AXNT20 KNHC 200606

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 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 0000 UTC surface analysis and satellite imagery through 0545 UTC.


At 20/0600 UTC, major Hurricane Maria was located near 17.6N 65.1W or about 15 nm west-southwest of Saint Croix, and 75 nm southeast of San Juan, Puerto Rico. The present movement of Maria is west- northwest at 9 kt. The estimated minimum central pressure is 910 mb. Maximum sustained winds are 145 kt with gusts to 175 kt, a Category 5. Numerous strong convection is within 90 nm of the center. Scattered moderate convection is elsewhere within 180 nm of the center. The eye of Maria will cross Puerto Rico today Wednesday, and 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 20/0600 UTC, Tropical Storm Jose was located about 175 nm south of Nantucket Massachusetts near 38.2N 70.5W, moving northeast at 8 kt. The estimated minimum central pressure is 973 mb. Maximum sustained winds are 60 kt with gusts to 75 kt. Scattered moderate convection lays on the NW quadrant of the storm from 37N to 41N between 70W and 73W. 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 17N44W. Showers and thunderstorms have increased near the low pressure area and gale- force winds are already in the E quadrant of the low...within 75 nm of the center. Numerous moderate/isolated strong convection is mainly to the north of the low from 16N to 20N between 41W and 45W. 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 18N25W to 06N26W, moving west at 20 kt. The wave is mainly within a region of abundant low to middle level moisture as shown by CIRA TPW imagery. However, enhanced IR imagery show intrusion of Saharan dry air and dust to the W environment of the wave. This is limiting the convection to scattered moderate from 07N to 14N between 24W and 30W.

A tropical wave is over the western Caribbean with axis extending from 21N85W to 09N86W, 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 13N17W to 10N27W to 07N34W. The ITCZ extends from 07N34W to 08N43W to 08N50W. Aside from the convection associated with the tropical wave, scattered moderate convection is from 04N to 10N between 30W and 40W.



Weak surface ridging prevails over the Gulf of Mexico basin with light and variable winds over most of the basin with the exception of moderate locally fresh SE winds within 90 nm of the coast of Texas. Ridging aloft over the entire Gulf along with dry air subsidence continue to support clear skies, except for scattered showers and tstms over the E Bay of Campeche associated with the 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 5 Hurricane Maria is moving across the northeast Caribbean waters and is expected to reach southeastern Puerto Rico this morning. The eye of Maria then will cross Puerto Rico during the day, and pass just north of the northeast coast of the Dominican Republic Wednesday night 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 scattered showers and isolated tstms in the SW Caribbean from S of 15N W of 77W. Expect the wave to continue moving west with convection mainly east-southeast of the wave axis. Scatterometer data shows mainly light to gentle trade winds west of 71W, with the remainder of the basin N of 15N experiencing cyclonic winds associated with Hurricane Maria. Fresh to locally strong winds are off the Nicaragua coast associated with the aforementioned convection.


Isolated showers are in the Windward Passage and southern Haiti adjacent waters. Mostly fair weather prevails across the island. Weather conditions will deteriorate across the Island starting Wed morning associated with the outer rainbands of Hurricane Maria moving across Puerto Rico. These showers will increase as the system moves WNW very close of the Island on Thu.


Please refer to Special Features section for more information on Hurricanes Maria and recently downgraded Tropical Storm Jose. There is a gale warning associated with the remnants of former tropical cyclone Lee along with strong 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