5:00 AM AST Thu Sep 21 - Major Hurricane Maria - 115 mph 959 mb NW at 9 mph
Posted by cypresstx on 9/21/2017, 6:01 am
http://www.nhc.noaa.gov/cyclones/

from Advisory:

DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 500 AM AST (0900 UTC), the large eye of Hurricane Maria was located near latitude 19.6 North, longitude 68.4 West.  Maria is moving toward the northwest near 9 mph (15 km/h), and this general motion is expected through tonight.  A turn toward the north-northwest is forecast on Friday.  On the forecast track, the eye of Hurricane Maria will continue to pass offshore of the northeastern coast of the Dominican Republic today.  Maria should then move near the Turks and Caicos Islands and the southeastern Bahamas tonight and Friday.

Maximum sustained winds are near 115 mph (185 km/h) with higher gusts.  Maria is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.  Some strengthening is possible during the next day or so.

Hurricane-force winds extend outward up to 60 miles (95 km) from the center and tropical-storm-force winds extend outward up to 150 miles (240 km).  Punta Cana in the eastern Dominican Republic recently reported a wind gust to 56 mph (91 km/h).

The estimated minimum central pressure is 959 mb (28.32 inches).


HAZARDS AFFECTING LAND
----------------------
WIND:  Strong gusty winds are still occurring over portions of Puerto Rico, but should continue to gradually subside this morning. Tropical storm or hurricane conditions are continuing across portions of the warning areas in the Dominican Republic.  Hurricane conditions are expected to begin in portions of the Turks and Caicos Islands and the southeastern Bahamas tonight, with tropical storm conditions beginning in these areas later today.

STORM SURGE:  Water levels in Puerto Rico should continue receding during the next few hours.

A dangerous storm surge accompanied by large and destructive waves will raise water levels by as much as 4 to 6 feet above normal tide levels in the hurricane warning area in the Dominican Republic, and 1 to 3 ft elsewhere along the northern coasts of the Dominican Republic and Haiti.

A dangerous storm surge accompanied by large and destructive waves will raise water levels by as much as 9 to 12 feet above normal tide levels within the hurricane warning area of the southeastern Bahamas and the Turks and Caicos Islands.

RAINFALL: Maria is expected to produce the following rainfall accumulations through Saturday:

Puerto Rico...additional 4 to 8 inches, isolated maximum storm total amounts 35 inches.
U.S. and British Virgin Islands...additional 2 to 4 inches.
Northern and eastern Dominican Republic, Turks and Caicos, and Mayaguana in southeast Bahamas... 8 to 16 inches, isolated 20 inches.
Inagua Islands, Crooked Island, and rest of southeast Bahamas... 4 to 8 inches.
Northern Haiti... 2 to 4 inches.

Rainfall on these islands will continue to cause life-threatening flash floods and mudslides.

SURF:  Swells generated by Maria are still affecting the Leeward Islands, Puerto Rico, and the Virgin Islands.  These swells are also affecting the northern coast of Hispaniola, the Turks and Caicos Islands, and should begin in the Southeastern Bahamas later today.  These swells are likely to cause life-threatening surf and rip current conditions.  Please consult products from your local weather office.


and Discussion:

Hurricane Maria Discussion Number  21
NWS National Hurricane Center Miami FL       AL152017
500 AM AST Thu Sep 21 2017

Although the large, 40 n mi diameter, eye of the hurricane is still a little ragged-looking, it is gradually becoming better defined, and a ring of cold cloud tops is intensifying around the eye.  The current intensity estimate is 100 kt based on earlier Air Force Hurricane Hunter data and recent Dvorak classifications from TAFB and SAB.  Maria is likely to move over warm waters with moderate southwesterly vertical shear for the next couple of days.  Maria's well-developed upper-level outflow suggests that shear is probably not having much influence over the hurricane at this time.  Although the numerical guidance is not very aggressive about intensification, based on the current trends of the cloud pattern, some strengthening seems likely over the next day or so.  Later in the forecast period, shear will probably cause gradual weakening.  The official intensity forecast is a little above the latest model consensus.

Maria continues its northwestward motion, at about 315/8 kt.  The hurricane is expected to turn north-northwestward and northward around a subtropical ridge over the Atlantic for the next 2 to 3 days.  Late in the forecast period, a mid-level high over the northeastern U.S. could slow the forward motion somewhat.  This high is forecast by the global models to subsequently weaken however, which should allow Maria to turn north-northeastward in the flow on the northwestern edge of a subtropical ridge over the west-central Atlantic.  The official track forecast lies between the corrected consensus guidance and the latest ECMWF prediction. This is quite similar to the previous NHC track.

KEY MESSAGES:

1. Heavy rainfall is expected to continue, and catastrophic flash flooding is occurring in Puerto Rico, especially in areas of mountainous terrain.  Everyone in Puerto Rico should continue to follow advice from local officials to avoid these life-threatening flooding conditions.

2. A Hurricane Warning is in effect for the northern coast of the Dominican Republic, the Turks and Caicos Islands, and the southeastern Bahamas, where Maria is expected to bring dangerous wind, storm surge, and heavy rainfall.

FORECAST POSITIONS AND MAX WINDS

INIT  21/0900Z 19.6N  68.4W  100 KT 115 MPH
12H  21/1800Z 20.5N  69.3W  105 KT 120 MPH
24H  22/0600Z 21.6N  70.4W  110 KT 125 MPH
36H  22/1800Z 22.9N  71.1W  105 KT 120 MPH
48H  23/0600Z 24.3N  71.7W  100 KT 115 MPH
72H  24/0600Z 27.4N  72.3W  100 KT 115 MPH
96H  25/0600Z 30.0N  72.0W   90 KT 105 MPH
120H  26/0600Z 32.5N  70.5W   80 KT  90 MPH

$$
Forecaster Pasch


NASA Maria  https://www.nasa.gov/feature/goddard/2017/maria-atlantic-ocean
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5:00 AM AST Thu Sep 21 - Major Hurricane Maria - 115 mph 959 mb NW at 9 mph - cypresstx, 9/21/2017, 6:01 am
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