Tag Archives: 19E

Norbert Regains Tropical Depression Status South of Baja California

Former Tropical Storm Norbert regained tropical depression status south of Baja California on Tuesday afternoon.  At 5:00 p.m. EDT on Tuesday the center of Tropical Depression Norbert was located at latitude 19.8°N and longitude 111.7°W which put it about 245 miles (390 km) south-southwest of the southern tip of Baja California.  Norbert 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 1007 mb.

After strong vertical wind shear weakened former Tropical Storm Norbert on Saturday, the lower levels of the circulation drifted slowly toward the northwest.  The surface circulation around the former tropical storm moved into a region where the upper level winds were not as strong on Monday.  More thunderstorms began to develop in bands revolving around around the center of the surface circulation.  Additional thunderstorms formed near the center of the low on Tuesday afternoon and the National Hurricane Center designated the system as Tropical Depression Norbert.

Tropical Depression Norbert will move through a region somewhat favorable for intensification during the next 12 to 24 hours.  Norbert will move over water where the Sea Surface Temperature is near 28°C during the next 12 hours.  It will remain over water warmer than 26°C until Wednesday afternoon.  After that time Norbert will start to move over even cooler water.  An upper level low west of central Baja California will produce southerly winds which will blow toward the top of Tropical Depression Norbert.  Those winds will produce vertical wind shear, but Norbert will remain east of the strongest shear for another 24 hours.  When Norbert gets closer to the upper level low later on Wednesday, then the shear will increase and will cause it to weaken.

Tropical Depression Norbert will move between the upper level low west of Baja Californa and and upper level ridge over the southwestern U.S. and northern Mexico.  Those two weather systems will steer Norbert toward the northwest during the next several days.  On its anticipated track Tropical Depression Norbert is forecast to move parallel to the west coast of Baja California.

Tropical Storm Norbert Develops Southwest of Mexico

Tropical Storm Norbert developed southwest of Mexico on Tuesday morning.  At 5: 00 a.m. EDT on Tuesday the center of Tropical Storm Norbert was located at latitude 13.7°N and longitude 106.2°W which put it about 385 miles (625 km) south-southwest of Manzanillo, Mexico.  Norbert was moving toward the northwest 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 1002 mb.

The wind speed increased around a low pressure system southwest of Mexico on Tuesday morning and the National Hurricane Center designated the system as Tropical Storm Norbert.  More thunderstorms formed near the center of Norbert.  Storms near the center of circulation started to generate upper level divergence which pumped mass away to the northeast of the tropical storm.  Bands of showers and thunderstorms were developing outside the center of Norbert.  The circulation around Tropical Storm Norbert was small.  Winds to tropical storm force extended out 25 miles from the center of circulation.

Tropical Storm Norbert will be in an environment that is somewhat favorable for intensification.  Norbert will move over water where the Sea Surface Temperature is near 29°C.  A large upper level trough extends from northern Mexico over the Eastern North Pacific Ocean.  The trough will produce southwesterly winds which will blow toward the top of Tropical Storm Norbert.  Those winds will cause vertical wind shear and the shear will inhibit intensification.  Tropical Storm Norbert could strengthen if the shear is not too strong.

Tropical Storm Norbert will be in a region where the steering currents are weak..  Norbert is not likely to move very much during the next several days.  If Tropical Storm Norbert remains in the same location for more than a day, its winds will mix cooler water to the surface.  That would limit the energy Norbert could extract from the ocean, and the tropical storm could weaken.

Elsewhere over the Eastern North Pacific, Tropical Storm Marie continued to churn west away from Baja California.  At 5:00 a.m. EDT on Tuesday the center of Tropical Storm Marie was located at latitude 21.7°W and longitude 134.3°W which put it about 1560 miles (2510 km) west of the southern tip of Baja California.  Marie was moving toward the west-northwest 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 1003 mb.

Tropical Storm Priscilla Develops Near West Coast of Mexico

Tropical Storm Priscilla developed near the west coast of Mexico on Sunday.  At 2:00 p.m. EDT on Sunday the center of Tropical Storm Priscilla was located at latitude 18.6°N and longitude 104.0°W which put it about 55 miles (90 km) southeast of Manzanillo, Mexico.  Priscilla was moving toward the north at 10 m.p.h. (16 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  1004 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Punta San Telmo to Playa Perula, Mexico.

A distinct low level center of circulation formed within a cluster of thunderstorms near the west coast of Mexico on Sunday and the National Hurricane Center designated the system as Tropical Storm Priscilla.  Thunderstorms were forming near the center of circulation.  Bands of showers and thunderstorms were also developing and the bands were revolving around the center of Priscilla.  Storms near the center were generating upper level divergence which was pumping mass away to the north of the tropical storm.  The circulation around Priscilla was small.  Winds to tropical storm force extended out 35 miles (55 km) from the center of circulation.

Tropical Storm Priscilla will move through an environment favorable for intensification during the next few hours.  The center of Priscilla will be over water where the Sea Surface Temperature is near 29°C.  It will be in a region where the upper level winds are not too strong and there will not be a lot of vertical wind shear.  However, the center of Tropical Storm Priscilla will be very close to Mexico.  The circulation around Priscilla will begin to pull drier air from over the land into the tropical storm.  Tropical Storm Priscilla could strengthen during the next few hours, but it is likely to weaken quickly when the center moves over Mexico.

Tropical Storm Priscilla will move around the western end of a high pressure system over Mexico.  The high will steer Priscilla on a track that will be a little to the west of straight north.  On its anticipated track, the center of Tropical Storm Priscilla will make landfall on the west coast of Mexico between Tecoman and Manzanillo within a few hours.  Priscilla could drop locally heavy rain which could cause flash floods in some places.

Tropical Depression Forms Over Gulf of California

Tropical Depression Nineteen-E formed over the Gulf of California on Wednesday morning.  At 11:00 a.m. EDT on Wednesday the center of Tropical Depression Nineteen-E was located at latitude 26.3°N and longitude 110.9°W which put it about 35 miles (55 km) northeast of Loreto, Mexico.  It was moving toward the north at 13 m.p.h. (20 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 1004 mb.

The circulation of Tropical Depression Nineteen-E was still organizing .  There was a cluster of thunderstorms near the center of circulation.  Most of the stronger storms were east of the center.  Several short bands of showers and thunderstorms were beginning to develop north and south of the center of circulation.  Storms near the center were generating some upper level divergence which was pumping mass away to the northeast of the depression.

Tropical Depression Nineteen-E will move through an environment somewhat favorable for intensification during the next 12 hours.  The water in the Gulf of California is very warm and the depression will move over water where the Sea Surface Temperature is near 31°C.  An upper level trough west of California will produce southwesterly winds which will cause moderate vertical wind shear.  Tropical Depression Nineteen-E could intensify during the next 12 hours and it has a chance to become a tropical storm.

The upper level trough west of California will steer Tropical Depression Nineteen-E toward the north-northeast.  On its anticipated track the depression will reach the west coast of Mexico near Guaymas in about 12 hours.  It could be a tropical storm when it reaches the coast.  It will bring some gusty winds, but locally heavy rain is the greatest risk.  There is the potential for flash floods in parts of Sinaloa, Sonora and Chihuahua.  The lower portion of Tropical Depression Nineteen will weaken quickly after it makes landfall and moves over mountains in western Mexico.  The upper portion of the circulation and some of the moist air will be transported farther northeast and the remnants of the circulation could enhance rainfall farther inland.

Olaf Becomes a Cat. 4 Hurricane

Hurricane Olaf intensified rapidly on Monday and it reached Category 4 on the Saffir-Simpson Scale.  At 11:00 p.m. EDT on Monday the center of Hurricane Olaf was located at latitude 10.1°N and longitude 139.5°W which put it about 1235 miles (1985 km) east-southeast of Hilo, Hawaii.  Olaf was moving toward the west at 10 m.p.h. (16 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 949 mb.

Olaf is a small but well organized hurricane.  The core is very symmetrical.  Hurricane Olaf has a clear eye with a diameter of about 12 miles (19 km/h) and the eye is surrounded by a ring of strong thunderstorms.  Several spiral rainbands are rotating around the inner core of the hurricane.  Upper level outflow channels to the northeast and southwest of Olaf are carrying mass away from the center of circulation, which is allowing the surface pressure to decrease.

Hurricane Olaf is moving just south of a band of stronger upper level westerly winds.  It is in an area of modest vertical wind shear.  The ocean beneath Hurricane Olaf has Sea Surface Temperatures  near 29°C.  The compact structure of Olaf allowed the hurricane to efficiently convert energy it extracted from the ocean to kinetic energy associated with higher wind speeds.  Olaf could remain in a favorable environment for another day or two, which may allow for further intensification.  However, if eyewall replacement cycles begin to occur, they will cause fluctuations in the intensity of Hurricane Olaf.

A subtropical ridge north of Olaf is steering the hurricane toward the west and that general steering motion is expected to continue for another day or two.  The western end of the subtropical ridge is expected to weaken later this week and that should allow Olaf to turn toward the north.  On its anticipated track, Olaf would turn toward the north before it reaches the Hawaiian Islands.

Olaf Becomes a Hurricane Between Baja and Hawaii

The core of the circulation of Olaf consolidated on Sunday and the National Hurricane Center upgraded it to a hurricane.  At 11:00 a.m. EDT on Sunday the center of Hurricane Olaf was located at latitude 9.5°N and longitude 133.2°W which put it about 1620 miles (2610 km) east-southeast of Hilo, Hawaii.  Olaf was moving toward the west at 12 m.p.h. (19 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 989 mb.

The circulation of Hurricane Olaf consists of a small core of thunderstorms around the center of circulation and a primary rainband that spirals around the western and southern sides of the hurricane.  The core of thunderstorms is producing some upper level divergence, but upper level winds are inhibiting the outflow on the western side of the center.

Hurricane Olaf is moving over water where the Sea Surface Temperature is near 30°C and there is plenty of energy in the upper ocean to support intensification.  However, an upper level trough north of Olaf is producing westerly winds which are blowing over the top of the hurricane.  The upper level winds are blocking upper level outflow on the western side of Olaf and the vertical wind shear is inhibiting the intensification of Olaf.  If the wind shear decreases, then further intensification will be possible.

A subtropical ridge is steering Hurricane Olaf toward the west and that general motion is expected to continue for another day or two.  When Olaf reaches the western end of the ridge, it will start to turn more toward the north.