Tag Archives: Tropical Depression Norbert

Norbert Weakens to a Tropical Depression

Former Tropical Storm Norbert weakened to a tropical depression as it moved over the Central North Pacific Ocean on Monday evening.  At 11:00 p.m. EDT on Monday the center of Tropical Depression Norbert was located at latitude 20.2°N and longitude 140.5°W which put the center about 950 miles (1525 km) east of Hilo, Hawaii.  Norbert was moving toward the west-northwest at 15 m.p.h. (24 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 1006 mb.

Former Tropical Storm Norbert weakened to a tropical depression on Monday evening.  Drier air caused many of the thunderstorms in Tropical Depression Norbert to weaken on Monday.  A few thunderstorms were still occurring in bands on the periphery of Norbert’s circulation.  Many of the bands revolving around the center of Tropical Depression Norbert consisted primarily of showers and lower clouds.  Since there were few thunderstorms near the center of Norbert, there was very little upper level divergence.  Convergence of mass in the lower levels of the atmosphere caused the surface pressure to increase on Monday.

Tropical Depression Norbert will move through an environment that will be unfavorable for intensification during the next 24 hours.  Norbert will move over water where the Sea Surface Temperatures are near 26°C.  An upper level low that is northeast of Hawaii will continue to produce southwesterly winds that will blow toward the top of Norbert’s circulation.  Those winds will continue to cause moderate vertical wind shear.  Norbert will also continue to move through a mass of drier air that is east of Hawaii.  Tropical Depression Norbert is likely to continue to weaken on Tuesday because of the moderate vertical wind shear and the drier air.

Tropical Depression Norbert will move around the southern part of a high pressure system that is over the Central North Pacific Ocean.  The high pressure system will steer Norbert toward the west during the next 24 hours,  On its anticipated track, Tropical Depression Norbert will still be far to the east of Hawaii on Tuesday.

Elsewhere, Tropical Depression Fifteen-E continued to move farther away from Baja California.

At 11:00 p.m. EDT on Monday the center of Tropical Depression Fifteen-E was located at latitude 16.5°N and longitude 121.6°W which put the center about 880 miles (1415 km) west-southwest of the southern tip of Baja California.  The tropical depression was moving toward the west at 10 m.p.h. (16 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 1005 mb.

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.