Harvey to be Category 4 at landfall (Texas coast)
Abbott declares state of disaster for 30 counties (Texas)
Hurricane Harvey poised to unleash flooding disaster on Texas into early next week
National Hurricane Center Preparedness Tips
As Harvey approaches, tips on how to prepare for your first storm
National Hurricane Center - Page for Harvey
NWS Southern Region Tropical page
US Naval Research Laboratory - Tropical Cyclone page
Plymouth State Weather Center - Tropical page
NOAA Tropical Atlantic satellite imagery
NOAA Tropical hurricane models
NOAA Doppler Radar for the Gulf Coast
Saffir-Simpson Hurricane Scale table
000
WTNT34 KNHC 242359
TCPAT4
BULLETIN
Hurricane Harvey Intermediate Advisory Number 18A
NWS National Hurricane Center Miami FL AL092017
700 PM CDT Thu Aug 24 2017
...HARVEY MOVING NORTHWESTWARD TOWARD THE TEXAS COAST...
...LIFE-THREATENING AND DEVASTATING FLOODING EXPECTED NEAR THE
COAST DUE TO HEAVY RAINFALL AND STORM SURGE...
SUMMARY OF 700 PM CDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...25.0N 94.3W
ABOUT 275 MI...445 KM SE OF CORPUS CHRISTI TEXAS
ABOUT 270 MI...435 KM SSE OF PORT OCONNOR TEXAS
MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H
PRESENT MOVEMENT...NW OR 325 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...974 MB...28.76 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
None.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for...
* Port Mansfield to High Island Texas
A Storm Surge Watch is in effect for...
* South of Port Mansfield Texas to the Mouth of the Rio Grande
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
* South of Port Mansfield Texas to the Mouth of the Rio Grande
A Hurricane Watch is in effect for...
* South of Port Mansfield Texas to the Mouth of the Rio Grande
A Tropical Storm Watch is in effect for...
* South of the Mouth of the Rio Grande to Boca de Catan Mexico
A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
during the next 36 hours 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. Persons located within these areas
should take all necessary actions to protect life and property from
rising water and the potential for other dangerous conditions.
Promptly follow evacuation and other instructions from local
officials.
A Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area. A warning is typically issued
36 hours before the anticipated first occurrence of tropical-storm-
force winds, conditions that make outside preparations difficult or
dangerous. Preparations to protect life and property should be
rushed to completion.
A Storm Surge Watch means there is a possibility of life-
threatening inundation, from rising water moving inland from the
coastline, in the indicated locations during the next 48 hours.
A Hurricane Watch means that hurricane conditions are possible
within the watch area.
In addition, interests in southwestern Louisiana should continue to
monitor the progress of this system.
For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area outside
the United States, please monitor products issued by your national
meteorological service.
DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 700 PM CDT (0000 UTC), the eye of Hurricane Harvey was located
near latitude 25.0 North, longitude 94.3 West. Harvey is moving
toward the northwest near 10 mph (17 km/h). This general motion is
expected to continue with a decrease in forward speed during the
next couple of days. On the forecast track, Harvey will approach
the middle Texas coast on Friday and make landfall Friday night or
early Saturday. Harvey is then likely to stall near or just inland
of the middle Texas coast through the weekend.
Reports from an Air Force Reserve Hurricane Hunter aircraft
indicate that maximum sustained winds remain near 85 mph (140 km/h)
with higher gusts. While Harvey has changed little in strength
over the past few hours, strengthening is expected to resume during
the next few hours, and Harvey is expected to become a major
hurricane by Friday before it reaches the middle Texas coast.
Hurricane-force winds extend outward up to 25 miles (35 km) from
the center, and tropical-storm-force winds extend outward up to 90
miles (150 km).
The minimum central pressure just reported by the Hurricane Hunter
Aircraft is 974 mb (28.76 inches).
HAZARDS AFFECTING LAND
----------------------
RAINFALL: Harvey is expected to produce total rain accumulations
of 15 to 25 inches and isolated maximum amounts of 35 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 7 to 15 inches in far south Texas and the Texas
Hill Country over through central and southwest Louisiana, with
accumulations of up to 7 inches extending into other parts of Texas
and the lower Mississippi Valley. Rainfall from Harvey will cause
devastating 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...5 to 7 ft
Jamaica Beach to High Island...2 to 4 ft
Mouth of the Rio Grande to Port Mansfield...2 to 4 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: Hurricane conditions are likely within the hurricane warning
area late Friday or Friday night, with tropical storm conditions
expected to first reach the coast in the hurricane warning area
Friday.
SURF: Swells generated by Harvey are likely to affect the Texas,
Louisiana, and northeast Mexico coasts by Friday. These swells are
likely to cause life-threatening surf and rip current conditions.
Please consult products from your local weather office.
TORNADOES: Isolated tornadoes are possible across portions of the
middle and upper Texas coast on Friday.
NEXT ADVISORY
-------------
Next complete advisory at 1000 PM CDT.
$$
Forecaster Beven
WTNT24 KNHC 242044
TCMAT4
HURRICANE HARVEY FORECAST/ADVISORY NUMBER 18
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092017
2100 UTC THU AUG 24 2017
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...
THE HURRICANE WARNING HAS BEEN EXTENDED NORTHEAST OF MATAGORDA TO
SARGENT TEXAS.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
A STORM SURGE WARNING IS IN EFFECT FOR...
* PORT MANSFIELD TO HIGH ISLAND TEXAS
A STORM SURGE WATCH IS IN EFFECT FOR...
* SOUTH OF PORT MANSFIELD TEXAS TO THE MOUTH OF THE RIO GRANDE
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
* SOUTH OF PORT MANSFIELD TEXAS TO THE MOUTH OF THE RIO GRANDE
A HURRICANE WATCH IS IN EFFECT FOR...
* SOUTH OF PORT MANSFIELD TEXAS TO THE MOUTH OF THE RIO GRANDE
A TROPICAL STORM WATCH IS IN EFFECT FOR...
* SOUTH OF THE MOUTH OF THE RIO GRANDE TO BOCA DE CATAN MEXICO
A STORM SURGE WARNING MEANS THERE IS A DANGER OF LIFE-THREATENING
INUNDATION...FROM RISING WATER MOVING INLAND FROM THE COASTLINE...
DURING THE NEXT 36 HOURS 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. PERSONS
LOCATED WITHIN THESE AREAS SHOULD TAKE ALL NECESSARY ACTIONS TO
PROTECT LIFE AND PROPERTY FROM RISING WATER AND THE POTENTIAL FOR
OTHER DANGEROUS CONDITIONS. PROMPTLY FOLLOW EVACUATION AND OTHER
INSTRUCTIONS FROM LOCAL OFFICIALS.
A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED
SOMEWHERE WITHIN THE WARNING AREA. A WARNING IS TYPICALLY ISSUED
36 HOURS BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL-STORM-
FORCE WINDS...CONDITIONS THAT MAKE OUTSIDE PREPARATIONS DIFFICULT
OR DANGEROUS. PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE
RUSHED TO COMPLETION.
A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.
A STORM SURGE WATCH MEANS THERE IS A POSSIBILITY OF LIFE-
THREATENING INUNDATION...FROM RISING WATER MOVING INLAND FROM THE
COASTLINE...IN THE INDICATED LOCATIONS DURING THE NEXT 48 HOURS.
A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE
WITHIN THE WATCH AREA.
A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA.
IN ADDITION...INTERESTS IN SOUTHWESTERN LOUISIANA SHOULD CONTINUE
TO MONITOR THE PROGRESS OF THIS SYSTEM.
HURRICANE CENTER LOCATED NEAR 24.7N 93.9W AT 24/2100Z
POSITION ACCURATE WITHIN 15 NM
PRESENT MOVEMENT TOWARD THE NORTH-NORTHWEST OR 330 DEGREES AT 9 KT
ESTIMATED MINIMUM CENTRAL PRESSURE 976 MB
EYE DIAMETER 20 NM
MAX SUSTAINED WINDS 75 KT WITH GUSTS TO 90 KT.
64 KT....... 20NE 0SE 0SW 0NW.
50 KT....... 30NE 20SE 20SW 30NW.
34 KT....... 80NE 40SE 30SW 60NW.
12 FT SEAS..120NE 75SE 75SW 75NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
REPEAT...CENTER LOCATED NEAR 24.7N 93.9W AT 24/2100Z
AT 24/1800Z CENTER WAS LOCATED NEAR 24.4N 93.6W
FORECAST VALID 25/0600Z 25.5N 94.8W
MAX WIND 95 KT...GUSTS 115 KT.
64 KT... 30NE 15SE 10SW 15NW.
50 KT... 50NE 40SE 30SW 40NW.
34 KT...110NE 70SE 50SW 80NW.
FORECAST VALID 25/1800Z 26.7N 96.0W
MAX WIND 110 KT...GUSTS 135 KT.
64 KT... 35NE 30SE 20SW 30NW.
50 KT... 60NE 50SE 40SW 50NW.
34 KT...130NE 100SE 70SW 100NW.
FORECAST VALID 26/0600Z 27.8N 96.7W
MAX WIND 105 KT...GUSTS 130 KT.
64 KT... 35NE 30SE 30SW 35NW.
50 KT... 60NE 60SE 50SW 60NW.
34 KT...140NE 110SE 80SW 90NW.
FORECAST VALID 26/1800Z 28.5N 97.1W...INLAND
MAX WIND 85 KT...GUSTS 105 KT.
50 KT... 50NE 50SE 40SW 40NW.
34 KT...130NE 110SE 80SW 80NW.
FORECAST VALID 27/1800Z 28.7N 97.2W...INLAND
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 90NE 70SE 60SW 50NW.
EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
ON DAY 4 AND 200 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY
OUTLOOK VALID 28/1800Z 28.5N 96.5W...INLAND
MAX WIND 35 KT...GUSTS 45 KT.
OUTLOOK VALID 29/1800Z 29.0N 95.0W...OVER WATER
MAX WIND 35 KT...GUSTS 45 KT.
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 24.7N 93.9W
NEXT ADVISORY AT 25/0300Z
$$
FORECASTER BERG
ZCZC MIATCDAT4 ALL
TTAA00 KNHC DDHHMM
Hurricane Harvey Discussion Number 18
NWS National Hurricane Center Miami FL AL092017
400 PM CDT Thu Aug 24 2017
Since the issuance of the special advisory at 1800 UTC, data from a
dropsonde released by a NOAA Hurricane Hunter aircraft indicated
that Harvey's central pressure has dropped to 976 mb. However, the
plane has not measured winds stronger than what was observed by the
previous Air Force flight (although the NOAA P3 is flying a
research mission at a nonstandard level). For now, the initial
intensity will remain 75 kt pending data from another Air Force
flight this evening.
Harvey's initial motion estimate is 330/9 kt. A strengthening
mid-level high over the eastern Gulf of Mexico is expected to push
Harvey northwestward by tonight, and a northwest or north-northwest
motion should continue up until landfall. However, a stronger
mid-level high centered over the western United States is forecast
to cause Harvey to slow down considerably and stall near or just
inland of the Texas coast by days 3 and 4. After that time, the
track models have trended toward showing Harvey moving slowly
eastward by day 5, but it's too early to know if the center will
remain over land or re-emerge over the northwestern Gulf of Mexico.
The track guidance is very tightly clustered for the first 36-48
hours, which covers the period of landfall, but then there is much
greater spread in the models after 48 hours when Harvey is forecast
to slow down. Such guidance is usually an indication that the
cyclone will move very little, which is reflected in the official
forecast.
Harvey remains in an environment for further strengthening.
Vertical shear is low, and the hurricane will be moving over a warm
eddy of relatively higher oceanic heat content within the next
12-24 hours. As a result, the NHC intensity forecast calls for
additional intensification at least for the next 24 hours, with
Harvey expected to attain major hurricane strength on Friday.
There may be some fluctuations in intensity up until landfall due to
the possibility of an eyewall replacement or cooling of the shallow
shelf waters of Texas, but regardless Harvey is forecast to reach
the coast as a major hurricane. The intensity forecast after 48
hours is tricky because it all depends on how far inland Harvey
moves into Texas. If it stays stalls closer to the coast, as recent
model trends have suggested, then the cyclone may be able to
maintain a higher intensity with a greater proportion of its
circulation remaining over water. For that reason, the updated NHC
intensity forecast keeps Harvey as a tropical storm on days 3
through 5, but there is greater-than-normal uncertainty in this
part of the forecast.
It is critical that users not focus on the exact forecast track
of Harvey, since cycle-to-cycle adjustment are likely. All
locations within the hurricane and storm surge warning areas should
be preparing for the possibility of major hurricane-force winds and
life-threatening storm surge.
Key Messages:
1. Harvey is expected to be a major hurricane at landfall, bringing
life-threatening storm surge, rainfall, and wind hazards to portions
of the Texas coast. Preparations to protect life and property should
be completed by tonight, as tropical-storm-force winds will first
arrive in the hurricane and storm surge warning areas on Friday.
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.
3. Devastating and life-threatening flooding is expected across the
middle and upper Texas coast from heavy rainfall of 15 to 25 inches,
with isolated amounts as high as 35 inches, from Friday through next
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.
4. The Potential Storm Surge Flooding Map is available on the NHC
website. This product depicts a reasonable worst-case scenario -
the amount of inundation that has a 10 percent chance of being
exceeded at each individual location. This map best represents
the flooding potential in those locations within the watch and
warning areas.
FORECAST POSITIONS AND MAX WINDS
INIT 24/2100Z 24.7N 93.9W 75 KT 85 MPH
12H 25/0600Z 25.5N 94.8W 95 KT 110 MPH
24H 25/1800Z 26.7N 96.0W 110 KT 125 MPH
36H 26/0600Z 27.8N 96.7W 105 KT 120 MPH
48H 26/1800Z 28.5N 97.1W 85 KT 100 MPH...INLAND
72H 27/1800Z 28.7N 97.2W 45 KT 50 MPH...INLAND
96H 28/1800Z 28.5N 96.5W 35 KT 40 MPH...INLAND
120H 29/1800Z 29.0N 95.0W 35 KT 40 MPH...OVER WATER
$$
Forecaster Berg
NNNN
Updated at 00:20 UTC. Forecaster Weatherwax