JUNE 2018: Drying Trend & Summer Heat Returns

[jasons2k]

It poured on the way home going through Oak Ridge and coming into the neighborhood. That little cell just dumped. Unfortunately, by the time I got home, it was bone dry. Missed it by half a mile. Just a few streets away the water is ponding...

[jasons2k]

The latest HPC 7-day rainfall map has cut my total in about half too.

[don]

18z GFS is back in line with the Euro showing most of the precipitation in Texas, instead of Louisiana it has some areas in the coastal counties getting 8+ inches fwiw. It's pretty normal for the models to fluctuate from run to run on rain amounts this far out.

https://www.tropicaltidbits.com/analysi ... cus_29.png

[jasons2k]

That's one heckuva rainfall gradient.

[TexasBreeze]

Coastal convergence could become a factor where storms focus on the coast early in the morning robbing inflow for inland storms resulting in them being more scattered inland with heating.

[MontgomeryCoWx]

At this point, I'll take what I can get rain wise.

[unome]

down to 0% for 2 day, but still 20% thru 5

https://www.nhc.noaa.gov/text/refresh/M ... WOAT.shtml

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Tue Jun 12 2018

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Disorganized showers and thunderstorms located over the western
Caribbean Sea are associated with a surface trough. This activity
is forecast to move westward to northwestward over Central America
and the Yucatan Peninsula during the next couple of days, with no
development expected. Environmental conditions could become
slightly more conducive for some development if the system moves
into the southwestern Gulf of Mexico by the end of the week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Avila

[DoctorMu]

Area Forecast Discussion
National Weather Service Houston/Galveston TX
644 PM CDT Tue Jun 12 2018

.AVIATION [00Z TAF Issuance]...

Surface analysis this evening shows an outflow boundary across
north Texas, cold front in the Texas panhandle stretching NW into
central Kansas. Southerly winds remain over the area with the
general synoptic pressure gradient in support. Water vapor imagery
shows upper level low over the NW Gulf with generally northerly
flow aloft. A few isolated showers/storms developed late this
afternoon but are dissipating mainly between KCLL and KUTS.

Going forward we expect mainly VFR/MVFR ceilings with MVFR
ceilings expected for KCLL/KUTS/KCXO in the morning. There will
likely be some scattered stratocumulus farther south over the
Houston terminals and coast. Mesoscale models hint at a few
showers and maybe an isolated storm like today for tomorrow
afternoon. TAFs include VCSH for now but something to monitor
going forwards. Upper low should drop farther south into the Gulf
which may bring back SE flow aloft and maybe an increase in large
scale ascent. Model soundings show weaker capping (not that there
was much capping today) with precipitable water values around 1.7
inches. Environment at least support some convective activity with
diabatic heating.

Overpeck

&&

.PREV DISCUSSION /Issued 407 PM CDT Tue Jun 12 2018/...

.DISCUSSION...
A few showers and a stray thunderstorm have managed to develop
this afternoon generally along and north of a Snook to Houston to
Winnie line as temperatures have risen into the low to mid 90s.
Expect this activity to quickly peter out towards sunset as
insolation decreases. Remnants of a decaying thunderstorm complex
over Oklahoma this morning have made it into northeast Texas, but
decreasing surface pressure rises as the associated cold pool
modifies indicate that it will be difficult for the complex to
make it into the region. Keeping low 10-15 PoPs in for the evening
across the Piney Woods and Brazos Valley to account for any
glancing blows, but expect most of the region to be dry overnight
with lows in the 70s to lower 80s.

Speed convergence along the coast may result in a few showers near
the coast by sunrise Wednesday with this activity expected to
spread into the coastal counties and possibly as far north as the
Interstate 10 corridor with the sea breeze during the day.
Otherwise, expect the heat to continue with highs in the upper
80s along the coast to mid 90s inland. Similar conditions are
expected on Thursday with lows in the 70s to low 80s rising into
the upper 80s to mid 90s in the afternoon. Isolated to possibly
scattered showers will also be possible along the sea breeze on
Thursday for the coastal counties.

A tropical wave located near the coast of Nicaragua this afternoon is
expected to continue translating eastward towards the Yucatan
Peninsula and eventually into the Bay of Campeche by the end of
the work week. Tropical cyclone development still remains somewhat
uncertain with this system, especially as it crosses into the Bay
of Campeche. Upper level shear in the southern half of the bay
may be too strong during the weekend to really support additional
strengthening of the tropical wave (which is supported by
solutions from the GFS and European as well as the GFS ensembles).
However, a more northern trajectory could take the wave into a
more favorable environment for development with weaker shear...
but this trajectory is all largely contingent on the placement and
strength of an upper ridge over the northern Gulf. Given the
general consensus for a more southerly/open wave type track have
leaned towards that with the forecast for the weekend. This may
mean that rain chances may need to be lowered a bit for Friday in
subsequent forecasts as if the southerly trajectory trend
continues as it would result in tropical moisture arriving slower.

Deep tropical moisture (precipitable water values over 2 inches)
surge into the area by Saturday which will herald the development
of numerous showers and thunderstorms. The weekend will also need
to be monitored as these buoyant tropical airmasses are notorious
for producing tropical funnel clouds. The presence of this deeper
tropical moisture will also mean that at least brief heavy
downpours will be possible. 12Z guidance today shifted the axis of
what appears to be the highest rain totals closer towards the
Sabine Pass (and away from Galveston Bay), but surface streamlines
show surface confluence closer to Galveston Bay Sunday and
Monday. This may indicate that we see this QPF axis waffle back
and forth over the next few days as guidance gets a better handle
on where the best low level focus may set up. Have decided to not
make too many dramatic changes to the ongoing QPF. While brief
heavy rain remains possible, antecedent conditions across the
region are very dry. The latest Drought Monitor shows areas of
abnormally dry to moderate drought conditions along the coast
(which may be the most likely area to see rain this weekend). As a
result, rain rates will be the primary driver in any flooding
concerns which are difficult to determine almost 5 days out.
Cannot rule out a flooding potential, but cannot speak to its
certainty just yet. Otherwise, expect increasing cloud cover and
rain potential will help moderate high temperatures a few degrees
down into the 80s by the end of the weekend and into the beginning
of next week.

Huffman

[unome]

our panhandle peeps are getting some rain relief

[Katdaddy]

A few showers along the coast and offshore this morning. Another hot and humid day across SE TX with only a slight chance of scattered showers or an isolated thunderstorm. Invest 91L remains disorganized but still likely to bring tropical moisture with increasing in rain chances this weekend and early next week.

[srainhoutx]

91L appears to have lost its deep convection overnight. Looks like a rain maker, not a wind threat to Texas and Louisiana as of this morning.

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Wed Jun 13 2018

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Disorganized showers and thunderstorms over the western Caribbean
Sea are associated with a weak surface trough. This activity is
forecast to move westward to northwestward over Central America and
the Yucatan Peninsula during the next couple of days with no
significant development. Environmental conditions could become
slightly more conducive for some development if the system moves
into the southwestern Gulf of Mexico by the end of the week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Stewart

[srainhoutx]

Wednesday morning briefing from Jeff:

Rain chances will be increasing as moisture begins to arrive into the area from the Gulf of Mexico

Heavy rainfall will be possible Saturday-Monday

Tropical feature (91L) continues to fester in the SW Caribbean Sea with little change in organization in the last 24 hours. Surface analysis continues to show this feature as an open trough of low pressure with no defined low level circulation. Given the proximity of this feature to the land areas of central America no development is expected through the next 48 hours. Eventually this feature will move into the Bay of Campeche and southern Gulf of Mexico Friday into Saturday. Strong wind shear of 40-50kts is currently in place across the western and southwestern Gulf of Mexico and while this shear will likely weaken some as tropical storm Bud in the eastern Pacific weakens, there is forecast to remain a good bit of shear across the western Gulf into the weekend. This should prevent any sort of defined organization to the tropical wave axis and the NHC currently gives the potential for development at a low 20% through the next 5 days.

As mentioned…regardless of development…a large plume of deep tropical moisture with PWS values of 2.0-2.5 inches will be crossing the Gulf of Mexico Friday and arriving along the TX coast Saturday-Monday. This air mass will have origins in the extreme SW Caribbean Sea and also a tap of mid and high level moisture from the remains of Bud in the eastern Pacific. Expect the air mass over SE TX to saturate Saturday with numerous showers and thunderstorms spreading inland in waves from the Gulf of Mexico. There is some decent agreement in the model guidance that the “stream” of moisture will continue to be aimed at the NW Gulf coast roughly between Matagorda Bay and SW LA into Monday with bands of rainfall developing and spreading across that region. Overall the pattern looks wet starting Saturday and continuing well into next week.

Rainfall Amounts:
Global model guidance is in general agreement favoring the areas between Matagorda Bay and SW LA for the highest rainfall totals over the next 7 days, but exactly where any sort of training bands develop in the that region remains a question. The time period from Sunday into Monday may feature the greatest chance for widespread rainfall over the area, but the confidence is still not high. Widespread rainfall amounts of 2-4 inches appear possible over the region with higher isolated amounts. Those higher isolated amounts will be a result of any sustained training bands that might anchor in the very tropical air mass. This is the type of air mass that will result in intense short duration rainfall totals of 2-3 inches in an hour. One other potential to watch for in the coming days will be the idea for morning storms near the coast or just offshore to “rob” the inland flow of moisture and focus the heaviest rainfall near the coast or just offshore. These sort of very tropical air masses tend to like to focus development in the early morning hours (2-7am) near the coast. This type of pattern could result in the maximum totals close to the coast or offshore

Rainfall totals will need adjusting over the next 24-72 hours as confidence increases where the greatest moisture axis will establish and where the potential for training rainfall will be greatest.

Hydro:
Grounds across much of SE TX are dry to very dry with the lack of recent rainfall. Moderate to severe drought conditions are in place especially across the SW half of the region. Initial rainfall will likely be quickly absorbed by the dry grounds and run-off will be limited, but grounds will gradually saturate and run-off increase as the event prolongs over multiple days. Flash Flood guidance for Harris County is running about 4 inches in 1 hour up to 5.5 inches in 6 hours before significant amounts of run-off would occur. Over the region the 6-hr flash flood guidance ranges between 5.0-6.4 inches. Overall the grounds will be able to handle much of the expected rainfall as long as it does not all fall in a short period of time.

Marine:
Tropical wave axis will move into the coastal waters starting Friday evening with increasing numerous showers and thunderstorms and squalls over the weekend. Winds will increase out of the ESE/SE starting late Friday into the 20-25kt range by Sunday. Seas will build through the day on Saturday into the 5-7 foot range and 7-9 feet on Sunday. Long period swells and ESE fetch will likely result in minor wave and water level run-up on the Gulf beaches by late in the weekend into early next week. Water levels along the coast late this weekend into early next week are currently forecasted to remain below advisory levels, but could be running 1.5-2.5 feet above MLLW by Saturday.

7 Day Forecasted Rainfall Totals (Much of this will fall Saturday-Monday):

ET Surge Tidal Forecast for Galveston Pleasure Pier (MLLW):

[tireman4]

Tropical Weather Outlook

[tireman4]

This is what Jeff and Srain were alluding to...

[DoctorMu]

Where and how much rain remains in question 3-6 in in Houtson seems about the mean. 2-3 in in CLL

[tireman4]

Jeff Lindner
‏
Rain chances will be increasing starting this weekend and lasting into early next week regardless of development of #91L. Some heavy rainfall will be possible Sat-Mon. Monitor weather forecasts closely and track rainfall and water levels at http://www.harriscountyfws.org #houwx #hounews

[Cromagnum]

It's interesting that lately we seem to be in a drought and get caught up in rain all at once only to go back to drought a few weeks later. Hoping for 3-4 days of good soaking rains from this.

[jasons2k]

It's interesting that lately we seem to be in a drought and get caught up in rain all at once only to go back to drought a few weeks later. Hoping for 3-4 days of good soaking rains from this.

Been that way for years, seems like it really started with the Rita near-miss in 2005. Since then, the tree canopy has been almost decimated by pine beetles and intermittent droughts. Just when we get enough moisture to pull things out of stress, it starts up again.

[Rip76]

I started to notice it just after the cool front swept through after Ike.

[srainhoutx]

Interesting to see the 12Z ECMWF finally showing a much sharper trough nearing the Texas Coast Sunday morning...lol