AXNT20 KNHC 201106

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
706 AM EDT Wed Sep 20 2017

Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through 1130 UTC.


At 20/1035 UTC, major Hurricane Maria was located near 18.0N 65.8W or about 15 nm west-southwest of Vieques, and 30 nm southeast of San Juan, Puerto Rico. The present movement of Maria is northwest at 9 kt. The estimated minimum central pressure is 917 mb. Maximum sustained winds are 135 kt with gusts to 165 kt, a Category 4. Numerous strong convection is within 120 nm of the center. Scattered moderate convection is elsewhere within 175 nm of the center. Maria is moving across Puerto Rico today, and will pass just north of the northeast coast of the Dominican Republic tonight and Thursday. Please see the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT5/WTNT35 KNHC for more details.

At 20/0900 UTC, Tropical Storm Jose was located about 165 nm south of Nantucket Massachusetts near 38.4N 70.3W, moving northeast at 7 kt. The estimated minimum central pressure is 975 mb. Maximum sustained winds are 55 kt with gusts to 70 kt. Scattered moderate convection lays on the NW quadrant of the storm from 38N to 41N between 70W and 75W. The center of Jose is expected to pass well to the east of the New Jersey coast today, and pass offshore of southeastern Massachusetts Thursday. Please see the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details.


A 1008 mb low in the central Atlc, or the remnants of former tropical cyclone Lee, are located near 18N46W. Showers and thunderstorms have significantly decreased near the low pressure area the last couple of hours. Scattered moderate convection and tstms are in the NE quadrant of the low center from 17N to 25N between 40W and 46W. Gale-force winds prevails in the NE quadrant of the low...within 270 nm of the center. An increase in the organization of the deep convection would result in the regeneration of Lee as it moves northward over the central Atlantic Ocean. There is a medium chance for tropical cyclone re- development within the next 48 hours.


A tropical wave is in the E Atlc with axis extending from 18N27W to 06N27W, moving west at 20 kt. CIRA LPW imagery show dry air has increased in the wave environment the last couple of hours due to intrusion of Saharan dry air and dust. This is limiting the convection to scattered moderate SW of the wave axis from 05N to 12N between 28W and 32W.

A tropical wave is in the W Caribbean with axis extending from 20N85W to 07N88W, moving west at 20 kt. CIRA TPW imagery indicates the presence of dry air in the wave environment that along with strong subsidence from aloft, and strong vertical wind shear support lack of convection in the far NW Caribbean W of 84W.


The monsoon trough extends southwest from the African coast near 12N16W to 11N28W to 08N42W. The ITCZ extends from 08N42W to 09N48W to 09N59W. Aside from the convection associated with the tropical wave, scattered moderate convection is from 04N to 11N between 32W and 40W.



Weak surface ridging prevails over the Gulf of Mexico basin with light and variable winds over most of the basin. Ridging aloft over the entire Gulf along with dry air subsidence continue to support clear skies, except for scattered showers and tstms over the Bay of Campeche due to proximity of a tropical wave that already moved over the EPAC waters S of Mexico. Winds will shift from SE to E Thursday afternoon.


Category 4 Hurricane Maria is moving across Puerto Rico this morning. The eye of Maria is forecast to exit Puerto Rico by the north during the afternoon hours, and pass just north of the northeast coast of the Dominican Republic tonight and Thursday. See the special features section for further details. Low level wind convergence east of a tropical wave in the western Caribbean is producing a large area of isolated showers and tstms in the SW Caribbean from S of 15N W of 77W. Scatterometer data shows mainly light to gentle trade winds west of 71W, with the remainder of the basin N of 12N experiencing cyclonic winds associated with Hurricane Maria.


Scattered showers are in the Mona Passage and E Dominican Republic adjacent waters. Mostly fair weather prevails across the island. However, weather conditions will deteriorate across the Island this morning associated with the rainbands of Hurricane Maria moving across Puerto Rico. These showers will increase as the system moves NW very close of the Island on Thu.


Please refer to Special Features section for more information on Hurricanes Maria and Tropical Storm Jose. There is a gale warning associated with the remnants of former tropical cyclone Lee along with scattered moderate convection. See gale warning section above. A surface trough over the central Atlantic extends from 32N41W to 30N42W to 25N44W. Scattered moderate convection is observed east of the trough north of 23N between 38W-44W. The remainder of the basin remains under the influence of a broad surface ridge centered north of the area.

For additional information please visit http://www.hurricanes.gov/marine

$$ Ramos