Tropical Storm Franklin Develops Over Northwest Caribbean Sea

A center of circulation developed in a system previously designated as Potential Tropical Cyclone Seven and the National Hurricane Center named the system Tropical Storm Franklin on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Franklin was located at latitude 16.4°N and longitude 83.0°W which put it about 380 miles (610 km) east-southeast of Chetumal, Mexico.  Franklin was moving toward the west-northwest at 13 m.p.h. (20 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 1006 mb.

A Tropical Storm Warning is in effect for the portion of the coast from Chetumal to Campeche, Mexico.  A Tropical Storm Watch is in effect for the portion of the coast from Belize City, Belize northward to the Belize/Mexico border.

Visible satellite images just before sunset suggested that a center of circulation had formed in the tropical wave previously designated Potential Tropical Cyclone Seven and the National Hurricane Center named it Tropical Storm Franklin.  The circulation of Tropical Storm Franklin is still not well organized.  The apparent center is located near the western edge of an area of thunderstorms.  Most of the thunderstorms are still forming east of the system, which indicates that vertical wind shear is probably still affecting the circulation.  The thunderstorms are producing some upper level divergence which is pumping mass away to the east of the tropical storm.

The environment ahead of Tropical Storm Franklin will become more favorable for intensification.  Franklin will move over water where the Sea Surface Temperature is near 30°C.  An upper level trough west of Franklin is producing westerly winds which are causing the vertical wind shear.  The trough is expected to weaken on Monday and when that happens the shear will diminish.  Warm water and less shear should allow Tropical Storm Franklin to strengthen before it reaches the Yucatan peninsula.  Franklin will weaken when it moves over land, but it is likely to re-intensify when it moves over the southern Gulf of Mexico.

Tropical Storm Franklin is being steered toward the west-northwest by a subtropical high centered over the Atlantic Ocean.  A general west-northwesterly motion is expected to continue.  On its anticipated track Tropical Storm Franklin could approach the Yucatan peninsula in about 24 hours.  Franklin will bring gusty winds and locally heavy rain to that area.  The heavy rain could cause flooding in some locations.

Typhoon Noru Skirts Coast of Shikoku on Way to Honshu

The eye of Typhoon Noru skirted the coast of Shikoku on Sunday as it moved closer to a landfall on Honshu.  At 11:00 p.m. EDT on Sunday the center of Typhoon Noru was located at latitude 33.6°N and longitude 134.5°W which put it about 85 miles (135 km) southwest of Osaka, Japan.  Noru was moving toward the 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 970 mb.

The structure of Typhoon Noru improved on Sunday.  The circulation contracted around an eye with a diameter of approximately 20 miles (32 km).  They eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in the ring of storms.  Additional spiral bands were revolving around the core of Typhoon Noru.

An upper level trough northwest of Japan steered Typhoon Noru toward the northeast on Sunday.  The eye of Noru moved near the south coast of Shikoku.  The eye passed south of Kochi and very near Muroto, Toyo and Kainan.  Typhoon Noru brought gusty winds and heavy rain to the southern parts of Shikoku.

Typhoon Noru is expected to continue to move toward the northeast on Monday.  On its anticipated track the center of Typhoon Noru is expected to skirt the east coast of Shikoku and make landfall on Honshu near Wakayama.   After it makes landfall, Typhoon Noru is forecast to pass near Osaka and Kyoto.  Typhoon Noru will weaken as it moves across Honshu, but it will produce gusty winds and locally heavy rain.  The rain could cause floods in some locations.

Tropical Storm Warning Issued for Mexico Due to Potential Tropical Cyclone Seven

The National Hurricane Center changed the designation of Invest 90L to Potential Tropical Cyclone Seven because of the need to issue a Tropical Storm Warning for portions of Mexico.  At 5: 00 p.m. EDT on Sunday the center of Potential Tropical Cyclone Seven was located at latitude 15.6°N and longitude 82.0°W which put it about 90 miles (145 km) east-northeast of Cabo Gracias a Dios.  It was moving toward the west-northwest at 12 m.p.h. (19 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.

A Tropical Storm Warning has been issued for the portion of the coast from Chetumal to Campeche, Mexico.  A Tropical Storm Watch has been issued for the portion of the coast from Belize City to the Belize/Mexico border.

A broad area of low pressure formed in a strong tropical wave over the northwestern Caribbean Sea.  There is not a well defined center of circulation within the broad area of low pressure.  Most of the thunderstorms are developing in the eastern half of the circulation.  There are few thunderstorms in the western half of the system.  The thunderstorms in the eastern half of the low are generating some upper level divergence which is pumping out mass to the east of the low.

Potential Tropical Cyclone Seven will move through a relatively favorable environment over the northwestern Caribbean Sea.  It will move over water where the Sea Surface Temperature is 30°C.  A small upper level trough to the west of the low is producing westerly winds which are causing moderate vertical wind shear.  The wind shear is probably the reason why most of the thunderstorms are in the eastern side of the circulation.  The upper trough is forecast to weaken and the shear is expected to diminish.  Potential Tropical Cyclone Seven could become a tropical storm over the northwestern Caribbean Sea, which is why the Tropical Storm Warning was issued.

Potential Tropical Cyclone Seven is being steered to the west-northwest by a subtropical high pressure system centered over the Atlantic Ocean.  That general motion is expected to continue for the next several days.  On its anticipated track Potential Tropical Cyclone Seven could reach the Yucatan Peninsula within 36 hours.  It could bring gusty winds and heavy rain when it moves over the Yucatan.  The system could restrengthen when it moves over the southern Gulf of Mexico.

Typhoon Noru Reaches Kyushu

The eye of Typhoon Noru reached the southern coast of Kyushu near Uchinoura on Saturday.  At 11:00 p.m. EDT on Saturday the center of of Typhoon Noru was located at latitude 31.0°N and longitude 131.2°E which put it about 65 miles (105 km) south-southwest of Miyazaki, Japan.  Noru was moving toward the northeast 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 970 mb.

Typhoon Noru weakened as it made a slow clockwise loop on Saturday.  The winds of the typhoon may have mixed cooler water to the surface of the ocean.  Typhoon Noru also appears to be drawing cooler, drier air into the northern half of the circulation.  There is still an eye at the center of Noru, but the strong thunderstorms are all in the southern half of the circulation.  The strongest winds are occurring in the thunderstorms at the southern edge of the eye.  There are several bands of showers and thunderstorms outside the core of Typhoon Noru.

Typhoon Noru is moving over water where the Sea Surface Temperature is near 29°C.  So, there is sufficient energy to support the circulation of a typhoon.  However, drier air in the northern half of the circulation is reducing the amount of energy that is reaching the core of the typhoon.  An upper level trough is approaching Typhoon Noru from the west and the vertical wind shear will increase when the trough gets closer to the typhoon.  Typhoon Noru could maintain its intensity for another 12 to 18 hours, but eventually the combination of drier air, more vertical shear and interaction with land will cause Noru to weaken.

Typhoon Noru was in an area where the steering currents were weak and it made a slow, tight clockwise loop on Saturday.  The upper level trough approaching from the west will start to steer Typhoon Noru toward the northeast.  Noru will move along the south coast of Kyushu.  On its anticipated path the center of Typhoon Noru could be near Kochi on the south coast of Shikoku in about 24 hours.  Noru could be near Osaka and Kyoto on Honshu in about 36 hours.

Typhoon Noru has the potential to bring strong winds, heavy rain and the potential for floods to southern Kyushu, Shikoku and parts of Honshu.

Typhoon Noru Bringing Wind and Rain to Northern Ryukyu Islands

Typhoon Noru was bringing gusty winds and heavy rain to the northern Ryukyu Islands on Friday.  At 5:00 p.m. EDT on Friday the center of Typhoon Noru was located at latitude 29.3°N and longitude 130.3°E which put it about 90 miles (140 km) south of Kagoshima, Japan.  Noru was moving toward the northwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 90 m.p.h. (140 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 959 mb.

The structure of Typhoon Noru has not changed much during the past 24 hours.  A large eye with a diameter of approximately 80 miles (130 km) occupies the center of the typhoon.  A broken eyewall surrounds the eye.  Strong thunderstorms surround the eastern side of the eye, while a broken ring of weaker showers and storms mark the western edge of the eye.  The strongest winds are occurring in the thunderstorms on the eastern edge of the eye.  Thunderstorms in the core of the circulation are generating upper level divergence which is pumping away mass in all directions.  A primary rainband extends from the eastern side of Typhoon Noru around the southern and western sides of the circulation.  Several other shorter bands are outside this primary rainband.  Typhoon Noru continues to exhibit a structure similar to an annular hurricane.

Although the core of Typhoon Noru is fairly large, the overall size of the storm is not as big as some typhoons.  Winds to typhoon force extend out about 40 miles in all directions from the center of circulation.  Winds to tropical storm force extend out about 160 miles (260 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Noru is 13.9.  The Hurricane Size Index (HSI) is 17.0 and the Hurricane Wind Intensity Size Index (HWISI) is 30.9.

Typhoon Noru will be in an environment favorable for intensification for about another 24 hours.  Noru will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge north of Noru is producing northerly winds which are blowing toward the top of the typhoon.  Those winds are fairly weak and there is not much vertical wind shear.  Typhoon Noru is likely to intensify during the next 24 hours and it could strengthen into the equivalent of a major hurricane again.  In a day or so, an upper level trough will approach from the west and wind shear will increase.  Typhoon Noru will weaken faster after it makes landfall in Kyushu.

Typhoon Noru is moving slowly around the western end of a subtropical ridge.  Noru is in an area where the steering currents are weak and the will remain weak for another 24 to 48 hours.  An upper level trough will approach Noru from the west in a day or so.  Southwesterly winds ahead of the trough will start to steer Typhoon Noru toward the northeast at a faster rate.  On its anticipated track Typhoon Noru could make landfall in Kyushu in less than 36 hours.

The large core and strength of Typhoon Noru make it capable of bringing strong winds and heavy rain to a large area.  Typhoon Noru will continue to bring wind and rain to the northern Ryukyu Islands for another 24 to 36 hours.  Noru could also cause wind damage, heavy rain and floods on Kyushu, Shikoku and western Honshu when it moves over those regions.

Tropical Depression Eleven-E Forms West of Mexico

Tropical Depression Eleven-E formed west of Mexico on Friday.  At 11:00 a.m. EDT on Friday the center of Tropical Depression Eleven-E was located at latitude 17.7°N and longitude 109.2°W which put it about 335 miles (535 km) west-southwest of Manzanillo, Mexico.  The depression was moving toward the west-northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1009 mb.

The circulation of Tropical Depression Eleven-E is not particularly well organized.  The depression does have a distinct center of circulation which can be seen on visible satellite images.  Most of the showers and thunderstorms are occurring in the western half of the circulation.  The rainbands east of the center of circulation are thin and consist mainly of lighter showers.  The thunderstorms west of the center of circulation are generating only a little upper level divergence which is carrying mass to the west of the depression.

Tropical Depression Eleven-E is in an environment that is only marginally favorable for intensification.  The depression is moving over water where the Sea Surface Temperature is near 28.5°C.  So, there is sufficient energy in the upper ocean to support intensification.  However, an upper level ridge centered over northern Mexico is producing strong northeasterly winds which are blowing across the top of the depression.  Those winds are causing significant vertical wind shear.  The shear is probably the reason for the asymmetrical pattern with all of the thunderstorms in the western half of the circulation.  The shear is forecast to continue and if it does, there will be little or no intensification.  If the shear is less, then some intensification could occur.

Tropical Depression Eleven-E is being steered to the west-northwest by the ridge to its north.  A general west-northwesterly motion is forecast to continue for the next several days.  If the vertical wind shear increases and the depression weakens to a low level system, then winds closer to the surface would steer it more toward the west.  On its anticipated track the depression is expected to move away from Mexico.

Typhoon Noru Threatens Southwestern Japan

Typhoon Noru posed an increased threat to southwestern Japan as it slowly moved closer on Thursday.  At 11:00 p.m. EDT on Thursday the center of Typhoon Noru was located at latitude 28.6°N and longitude 131.3°E which put it about 145 miles (235 km) south-southeast of Kagoshima, Japan.  Noru was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were gusts to 105 m.p.h. (170 km/h).  The minimum surface pressure was 962 mb.

Although Noru is still a powerful and dangerous typhoon, it is not quite as well organized as it was several days ago.  A very large eye with a diameter of 95 miles (150 km) is at the center of circulation.  A broken ring of thunderstorms surrounds the eye.  There are breaks on both the eastern and western sides of the eyewall.  A broad rainband wraps around the southern and eastern sides of the circulation.  Thunderstorms in the core of Noru are generating strong upper level divergence which is pumping mass away from the typhoon.  There are few showers and thunderstorms in the northwestern quadrant and there may be drier air in that part of Typhoon Noru.

Winds to typhoon force extend out about 40 miles (65 km/h) from the center of circulation.  Winds to tropical storm force extend out about 185 miles (295 km/h) from the center.  The Hurricane Intensity Index (HII) for Typhoon Noru is 12.7.  The Hurricane Size Index (HSI) is 16.4 and the Hurricane Wind Intensity Size Index (HWISI) is 29.1

Typhoon Noru will move through an environment that may be somewhat favorable for intensification.  Noru will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge northwest of Noru is producing northeasterly winds which are blowing toward the top of the typhoon.  Those winds are creating moderate vertical wind shear.  The typhoon could also pull in drier air on the northwestern side of the circulation.  Even though the environmental factors are mixed, some intensification may be possible during the next 24 to 48 hours.

Typhoon Noru is approaching the western end of a subtropical ridge which has been steering the typhoon toward the west.  Noru is forecast to slow as the steering currents weaken.  Typhoon Noru is forecast to turn slowly northward during the next 24 hours.  In about 48 hours westerly winds in the middle latitudes will begin to carry the typhoon more quickly toward the northeast.  On its anticipated track Typhoon Noru could approach the northern Ryukyu Islands on Friday.  It could bring strong winds to Amami-O-Shima.  The center could pass near Yaku-Shima and Tanega-Shima during the weekend.  In a little over two days Typhoon Noru could reach southwestern Kyushu.  Typhoon Noru has the potential to bring strong winds and heavy rain to parts of southwestern Japan during the next few days.  The heavy rain could also cause flash floods.

NHC Monitoring Two Areas for Tropical Development

The National Hurricane Center (NHC) was monitoring two areas for possible tropical development on Thursday afternoon.  A strong tropical wave was moving through the southeastern Caribbean Sea and the wave was designated as Invest 90L.  At 2:00 p.m. EDT on Thursday the center of Invest 90L was located at latitude 12.2°N and longitude 65.8°W which put it about 160 miles (260 km) east of Bonaire.  The tropical wave was moving toward the west at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 35 m.p.h. (55km/h) and there were gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1011 mb.

Another tropical wave moved off the coast of West Africa on Thursday and NHC designated that wave as Invest 99L.  At 2:00 p.m. EDT on Thursday the center of Invest 99L was located at latitude 10.2°N and longitude 20.9°W which put it about 370 miles (595 km) south-southeast of the Cabo Verde Islands.  The tropical wave was moving toward the west at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1010 mb.

The tropical wave over the southeastern Caribbean Sea will have the most immediate impact to land.  The wave could bring gusty winds to Aruba, Bonaire and Curacao within 24 hours.  The circulation of Invest 90L is elongated in an east-west direction and that is probably because of strong easterly winds blowing in the lower atmosphere.  There are some indications of a counterclockwise rotation on loops of visible satellite imagery, but it is not clear if the rotation extends all the way down to the surface.  The tropical wave is generating winds to near tropical storm force in the northern portion of the wave.  There are numerous thunderstorms developing along the axis of the wave.

Invest 90L is moving under the western end of an upper level ridge.  The ridge is producing southerly winds which are blowing over the top of the tropical wave and those winds are contributing to moderate vertical wind shear.  The strong easterly winds in the lower levels are also contributing to the shear.  Invest 90L could develop into a tropical cyclone when it moves farther west.  The shear could diminish and the Sea Surface Temperatures in the western Caribbean Sea and Bay of Campeche are very warm.  NHC is indicating that there is a 20% probability Invest 90L will become a tropical cyclone during the next five days.

The tropical wave over the far eastern Atlantic has a better chance of developing into a tropical cyclone.  Invest 99L is moving over water where the Sea Surface Temperature is near 28°C.  It is moving under the eastern end of an upper level ridge.  The ridge is causing northeasterly winds which are blowing toward the top of the tropical wave.  Those winds are producing moderate vertical wind shear.  When the wave moves farther west, it will move under weaker winds and the wind shear will decrease.  NHC is indicating that there is a 70% probability that Invest 99L will become a tropical cyclone during the next five days.

Typhoon Noru Turns Toward Southwestern Japan

Typhoon Noru turned toward southwestern Japan on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Typhoon Noru was located at latitude 25.6°N and longitude 136.2°E which put it about 525 miles (850 km) south-southeast of Miyazaki, Japan.  Noru was moving toward the northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 942 mb.

Typhoon Noru has a very symmetrical circulation that looks similar to what are sometimes called annular hurricanes.  There is a large circular eye at the center of Typhoon Noru.  The eye has a diameter of 35 miles (55 km).  The eye is surrounded by a wide ring of strong thunderstorms.  There are few bands of showers and thunderstorms outside the core of the typhoon.  The thunderstorms in the core of Noru are generating strong upper level divergence which is pumping mass away from the typhoon.

Typhoon Noru will be moving through a favorable environment during the next several days.  Noru will move over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is little vertical wind shear.  Typhoons and hurricanes that have an annular structure like that of Typhoon Noru tend to maintain a fairly steady intensity.  Given the favorable environment, Noru could strengthen during the next few days.

A subtropical ridge is steering Typhoon Noru slowly toward the northwest.  The ridge is forecast to strengthen and to steer Noru more toward the west-northwest during the next several days.  On its anticipated track Typhoon Noru could approach southwestern Japan in about three days.

Tropical Storm Emily Makes Landfall on West Coast of Florida

Tropical Storm Emily made landfall on the west coast of Florida at Anna Maria Island late Monday morning.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Emily was located at latitude 27.5°N and longitude 82.7°W which put it about 10 miles (15 km) northwest of Bradenton, Florida.  Emily was moving toward the east at 9 m.p.h. (15 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 in effect for the portion of the coast from Anclote River to Bonita Beach, Florida.

Thunderstorms developed near the center of the non-tropical low pressure system over the eastern Gulf of Mexico.  Latent energy released higher in the atmosphere by condensation in those storms created a warm core and the low pressure system made a transition to Tropical Storm Emily.  Thunderstorms near the core of Emily were generating a small area of upper level divergence.  Thunderstorms near the core, a warm core and upper level divergence are part of the typical structure of a tropical cyclone, which is why the National Hurricane Center classified the system as Tropical Storm Emily.  Emily has a well developed circulation, but most of the bands of showers and thunderstorms are in the eastern half of the tropical storm.  Drier air northwest of Emily and vertical wind shear are the probable causes of the asymmetrical distribution of precipitation.

Tropical Storm Emily is bringing gusty winds and heavy rain to parts of Central Florida.  A surface weather station in Sarasota (KSRQ) reported a sustained wind of 39 m.p.h. (63 km/h) and a wind gust of 49 m.p.h. (80 km/h).  The Skyway Bridge over Tampa Bay was closed due to strong winds.

Tropical Storm Emily is likely to weaken as it moves eastward across Central Florida.  When Emily moves over the Atlantic Ocean, it will move over water where the Sea Surface Temperature is near 29°C.  Emily could strengthen back into a tropical storm at that time.

Emily is being steered toward the east by a high pressure system north of the tropical storm.  An upper level trough over the Midwestern U.S. is forecast to move southeastward.  When Emily reaches the Atlantic Ocean southwesterly winds ahead of the trough will turn the tropical storm toward the northeast.