AXNT20 KNHC 232112

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sun Sep 24 2023

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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through 2030 UTC.


Tropical Storm Ophelia is centered over SE Virginia near 36.8N 77.3W at 23/2100 UTC or 40 nm S of Richmond Virginia, moving N at 10 kt. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas which are N of the area are currently around 16 ft offshore Hampton Roads and also SE of New Jersey. Numerous moderate convection is noted within 45 nm of the center, except out to 120 nm in the NE quadrant of Ophelia. Additional convection extends well away from the system. On the forecast track, the center of Ophelia is expected to continue moving over southeastern Virginia through tonight, and then over the Delmarva Peninsula by tomorrow. Ophelia is likely to become a post-tropical cyclone tomorrow. Swells generated by Ophelia will continue to affect much of the east coast of the United States through the weekend. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. Heavy rainfall from Ophelia may produce locally considerable flash and urban flooding impacts across portions of the Mid-Atlantic states from North Carolina to New Jersey through Sunday.

Recently upgraded Tropical Storm Philippe is centered near 15.6N 39.7W at 23/2100 UTC or 910 nm W of the Cabo Verde Islands, moving W at 12 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas with Philippe are 14-15 ft. Numerous moderate scattered strong convection is noted within 150 nm in the NE semicircle. Scattered moderate convection is noted elsewhere from roughly 13N to 21N between 30W and 42W. A continued westward motion at a slightly slower forward speed is expected into early next week. Very gradual strengthening is expected during the next several days.

Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Philippe NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details on both Ophelia and Philippe.


A tropical wave is in the eastern Atlantic Ocean between the coast of Africa and the Cabo Verde Islands along 20W/21W, from 20N southward, moving W at around 10 kt. No significant convection is noted.

A tropical wave is in the eastern Caribbean Sea along 65W/66W from near the Anegada Passage southward to central Venezuela, moving W at around 10 kt. No significant convection is noted.


The monsoon trough passes through the coastal plains of Guinea-Bissau near 12N16W to 10N24W to 14N34W. No ITCZ is analyzed in the Atlantic Ocean. Scattered moderate isolated strong convection is noted from 07N to 14N between 25W and 29W, and from 05N to 07N between 44W and 50W.


An elongated surface trough extends from the NW Caribbean through near the Yucatan Channel to the eastern Gulf near 27N86W. This surface feature combined with mid to upper level support is aiding scattered showers and thunderstorms S of 26N and E of 87W. Otherwise fair weather prevails across the basin. Gentle to moderate NE-E winds and 2-4 ft seas prevail E of 90W near the surface trough, with light to gentle winds and 1-3 ft seas W of 90W.

For the forecast, the surface trough over the southeast Gulf will drift slowly into the western Gulf through early next week and dissipate. Meanwhile, weak high pressure will persist over the north-central and northeast Gulf. This pattern will support gentle to moderate NE to E winds and slight seas across the basin through the middle of next week.


Refer to the Tropical Waves section for details on a tropical wave in the eastern Caribbean. A surface trough extends from the SE Gulf of Mexico into the NW Caribbean Sea with some isolated to widely scattered showers and thunderstorms near it. Thunderstorms are prevalent from W of Haiti to between Cuba and Jamaica aided by a mid to upper level trough. Light to gentle winds are evident W of 80W, with moderate trades E of 80W, except fresh offshore NW Venezuela and N Colombia. Seas are 1-3 ft in the NW Caribbean, and 3-6 ft elsewhere, highest in the central Caribbean.

For the forecast, the Atlantic high pressure will support moderate to fresh trade winds across most of the eastern and central Caribbean through early next week, with fresh to strong pulses off northwest Venezuela and northeast Colombia during mainly the overnight and early morning hours. Looking ahead, seas will build in mixed NE and E swell across waters east of the Leeward Islands starting Mon, ahead of newly formed Tropical Storm Philippe, currently over the eastern Atlantic. Philippe is expected to turn NW before reaching 55W next week, and move into the central Atlantic.


Refer to the Special Features section for details on Tropical Storm Ophelia and recently upgraded Tropical Storm Philippe.

Scattered showers and thunderstorms are noted from 20N to 31N between 70W and 80W due to a mid to upper level trough. Similar activity is from 22N to 28N between 53W and 60W. Elsewhere, high pressure ridging in the wake of Ophelia dominates the Atlantic waters. Mainly gentle to moderate trades prevail away from Philippe, locally fresh from 14N to 25N between the coast of Africa and 55W, and also from 25N to 31N between 55W and 75W. Seas if 5-8 ft dominate the Atlantic basin away from Philippe.

For the forecast W of 55W, large northerly swell from Ophelia, now inland over SE Virginia, will continue to impact the waters N of 29N and W of 70W through this evening. A weak ridge has built into the central Bahamas in the wake of Ophelia and will persist through early next week, while a trough will persist across the northern Bahamas through Mon. Looking ahead, seas will build in mixed NE and E swell across waters northeast of the Leeward Islands starting Mon, ahead of Tropical Storm Philippe. Tropical Storm Philippe is expected to turn NW by Tue and brush along the far eastern zones on Wed and Thu.

$$ Lewitsky