Tag Archives: Mexico

TD 6E Strengthens Into Tropical Storm Fernanda

Tropical Depression Six-E strengthened into Tropical Storm Fernanda on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Fernanda was located at latitude 11.9°N and longitude 113.1°W which put it about 790 miles (1270 km) south-southwest of the southern tip of Baja California.  Fernanda was moving toward the west 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 1004 mb.

Thunderstorms on the western side of the center of Tropical Storm Fernanda increased on Wednesday night.  Several bands of showers of thunderstorms formed in the western half of the circulation, but the distribution of convection remained asymmetrical.  There were few showers and thunderstorms in the eastern half of the circulation.  The thunderstorms in the western half of the were generating upper level divergence which was pumping out mass to the west of Tropical Storm Fernanda.

Tropical Storm Fernanda is currently in an environment that is moderately favorable for intensification.  It is moving over water where the Sea Surface Temperature (SST) is near 29.5°C.  An upper level ridge north of Fernanda is producing easterly winds which are blowing toward the top of the tropical storm.  Those winds are causing moderate vertical wind shear and the shear may be the cause of the asymmetrical distribution of thunderstorms.  Fernanda is likely to move into an area where the upper level winds are weaker and the shear will decrease.  Warm SSTs and less wind shear should allow Tropical Storm Fernanda to intensify into a hurricane later this week.  Once an eye forms, a period of rapid intensification will be possible and Fernanda could eventually become a major hurricane.

A subtropical ridge north of Fernanda is steering the tropical storm westward and a general westerly motion is expected to continue for the next few days.  On its anticipated track Tropical Storm Fernanda will move away from Mexico and it could move into the Central Pacific in a few days.

Tropical Depression Six-E Forms West of Mexico

The Eastern North Pacific basin continues to be active tropically.  Tropical Depression Six-E formed west of Mexico on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Depression Six-E was located at latitude 12.2°N and longitude 109.9°W which put it about 740 miles (1190 km) south of the southern tip of Baja California.  It was moving toward the west 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 1007 mb.

A center of circulation consolidated within a large area of thunderstorms south of Baja California on Tuesday.  A primary band of showers and thunderstorms wrapped around the western and southern sides of the center of circulation.  Additional bands of showers and thunderstorms were beginning to form north and west of the center.  There were not many showers and storms in the eastern half of the circulation.  The thunderstorms near the core of the circulation were beginning generate upper level divergence which was pumping away from depression.

Tropical Depression Six-E will move through an environment that will be favorable for intensification.  It will move over water where the Sea Surface Temperature (SST) is near 29°C.  Tropical Depression Six-E is near the western end of an upper level ridge and the upper level winds are relatively weak.  Warm SSTs and little vertical wind shear should allow the depression to strengthen during the next several days.  Tropical Depression Six-E is likely to become a tropical storm on Wednesday and it could become a hurricane later this week.

Tropical Depression Six-E is moving south of a subtropical ridge which is steering the depression toward the west.  The subtropical ridge is expected to continue to steer the depression toward the west during the next few days.  On its anticipated track the depression is expected to move away from the coast of Mexico.

Eugene Becomes a Hurricane Southwest of Baja California

Tropical Storm Eugene strengthened rapidly into a hurricane on Saturday as it moved southwest of Baja California.  At 11:00 p.m. EDT on Saturday the center of Hurricane Eugene was located at latitude 14.4°N and longitude 113.5°W which put it about 630 miles (1020 km) south-southwest of the southern tip of Baja California.  Eugene was moving toward the northwest at 8 m.p.h. (13 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 990 mb.

A primary raindband wrapped around the center of Hurricane Eugene on Saturday and an eye formed at the center of circulation.  The eye had a diameter of 30 miles (50 km).  Additional bands of showers and thunderstorms were revolving around the core of the circulation.  Thunderstorms were generating well developed upper level divergence which was pumping mass away in all directions.  The circulation of Hurricane Eugene was symmetrical and well organized.

Hurricane Eugene was moving over water where the Sea Surface Temperature (SST) was near 29°C.  Eugene was underneath the western end of an upper level ridge.  The ridge was producing southerly winds which were blowing toward the top of the hurricane, but the vertical wind shear was not very strong.  Eugene is likely to intensify on Sunday.  It will gradually move over cooler SSTs and Hurricane Eugene will move over water where the water is cooler than 26°C on Monday.  When Eugene reaches the cooler SSTs, it will begin a steady weakening trend.

Hurricane Eugene is moving around the western end of a subtropical ridge which is steering it toward the northwest.  Eugene is expected to continue to move toward the northwest during the next several days.  On its anticipated track Hurricane Eugene will move parallel to the west coast of Baja California.

Tropical Storm Eugene Forms South of Baja California

A distinct center of circulation consolidated within a broader area of low pressure south of Baja California on Friday and the National Hurricane Center classified the system as Tropical Storm Eugene.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Eugene was located at latitude 11.9°N and longitude 111.2°W which put it about 765 miles (1230 km) south of the southern tip of Baja California.  Eugene was moving toward the northwest at 8 m.p.h. (13 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.

The circulation of Tropical Storm Eugene is large and there are numerous bands of showers and thunderstorms rotating around the center of circulation.  A primary rainband is wrapping around the southern and eastern sides of the center and the strongest winds are occurring northeast of the center of circulation.  The circulation is circular and symmetrical.  Thunderstorms around the core of Eugene are beginning to generate upper level divergence which is pumping out mass in all directions.

Tropical Storm Eugene will move through an environment that is favorable for intensification.  Eugene will move over water where the Sea Surface Temperature is near 29°C.  The upper level winds over Tropical Storm Eugene are relatively weak and there is not a lot of vertical wind shear.  The circulation of Tropical Storm Eugene will continue to consolidate and it is likely to intensify during the weekend.  It is likely to become a hurricane and it could intensify rapidly if an eye forms.

Tropical Storm Eugene is moving near the western end of a subtropical ridge which is steering it toward the northwest.  A generally northwesterly motion is expected to continue during the next few days.  On its anticipated track Tropical Storm Eugene would move parallel to the west coast of Baja California and the center would remain west of the coast.

Hurricane Dora Weakens South of Baja California

Hurricane Dora weakened as it moved over cooler water south of Baja California on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Dora was located at latitude 19.6°N and longitude 111.4°W which put it about 245 miles (400 km) south-southwest of the southern tip of Baja California. Dora as moving toward the west-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 995 mb.

Tropical Storm Dora is moving over water where the Sea Surface Temperature (SST) is near 24°C.  The circulation of Tropical Storm Dora is still very well organized but it is unable to extract sufficient energy from the upper ocean to maintain its intensity.  As a result, the showers and thunderstorms are not rising as far into the atmosphere and the circulation is spinning down.  There is little vertical wind shear and so the circulation is still symmetrical, but it is not as vigorous.  The lack of wind shear will cause the weakening to occur more slowly than it would have if the upper level winds were stronger.

A subtropical ridge is steering Tropical Storm Dora toward the west-northwest and that general motion is expected to continue for anther day or two.  On its anticipated track, Tropical Storm Dora will move farther away from Baja California.  The forecast track would keep Dora over cooler SSTs and it should continue to weaken.

Dora Rapidly Intensifies Into First Eastern Pacific Hurricane of 2017

Tropical Storm Dora intensified rapidly into a hurricane during the overnight hours.  Dora is the first hurricane to develop over the Eastern North Pacific during 2017.  At 11:00 a.m. EDT on Monday the center of Hurricane Dora was located at latitude 17.3°N and longitude 106.3°W which put it about 220 miles (350 km) south of Cabo Corrientes, Mexico.  Dora was moving toward the west-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 85 m.p.h. (140 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 985 mb.

The circulation of Hurricane Dora is very well organized.  A circular eye exists at the center of circulation.  A ring of strong thunderstorms surrounds the eye.  Additional bands of showers and thunderstorms are revolving around the core of the circulation.  Thunderstorms in Dora are generating well developed upper level divergence which is pumping large quantities of mass out in all directions.

Dora is a small hurricane.  Wind to hurricane force extend out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extend out about 80 miles (130 km) from the center.  The Hurricane Intensity Index (HII) is 12.7.  The Hurricane Size Index (HSI) is 7.3.  The Hurricane Wind Intensity Size Index (HWISI) is 20.0.

Hurricane Dora will move through an environment favorable for intensification for another 12 to 18 hours.  It is currently over water where the Sea Surface Temperature (SST) is near 28°C.  Dora will move over SSTs that will gradually be cooler, but they should be warm enough to support further intensification for another 12 to 18 hours.  Hurricane Dora is moving through an area where upper level winds are weak and there is almost no vertical wind shear.  Hurricane Dora is likely to strengthen further during the next few hours.  Dora will move over much cooler SSTs when it passes south of Baja California and it will begin to weaken on Tuesday.

A subtropical ridge to the north of Dora is steering the hurricane toward the west-northwest and that general motion is expected to continue for another 24 to 48 hours.  On its anticipated track the center of Hurricane Dora will pass south of Baja California.

TD 04E Strengthens Rapidly Into Tropical Storm Dora

Tropical Depression Four-E strengthened rapidly into Tropical Storm Dora on Sunday.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Dora was located at latitude 16.4°N and longitude 104.3°W which put ti about 290 miles (470 km) south-southeast of Cabo Corrientes, Mexico.  Dora was moving toward the west-northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 996 mb.

The circulation of Tropical Storm Dora organized quickly on Sunday.  A primary rainband wrapped tightly around the center of circulation.  An eyelike feature appeared to be forming on microwave and infrared satellite images.  Additional bands of showers and thunderstorms developed outside the core of Tropical Storm Dora.  Thunderstorms around the core generated upper level divergence which pumped out mass in all directions.

Tropical Storm Dora will be moving through an environment very favorable for intensification on Monday.  It will move over water where the Sea Surface Temperature (SST) is near 29°C.  An upper level ridge over Mexico is producing easterly winds that are blowing toward the top of the circulation, but there is little vertical wind shear.  A combination of warm water and little shear will allow Dora to intensify into a hurricane during the next 24 hours.  The rate of intensification could increase once the formation of the eye is complete.  Dora will move over cooler SSTs on Tuesday.  The cooler SSTs will initially halt the intensification.  When Dora is unable to extract sufficient energy from the upper ocean it will start to weaken.

A subtropical ridge northeast of Dora is steering the tropical storm toward the west-northwest and a general west-northwesterly motion is expected to continue for another day or two.  On its anticipated track the center of Tropical Storm Dora will remain southwest of Mexico.  Dora will pass south of Baja California on Tuesday.

Tropical Depression Four-E Forms South of Acapulco

Tropical Depression Four-E formed south of Acapulco, Mexico on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Depression Four-E was located at latitude 14.3°N and longitude 100.0°W which put it about 180 miles (290 km) south of Acapulco.  It was moving toward the west-northwest at 10 m.p.h. (16 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 1006 mb.

A distinct surface center of circulation developed within a larger area of thunderstorms south of Mexico on Saturday.  Showers and thunderstorms began to consolidate near the center.  Additional bands of showers and thunderstorms formed outside the core of the circulation.  The thunderstorms began to produce upper level divergence which pumped mass away from the core of the depression.

Tropical Depression Four-E will move through an environment favorable for intensification during the next several days.  It will move over water where the Sea Surface Temperature is near 30°C.  An upper low over the western Gulf of Mexico is enhancing the upper level divergence to the northeast of the tropical depression.  An upper level ridge over Mexico is producing easterly winds which are blowing toward the top of the circulation, but the vertical wind shear is minimal.  Tropical Depression Four-E could intensify in a tropical storm on Sunday.  It has a chance to become a hurricane early next week before it reaches cooler water south of Baja California.

A subtropical ridge over Mexico is steering Tropical Depression Four-E toward the west-northwest and that general motion is expected to continue for another two or three days.  On its anticipated track the center of Tropical Depression Four-E is expected to remain south of the coast of Mexico.  Rainbands in the northern portion of the circulation could produce locally heavy rain over parts of southern Mexico.  The greatest risk would be for flash floods in those areas.

Invests 92L, 93L Monitored for Possible Development

Two weather systems designated as Invest 92L and Invest 93L are being monitored for possible development into tropical cyclones.  Invest 92L is a tropical wave that is speeding toward the Windward Islands.  At 2:00 p.m. EDT on Sunday the center of Invest 92L was located at latitude 7.3°N and longitude 49.4°W which put it about 800 miles (1290 km) east-southeast of the Windward Islands.  It was moving toward the west-northwest at 24 m.p.h. (39 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.

Invest 93L consists of a broad area of low pressure over the northwestern Caribbean Sea.  At 2:00 p.m. EDT on Sunday the surface center of Invest 93L was located at latitude 19.0°N and longitude 87.1°W which put it about 145 miles (230 km) south of Cancun, Mexico.  It was moving toward the north-northwest at 5 m.p.h. (8 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.

Invest 92L is a tropical wave and it has not yet develop a well defined surface center.  There is some evidence of cyclonic rotation on visible satellite imagery and there could be a center in the middle levels of the circulation.  Most of the stronger thunderstorms are located north and west of the center.  The are some bands of showers and thunderstorms south and west of the center.  There is some upper level divergence from the thunderstorms north and west of the center, but it is not well developed at the current time.

Invest 92L is in an environment that is moderately favorable to development of a tropical cyclone.  It is moving over water where the Sea Surface Temperature is near 28°C.  It is in a region of rapid easterly flow, but the wind speed is fairly similar at all levels.  So, there is not a lot of vertical wind shear.  The rapid easterly flow could be inhibiting the formation of a well defined center of circulation.  Invest 92L will be in a moderately favorable environment for about another 36 hours.  An upper level trough over the eastern Caribbean Sea will create increased vertical wind shear when Invest 92L reaches that location.  The National Hurricane Center is indicating that there is a 60% probability that Invest 92L will develop into a tropical cyclone during the next two days.

Invest 92L is being steered rapidly toward the west-northwest by a subtropical high north of it.  A fairly quick motion toward the west-northwest is expected to continue for the next few days.  On its anticipated track Invest 92L could be near the Windward Islands by late Monday.  Even it if does not develop into a tropical cyclone, the system will bring gusty winds and locally heavy rain to those islands.

The structure of Invest 93L is much more complicated.  There is a very broad but weak surface low pressure system over the Yucatan peninsula and the center of that low is being used as the center of the Invest.  However, there is a strong mid-level center of circulation near latitude 18.7°N and longitude 82.9°W which is about 115 miles (185 km) west-southwest of Grand Cayman.  Invest 93L is producing winds to near tropical storm force and those winds are occurring in thunderstorms associated with the mid-level circulation.  It is possible that downdrafts in those thunderstorms could transport enough momentum to the surface to generate a new surface center beneath the mid-level center.

Invest 93L is moving in an environment that will be favorable for the development of a tropical cyclone.  An upper level ridge is building between the trough over the eastern Caribbean Sea and another upper level trough over the northwestern Gulf of Mexico.  The trough over the northwestern Gulf is producing strong southwesterly winds which are causing vertical wind shear over the surface low over the Yucatan peninsula.  However, the upper level ridge is producing an area of slower winds over the mid-level center and there is less vertical wind shear there.  In fact, the upper level ridge is enhancing upper level divergence over the mid-level center.  If that continues, surfaces pressure will begin to decrease in that region.  The National Hurricane is indicating that there is a 70% probability of development of a tropical cyclone or a subtropical cyclone during the next two days.

Invest 93L is moving slowly north-northwestward around the western end of the subtropical high over the Atlantic Ocean.  A general north-northwesterly motion is expected to continue for another day or two, but there is some spread in the guidance from the numerical models.  If a cyclone forms from the surface low over the Yucatan peninsula, then the greatest risk would be to the western Gulf of Mexico.  If a new surface center forms farther east under the mid-level center, then there would be a greater risk for the central and eastern Gulf of Mexico.  Interests around the Gulf should monitor Invest 93L.

Two Areas to Watch for Potential Tropical Development

There are two areas to watch for the potential development of a tropical cyclone during the next week.  One location to watch for potential development is the area around the western Caribbean Sea, Yucatan peninsula and southern Gulf of Mexico.  The other area to watch is the tropical Atlantic between Africa and the Lesser Antilles.

Numerical models have been suggesting possible development of an area of low pressure somewhere over the western Caribbean Sea, Yucatan peninsula or southern Gulf of Mexico.  The scenario suggested by the models includes a surge of southerly winds across Central America, which contributes to the spinning up of an area of low pressure.  There are currently strong westerly winds in the upper levels over this area.  The strong vertical wind shear will prevent development of a tropical cyclone in the short term.  An upper level ridge could develop over the area in several days.  If that happens, the wind shear would decrease.  Some runs of the numerical models create a broad, weak area of low pressure, which would primarily be a rain threat for the Yucatan peninsula and nearby regions.  Other models develop a low pressure system that is a little stronger, although those lows also weaken when they move over the Yucatan.  The models generally move the low pressure system northwestward over the southern Gulf of Mexico.  However, there are fairly significant deviations in how far north the low moves once it is in the Gulf.  As of 8:00 p.m. EDT on June 14 the National Hurricane Center was indicating that there was a 30% probability of the development of a tropical cyclone in this area during the next five days.

Some numerical models have also been suggesting potential development of a tropical cyclone near latitude 10°N over the tropical Atlantic Ocean between Africa and the Lesser Antilles.  A tropical wave is interacting with the Intertropical Convergence Zone and there has been a persistent area of showers and thunderstorms.  The disturbance is moving slowly toward the west.  There is some vertical wind shear in this region, but the stronger upper level winds are north of the disturbance.  The disturbance is over water where the Sea Surface Temperature is near 27°C.  It would be unusual to see a tropical cyclone develop over the tropical Atlantic in June, but it has happened at least three times in the past.  As of 8:00 p.m. EDT on June 14 the National Hurricane Center is indicating that there is a 20% probability of the development of a tropical cyclone in this region during the next five days.