Texas Summer 2017

[Ntxw]

It could still get some rain out of Harvey according to the GFS.

really really depends on track... would need to come up 35 pretty far basically to get significant rain here(more than a band or two)... if it trends more east towards Galveston and Louisiana we'll be dry

We got to hope for a south of Galveston landfall.

Its going to make a hard right turn as it comes up with exiting trof. A weaker system might be better for us

[starsfan65]

Are we going to get some rain before the front moves in?

[Brent]

yeah its going to turn east its just a matter of where it is... personally I'm not feeling significant impacts in DFW but we'll see how it goes. The northwest side is never that great... maybe a band or two but mostly clouds and a dry cool flow

now if it stays disorganized and isn't some powerful hurricane then our odds are better for rain

[starsfan65]

yeah its going to turn east its just a matter of where it is... personally I'm not feeling significant impacts in DFW but we'll see how it goes. The northwest side is never that great... maybe a band or two but mostly clouds and a dry cool flow

now if it stays disorganized and isn't some powerful hurricane then our odds are better for rain

It has to be a tropical storm for us to get any rain.

[Brent]

yeah its going to turn east its just a matter of where it is... personally I'm not feeling significant impacts in DFW but we'll see how it goes. The northwest side is never that great... maybe a band or two but mostly clouds and a dry cool flow

now if it stays disorganized and isn't some powerful hurricane then our odds are better for rain[/quote0]
It has to be a tropical storm for us to get any rain.

You want broad and messy for more widespread impacts up here if it tightens up with a core in a hurricane not so much

[Yukon Cornelius]

Sorry to be the Debbie Downer but I honestly hope it stays in the Southern half of the state. Ive been rained out or its been too muddy every weekend that I have needed to get feeders up and going and game cams out and I have some time next week to get it done and dry weather would be a blessing.

[Texas Snowman]

Sorry to be the Debbie Downer but I honestly hope it stays in the Southern half of the state. Ive been rained out or its been too muddy every weekend that I have needed to get feeders up and going and game cams out and I have some time next week to get it done and dry weather would be a blessing.

Yes sir, deer season is coming fast!

Depending upon the path, this is the kind of potential wet storm that can fill up lakes in deep south and western Texas like Choke Canyon, Falcon and O.H. Ivie. All are still lagging far behind other lakes in other parts of the state.

[Tireman4]

Sorry to be the Debbie Downer but I honestly hope it stays in the Southern half of the state. Ive been rained out or its been too muddy every weekend that I have needed to get feeders up and going and game cams out and I have some time next week to get it done and dry weather would be a blessing.

Hey Hey Hey...we dont want it either....ok..maybe Austin needs a sprinkle....LOL

[JDawg512]

The rain can't come soon enough for this rain miser, but there's only so much even I would accept. I like it wet, not under water...

[Yukon Cornelius]

Sorry to be the Debbie Downer but I honestly hope it stays in the Southern half of the state. Ive been rained out or its been too muddy every weekend that I have needed to get feeders up and going and game cams out and I have some time next week to get it done and dry weather would be a blessing.

Yes sir, deer season is coming fast!

Depending upon the path, this is the kind of potential wet storm that can fill up lakes in deep south and western Texas like Choke Canyon, Falcon and O.H. Ivie. All are still lagging far behind other lakes in other parts of the state.

Such a happy chunk of the year. Deer season, cooler weather, some cold weather, Thanksgiving and Christmas!

[Portastorm]

Troubling consistency between the 0z and 12z Euro control runs. While Harvey is much weaker at landfall in the latter, BOTH runs show a foot or more of rain in Travis County by early Tuesday.

[weatherdude1108]

Troubling consistency between the 0z and 12z Euro control runs. While Harvey is much weaker at landfall in the latter, BOTH runs show a foot or more of rain in Travis County by early Tuesday.

What about the Hill Country? That's where it counts as far as the water supply.

[Cpv17]

Euro near or just a tad south of Corpus Christi, weaker

All of my life I've wanted to experience a hurricane, but definitely not what the GFS was showing. A cat 4 right over my house. Maybe a strong cat one or a weak cat 2 would be about as much as I'd ever want to experience so this run of the Euro pleases me much more than what the GFS was showing.

Never been through one? Where you from?

I'm just southwest of you down 59 by Wharton and El Campo. We got absolutely nothing here from Ike cuz we were on the dry side. All we got was overcast skies and maybe 20-30 mph winds that's it.

[Portastorm]

Troubling consistency between the 0z and 12z Euro control runs. While Harvey is much weaker at landfall in the latter, BOTH runs show a foot or more of rain in Travis County by early Tuesday.

What about the Hill Country? That's where it counts as far as the water supply.

Broadbrushing it but from what I saw, anywhere from 2-8" with areas further NW in the Hill Country getting less and the southeast half getting more.

[South Texas Storms]

Just went to the store and gas station to restock essentials. Preparing for a lot of rain and some wind in Houston. Hopefully SA and Austin can get some beneficial rain from this system.

[weatherdude1108]

051
FXUS64 KEWX 221959
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
259 PM CDT Tue Aug 22 2017

.SHORT TERM (Tonight through Wednesday Night)...

Main weather highlight will be the continued hot temperatures and
elevated heat index values today and again tomorrow. Heat index
values will reach upwards of 100-105F during the afternoons. In
addition, a weak front will likely reach far northern areas of
south-central Texas that will help scattered showers and
thunderstorms develop. Attention will also turn to the tropics in the
long-term section below with heavy rainfall and flooding potential
increasing.

A retreating H5 ridge over west Texas is shifting farther westward
today with a TUTT low analyzed over the western Gulf of Mexico today.
A few coastal plains showers will occur this afternoon and early
evening but will weaken quickly post-sunset as stabilization occurs.

For Wednesday, a weak convectively-forced boundary will shift south
towards the region and help provide more low-level convergence to aid
in scattered thunderstorm growth over the Hill Country and portions
of the Edwards Plateau. CAPE values are advertised to remain near
1000 J/Kg and this should keep storms from being too strong. Most of
the activity, again, should decrease after sunset. Heat index values
Wednesday afternoon will be in the 100-106F range, minus the Hill
Country area.

&&

.LONG TERM (Thursday through Tuesday)...

Concern for heavy rain and flooding from a likely reengergized
landfalling tropical cyclone Harvey continues to increase for late
Friday and through the entire weekend for much of the region. While
models still need to resolve the tropical system as it is in the
midst of forming, and also its future track, the guidance envelope
suggests the possibility for moderate to high impacts in the form of
heavy rain leading to river and flash flooding.

Thursday will be will be a dynamic day as two systems driving the
weather will be at play. The aforementioned boundary will linger
across the region and likely support a weak convergence zone to
support diurnal showers and thunderstorms for a 20-40% chance of
scattered activity. While most of this activity should remain
scattered enough not to cause any flooding impacts itself, it will
act to help saturate some soils ahead of the possible tropical
cyclone rainfall totals over the weekend. This preceding rain could
exacerbate possible flooding impacts Friday afternoon and into the
weekend depending on evolution/track of Harvey.

Greater concern for heavy rain and flooding impacts across at least
the I-35 corridor and eastward are increasing per latest model
envelope guidance. The NHC is current giving the remnants of Harvey
a 100% chance of redevelopment into a tropical depression and storm
over the next couple days. This development could occur as early as
tomorrow morning with possible advisories along the Texas coast in
the next 24-48 hours, if not sooner. Both the GFS and EC are in
decent agreement of a strengthening tropical system nearing the
southern to middle Texas coast Friday morning. Anywhere from
Brownsville to Houston could be a possibility as the storm is in its
formation stages currently. Many models are depicting high rainfall
totals across portions of the region. Based on the EC/GFS at least
2-6" is expected along and east of I-35 corridor Friday afternoon
through Sunday afternoon. This total will change and depending on the
track could go significantly higher if the track is farther south
and west or if the EC/GFS solutions pan out. Confidence in these
solutions is slowly growing. Of note, there will be a tight western
rainfall amount gradient somewhere. It is too far out at this time to
speculate where that will be. The rainfall amounts will be refined
and updated as new model guidance and upper-air balloon data are
collected. In addition to heavy rainfall leading to river and flash
flooding, some areas of the eastern Coastal Plains could see tropical
storm force winds Friday into early Saturday. Will not get into
specifics as of yet until the NHC begins advisories on the system.

The longevity of the rainfall this weekend will be due to the system
being advertised to stall near or over the region as it is blocked
by an H5 ridge over the four-corners and attempts to be picked up by
only weak troughing across the mid-Mississippi River Valley. With
tropical downpours and the potential for the system to move slowly,
excessive rainfall amounts are appearing to look possible. Again,
stay tuned through the next 24-48 hours as totals and the track are
refined with extra data being collected.

[gboudx]

From jeff:

***Hurricane landfall along the TX coast increasing likely Friday or Saturday***

Review hurricane response plans and be fully prepared to enact those plans starting tomorrow.

Discussion:
Satellite images show an increasingly well defined surface circulation across the NW Yucatan currently that will be moving over the southern Gulf of Mexico in the next several hours. The system currently lacks any deep convection near the center with thunderstorms currently displaced to the north along the northern coast of the Yucatan. The circulation is moving toward the NW around 10-12mph and this motion is expected to continue.

Track:
There has been little change in the forecast track reasoning today with a general NW track toward the TX coast expected Wed-Fri. Major global models continue to be in decent agreement moving Harvey into a weakness over the TX coast between a building ridge of high pressure over the SW US and high pressure over the SE US and a trough across the Great Lakes. Landfall locations continue to shift around with each model run, but the main consensus continues to be in the region between Corpus Christi and Matagorda Bay.

The steering flow nearly collapses as Harvey reaches the coast and expect a decrease in forward speed as the system moves inland over the coastal bend on Friday night. This is where the forecast becomes greatly complicated as Harvey becomes trapped in a weak steering regime across SC/SE TX into the early portion of next week. The system is effectively left to meander and loop somewhere in the region bounded by Matagorda Bay, Austin, and Galveston. Eventually it appears Harvey will slowly track E to ENE either along the coast or inland of the coast across SE TX Saturday-Tuesday.

Intensity:
Conditions appear favorable for intensification of Harvey up to landfall on the TX coast. All parameters appear to be satisfied including warm SST’s, 200mb high pressure over the center of the system, potential dual outflow channels to the NE and SW of the center. It is possible that a period of rapid intensification could occur as Harvey nears the middle TX coast on Friday. Intensity forecast skills are poor especially when dealing with rapid intensification…this aspect will need to be monitored closely over on Thursday and Friday as Harvey approaches. Current coordinated NHC/WPC positions bring s minimal hurricane into the coast in the reach between Corpus and Port O Connor Friday evening.

Impacts:
Without any sort of NHC track guidance the following impacts are based on the TCVN (consensus model track) with storm surge forecast off ET surge, but I have cut it back some based on the latest GFS run. Have also taken a good look at the cat 1 SLOSH output for a NW tracking hurricane into just W of Matagorda Bay and merging those values with ET surge seems to be a good compromise at the moment. Additionally, there has been some coordination with the storm surge unit at NHC via the local WFO today. Rainfall has been coordinated with local WFO’s and WPC…mainly to encourage WPC to raise expected totals.

Rainfall:
I have never seen the GFS and ECWMF models forecasting such a large amount of rainfall over such a large area. Widespread rainfall amounts of 8-12 inches is likely with isolated totals of 20 inches or more. River, creek, bayou, and flash flooding would be a given with totals of this magnitude. Unlike so many of the flood events we deal with across this area where isolated areas get the very high totals…the potential here is for a very large area to see excessive amounts of rainfall.

Widespread: 8-12 inches (all areas)
Isolated: 20 inches +

Storm Surge:
Will start to see increasing tides Thursday afternoon and possible we may hit 3.0 ft total water level Thursday afternoon/evening especially Matagorda Bay southward toward Mustang Island. Will go with total water levels Friday rising to 4.0-5.0 feet along all of the upper and middle coast and likely nearing 6.0 feet around Matagorda Bay. 4.5 feet is our critical warning threshold along much of the upper coast for the start of impacts and think we will hit those levels on Friday especially Matagorda Bay. Overwash and coastal flooding appears likely Friday from Palacios southward including Matagorda Island and along the west side of Matagorda Bay.

Tides will increase Friday night across the coast NE of Palacios as SE winds pile water and wave action onto the coast. Will build to 4.0-5.5 feet Friday night along Brazoria, Galveston, and SE Harris coast with overwash likely on the west end of Galveston and Bolivar. With the continued onshore flow well into Saturday and Sunday tides will only worsen over the weekend as water becomes trapped in the bays…especially the western side of Galveston Bay. Certainly looking at potential coastal flooding around Clear Lake, Kemah, Seabrook, Galveston Island, Bolivar on Saturday…but don’t want to go much more than 5.5-6.0 feet total water level at this time as a lot of factors are in play.

Matagorda Bay: 4-5 ft (Friday/Saturday)
Galveston Bay: 4-5 ft (late Friday/Saturday)
Gulf Beaches: 4.5-5.5 ft (Friday/Saturday)

Onset of 3.0 ft total water level rise Thursday afternoon/evening

Winds:
A lot of uncertainty with this aspect.

Tropical storm conditions (40mph sustained) will begin to reach the middle coast on Friday around midday and spread inland into the evening hours. Will bring Jackson, Matagorda, Calhoun, and Wharton Counties into the TS force winds by Friday evening and build to hurricane force (75mph sustained) over Calhoun County southward to near Corpus Friday night. Could be very near hurricane conditions into much of Matagorda Bay Friday night and possibly Matagorda County with tropical storm conditions up to Galveston by Saturday morning. If the system does in fact turn NE/ENE just inland this will bring tropical storm and potential hurricane conditions across a larger portion of SE TX.

Should get better details on this tomorrow if NHC starts advisories.


Actions:

Hurricane plans should be fully prepared to be enacted on Wednesday including fully stocked hurricane kits.

Ride out teams should be notified and activation of COOP’s is recommended starting Wednesday.

Preparations should include the potential for loss of power and prolonged excessive rainfall and flooding along with prolonged high coastal tides. Some areas near the coast may become cut-off as early as Friday.

Significant rises on area rivers, creeks, and bayous is a real threat and residents living in flood prone areas should be prepared for rising water and potentially significant flooding.

Note:
GIV upper air mission is underway over the Gulf of Mexico which should help firm up model guidance for the 12Z runs on Wednesday…some of the samples may get into the 00Z runs this evening.

USAF/NHC have several C-130 53rd missions planned into Harvey starting tomorrow and this will continue up to landfall…so there will be nearly constant checking on intensity trends.

Tropical storm, hurricane, and storm surge watches and/or warnings may be required for portions of the TX coast on Wednesday

I'm expecting clear skies under subsidence this far north. At least it won't be in the upper 90's.

[Texas Snowman]

High SST, high pressure over the storm, dual outflow channels, possible rapid intensification.

Jeff didn't mince his words.

Folks along the Texas Coast need to begin paying attention to this.

[Cpv17]

The latest run of the GFS just gave Wharton County 15-25" of rain through Wednesday

[TheProfessor]

So Uh, can we all agree that we hope the 3k NAM is Waaaaaaaaaaaaay Wrong?