves over
the ridge into the main long wave trough. Overall this does not
affect any of the sensible weather for the area.

We do think there will at least be some chance of rain mainly
along the coast Saturday into Sunday. How much is hard to say as
models have not been all that consistent with amounts.
Precipitable water values get above 1.6 inches to maybe 1.9
inches. We will keep with maybe 30 to 40 PoPs during this time.
There will be some lower heights aloft so there will not be much
capping or subsidence to overcome. Moisture does linger around for
the first couple of days next week so the forecast will maintain
a daily chance of rain. No any one day looks better than the
others for rain chances. It really will be a matter of whether you
win the rainfall lottery or not.

Overpeck

&&

.MARINE...
Moderate E/NE winds will gradually veer to the E/SE tonight and
Friday. With the corresponding increase in moisture levels, it looks
like there will be periods of scattered to occasionally numerous
shra/tstms this weekend offshore. Other than the typical hazards
that go along with those, do not see anything of particular
significance. Onshore winds/seas should remain below caution levels
into next week. 33

&&


&&

.PRELIMINARY POINT TEMPS/POPS...

College Station (CLL) 68 93 72 95 74 / 0 0 0 10 10
Houston (IAH) 68 92 74 92 76 / 0 0 10 40 20
Galveston (GLS) 78 86 80 88 80 / 10 20 40 40 40

&&

.HGX WATCHES/WARNINGS/ADVISORIES...

TX...None.
GM...None.

&&

$$

DISCUSSION...Overpeck
SHORT TERM...33
LONG TERM...Overpeck
AVIATION...33
MARINE...33

[aunneste]

Just enough rain here to wet my gardens appetite...
this is really July in Texas............

Why does it regularly rain so much during the summers in the southeast and here in Texas we have a difficult time getting rain?I’ve always wondered that. Can’t really complain too much this summer though. We haven’t even reached the upper 90’s yet here in Wharton County.

But limited summer rain is par for the course in the Brazos Valley. Sea breeze fronts usually fizzle out about Navasota.

And...nothing once again

Oh I know, but it does that over there seemingly every year. Only happens sometimes here.

Notice many times Texas falls into the rainfall "donut hole", the high pressure isn't actually overhead across the state, but just to the west/northwest, over New Mexico. Meanwhile, SE US locales like Florida still get tons of rain even with 594s overhead: the only difference is the rain being confined to the sea-breeze, rather than completely cancelled like in Texas.

Therefore, it isn't actually direct high pressure subsidence limiting summer rain over Texas, but rather, the dry air from Western elevations rotating around the cell. Since the air came from elevation, it's above the surface by the time it reaches Texas, forming a cap that inhibits convection. Same process as during spring, except just replace the Mexican Plateau with the Colorado Plateau/Southern Rockies, and low pressures with stationary high pressure.

The dry Texas/wet SE summer gradient is maintained/reinforced by East Coast US troughing. Not only by anchoring and positioning the high pressure cell in that New Mexico position, but also by "stealing" lots of tropical moisture that would've headed to Texas and overpowered the heights, instead sending it SW-NE through Florida and the East Coast. Exactly what has been happening with a lot of summers since 2009.

[aunneste]

North America also lacks a true monsoonal cycle/seasonal wind belt shift as seen with other continents like Asia, Africa, and Australia. As a result, the continent remains very much at the mercy of the westerly jet stream, and emanating extremes in weather from its meridonals: Texas summer drought, California winter drought, Central US spring floods, SE US summer floods, etc.

With a more consistent monsoon pattern like in other continents, Texas would have no issues getting summer rain. More consistent easterly disturbances at least. Or even equatorial southwesterlies if the shift is strong enough. At the same time, winters would be milder, more stable, without low pressure disturbances that drag down deep cold air from Canada.

[MontgomeryCoWx]

North America also lacks a true monsoonal cycle/seasonal wind belt shift as seen with other continents like Asia, Africa, and Australia. As a result, the continent remains very much at the mercy of the westerly jet stream, and emanating extremes in weather from its meridonals: Texas summer drought, California winter drought, Central US spring floods, SE US summer floods, etc.

With a more consistent monsoon pattern like in other continents, Texas would have no issues getting summer rain. More consistent easterly disturbances at least. Or even equatorial southwesterlies if the shift is strong enough. At the same time, winters would be milder, more stable, without low pressure disturbances that drag down deep cold air from Canada.

Yeah, no thanks.

[Ptarmigan]

I remember the August 2004 front that was really nice...

The 2004 Summer Olympics started in Athens. Hurricane Charles made landfall on Punta Gorda. I went starwatching with my telescope and saw many nebulas.

[aunneste]

Yeah, no thanks.

Why not? Texas gets more equable in that scenario. No worries about extreme weather with a monsoon.

[Texaspirate11]

Thank you aunneste!

[Cpv17]

Thank you aunneste!

Ditto. Good stuff.

[MontgomeryCoWx]

Yeah, no thanks.

Why not? Texas gets more equable in that scenario. No worries about extreme weather with a monsoon.

Loved the explanation. I’d rather take my chances at seeing cold weather. I hate Summer, but I’d really hate not having a Winter

[LightningBolt]

North America also lacks a true monsoonal cycle/seasonal wind belt shift as seen with other continents like Asia, Africa, and Australia. As a result, the continent remains very much at the mercy of the westerly jet stream, and emanating extremes in weather from its meridonals: Texas summer drought, California winter drought, Central US spring floods, SE US summer floods, etc.

With a more consistent monsoon pattern like in other continents, Texas would have no issues getting summer rain. More consistent easterly disturbances at least. Or even equatorial southwesterlies if the shift is strong enough. At the same time, winters would be milder, more stable, without low pressure disturbances that drag down deep cold air from Canada.

Thanks for your analysis!

[tireman4]

000
FXUS64 KHGX 261130
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
630 AM CDT Fri Jul 26 2019

.AVIATION...
Weak moisture coupled with weak isentropic upglide will create
SCT/BKN deck this morning that will scatter out this afternoon.
VFR ceilings will be possible this morning. Clouds are expected to
thin this evening before another surge of moisture approaches
after 09z. A SCT/BKN deck will be possible near the coast between
09-12z and even a few showers could affect GLS by 12z.

&&

.PREV DISCUSSION... /ISSUED 412 AM CDT Fri Jul 26 2019/

SHORT TERM [Through Sunday]...
With about another 2-3 hours of cooling left, it appears that IAH
might reach a record low temperature this morning (68/1972).

Surface high pressure situated from the Eastern Seaboard into
Texas that has been maintaining our stretch of nice comfortable
July wx will be losing its grip across the area this weekend. Remnant
frontal boundary/trof offshore will be drifting northward back to
the coast and inland. Not expecting much, if any, inland precip
today as deeper moisture remains well off the coast. But as we head
into Saturday PW`s will climb back to around 1.3-1.5" and Sunday
1.8-2.0" so corresponding shra/tstm chances and coverage (mainly
diurnal in nature) will follow that upward trend.

LONG TERM [Sunday Night Through Friday]...
We should generally remain on the eastern periphery of a strong
mid/upper ridge centered over the sw states into early next week.
Though there will be some subsidence to overcome, isolated to
maybe scattered precip remains a possibility each day dependent on
moisture fluctuations. Guidance hints at a disturbance riding
down in the northerly flow aloft Tue/Tue night which will be
something to keep an eye on in regards precip chances. Otherwise,
the ridge makes a slow ene track into NM & western TX/OK as we
head into late next week. Heights don`t look to change all that
much locally...so it`ll probably just be a fcst of persistence as
we head into the month August. 47

MARINE...
A light to moderate northeast flow will become east this afternoon
and SE on Saturday as high pressure over the Ozark plateau moves to
the east. A light to moderate S-SE flow will then continue into
early next week with high pressure over the central Gulf of Mexico
and a weak trough of low pressure in the lee of the Rockies.
Scattered showers and thunderstorms will be possible this weekend as
a weak disturbance moves into the area. Water levels are expected to
remain below critical thresholds and a rip current statement will
not be needed today. 43

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 93 72 94 74 94 / 0 0 10 0 20
Houston (IAH) 92 73 92 75 92 / 0 10 30 10 40
Galveston (GLS) 91 80 90 80 89 / 10 30 40 30 40

&&

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

$$

Discussion...47
Aviation/Marine...43

[tireman4]

Houston Forecast...

[tireman4]

00
FXUS64 KHGX 261731
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1231 PM CDT Fri Jul 26 2019

.AVIATION...

Mainly VFR cigs and visibilities continue through the duration of
the TAF period. Winds will remain out of the E/SE around 5-10 kts
through this evening before shifting more to the SE by tomorrow
morning. With increased moisture advection and the redevelopment
of a more typical summertime flow pattern, high-resolution
model guidence suggests that scattered SHRA/TSRA should form over
the coastal waters tomorrow morning around GLS, progressing
inland towards IAH and HOU by approximately 15Z.

Cady

[Cromagnum]

Some popup showers starting to appear. Maybe we get lucky

[DoctorMu]

Reality hits after 4 gorgeous days in TX in July. Unprecedented really.

The American monsoon doesn't have the source of moisture, temperature gradient, or lift (Tibetan plateau) that the Asian monsoon. Indian Ocean >> Gulf of California

That upper level ridge often extends to Texas and can park over interior regions. The Bermuda High pulls more Gulf moisture into Louisiana, MS, AL, GA than for us. The BH generates easterlies over Florida, where there's an afternoon shower a few days a week.

GoM - can't live with it, can't live without it. Without the Gulf, east Texas would be semi-arid to desert like much of the land at our latitude, not subject to the Asian monsoon.

[mckinne63]

Humidity back for sure. Can't get out of the car or walk out of the store without my glasses fogging up. The 4 days of gorgeous temps are but a memory. But, we have had worse July's. Thankful for air conditioning.

[Cromagnum]

Storming just to my north but not moving this way

[aunneste]

Loved the explanation. I’d rather take my chances at seeing cold weather. I hate Summer, but I’d really hate not having a Winter

Ah, that's fair enough.

[aunneste]

The American monsoon doesn't have the source of moisture, temperature gradient, or lift (Tibetan plateau) that the Asian monsoon. Indian Ocean >> Gulf of California

It's more a matter of lack of land at lower latitudes. Even Australia, a mostly low-elevation continent, still gets stronger monsoonal action than the Americas. The ITCZ just doesn't go poleward in the Americas as it does in the Eastern Hemisphere, the low latitude area is mostly water with slim strips of land.

That upper level ridge often extends to Texas and can park over interior regions. The Bermuda High pulls more Gulf moisture into Louisiana, MS, AL, GA than for us. The BH generates easterlies over Florida, where there's an afternoon shower a few days a week.

Due to the tendency for Eastern US troughing (which has increased since 2009, hence the US hurricane drought before Harvey), the height-fields are often pinched off into cells, the western of which is often in position to dry Texas out, through elevated dry air from the Rockies. It's not from subsidence, since the areas of Texas in the donut hole during dry spells often aren't where the strongest heights are.

There's obviously similar low-level moisture content in East Texas compared to the Southeast, given the similar high dewpoints/humidity. Texas can get continuous rain so long the high is more continuous longitudinally. The same wind shifts of the North American monsoon also bring rain to Gulf Coastal Mexico, moisture from which delivers heavy rains to Texas. So a stronger monsoon would actually benefit (southern) Texas with summer rainfall, while bringing more continuous rain to the SW desert lowlands/Gulf of California coast.

GoM - can't live with it, can't live without it. Without the Gulf, east Texas would be semi-arid to desert like much of the land at our latitude, not subject to the Asian monsoon.

There could actually be an even further shift of the ITZC northward without the Gulf, since there'd be much landmass at lower latitude. So even if East Texas becomes desert/semi-arid, it may at least come with stronger summer seasonality of rain. See: current parts of Desert SW, Sahel in Africa, Thar Desert of India, etc.