Major Hurricane Harvey continues to intensify this afternoon. Maximum sustained winds are now at 125 MPH with higher gusts. Additional strengthening is possible before landfall later tonight, but the difference between a 125 MPH Category 3 or a 130 MPH category 4 hurricane is minimal. Life-threatening storm surge is already impacting the Middle Texas Coast with bay flooding in Corpus Christi. Sustained tropical storm force winds are impacting Corpus Christi and the Middle Texas Coast and Coastal Bend. Sustained hurricane force winds will arrive by 6 PM on the Coastal Bend – including Corpus Christi. The time to evacuate has ended. Traveling is too dangerous. Stay where you are and hunker down. Harvey’s forward motion will slow later this evening and bring a prolonged period of life-threatening storm surge and destructive hurricane force winds to the Coastal Bend and Middle Texas Coast. Tornadoes are also possible tonight in the Coastal Plains and Southeast Texas as the feeder bands of Harvey continue to pivot on-shore.

Harvey is expected to stall or meander around South Texas through next Wednesday – at least. This will result in a historic and catastrophic flooding event with widespread 20 to 30 inches of rain. Localized amounts of 40 inches are anticipated, and I’m afraid that number may have to be raised in future forecasts. The western edge of the flooding rains will have a sharp cutoff – west of Harvey’s eventual track. Please see the rainfall forecast map below for that aspect of this very serious forecast.

Hurricane Harvey Advisory Number 22
NWS National Hurricane Center Miami FL AL092017
400 PM CDT Fri Aug 25 2017

…MAJOR HURRICANE HARVEY BEARING DOWN ON THE TEXAS COAST…
…CATASTROPHIC FLOODING EXPECTED DUE TO HEAVY RAINFALL AND STORM
SURGE…

 

SUMMARY OF 400 PM CDT…2100 UTC…INFORMATION
———————————————-
LOCATION…27.5N 96.5W
ABOUT 60 MI…95 KM ESE OF CORPUS CHRISTI TEXAS
ABOUT 60 MI…100 KM S OF PORT OCONNOR TEXAS
MAXIMUM SUSTAINED WINDS…125 MPH…205 KM/H
PRESENT MOVEMENT…NW OR 325 DEGREES AT 10 MPH…17 KM/H
MINIMUM CENTRAL PRESSURE…941 MB…27.79 INCHES

 

WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY:

The Tropical Storm Warning has been discontinued south of Port
Mansfield, Texas.

The Storm Surge Watch has been discontinued south of Port
Mansfield, Texas.

The government of Mexico has discontinued the Tropical Storm Watch
north of Boca de Catan.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Storm Surge Warning is in effect for…
* Port Mansfield to High Island Texas

A Hurricane Warning is in effect for…
* Port Mansfield to Sargent Texas

A Tropical Storm Warning is in effect for…
* North of Sargent to High Island Texas

A Storm Surge Warning means there is a danger of life-threatening
inundation from rising water moving inland from the coastline in the
indicated locations. For a depiction of areas at risk, please see
the National Weather Service Storm Surge Watch/Warning Graphic,
available at hurricanes.gov. This is a life-threatening situation.

A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area, in this case within the next few
hours. Preparations to protect life and property should already be
complete.

Interests in southwestern Louisiana should continue to monitor the
progress of this system.

For storm information specific to your area, including possible
inland watches and warnings, please monitor products issued by your
local National Weather Service forecast office.

 

DISCUSSION AND 48-HOUR OUTLOOK
——————————
At 400 PM CDT (2100 UTC), the eye of Hurricane Harvey was located
by aircraft reconnaissance aircraft and NOAA Doppler radar near
latitude 27.5 North, longitude 96.5 West. Harvey is moving toward
the northwest near 10 mph (17 km/h), but its forward speed is
expected to decrease significantly during the next couple of days.
On the forecast track, Harvey will make landfall on the middle Texas
coast tonight or early Saturday. Harvey is then likely to meander
near or just inland of the middle Texas coast through the weekend.

Data from an Air Force Reserve Hurricane Hunter aircraft indicate
that maximum sustained winds have increased to near 125 mph
(205 km/h) with higher gusts. Harvey is a category 3 hurricane on
the Saffir-Simpson Hurricane Wind Scale. Some additional
strengthening is possible before Harvey makes landfall overnight.
Weakening is then expected over the weekend while the center moves
inland over Texas.

Hurricane-force winds extend outward up to 35 miles (55 km) from the
center, and tropical-storm-force winds extend outward up to 140
miles (220 km). A station at Aransas Pass, Texas, recently
reported a sustained wind 56 mph and a gust to 71 mph.

The minimum central pressure based on aircraft reconnaissance data
is 941 mb (27.79 inches).

 

HAZARDS AFFECTING LAND

———————-
RAINFALL

Harvey is expected to produce total rain accumulations of 15 to 30 inches and isolated maximum amounts of 40 inches over the middle and upper Texas coast through next Wednesday. During the same time period Harvey is expected to produce total rain accumulations of 5 to 15 inches in far south Texas and the Texas Hill Country over through southwest and central Louisiana. Rainfall of this magnitude will cause catastrophic and life-threatening flooding.

STORM SURGE

The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water is expected to reach the following heights above ground if the peak surge occurs at the time of high tide…

N Entrance Padre Island Natl Seashore to Sargent…6 to 12 ft
Sargent to Jamaica Beach…5 to 8 ft
Port Mansfield to N Entrance Padre Island Natl Seashore…3 to 5 ft
Jamaica Beach to High Island…2 to 4 ft
Mouth of the Rio Grande to Port Mansfield…1 to 3 ft
High Island to Morgan City…1 to 3 ft

The deepest water will occur along the immediate coast near and to the northeast of the landfall location, where the surge will be accompanied by large and destructive waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office.

WIND

Tropical storm conditions are occurring in portions of the hurricane and tropical storm warning areas, and hurricane conditions are expected to begin within the hurricane warning area in the next few hours. Tropical storm conditions are likely to persist along portions of the coast through at least Sunday.

SURF

Swells generated by Harvey are affecting the Texas, Louisiana, and northeast Mexico coasts. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.

TORNADOES

A few tornadoes are possible through Saturday near the middle and upper Texas coast into far southwestern Louisiana.

 

NEXT ADVISORY
————-
Next intermediate advisory at 700 PM CDT.
Next complete advisory at 1000 PM CDT.

Key Messages:

1. Harvey will make landfall tonight, bringing life-threatening
storm surge, rainfall, and wind hazards to portions of the Texas
coast. Tropical-storm-force winds have moved onshore in portions of
the warning areas and conditions will continue to deteriorate as
the eye of Harvey approaches the middle Texas coast tonight.

2. A Storm Surge Warning is in effect for much of the Texas coast.
Life-threatening storm surge flooding could reach heights of 6 to 12
feet above ground level at the coast between the north entrance of
the Padre Island National Seashore and Sargent. For a depiction of
areas at risk, see the Storm Surge Watch/Warning Graphic at
hurricanes.gov. Due to the slow motion of Harvey and a prolonged
period of onshore flow, water levels will remain elevated for
several days.

3. Catastrophic and life-threatening flooding is expected across the
middle and upper Texas coast from heavy rainfall of 15 to 30 inches,
with isolated amounts as high as 40 inches, through Wednesday.
Please refer to products from your local National Weather Service
office and the NOAA Weather Prediction Center for more information
on the flooding hazard.