Written by Sig Silber
This Article has been updated due to the rapidly changing situation. You can access the updated article by clicking on Maria has reached the Virgin Islands and Puerto Rico 20Sep2017
6:30 PM EDT Sept 19, 2017: LATEST FROM NHC: “WEATHER CONDITIONS RAPIDLY DETERIORATING IN THE U.S. VIRGIN ISLANDS…” “Maria’s core is expected to move near or over St. Croix and Puerto Rico tonight and Wednesday, bringing life-threatening wind, storm surge, and rainfall impacts to portions of those islands.” “Maria has continued to strengthen this afternoon, with surface and flight-level winds from an Air Force Reserve Hurricane Hunter aircraft supporting an intensity of 145 kt, and the central pressure inside the 5 n mi wide eye falling to 916 mb. The aircraft data also indicates that an outer wind maximum is present about 20-30 n mi from the center, but this has not yet developed into enough of an outer eyewall to stop the intensification in the inner eyewall.”
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This is an active period in the tropics so we are starting with the overview of the situation in both the Pacific and the Atlantic. Those potentially impacted by any of these storms should consult their local sources of information. The Public Advisories and other information that is available from the NOAA National Hurricane Center can be found here. Information from the Weather Prediction Center can be found here.
First the Atlantic
More Detail
And now the Pacific.
We start our Report with Now Hurricane Maria. The”M” Designation means a very powerful storm: Category 3 or higher.
And the Discussion
Hurricane Maria Discussion Number 15 NWS National Hurricane Center Miami FL 500 PM AST Tue Sep 19 2017
Maria has continued to strengthen this afternoon, with surface and flight-level winds from an Air Force Reserve Hurricane Hunter aircraft supporting an intensity of 145 kt, and the central pressure inside the 5 n mi wide eye falling to 916 mb. The aircraft data also indicates that an outer wind maximum is present about 20-30 n mi from the center, but this has not yet developed into enough of an outer eyewall to stop the intensification in the inner eyewall.
The initial motion remains 300/9. The forecast track philosophy remains the same, with the eye of Maria expected to move near the U. S. Virgin Islands tonight and across Puerto Rico on Wednesday, followed by a motion just north of the eastern Dominican Republic Wednesday night and Thursday. Subsequently, a break in the subtropical ridge caused in part by Hurricane Jose should allow Maria to turn north-northwestward and northward by the end of the forecast period. Only minor changes have occurred in the track guidance since the last advisory, and the new track has only minor adjustments from the previous track.
Some additional strengthening is possible this evening before the outer eyewall becomes better defined or the cyclone reaches its maximum potential intensity. It now appears likely that Maria will be at category 5 intensity when it moves over the U. S. Virgin Islands and Puerto Rico, although there is a chance that the start of the eyewall replacement cycle might reduce the intensity a little bit. The hurricane should weaken as it crosses Puerto Rico, and after that proximity to Hispaniola and less favorable upper-level winds are likely to lead to continued slow weakening. The new intensity forecast remains at the upper edge of the intensity guidance.
KEY MESSAGES:
1. Maria’s core is expected to move near or over St. Croix and Puerto Rico tonight and Wednesday, bringing life-threatening wind, storm surge, and rainfall impacts to portions of those islands. Everyone in these areas should follow advice from local officials to avoid life-threatening flooding from storm surge and rainfall.
2. Wind speeds atop and on the windward sides of hills and mountains and on high-rise buildings could be much stronger than the near-surface winds indicated in this advisory.
3. A hurricane warning also in effect for the remainder of the Virgin Islands and the northern coast of the Dominican Republic, where Maria is expected to bring dangerous wind, storm surge, and heavy rainfall.
4. A hurricane watch is in effect for the southeastern Bahamas and the Turks and Caicos, where Maria could bring hurricane conditions on Thursday.
FORECAST POSITIONS AND MAX WINDS
INIT 19/2100Z 16.8N 64.0W 145 KT 165 MPH
12H 20/0600Z 17.5N 65.2W 145 KT 165 MPH
24H 20/1800Z 18.4N 66.7W 130 KT 150 MPH…OVER PUERTO RICO
36H 21/0600Z 19.3N 68.1W 125 KT 145 MPH…OVER WATER
48H 21/1800Z 20.2N 69.4W 120 KT 140 MPH
72H 22/1800Z 22.5N 71.0W 115 KT 130 MPH
96H 23/1800Z 25.5N 72.0W 110 KT 125 MPH
120H 24/1800Z 28.5N 72.5W 95 KT 110 MPH
HURRICANE MARIA FORECAST/ADVISORY NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL 2100 UTC TUE SEP 19 2017
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY…
THE METEOROLOGICAL SERVICE OF THE BAHAMAS HAS ISSUED A HURRICANE WATCH FOR THE TURKS AND CAICOS ISLANDS AND THE SOUTHEASTERN BAHAMAS.
THE METEOROLOGICAL SERVICE OF ANTIGUA HAS DISCONTINUED THE TROPICAL STORM WARNING FOR ANTIGUA AND BARBUDA.
THE METEOROLOGICAL SERVICE OF BARBADOS HAS DISCONTINUED THE HURRICANE WARNING FOR DOMINICA.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT…
A HURRICANE WARNING IS IN EFFECT FOR…
* ST. KITTS…NEVIS…AND MONTSERRAT
* U.S. VIRGIN ISLANDS
* BRITISH VIRGIN ISLANDS
* PUERTO RICO…CULEBRA…AND VIEQUES
* CABO ENGANO TO PUERTO PLATA
A TROPICAL STORM WARNING IS IN EFFECT FOR…
* SABA AND ST. EUSTATIUS
* ST. MAARTEN
* ANGUILLA
* GUADELOUPE
* WEST OF PUERTO PLATA TO THE NORTHERN BORDER OF THE DOMINICAN
REPUBLIC AND HAITI
* WEST OF CABO ENGANO TO PUNTA PALENQUE
A HURRICANE WATCH IS IN EFFECT FOR…
* SABA AND ST. EUSTATIUS
* ST. MAARTEN
* ST. MARTIN AND ST. BARTHELEMY
* ANGUILLA
* ISLA SAONA TO CABO ENGANO
* TURKS AND CAICOS ISLANDS AND THE SOUTHEASTERN BAHAMAS
Here is the current Track Map for Jose.
Jose Discussion
Hurricane Jose Discussion Number 58 NWS National Hurricane Center Miami FL 500 PM EDT Tue Sep 19 2017
Satellite imagery indicate that Jose’s cloud pattern has improved since the previous advisory. Curved band features have become more evident in all quadrants and the upper-level outflow has also expanded and become more anticyclonic. Jose actually looks more like a tropical cyclone now. Satellite intensity estimates have increased and were a consensus T3.5/55 kt at 1800Z. Since that time, the convective pattern has continued to improve, including a burst of convection with cloud tops colder than -60C having developed near and over the well-defined low-level center. Given the much improved satellite cloud pattern, the intensity will remain 65 kt. An Air Force Reserve Hurricane Hunter aircraft is scheduled to investigate Jose by 2300Z.
Jose has made the much anticipated turn toward the north-northeast and is now moving 025/07 kt. There is no significant change to the previous track forecast or reasoning. The latest NHC model guidance remains in good agreement on Jose slowing down and turning toward the northeast by Wednesday morning, followed by a turn toward the east on Thursday as the cyclone moves around the north side of deep-layer ridge. During the 72-120 hour period, a high-latitude ridge is forecast to build to the north of Jose, forcing the cyclone slowly southward and southwestward over the far North Atlantic. The new official forecast track lies a little to the east of the consensus models, closer to the ECMWF solution.
The center and much of the inner core of Jose will be moving over 21-22C SSTs by 36-48 h. However, a large portion of the hurricane’s circulation will still be located over much warmer water, which will maintain a long, southerly fetch of unstable air into and to the north of the center. Since the vertical wind shear is expected to be 20 kt or less, only gradual weakening is expected as per the previous intensity forecasts, and the intensity models IVCN and HCCA.
The 34-kt wind radii were increased slightly in the northwestern quadrant based on 14-15Z ASCAT scatterometer wind data, offshore buoy reports, and a 40-45 kt wind report from ship VRGH3.
KEY MESSAGES:
1. While the center of Jose is forecast to remain offshore of the U.S. east coast, the large cyclone is expected to cause some direct impacts in portions of New England, and a tropical storm warning is in effect for Cape Cod, Block Island, Martha’s Vineyard, and Nantucket. Any deviation to the left of the NHC forecast track would increase the likelihood and magnitude of impacts along the coast from Long Island to southern New England.
2. Minor to moderate coastal flooding is possible from Delaware to southern New England during the next several days. Please see products issued by local National Weather Service forecast offices.
3. Swells generated by Jose are affecting Bermuda, the Bahamas, and much of the U.S. east coast. These swells are likely to cause dangerous surf and rip current conditions for the next several days in these areas.
4. Jose will produce heavy rain over a small part of southern New England and eastern Long Island as it passes offshore of these locations on Tuesday and Wednesday. Total accumulations of 1 to 3 inches are expected over eastern Long Island, southeast Connecticut, southern Rhode Island, and southeast Massachusetts. 3 to 5 inches are expected for Martha’s Vineyard, Nantucket, and Cape Cod. This rainfall could cause isolated flooding.
FORECAST POSITIONS AND MAX WINDS
INIT 19/2100Z 37.2N 71.3W 65 KT 75 MPH
12H 20/0600Z 38.2N 70.6W 65 KT 75 MPH
24H 20/1800Z 39.2N 69.2W 60 KT 70 MPH
36H 21/0600Z 39.7N 68.0W 55 KT 65 MPH
48H 21/1800Z 39.5N 67.5W 50 KT 60 MPH
72H 22/1800Z 39.0N 67.6W 45 KT 50 MPH…POST-TROPICAL
96H 23/1800Z 38.6N 68.1W 40 KT 45 MPH…POST-TROPICAL
120H 24/1800Z 38.3N 69.0W 35 KT 40 MPH…POST-TROPICAL
HURRICANE JOSE FORECAST/ADVISORY NUMBER 58 NWS NATIONAL HURRICANE CENTER MIAMI FL 2100 UTC TUE SEP 19 2017
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY…
THE TROPICAL STORM WARNING HAS BEEN DISCONTINUED FROM HULL SOUTHWARD TO SAGAMORE BEACH AND ALSO WEST OF WOODS HOLE.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT…
A TROPICAL STORM WARNING IS IN EFFECT FOR…
* WOODS HOLE TO SAGAMORE BEACH…INCLUDING CAPE COD
* BLOCK ISLAND
* MARTHA’S VINEYARD
* NANTUCKET
A TROPICAL STORM WATCH IS IN EFFECT FOR…
* THE COAST OF LONG ISLAND FROM FIRE ISLAND INLET TO PORT JEFFERSON
General Weather Situation
We believe that it is easier to understand what is going on with individual storms if they are put into the context of the overall weather situation.
Some of the graphics below show the two storms of most interest. Other graphics will be more relevant for Jose as it moves north and comes into view.
Additional Graphics
This is a national animation of weather fronts and precipitation forecasts with four 6-hour projections of the conditions that will apply covering the next 24 hours and a second day of two 12-hour projections the second of which is the forecast for 48 hours out and to the extent it applies for 12 hours, this animation is intended to provide coverage out to 60 hours. This graphic is now very relevant as one can see four perhaps five storms in this graphic. .
