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NHC Tropical Weather Discussion (Atlantic)

• NHC Atlantic Tropical Weather Discussion
  
  000
  AXNT20 KNHC 222108
  TWDAT
  
  Tropical Weather Discussion
  NWS National Hurricane Center Miami FL
  0005 UTC Sat Sep 23 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
  2100 UTC.
  
  ...SPECIAL FEATURES...
  
  Tropical Storm Ophelia is centered near 32.9N 76.3W at 22/2100
  UTC or 100 nm SE of Cape Fear North Carolina, moving NNW at 11
  kt. Estimated minimum central pressure is 986 mb. Maximum
  sustained wind speed is 60 kt with gusts to 75 kt. Scattered
  moderate and isolated strong convection is noted within 150 nm in
  the W quadrant of Ophelia. Peak seas are currently around 23 ft SE
  of Cape Fear, North Carolina, per the Ocean Prediction Center
  based on nearby observations from NDBC buoys. On the forecast
  track, the center of Ophelia will approach the coast of North
  Carolina tonight, and then move across eastern North Carolina,
  southeastern Virginia, and the Delmarva Peninsula Saturday and
  Sunday. Little change in strength is forecast before landfall
  along the coast of North Carolina. Weakening is expected after
  landfall through the rest of the weekend. Swells generated by
  this system will affect much of the U.S. east coast through the
  weekend, likely causing life-threatening surf and rip currents.
  Heavy rainfall from this system could produce locally considerable
  flash, and urban flooding impacts across portions of the Mid-
  Atlantic states from North Carolina to New Jersey through Sunday.
  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
  Ophelia NHC Forecast/Advisory and Public Advisory at
  www.hurricanes.gov for more details.
  
  Invest 90L in the Central Tropical Atlantic: The axis of a
  tropical wave is analyzed along 35W with a 1009 mb low centered
  at 14N35W, or several hundred nautical miles west of the Cabo
  Verde Islands. Maximum winds are currently 25 kt and peak seas
  are up to 10-11 ft. Shower and thunderstorm activity associated
  with this area of low pressure has decreased slightly over the
  last few hours, however, further development is still expected.
  Scattered moderate convection is noted within about 420 nm in the
  NW semicircle of the low. A tropical depression is likely to
  form during the next couple of days while the system moves
  generally westward at 10 to 15 kt. The system is then expected to
  turn west-northwestward early next week as it moves over the
  central tropical Atlantic. The formation chance through 48 hours
  is high. Please see the latest Tropical Weather Outlook at
  www.hurricanes.gov for more information.
  
  ...TROPICAL WAVES...
  
  Please see the Special Features Section for details on the
  tropical wave (Invest 90L) along 35W.
  
  A tropical N Atlantic tropical wave has its axis along 58W, south
  of 22N, moving westward around 10 kt. Scattered moderate
  convection is noted from 08N to 15N between 56W and 64W, including
  over inland portions of NE South America.
  
  ...MONSOON TROUGH/ITCZ...
  
  The monsoon trough reaches the Atlantic through the coast of
  Senegal near 14N17W and continues westward to the aforementioned
  low pressure near 14N35W, before terminating near 09N47W. No ITCZ
  is evident in the tropical Atlantic at this time. Scattered
  moderate convection is noted from 12N to 19N between 43W and 47W.
  
  GULF OF MEXICO...
  
  A weak surface trough is analyzed from 26N90W to 23N85W. Scattered
  showers and thunderstorms are noted between 60 nm and 180 nm NE of
  the trough. Moderate NE-E winds and 3-4 ft seas are NE of the
  trough. Otherwise, weak high pressure over the lower Mississippi
  Valley is supporting only light to gentle NE to E breezes and
  slight seas across the remainder of the basin this afternoon,
  along with 1-3 ft seas.
  
  For the forecast, weak high pressure over the lower Mississippi
  Valley extending across the northern Gulf will control the weather
  pattern across basin through early next week. This will support
  mostly gentle to moderate winds and slight seas, except for
  moderate winds pulsing to fresh winds offshore the western Yucatan
  Peninsula in the evenings.
  
  CARIBBEAN SEA...
  
  Weak surface ridging north of the Caribbean is forcing only
  gentle trades N of a line from the SW tip of Haiti to central
  Jamaica to the border of Nicaragua and Honduras, where seas are
  mainly 2-3 ft. Moderate to fresh trades prevail SE of there,
  highest in the central Caribbean with the pressure gradient is
  relatively tight, along with 3-6 ft seas, locally 7 ft near
  11.5N76.5W. No deep convection is noted today over the Caribbean.
  
  For the forecast, moderate to fresh trade winds in the central
  Caribbean will change little through Sat. Winds across central
  portions will increase modestly Sun through Mon as high pressure
  strengthens across the region. Fresh to strong trade winds will
  pulse offshore of northern Colombia and northwest Venezuela during
  mainly the overnight and early morning hours into early next
  week. Looking ahead, seas will build in mixed NE and E swell
  across waters east of the Leeward Islands starting early Mon,
  ahead of low pressure moving westward across the tropical
  Atlantic, possibly as the next tropical cyclone.
  
  ATLANTIC OCEAN...
  
  Please see the Special Features section section above for
  information on Tropical Storm Ophelia and Invest 90L.
  
  A mid-level trough extends from 31N73W to near Key Largo, Florida.
  Scattered showers and thunderstorms are noted within 120 nm SE of
  this feature, with similar activity from 22N to 27N between 67W
  and 72W. A weak surface trough is analyzed from 31N28.5W to
  29.5N35W to 30N40W with a parent front just N of 31N. Elsewhere,
  ridging extends across the Atlantic along roughly 30N/31N. Between
  the ridge and the monsoon trough/ITCZ, the trades are gentle to
  moderate with seas 5-8 ft. Winds and seas are higher in the
  vicinity of Ophelia extending S into our area to 29N, and also
  near Invest 90L. Isolated to widely scattered moderate convection
  is noted from 19N to 28N between 45W and 59W in association with
  an upper-level trough.
  
  For the forecast west of 55W, Ophelia will move further northward and
  inland across coastal North Carolina on Sat. Large northerly swell
  will move through the waters W of 70W tonight through early Sun
  before fading. A weak ridge will build in the wake of Ophelia off
  Florida through early next week, although a trough will persist
  across the 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 low pressure moving westward across
  the tropical Atlantic, possibly as the next tropical cyclone.
  
  $$
  Lewitsky