Monthly Archives: October 2016

Typhoon Sarika Near Catanduanes Island, Threatens Luzon

The center of Typhoon Sarika is located near Catanduanes Island and Sarika poses a serious threat to Luzon.  At 5:00 p.m. EDT on Friday the center of Typhoon Sarika was located at latitude 14.4°N and longitude 124.8°E which put it about 280 miles (455 km) east of Manila, Philippines.  Sarika was moving toward the west-northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 981 mb.

The circulation of Typhoon Sarika is well organized.  An eye has appeared at times on conventional and microwave satellite imagery.  A primary rainband wrapped around the eye and strong thunderstorms are occurring in the eyewall.  Additional, well formed rainbands are rotating around the core of the circulation.  The convection around the core is generating well developed upper level divergence which is pumping away mass.

Typhoon Sarika is moving through a very favorable environment.  It is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  Typhoon Sarika will continue to intensify as long as the center stays over the water and it could intensify rapidly now that the circulation is well organized.

A subtropical ridge north of Sarika is steering the typhoon toward the west-northwest and that general motion is expected to continue for several more days.  On its anticipated track the center of Typhoon Sarika will remain north of Catanduanes Island.  It will pass just to the north of Daet and Labo on Saturday.  The center of Typhoon Sarika could be near or just to the north of the Polillo Islands in 12-16 hours.  Sarika could make a landfall near Baler on Luzon in 18-24 hours.

Sarika is a well organized intensifying typhoon.  It could bring strong winds to portions of northern Luzon.  Typhoon Sarika will also bring very heavy rain and create the potential for flash floods and mudslides.  Sarika will generate a storm surge in places where the wind blows the water toward the coast.

Tropical Storm Sarika Forms East of the Philippines

Tropical Storm Sarika formed east of the Philippines on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Sarika was located at latitude 13.8°N and longitude 127.0°W which put it about 425 miles (685 km) east of Manila, Philippines.  Sarika was moving toward the west at 11 m.p.h. (18 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 997 mb.

The circulation of Tropical Storm Sarika is still organizing.  Most of the thunderstorms are occurring in a broad rainband that curls around the western and southern sides of the circulation.  There are a few thunderstorms in thinner rainbands in the eastern half of the circulation.  More thunderstorms are developing closer to the center of circulation.  Those thunderstorms are beginning to produce upper level divergence which is pumping out mass.  As the mass is removed, the pressure decreases and the wind speeds increase.

Tropical Storm Sarika is moving through an environment that is generally favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  An upper level ridge to the north of Sarika is producing easterly winds which are blowing across the top of the tropical storm.  The vertical wind shear may account for the asymmetrical distribution of thunderstorms, but it is not strong enough to prevent Sarika from intensifying.  The vertical wind shear could slow the rate of intensification while the core of the circulation becomes better organized.  Sarika could strengthen into a typhoon with the next 24 to 36 hours.

A subtropical ridge north of Sarika is steering the tropical storm toward the west and that general motion is expected to continue for another 12 to 24 hours.  In a day or so Tropical Storm Sarika is forecast to turn more toward the west-northwest.  On its anticipated track Tropical Storm Sarika could be near Catanduanes Island in about 24 hours.  Sarika could be near Central Luzon in about 48 hours.

Tropical Storm Sarika is expected to intensify into a typhoon.  It could bring strong winds and very heavy rain to parts of the northern Philippines.  The heavy rain could cause flash floods and mudslides.

Hurricane Nicole Bringing Strong Winds and Heavy Rain to Bermuda

Hurricane Nicole is bringing strong winds and heavy rain to Bermuda on Thursday morning.  At 11:00 a.m. EDT on Thursday the center of Hurricane Nicole was located at latitude 32.3°N and longitude 64.6°W which put it about 10 miles (15 km) east of Bermuda.  Nicole was moving toward the northeast at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 140 m.p.h. (225 km/h).  The minimum surface pressure was 961 mb.  A Hurricane Warning remains in effect for Bermuda.

Nicole is a large powerful hurricane.  Winds to hurricane force extend out about 65 miles (105 km) from the center of circulation.  Winds to tropical storm force extend out about 180 miles (290 km) from the center.  The diameter of the eye is approximately 35 miles (55 km).

A weather station on Pearl Island reported sustained winds to 87 m.p.h. (141 km/h) with wind gusts to 119 m.p.h. (191 km/h).  An elevated weather station at Commissioner’s Point reported sustained winds to 92 m.p.h. (148 km/h) and wind gusts to 122 m.p.h. (196 km/h).

Hurricane Nicole is moving toward the northeast at 16 m.p.h. (26 km/h).  So, it will take approximately two hours for the eye of Hurricane Nicole to move across Bermuda.  After the eye passes, hurricane force winds in the southern half of Nicole will affect Bermuda.  The winds should gradually diminish later today when Hurricane Nicole moves northeast of Bermuda.

Powerful Major Hurricane Nicole Nearing Bermuda

Hurricane Nicole intensified into a powerful major hurricane late on Thursday as it moved closer to Bermuda.  At 11:00 p.m. EDT on Thursday the center of Hurricane Nicole was located at latitude 30.1°N and longitude 66.4°W which put it about 180 miles (290 km) south-southwest of Bermuda.  Nicole was moving toward the north-northeast at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 950 mb.  Nicole is a Category 4 hurricane on the Saffir-Simpson Scale.  A Hurricane Warning is in effect for Bermuda.

Hurricane Nicole intensified very rapidly during the past 12 hours.  The maximum sustained wind speed increased from 100 m.p.h. (160 km/h) to 130 m.p.h. (215 km/h) during that time period.  The minimum surface pressure decreased from 970 mb to 950 mb at the same time.  Hurricane Nicole now has a large circular eye with a diameter of 35 m.p.h. (55 km).  Hurricane Nicole also increased in size as it intensified.  Winds to hurricane force now extend out 65 miles (105 km) from the center of circulation.  Wind to tropical storm force extend out 160 miles (260 km) from the center.

Nicole is a large powerful hurricane. The Hurricane Intensity Index (HII) is 25.1.  The Hurricane Size Index (HSI) is 20.6 and the Hurricane Wind Intensity Size Index (HWISI) is 45.7.  The indices indicate that Hurricane Nicole is capable of causing widespread significant wind damage.

Southwesterly winds on the eastern side of a upper level trough will steer Hurricane Nicole toward the northeast.  When Nicole moves further north, westerly winds will steer it more toward the northeast.  On its anticipated track the core of Hurricane Nicole will reach Bermuda on Thursday morning.  Nicole has the potential to be a very destructive hurricane.

Nicole Strengthens Into a Hurricane, Warning for Bermuda

Tropical Storm Nicole intensified into a hurricane on Tuesday afternoon and a Hurricane Warning was issued for Bermuda.  At 5:00 p.m. EDT on Tuesday the center of Hurricane Nicole was located at latitude 27.4°N and longitude 66.4°W which put it about 350 miles (565 km) south-southwest of Bermuda.  Nicole was moving toward the northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 95 m.p.h. (155 km/h).  The minimum surface pressure was 980 mb.

The organization of the circulation of Hurricane Nicole improved rapidly on Tuesday afternoon.  The primary rainband wrapped around the center of circulation and an eye developed.  The eye currently has a diameter of about 30 miles (48 km).  A ring of strong thunderstorms surrounds the eye.  Those thunderstorms are producing well developed upper level divergence which is pumping out mass in all directions.  Additional rainbands are developing in the rest of the circulation.  Nicole is a relatively small hurricane.  Hurricane force winds only extend out about 35 miles (55 km) from the center and tropical storm force winds on extend out about 120 miles (195 km) from the center.

The environment around Hurricane Nicole became much more favorable on Tuesday afternoon.  The winds in the upper level weakened and the vertical wind shear diminished.  The weaker upper level winds also allowed the upper level divergence to pump out more mass and the pressure decreased 10 mb in six hours on Tuesday afternoon.  Less vertical wind shear allowed Hurricane Nicole to extract energy more efficiently from the ocean.  Hurricane Nicole is moving over water where the Sea Surface Temperature is near 28.5°C.  Nicole is likely to intensify for another 36 to 48 hours.  So, Hurricane Nicole will continue to intensify and it could intensify rapidly.  Nicole could be a major hurricane by the time it nears Bermuda.

Nicole is moving around the western end of a subtropical high pressure system which is steering the hurricane toward the northwest.  When Hurricane Nicole reaches the western end of the high, it will turn more toward the north.  As Hurricane Nicole moves farther north, the westerly winds in the middle latitudes will turn it toward the northeast.  On its anticipated track, Hurricane Nicole could approach Bermuda on Thursday morning.  It could be a major hurricane at that time.

Tropical Storm Nicole Prompts Hurricane Watch for Bermuda

While water rescues continued in parts of North Carolina and recovery efforts accelerated after the passage of Hurricane Matthew, Tropical Storm Nicole prompted the issuance of a Hurricane Watch for Bermuda.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Nicole was located at latitude 26.3°N and longitude 65.4°W which put it about 415 miles (670 km) south of Bermuda.  Nicole was moving toward the north at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 992 mb.

After becoming a hurricane last Thursday Nicole weakened back to a tropical storm during the weekend.  A combination of intermittent vertical wind shear and drier air caused the structure of Tropical Storm Nicole to deteriorate.  The eye disappeared and the thunderstorms in the rainbands weakened.  There appears to be a remnant of the eyewall, but it only consists of lower clouds and showers.  Several rainbands exist around the circulation, although they are not as strong as they were a few days ago.  Thunderstorms southeast of the center of circulation seem to have increased on Monday afternoon.  The new thunderstorms are generating some upper level divergence but it is not currently well developed.

Tropical Storm Nicole is an environment that is marginal for intensification.  An upper level trough north of Nicole is generating some vertical wind shear.  In addition cooler, drier air has moved close to the western part of the circulation of Tropical Storm Nicole.  On the other hand, Tropical Storm Nicole is moving over water where the Sea Surface Temperature is near 29°C.  So, there is plenty of energy in the upper ocean.  The vertical wind shear and drier air could prevent Tropical Storm Nicole from intensifying much on Tuesday.  The upper level trough will move off to the east and the vertical wind shear could decrease during the middle of the week.  If the shear diminishes and not much drier air gets pulled into the circulation, then Tropical Storm Nicole has a chance to intensify into a hurricane.

A high pressure system blocked the northward movement of Tropical Storm Nicole and the high even pushed Nicole toward the south at times during the weekend.  The high appears to be moving farther to the east, which is allowing Tropical Storm Nicole to move slowly toward the north.  As the high pressure system shifts to the east, it will start to steer Tropical Storm Nicole more toward the northwest.  When Nicole reaches the western end of the high, it will turn toward the northeast.  The westerly winds in the middle latitudes will accelerate Nicole toward the northeast later this week.  On its anticipated track the center of Tropical Storm Nicole could pass near Bermuda on Thursday.

Hurricane Matthew Causing Serious Flooding in the Carolinas

Hurricane Matthew produced heavy rainfall which led to serious flooding in South Carolina and North Carolina on Saturday.  The total rainfall in some locations exceeded 10 inches (25 cm) in numerous locations in those two states.  Heavy prolonged rain caused creeks and rivers to rapidly rise and flood.

The National Hurricane Center (NHC) still classified Hurricane Matthew as a hurricane in its 11:00 p.m. EDT advisory.  At 11:00 p.m. EDT on the center of Hurricane Matthew was located at latitude 34.1°N and longitude 76.5°W which put it about 35 miles (55 km) south of Cape Lookout, North Carolina.  Matthew was moving toward the east-northeast at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 982 mb.

A Hurricane Warning is in effect for the portion of the coast from Little River Inlet to Surf City, North Carolina.  A Hurricane Watch has been issued for the portion of the coast from Surf City to Duck, North Carolina including Pamlico and Albemarle Sounds.  A Tropical Storm Warning is in effect for the portion of the coast from Surf City to Duck, North Carolina including Pamlico and Albemarle Sounds.

According to NHC the center of Hurricane Matthew made an official landfall near Cape Romain southeast of McClellanville, South Carolina at 11:00 a.m. EDT on Saturday.  Since that time the center of Hurricane Matthew has moved back out over the Atlantic Ocean.  New bands of showers are forming closer to the center south of the coast of North Carolina.  The winds to hurricane force are occurring over a small area on the southwestern side of Hurricane Matthew.

Easterly winds blowing around the north side of Hurricane Matthew converged with northerly winds blowing along a cold front to generate a broad area of rising motion.  The rising motion and the existing rainbands of the hurricane combined to produce very heavy rain over South Carolina and the southeastern half of North Carolina.  The area of heavy rain spread into southeastern Virginia around Norfolk on Saturday night.  The prolonged heavy rainfall caused the water in creeks and rivers to rise very quickly.  Serious flooding was occurring in parts of South Carolina and North Carolina.  Numerous roads were closed because of flooding in those two states.

Along the coast of North Carolina southeasterly winds were blowing water toward the coast and Hurricane Matthew was still generating storm surges.  When Matthew moves east of the Outer Banks of North Carolina, the wind will change direction and it will blow from the northwest.  Those northwesterly winds will push water in Pamlico and Albemarle Sounds onto the western sides of the Outer Banks.  Storms surges caused by Hurricane Matthew caused varying amounts of damage from Florida to North Carolina.  The most destructive storm surges appear to have been near Jacksonville Beach, Florida, around the barrier islands of Georgia and South Carolina.  However, a full damage assessment has not been made of those locations at this time.

Even though the center of Hurricane Matthew stayed over the Atlantic Ocean most of the time, gusty winds caused power outages from Florida to North Carolina.  As the heavy rain saturated the ground, gusts of winds toppled trees which fell onto power lines.  More power outages are likely in eastern North Carolina and southeastern Virginia as more trees are uprooted.

Hurricane Matthew will slowly move out to sea on Sunday.  Matthew appears to be making a transition to an extratropical cyclone.  During that transition the wind field is likely to expand.  So, conditions should improve slowly over North Carolina and Virginia on Sunday.

Hurricane Matthew Bringing Wind and Heavy Rain to the Carolinas

Hurricane Matthew was bringing wind and heavy rain to South Carolina and North Carolina on Saturday morning after causing damage along the coasts of Florida and Georgia on Friday.  At 9:00 a.m. EDT on Saturday the center of Hurricane Matthew was located at latitude 32.6°N and longitude 79.7°W which put it about 30 miles (50 km) southeast of Charleston, South Carolina.  Matthew was moving toward the northeast at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 963 mb.

A Hurricane Warning is in effect for the portion of the coast from Altamaha Sound, Georgia to Surf City, North Carolina.  A Hurricane Watch is in effect for the portion of the coast from Surf City to Cape Lookout, North Carolina.  A Tropical Storm Warning is in effect for the portion of the coast from Surf City to Duck, North Carolina.

The center of Hurricane Matthew is moving just south of the coast of South Carolina.  The winds to hurricane force are occurring in a small area over the Atlantic ocean near the center of Matthew.  Wind gusts to near hurricane force were occurring occasionally at the coast.  Beaufort, South Carolina reported a wind gust to 71 m.p.h. (114 km/h).  Earlier on Saturday a pier at Foley Beach, South Carolina reported a wind gust to 76 m.p.h. (122 km/h).  Inland stations in South Carolina and North Carolina were reporting winds in the range of 20 to 50 m.p.h. (30 to 80 km) with occasional higher gusts.

The wind damage caused by Hurricane Matthew is likely to be minor in many locations.  The winds are strong enough to bring down trees and cause widespread power outages.  There are also some stronger thunderstorms in some of the rainbands that are capable of causing more severe local wind damage and could spin up brief tornadoes.  Hurricane Matthew is also producing heavy rain over South Carolina and North Carolina.  The relatively slow movement of Hurricane Matthew could produce prolonged periods of heavy rain and cause fresh water flooding.  In addition, southeasterly winds on the east side of Hurricane Matthew are pushing water toward the shore and are causing storm surges at the coast.

An upper level trough over the eastern U.S. is steering Hurricane Matthew toward the northeast and that general motion will continue to today.  On its anticipated track the center of Hurricane Matthew will move very near the coast of South Carolina and North Carolina.  Since about half of the circulation of Hurricane Matthew is over land, friction will cause the hurricane to weaken slowly.

Hurricane Matthew Brings Wind, Rain and Surge to Northeast Florida

Hurricane Matthew brought gusty winds, heavy rain and storm surges to northeast Florida as the center of the hurricane moved northward just east of Florida on Friday.  A weather station on the tip of Cape Canaveral reported a wind gust to 107 m.p.h. (170 km/h) when the western side of the eyewall moved over that location.  Wind gusts to 71 m.p.h. (115 km/h) were reported at Daytona Beach.  A wind gust to 86 m.p.h. (139 km/h) was reported by a C-MAN station in St. Augustine, Florida.  Some wind damage and numerous power outages were reported in conjunction with the strong winds.  Easterly winds pushing water toward the coast were generating storms surges along the coast.

At 5:00 p.m. EDT on Friday the center of Hurricane Matthew was located at latitude 30.2°N and longitude 80.7°W which put it about 40 miles (65 km) east of Jacksonville Beach, Florida and about 135 miles (215 km) south of Savannah, Georgia.  Matthew was moving toward the north at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 948 mb.  Hurricane Matthew was a Category 2 hurricane on the Saffir-Simpson Scale.

A Hurricane Warning is in effect for the portion of the coast from the Flagler/Volusia County line in Florida to Surf City, North Carolina.  A Tropical Storm Warning is in effect for the portion of the coast from Surf City to Duck, North Carolina including Pamlico and Albemarle Sounds.  A Tropical Storm Warning is also in effect for the portion of the coast from the Brevard/Volusia County lie to the Volusia/Flagler County line in Florida.

The eye and the core of Hurricane Matthew remained over the Atlantic Ocean as Matthew moved parallel to the east coast of Florida.  Occasionally, the western side of the eyewall would move over the coast and bring stronger winds to those areas.  The remnants of the smaller inner eyewall dissipated during the afternoon.  Once the eyewall cycle was completed the remaining outer eyewall began to contract.  Thunderstorms around the eye generated enough upper level divergence to pump out mass and limited the increase of the surface pressure.  As a result, a strong pressure gradient force is still producing winds of over 100 m.p.h. (160 km/h) in the north and northeastern parts of the eyewall.

Hurricane Matthew has been moving around the western end of a subtropical high pressure system which steered the hurricane toward the north on Friday.  An upper level trough over the Central U.S. will move east and southwesterly winds with the trough will start to steer Matthew toward the northeast later tonight.  It is not clear exactly when the turn will occur and the exact timing of the turn to the northeast is very important.  If Hurricane Matthew continues to move north, the northern eyewall which contains the strongest winds could reach Savannah and the coast of South Carolina in 6-10 hours.  If those winds reach the coast, then the damage will be more severe.  If Hurricane Matthew turns northeast before the northern eyewall reaches the coast, then the damage will be less.

Even though Hurricane Matthew weakened slightly to a Category 2 hurricane and is no longer officially a major hurricane, it is still capable of causing regional serious damage.  Matthew will cause wind damage and widespread power outages along the coasts of Georgia and South Carolina, even if the center of the eye does not officially make landfall.  If the center of the eye brings the northern eyewall over the coast, the winds will be much stronger and the damage will be greater.  In addition, easterly winds on the northern side of Hurricane Matthew will drive water toward the coast and create serious storm surges.  In places where the shape of the coast funnels water into smaller areas, the surges will be even more dangerous.

Hurricane Matthew Develops Concentric Eyewalls on Its Way Toward Florida

The structure of Hurricane Matthew changed on Thursday as it strengthened on its way toward Florida.  A second larger outer eyewall formed around the small tight inner eye and eyewall.   At 5:00 p.m. EDT on Thursday the center of Hurricane Matthew was located at latitude 26.2°N and longitude 78.6°W which put it about 25 miles (40 km) south-southeast of Freeport, Bahamas and about 100 miles (160 km) east-southeast of West Palm Beach, Florida.  Matthew was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 140 m.p.h. (220 km/h) and there were wind gusts to 165 m.p.h. (270 km/h).  The minimum surface pressure was 938 mb.  Hurricane Matthew was a Category 4 hurricane on the Saffir-Simpson Scale.

A Hurricane Warning is in effect for the portion of the coast from Golden Beach, Florida to South Santee River, South Carolina including Lake Okeechobee.  A Tropical Storm Warning is in effect for the portion of the coast South Santee River, South Carolina to Surf City, North Carolina.  A Tropical Storm Warning is in effect for the portion of the coast from Anclote River, Florida to Suwanee River.  A Tropical Storm Warning is in effect for the portion of the coast from Chokoloskee to Golden Beach, Florida and for the Florida Keys from Seven Mile Bridge eastward including Florida Bay.  A Tropical Storm Watch has been issued for the portion of the coast from Chokoloskee, Florida to Anclote River.  A Hurricane Warning is in effect for the northwestern Bahamas including the Abacos, Andros Island, Berry Islands, Bimini, Eleuthera, Grand Bahama Island and New Providence.

Hurricane Matthew began to strengthen early on Thursday morning.  The minimum surface pressure decreased from 961 mb at 11:00 p.m. EDT on Wednesday night to 940 mb at 8:00 a.m. EDT on Thursday morning.  A decrease of 17 mb in nine hours is a very rapid pressure fall, but the maximum wind speed only increased from 115 m.p.h. ((185 km/h) to 125 m.p.h. (205 mk/h) during that time period.  The rapid decrease in pressure and the increase in the pressure gradient force around the center of Hurricane Matthew contributed to the reformation of a small circular eye at the center of the hurricane.  Once the new eyewall was established, the wind speed increased to 140 m.p.h. (225 km/h) within three hours.

The structure of the circulation of Hurricane Matthew continued to improve during the day on Thursday as the hurricane moved over the very warm water around the Bahamas.  A circular inner eye with a diameter of 18 miles (29 km) was surrounded by a ring of strong thunderstorms.  A rainband wrapped all the way around the original eye and eyewall and a second outer eyewall formed.  The outer eyewall has a diameter of 70 miles (105 km).  The strongest winds in Hurricane Matthew are occurring in the inner eyewall.  Hurricane Matthew has maintained a double eyewall structure in recent hours.

Matthew is moving through an environment that is favorable for hurricanes.  The Sea Surface Temperature is near 30°C.  There upper level winds are weak and there is not much vertical wind shear.  Hurricane Matthew is likely to maintain its current intensity as long as the inner eyewall remains intact.  If the inner eye starts to dissipate, then the strongest winds would be found in the outer eyewall, but those winds are not as strong as the winds in the inner eyewall.  So the intensity of Hurricane Matthew would decrease if that happened.  However, the wind field of a hurricane typically gets larger if the outer eyewall becomes the strongest part of the circulation.

Hurricane Matthew is moving around the western end of a subtropical high pressure system which is steering it toward the northwest and that general motion is expected to continue until the hurricane gets close to the coast of Florida.  When Hurricane Matthew gets close to the coast, it will be at the western end of the high and the hurricane will turn north.  It is still unclear if the turn will occur just before Matthew reaches the coast or whether it will occur after the center of Matthew moves on shore.  Eventually, when Hurricane Matthew moves farther north, an upper level trough approaching form the west will steer it toward the northeast, but the timing of that turn is still uncertain too.

The future track of Hurricane Matthew will be a critical factor in determining the damage it causes.  If Matthew turns north before it reaches the east coast of Florida, the the strongest winds would stay over the Atlantic Ocean.  The same holds true for the turn toward the northeast.  If the turn occurs before Hurricane Matthew reaches Georgia and South Carolina, then the strongest winds would stay offshore.  A much more destructive scenario would unfold if Hurricane Matthew reaches the coast of Florida and then turns north.  If Matthew grinds its way north along the coast, the strongest winds and highest storm surge would occur.  Matthew could move over cities like Daytona Beach and Jacksonville.  If the turn to the northeast is delayed, then Matthew would also move near Savannah, Georgia and Charleston, South Carolina.

The Hurricane Intensity Index (HII) for Hurricane Matthew is 28.2.  The Hurricane Size Index (HSI) is 18.4 and the Hurricane Wind Intensity Size Index (HWISI) is 46.6  The indices indicate that Hurricane Matthew is stronger than Hurricanes Frances and Jeanne were when they hit southeast coast of Florida in 2004.  Matthew is smaller than Frances and Jeanne were in 2004.  The HWISI for Matthew is similar to the ones for Frances and Jeanne, which would suggest that Matthew is capable of causing similar damage.  Hurricane Frances cause 11 billion dollars of damage in 2004.  Hurricane Jeanne caused about 8 billion dollars of damage.  So, Hurricane Matthew has the potential to be a very destructive hurricane, but the damage it does will be determined by its ultimate path.  Matthew will do much less damage if the core of the hurricane stays offshore.

Hurricane Matthew will bring gusty winds and heavy rain to the southeast coast of Florida on Thursday night.  It will do the same to the northeast coast of Florida on Friday.  Strong easterly winds on the northern side of the center of circulation will drive water toward the shore and create dangerous storm surges as Hurricane Matthew moves along the coast.  The heavy rain is likely to cause fresh water flooding in some locations.  Hurricane Matthew could have the greats impact on the coasts of Georgia and South Carolina on Friday night and Saturday.