An Air Force Reserve Hurricane Hunter aircraft found that Hurricane Norbert was little stronger than was estimated based on satellite imagery.  At 2:00 p.m. EDT on Thursday the center of Hurricane Norbert was located at latitude 20.8°N and longitude 110.6°W which put it about 150 miles south-southwest of the southern tip of Baja California.  Norbert has been moving somewhat erratically, but the estimated motion was toward the northwest at 7 m.p.h.  The aircraft found that the maximum sustained wind speed was 90 m.p.h. and the minimum surface pressure was 970 mb.

Norbert is expected to move generally toward the northwest during the next several days and to move roughly parallel to the west coast of Baja California.  Although the center is expected to remain offshore, winds to tropical storm force may reach parts of Baja California.  For that reason a Tropical Storm Warning has been issued for the portion of the coast that extends from La Paz southward to the southern tip of Baja California and then northward to Cabo San Lazaro, Mexico.  Tropical Storm Watches have been issued for the portions of the coast from La Paz northward to San Evaristo and from Cabo San Lazaro northward to Puerto San Andresito.

The eye appears to be becoming more evident on visible satellite images.  There is some upper level shear from the northeast, but some additional intensification is possible during the next 24 hours.  When Norbert begins to move west of Baja California it will move over a very strong gradient of Sea Surface Temperatures (SSTs) toward colder water.  It will move from SSTs near 30°C to SSTs near 23°C.  The colder SSTs will greatly reduce the energy available to drive the circulation.  In addition, the atmosphere tends to be quite stable over the cooler SSTs, which will further inhibit convection and help to spin down the circulation.

Where the wind direction creates a flow up the slopes of mountains, locally heavy rainfall could occur and the potential for flooding exists in some locations.  Southerly flow around the eastern side of Norbert’s weakening circulation could transport moisture into portions of the southwestern U.S.