Monthly Archives: July 2020

Tropical Storm Douglas Strengthens Quickly

Tropical Storm Douglas strengthened quickly over the Eastern North Pacific Ocean on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Douglas was located at latitude 12.4°N and longitude 124.2°W which put it about 2110 miles (3390 km) east of Hilo, Hawaii.  Douglas was moving toward the west-southwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 998 mb.

The circulation around Tropical Storm Douglas exhibited much better organization on Tuesday morning.  The inner end of a rainband wrapped around the southern and eastern sides of the center of circulation.  Bands of showers and thunderstorms were revolving around around the center of Douglas.  The strongest bands were in the southern half of Tropical Storm Douglas.  Storms near the center of circulation were generating upper level divergence which was pumping mass away from the tropical storm.  Winds to tropical storm force extended out about 40 miles (65 km) from the center of Douglas.

Tropical Storm Douglas will move through an environment favorable for intensification during the next several days.  Douglas will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Douglas is likely to intensify into a hurricane during the next 24 hours and it could strengthen into a major hurricane later this week.

Tropical Storm Douglas will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high is likely to steer Douglas toward the west-northwest during the next few days.  On its anticipated track Tropical Storm Douglas could approach Hawaii by late in the weekend.

Elsewhere over the Eastern North Pacific Ocean, Tropical Depression Seven-E weakened over cooler water east of Hawaii.  At 11:00 a.m. EDT on Tuesday the center of Tropical Depression Seven-E was located at latitude 19.3°N and longitude 134.1°W which put it about 1575 miles (2535 km) west of the southern tip of Baja California.  The depression was moving toward west at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1009 mb.

Two Tropical Depressions Form Over Eastern Pacific

Two tropical depressions formed over the Eastern North Pacific Ocean on Monday.  At 11:00 a.m. EDT on Monday the center of Tropical Depression Seven-E was located at latitude 18.7°N and longitude 130.3°E which put it about 1345 miles (2170 km) west of the southern tip of Baja California.  The depression was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1008 mb.

At 11:00 a.m. EDT on Monday the center of Tropical Depression Eight-E was located at latitude 13.7°N and longitude 119.8°W which put it about 905 miles (1460 km) southwest of the southern tip of Baja California.  The depression was moving toward the west-southwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1008 mb.

The distribution of thunderstorms around Tropical Depression Seven-E was asymmetrical.  The strongest storms were occurring in bands southwest of the center of circulation.  Bands in other parts of the depression consisted primarily of showers and lower clouds.  The depression was already to moving over water where the Sea Surface Temperature was near 25°C.  It was moving under the southwestern part of an upper level ridge which was producing northeasterly winds.  Those winds were blowing toward the top of the depression and they were causing moderate vertical wind shear.  Cooler water and wind shear were contributing to the asymmetrical distribution of thunderstorms.

Tropical Depression Seven-E is likely to weaken since it will continue to move over cooler water.  The depression will move south of a subtropical high pressure system.  The high will steer the depression toward the west while it weakens.  On its anticipated track the depression will weaken long before it could pose a threat to Hawaii.

The distribution of thunderstorms around Tropical Depression Eight-E is also asymmetrical.  Many of the strongest storms were occurring in bands in the western half of the circulation.  Some thunderstorms began to develop in bands in the eastern half of the depression on Monday morning.  Storms on the western side of the circulation began to generate upper level divergence which pumped mass away from the depression.

Tropical Depression Eight-E will move through an environment favorable for intensification during the next several days.  The depression will move over water where the Sea Surface Temperature is near 29°C.  The upper level ridge over the Eastern North Pacific Ocean will produce northeasterly winds which will blow toward the top of the depression.  Those winds will cause some vertical wind shear, but the shear will have less effect because the depression will be over warmer water.  Tropical Depression Eight-E will strengthen during the next 48 hours and it could intensify into a hurricane.

Tropical Depression Eight-E will move around the southern side of the subtropical high pressure system over the Eastern North Pacific Ocean.  The high will steer the depression toward the west during the next few days.  On its anticipated track the depression will move in the general direction of Hawaii.

Tropical Storm Cristina Starts to Weaken

Tropical Storm Cristina started to weaken on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Cristina was located at latitude 20.6°N and longitude 121.0°W which put it about 730 miles (1175 km) west of the southern tip of Baja California.  Cristina was moving toward the west at 14 m.p.h. (22 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 999 mb.

Tropical Storm Cristina began to weaken on Saturday when it moved over cooler water.  Cristina moved over water where the Sea Surface Temperature was near 24°C.  The circulation around Tropical Storm Cristina was well organized, but the thunderstorms were not as tall,  A thin broken ring of thunderstorms surrounded the center of circulation and the strongest winds were occurring in that ring of storms.  Other bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center were still generating upper level divergence.  However, the circulation was unable to extract enough energy from the cooler water to maintain the stronger wind speeds.  Winds to tropical storm force extended out about 80 miles (130 km) from the center of circulation.

Tropical Storm Cristina will continue to weaken during the next few days when it moves over water where the Sea Surface Temperature is near 23°C.  Cristina could weaken to a tropical depression by Monday.

Tropical Storm Cristina will move south of a subtropical high pressure system over the Eastern North Pacific Ocean.  The high will steer Cristina toward the west during the next few days.  On its anticipated track Tropical Storm Cristina will move in the general direction of Hawaii while it weakens.

Tropical Storm Fay Weakens Over New York

Tropical Storm Fay weakened over New York on Friday night.  At 11:00 p.m. EDT on Friday the center of Tropical Storm Fay was located at latitude 41.0°N and longitude 74.2°W which put it about 15 miles (30 km) northwest of New York, New York.  Fay was moving toward the north at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1001 mb.

A Tropical Storm Warning was in effect for the portion of the coast from East Rockaway, New York to Watch Hill, Rhode Island including Long Island and Long Island Sound.

Tropical Storm Fay weakened on Friday night as the center moved across eastern New Jersey and into southeastern New York.  An upper level trough over the eastern U.S. was producing southwesterly winds which were blowing across the top of Fay.  Those winds were causing moderate vertical wind shear.  Drier air was wrapping around the southern side of the circulation and it was being pulled into the inner part of Tropical Storm Fay.  Bands near the center of Fay consisted of showers and lower clouds.  Heavier rain was falling in bands over northeastern Pennsylvania and central New York.  Winds to tropical storm force were occurring in the southeastern part of the circulation which is still over the Atlantic Ocean.  The wind speeds over land were much weaker.

The upper level trough will steer Tropical Storm Fay toward the north-northeast during the next several days.  Fay will continue to weaken as the tropical storm moves farther inland.  Tropical Storm Fay will also make a transition to an extratropical cyclone when it moves farther north.  Fay could still drop locally heavy rain over parts of the northeastern U.S. on Saturday.

Tropical Storm Fay Drops Heavy Rain on Delaware and New Jersey

Tropical Storm Fay dropped heavy rain on parts of Delaware and southern New Jersey on Friday morning.  At 8:00 a.m. EDT on Friday the center of Tropical Storm Fay was located at latitude 37.6°N and longitude 74.7°W which put it about 90 miles (145 km) south of Cape May, New Jersey.  Fay was moving toward the north at 10 m.p.h. (16 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 999 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Fenwick Island, Delaware to Watch Hill, Rhode Island including southern Delaware Bay, Long Island and Long Island Sound.

Tropical Storm Fay intensified slowly on Friday morning.  A reconnaissance aircraft reported that the minimum surface pressure decreased to 999 mb.  A ring of showers and lower clouds encircled the center of Tropical Storm Fay.  Bands of showers and thunderstorms wrapped around the northern and western sides of Fay.  Bands in the southern part of the circulation consisted primarily of showers and lower clouds.  Drier air was wrapping around the southern portion of the tropical storm.  Winds to tropical storm force extended out 140 miles (225 km) in the eastern side of Tropical Storm Fay.  Winds to tropical storm force extended out 80 miles (130 km) on the western side of the circulation.

Tropical Storm Fay will move through an environment that could allow for some additional intensification during the next few hours.  Fay will move over water where the Sea Surface Temperature is near 26°C.  An upper level trough over the eastern U.S. will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear.  The shear will inhibit intensification, but it may not be strong enough to prevent Tropical Storm Fay from strengthening a little more.

The upper level trough over the eastern U.S. and a high pressure system over the Atlantic Ocean will interact to steer Tropical Storm Fay toward the north-northeast during the next several days.  On its anticipated track Fay could approach the coast of New Jersey in a few hours.  Tropical Storm Fay will move across Long Island on Friday night.

Tropical Storm Fay will bring gusty winds to the coast of Delaware, New Jersey, New York, Connecticut and Rhode Island.  Locally heavy rain will fall over those areas as the center of Fay approaches.  Flood Watches have been issued for parts of Delaware, New Jersey, eastern Pennsylvania, southeastern New York, Connecticut and western Massachusetts.   Easterly winds blowing around the north side of Tropical Storm Fay could push water toward the coast.  Water Level rises of three feet (1 meter) could occur in some locations.

Tropical Storm Fay Forms East of Cape Hatteras

Tropical Storm Fay formed east of Cape Hatteras on Thursday afternoon.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Fay was located at latitude 35.5°N and longitude 74.9°W which put it about 40 miles (65 km) east-northeast of Cape Hatteras, North Carolina.  Fay was moving toward the north at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1005 mb.

A Tropical Storm Warning was issued for the portion of the coast from Cape May, New Jersey to Watch Hill, Rhode Island including Long Island and Long Island Sound.

A new center of circulation formed near the northern end of a band of showers and thunderstorms which was on the eastern side of a larger low pressure system that was previously designated as Invest 98L.  A reconnaissance aircraft detected winds to tropical storm force and the National Hurricane Center designated the system as Tropical Storm Fay.  Fay is the sixth named Atlantic tropical storm of 2020 and it formed earlier than any other sixth Atlantic tropical storm in the satellite era.

The circulation around Tropical Storm Fay was asymmetrical.  The strongest winds were occurring a band of showers and thunderstorms on the eastern side of Fay.  The inner end of the band was wrapping around the northern side of the center of circulation.  Bands on the western side of the tropical storm consisted primarily of showers and lower clouds.  Storms near the center began to generate upper level divergence which was pumping mass away to the north and east of the tropical storm.  Winds to tropical storm force extended out about 140 miles (225 km) in the eastern half of Tropical Storm Fay.  The winds in the western half of Fay were blowing at less than tropical storm force.

Tropical Storm Fay will move through an environment somewhat favorable for intensification during the next 18 to 24 hours.  Fay will move over water where the Sea Surface Temperature is near 26°C.  An upper level trough over the eastern U.S. will produce southwesterly winds which will blow toward the top of the tropical storm.  Those winds will impede upper level divergence to the west of Tropical Storm Fay and they will cause moderate vertical wind shear.  The wind shear will inhibit intensification, but it will not likely to be strong enough to prevent Fay from strengthening.  Tropical Storm Fay could intensify during the next 12 to 18 hours.

The upper level trough and a high pressure system over the Atlantic Ocean will interact to steer Tropical Storm Fay toward the north during the next day or two.  On its anticipated track the center of Tropical Storm Fay could approach southern New Jersey on Friday afternoon.  Fay could move across Long Island on Friday night.

Since the strongest rainband and winds are on the eastern side of Tropical Storm Fay, the portion of the coast south of New Jersey may not experience tropical storm force winds.  Gusty winds are likely along the coast of New Jersey, Long Island, southeastern New York, Connecticut and Rhode Island.  Heavy rain could also fall in those locations.  Easterly winds blowing around the northern side of Tropical Storm Fay will push water toward the coast.  The water level could rise several feet (one meter) at some locations.  Waves could also cause some beach erosion.

Potential Tropical Development Near East Coast of U.S.

There is the potential for the development of a tropical cyclone near the East Coast of the U.S. during the next several days.  A low pressure system, currently designated as Invest 98L developed over the northern Gulf of Mexico during the weekend.  The low moved slowly toward the northeast across the southeastern U.S.  At 2:00 a.m. EDT on Wednesday the low level center of Invest 98L was located at latitude 33.3°N and longitude 80.5°W which put it about 25 miles (40 km) west of Charleston, South Carolina.  The low was moving toward the east at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 25 m.p.h. (40 km/h) and there were wind gusts to 35 m.p.h. (55 km/h).  The minimum surface pressure was 1013 mb.

Invest 98L currently consists primarily of a lower level circulation.  Much of the circulation is over land and the center is west of Charleston, South Carolina.  Many of the bands revolving around the center of the low pressure system consist of showers and lower clouds.  There are bands of showers and thunderstorms on the far eastern edge of the circulation which is over the Gulf Stream.  An upper level trough over the southeastern U.S. is producing westerly winds which are blowing across the top of the low level circulation.

Invest 98L will move into an environment more favorable for the development of a tropical cyclone.  It will move over water where the Sea Surface Temperature is near 27°C when the center moves over the Atlantic Ocean.  The upper level trough will over the southeastern U.S. will cause moderate vertical wind shear.  The wind shear will inhibit development.  If thunderstorms develop closer to the center of circulation, those storms could cause the circulation grow vertically into the middle and upper troposphere.  If the thunderstorms release enough latent energy in the middle and upper troposphere, a warm core could form and Invest 98L could become a tropical cyclone.

The National Hurricane Center indicated in the 8:00 a.m. EDT Tropical Weather Outlook on Wednesday that the probability was 70% that a tropical or subtropical cyclone could form during the next five days.  An upper level trough approaching the eastern U.S. will steer the low pressure system toward the north-northeast during the next few days.  On its anticipated track the low pressure system will move near the East Coast of the U.S.  A reconnaissance aircraft is tentatively scheduled to investigate Invest 98L later on Wednesday, if necessary.

Tropical Storm Cristina Forms South of Acapulco

Tropical Storm Cristina formed south of Acapulco on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Cristina was located at latitude 11.2°N and longitude 101.3°W which put it about 405 miles (650 km) south-southwest of Acapulco, Mexico.  Cristina was moving toward the west-northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1005 mb.

A distinct low pressure center organized quickly in a tropical wave south of Mexico on Monday.  Satellite images showed a well developed counterclockwise rotation around the center of circulation.  Bands of showers and thunderstorms were revolving around the center of Tropical Storm Cristina.  The inner end of a rainband wrapped around the southern and eastern sides of the center of circulation.  Storms near the center of circulation were generating upper level divergence which was pumping mass away in all directions from the tropical storm,  Winds to tropical storm force extended out about 35 miles (55 km) from the center of Cristina.

Tropical Storms Cristina will move through an environment favorable for intensification during the next several days.  Cristina will move over water where the Sea Surface Temperature is near 29.5°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Cristina will continue to strengthen and it could intensify rapidly.  Cristina will intensify into a hurricane within 36 hours and it could strengthen into a major hurricane later this week.

Tropical Storm Cristina will move around the southwestern part of a ridge of high pressure over Mexico and the southwestern U.S.  The ridge will steer Cristina toward the west-northwest during the next few days.  On its anticipated track Tropical Storm Cristina will move away from the west coast of Mexico.

Tropical Depression Five Strengthens into Tropical Storm Edouard

Former Tropical Depression Five strengthened into Tropical Storm Edouard northeast of Bermuda on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Edouard was located at latitude 37.2°N and longitude 56.9°W which put it about 685 miles (1100 km) south-southwest of Cape Race, Newfoundland.  Edouard was moving toward the northeast at 35 m.p.h. (56 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1008 mb.  Tropical Storm Edouard became the earliest fifth named storm to form over the Atlantic Ocean during the satellite era since 1966.

Former Tropical Depression Five exhibited greater organization on satellite imagery and the National Hurricane Center designated the system as Tropical Storm Edouard.  More thunderstorms formed in bands east of the center of circulation.  Bands in the northern and western parts of Edouard consisted primarily of showers and lower clouds.  Winds to tropical storm force were occurring within 60 miles of the center in the southeastern quadrant of Tropical Storm Edouard.  The winds in the other parts of Edouard were blowing at less than tropical storm force.

Tropical Storm Edouard will move through an environment that could allow for a little more intensification during the next 12 hours.  Edouard will move over water where the Sea Surface Temperature is near 24°C.  It will move under the southern fringe of the upper level westerly winds in the middle latitudes.  Those winds will blow toward the top of the circulation and they will cause moderate vertical wind shear.  The relatively cool water temperatures and moderate vertical wind shear will limit future intensification.  Tropical Storm Edouard could get a little stronger on Monday.  Edouard will move over cooler water later on Monday and it will start a transition to an extratropical cyclone.

Tropical Storm Edouard will move around the northern side of a subtropical high pressure system over the Atlantic Ocean.  The high will steer Edouard toward the northeast.  On its anticipated track Tropical Storm Edouard will pass well south of Newfoundland.

Tropical Depression Five Forms West-southwest of Bermuda

Tropical Depression Five formed west-southwest of Bermuda on Saturday morning.  At 11:00 a.m. EDT on Saturday the center of Tropical Depression Five was located at latitude 31.1°N and longitude 68.7°W which put it about 245 miles (390 km) west-southwest of Bermuda.  The depression was moving toward the east-northeast at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1009 mb.

Visible satellite images showed that a small low pressure system west-southwest of Bermuda exhibited more organization on Saturday morning and the National Hurricane Center designated the system as Tropical Depression Five.  The circulation around Tropical Depression Five was small but it was fairly well organized.  The depression had a well defined center of circulation.  Thunderstorms were occurring in bands south and east of the center.  Bands in the northwestern part of Tropical Depression Five consisted primarily of showers and lower clouds.  Storms near the center of circulation were generating upper level divergence which was pumping mass away to the east of the depression.

Tropical Depression Five will move through an environment somewhat favorable for intensification during the next 12 to 24 hours.  The depression will move over water where the Sea Surface Temperature is near 25.5°C.  It will move under the southern edge of the upper level westerly winds in the middle latitudes.  Those winds will cause moderate vertical wind shear, but the shear may not be strong enough to prevent some intensification.  Tropical Depression Five could strengthen into a tropical storm during the next 24 hours.

Tropical Depression Five will move around the northwestern part of a subtropical high pressure system over the Atlantic Ocean.  The high will steer the depression toward the east-northeast during the next several days.  On its anticipated track Tropical Depression Five will move near Bermuda on Saturday night.  The depression could be a tropical storm when it passes by Bermuda.