June 2024

[brazoriatx]

Doesn't look like no warnings or watches for us

[Stratton20]

Brazoriatx remember this is a very broad system so impacts will extend well to the north of the center, i do expect to see some watches and warnings issued all the way up into galveston or so, se texas could possibly or likely see wind gusts to tropical storm force

[don]

Potential Tropical Cyclone One Discussion Number 1
NWS National Hurricane Center Miami FL AL012024
400 PM CDT Mon Jun 17 2024

Satellite, surface, and aircraft data show that the center of
the large low pressure area is over the Bay of Campeche with a
central pressure near 1001 mb. The system currently does not have
the structure of a tropical cyclone, as the associated convection
is poorly organized and the maximum winds are located about
200-250 n mi northeast of the center. The various global models
forecast this band of stronger winds to start moving onto the
western Gulf coast on Wednesday, and a Tropical Storm Watch is
required at this time. Thus, advisories are being initiated on
Potential Tropical Cyclone One.

The initial motion is 345/6. This general motion should continue
for the next 24 h or so, although there could be some erratic
motion due to center reformation. After that, the cyclone is
expected to turn west-northwestward and westward on the south side
of a mid- to upper-level ridge over the northern Gulf coast. This
should steer the system into northeastern Mexico between 48-72 h.
While there are differences in details due to the disorganized
nature of the system, the track guidance is in good agreement on
this general scenario.

The global models suggest that some deepening of the central
pressure could occur, although none of them currently forecast the
system to tighten up into a classic tropical cyclone. Based on
that, the intensity forecast calls for only modest strengthening.
There is a chance than a small-scale vorticity center inside the
large cyclonic envelope may develop enough convection to form a
tighter wind core as suggested by the GFS, and based on this
possibility the forecast has the system becoming a tropical storm in
about 36 h. However, there is a chance the system will never
become a tropical cyclone.

Key Messages:
1. Users are reminded to not focus on the exact forecast track of
this system. The disturbance is very large with rainfall, coastal
flooding, and wind impacts likely to occur far from the center
along the coasts of Texas and northeastern Mexico.

2. Rainfall associated with Potential Tropical Cyclone One will
impact large regions of Central America, northeastern Mexico
and southeastern Texas. This rainfall will likely produce
considerable flash and urban flooding along with new and renewed
river flooding. Mudslides are also possible in areas of higher
terrain across Central America into Northeast Mexico.

3. Moderate coastal flooding is likely along much of the Texas
Coast beginning early Tuesday and continuing through midweek.

4. Tropical storm conditions are possible beginning Wednesday over
portions of northeastern Mexico and the Texas coast south of Port
O’Connor, where a Tropical Storm Watch has been issued.


FORECAST POSITIONS AND MAX WINDS

INIT 17/2100Z 20.3N 93.2W 35 KT 40 MPH...POTENTIAL TROP CYCLONE
12H 18/0600Z 21.1N 93.4W 35 KT 40 MPH...POTENTIAL TROP CYCLONE
24H 18/1800Z 22.2N 93.8W 35 KT 40 MPH...POTENTIAL TROP CYCLONE
36H 19/0600Z 22.9N 95.0W 35 KT 40 MPH...TROPICAL CYCLONE
48H 19/1800Z 23.4N 96.4W 40 KT 45 MPH...TROPICAL CYCLONE
60H 20/0600Z 23.8N 97.7W 40 KT 45 MPH...TROPICAL CYCLONE
72H 20/1800Z 24.0N 98.9W 30 KT 35 MPH...INLAND
96H 21/1800Z 24.0N 101.4W 20 KT 25 MPH...INLAND

[brazoriatx]

Guess that vort to the north didn't materialize

[Cromagnum]

With that sharp of a turn that far to the south, I don't see all that much energy bringing heavy rains all the way up here like earlier models were showing.

[don]

Remember folks the storm was always going to stay well south of us. Our storm is not the center its the vortmax rotating around the COC.(The talk about a COC relocation is more of a technicality it doesn't really change things for us.)What matters for us is how far north those vortmax travel on the periphery of the Gyre. That's what we've been watching the last several days in the models, not the COC but the vortmax.


Tropical storm watch issued to high island.

URGENT - MARINE WEATHER MESSAGE
National Weather Service Houston/Galveston TX
402 PM CDT Mon Jun 17 2024

GMZ330-350-355-370-375-180515-
/O.CAN.KHGX.SC.Y.0052.000000T0000Z-240620T1200Z/
/O.NEW.KHGX.TR.A.1001.240617T2102Z-000000T0000Z/
Matagorda Bay-
Coastal waters from Freeport to Matagorda Ship Channel TX out
20 NM-Coastal waters from High Island to Freeport TX out 20 NM-
Waters from Freeport to Matagorda Ship Channel TX from 20 to
60 NM-Waters from High Island to Freeport TX from 20 to 60 NM-
402 PM CDT Mon Jun 17 2024

...SMALL CRAFT ADVISORY IS CANCELLED...
...TROPICAL STORM WATCH IN EFFECT...

* WHAT...East winds 20 to 30 kt with gusts up to 40 kt and seas
10 to 15 ft.

* WHERE...Portions of Gulf of Mexico.

* WHEN...Through Thursday morning.

* IMPACTS...Very strong winds will cause hazardous seas which
could capsize or damage vessels and reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should consider altering plans to avoid possible
hazardous conditions. Remain in port, seek safe harbor, alter
course, and/or secure the vessel for severe wind and seas.

&&

[don]

I think some people may be confused, we've been tracking the vortmax in the models not the COC,there were hints that a vortmax may become the dominate COC but regardless for us in SE Texas we were never relying on that for rain up here.A better way to explain it, is over the last week the models have been showing heavy rain here NOT because of the COC, but because of vortmax moving through. The system was always suppose to stay far south. Its how far north those vortmax get that matters to us.

TLDR Follow the VORTMAX on the models to determine which area of the state will be the bullseye.

1. Users are reminded to not focus on the exact forecast track of
this system. The disturbance is very large with rainfall, coastal
flooding, and wind impacts likely to occur far from the center
along the coasts of Texas and northeastern Mexico.

[Rip76]

Jeff's Latest

"NHC has begun advisories on Potential Tropical Cyclone 1

Tropical Storm Watch is issued from Port O Connor, TX to Boca De Catan, MX south of the mouth of the Rio Grande River.

Flood Watch issued for the following counties: Chambers, Galveston, Harris, Brazoria, Waller, Fort Bend, Austin, Washington, Wharton, Colorado, Matagorda, Jackson, and southern Liberty

Coastal Flood Warning (100am Tues-100am Thurs): Bolivar, coastal Chambers, coastal Brazoria, coastal Galveston and Galveston Island, and coastal Harris.

Discussion:
A large and complex low pressure system over the southern Gulf of Mexico continues to slowly become better organized and it is likely that a tropical cyclone will form with the next 24-36 hours IR Satellite Loop for Gulf of Mexico | Tropical Tidbits Since the system is currently not yet defined enough to be declared a tropical cyclone and impacts are within 48 hours of the coast the Potential Tropical Cyclone (PTC) was used so coastal watches could be issued. Regardless…this changes little with the forecast with heavy rains, gusty winds, elevated tides/coastal flooding, and high seas likely over much of coastal Texas from Tuesday-Thursday. It should be noted that 40 mph winds extend outward some 300 miles to the northeast of the broad center and encompass a large portion of the southern Gulf of Mexico.

Plume of tropical moisture continues to work its way inland out of the central Gulf of Mexico and has resulted in scattered showers today over the area. Satellite data clearly shows additional tropical moisture over the central Gulf poised to move inland along the upper TX coast on Tuesday. This is also the time when surface low pressure and stronger lift comes to bear over the area helping to enhance the showers and banding features offshore. These features will gradually push inland late Tuesday into the evening and overnight Wednesday morning and linger into Wednesday afternoon. Winds and seas will continue upward tonight into Tuesday along with coastal tides and impacts are likely by late Tuesday into Wednesday.

Impacts:

Rainfall:
Banding features will begin to approach the upper TX coast Tuesday afternoon and progress inland with time…mainly for areas south of I-10. Where the more persistent and sustained bands develop and potentially train will determine the greatest flash flood risk. Given the moisture in place high hourly rainfall amounts of 3-5 inches will be possible and this can lead to rapid onset flash flooding. The most favorable time for heavy rainfall over SE TX will be from Tuesday afternoon into Wednesday afternoon. The rainfall amounts below should be used as average…to be clear training bands in these types of set ups can quickly result in much higher totals and flash flooding and usually are spatially small in scale and can be near areas that see little rainfall or much lower totals.

Coastal Counties: 7-9 in (widespread) isolated totals over 12+ inches
I-10 corridor: 3-5 in (widespread) isolated totals up to 7 inches
North of I-10: 3-4 in (widespread) isolated totals up to 5 inches.



Hydro:
Responses on area watersheds will be determined on where the heaviest rains fall. Current thinking is most of the Harris County creeks and bayous will be able to handle 4-6 inches of rainfall…but isolated higher totals would be of concern. If totals were to exceed 8 inches in southern Harris County the following watersheds would be of concern:

1. Clear Creek and its tributaries
2. Armand Bayou
3. Willow Spring Bayou
4. Big Island Slough
5. Taylor’s Bayou
6. Goose Creek
7. Berry Bayou
8. Hunting Bayou
9. Keegans Bayou
10. Willow Waterhole

Tides:
Minor to moderate coastal flooding is likely (minor) Tuesday building to (moderate) Wednesday at times of high tide. Building seas and a long fetch of ESE/SE winds of 30-40mph over much of the Gulf of Mexico is going to push water levels into the 4.5-5.5 ft above MLLW (Barnacle) level or 2.5 to 3.5 above MHHW (normally dry ground at the shoreline) along the coast Tuesday and Wednesday. The Wednesday morning high tide looks to be the peak of the tidal flooding as this period will combine with the maximum lunar tide as well as the strongest onshore winds. Low lying roads in typically coastal flood areas will be impacted and likely overtopped/overwahsed…this includes the eastern parts of HWY 87 and Blue Water Highway. Flooding of low lying roads and under elevated structures is likely on Bolivar, west end of Galveston Island, Treasure Island, Quintana Beach, Tike Island, Bayou Vista, San Leon, Seabrook and the north side of Galveston Island. Bulkheads, piers, and some streets are likely to be overtopped/flooded around Clear Lake including Nassau Bay and El Lago and in Shoreacres. Lynchburg Ferry Landings are likely to be overtopped. It is possible water levels may get close to impacting Bolivar-Galveston Ferry operations.







NOTE: The graphic below indicates water levels above MHHW (or above normally dry ground at the shoreline). The difference between MLLW and MHHW along the upper TX coast is generally 1-2 ft



Winds:
The pressure gradient has already begun to tighten and winds will increase into the 25-35mph range tonight and 30-40mph range on Tuesday over the coastal waters and bays with gusts up to 45-50mph. Squalls will also produce gusty winds even well inland away from the coastal winds. Gusts in squall of 40-50mph will be possible. Isolated power outages are possible.

Marine/Seas:
Hazardous marine conditions are developing and will continue to deteriorate into Tuesday and Tuesday night with seas building 10-15 ft offshore and 6-9 feet nearshore with 5-8 feet in the bays. Frequent squalls with wind gust of 40-50mph will be likely along with blowing sea spray. Small craft should port immediately and remain in port until conditions improve."




Jeff Lindner
Director Hydrologic Operations Division/Meteorologist
Harris County Flood Control District
9900 Northwest Freeway | Houston, Texas 77092
346-286-4000 (main) | 346-286-4165 (direct) | 281-924-2091 (cell)
jeff.lindner@hcfcd.org | Twitter: @jefflindner1

[Stratton20]

GFS shifted south again

[don]

The latest 850mb vorticity from the HRRR as an example. The vorticities rotating around the main center almost act like "mini" TC's within the bigger system. Wherever on the coast of Texas that vorticity tracks is going to be who sees the most rain and wind from this. The HRRR has been tacking the brunt of rain towards us while other models take it towards the middle/lower Texas coast.

hrrr_2024-06-17-20Z_018_37.434_254.297_22.194_276.813_Vorticity_850 (1).png

hrrr_2024-06-17-20Z_018_37.434_254.297_22.194_276.813_Rain-Snow_Radar.png

[biggerbyte]

I mentioned yesterday there seemed to be a little rotation in the area the NWS is plotting today. Mexico was never really out of the question even though some of the models teased otherwise. If we get a TS out of this and it tightens up we can shift the heavy rain further south with it. In the meantime we watch for changes, which I'm sure there will be. At the moment, LA is getting most of the rain. Isn't that a hoot with all of the chatter as of late. East and South. LOL

[Stratton20]

Hopefully those rain bands come in further north

[don]

Will the HRRR cave towards the other mesoscale models tonight? Or vise versa? Stay tuned. LOL

[DoctorMu]

The more organized TS 1 is the farther south the rains are.



The issue up to now was not knowing the initial conditions...meaning modeling something that doesn't exist yet. For the moment, south of I-10 where the rain will be concentrated. 0z will be the first critical adjustment and better initial conditions and then we'll be pretty much NowCasting.

TS2 now become the focus...for now.

[djmike]

The 2nd system looks to do about the exact same thing it looks like. I know its way too early though.

[Stratton20]

NHC officially acknowledges the 2nd system potential for next week, buckle up folks!

[djmike]

Looks familiar. Lol

[djmike]

Well central and eastern LA were the rainfall winners today. Nothing really traversed westward today except some spotty showers.

[DoctorMu]

Next.

The tropical air felt good today, even through we just missed out on a shower. Looks like we'll probably need the sprinklers later in the week. We'll see. If the TS doesn't organize well we could get 0.5 inches, maybe a little more. Not counting on it.

[Pas_Bon]

Where the Hell is the rain?