Skip Navigation Links
NOAA NOAA United States Department of Commerce

Tropical Storm JOAQUIN


1100 PM EDT TUE SEP 29 2015

The cloud pattern of Joaquin has continued to become better
organized this evening.  The low-level center is located within the
northwestern portion of the deep convection and the outflow has
continued to expand over the northern semicircle, which suggests
that the shear continues to decrease.  The latest satellite
intensity estimates from TAFB and SAB are T3.5 or 55 kt on the
Dvorak scale.  Based on the earlier reconnaissance aircraft data and
the continued increase in organization this evening, the initial
wind speed has been raised to 60 kt.  Joaquin is forecast to be over
warm water and in an increasingly favorable upper-level wind pattern
during the next day or so.  These conditions favor intensification
and the NHC forecast calls for Joaquin to become a hurricane within
the next 12 hours.  The upper-level winds are shown by the global
models to become quite conducive for strengthening by 36 hours as an
upper-level anticyclone builds over the system, and additional
strengthening is anticipated.  The new NHC forecast is a bit
higher than the previous advisory, and is close to the IVCN
intensity consensus aid.  It should be noted, that the UKMET, GFS,
and ECMWF models all significantly deepen Joaquin during the next
few days, and the NHC forecast could be somewhat conservative.

Joaquin is moving west-southwestward at about 5 kt.  This general
motion is forecast to continue during the next 24-36 hours while the
cyclone remains to the southwest of a weak mid-level ridge. During
this time, the center of Joaquin is forecast to move near or over
portions of the Central Bahamas.  After 48 hours, a deepening mid-
to upper-level trough over the southeastern United States is
expected to cause a turn toward the north or north-northeast with an
increase in forward speed.  There remains large spread in the
guidance at days 4 and 5, with the ECMWF showing a northeastward
motion toward Bermuda.  Meanwhile, the 18Z GFS shifted significantly
westward and is close to the UKMET and HWRF, which are along the
western edge of the guidance envelope.  The NHC track has been
shifted westward, but it is not as far west as the multi-model
consensus. The new track is fairly close to the ECMWF-Ensemble Mean.

The government of the Bahamas has issued a Hurricane Watch for the
Central Bahamas.  Additional watches or warnings may be required
early Wednesday.

At this time it is very hard to gauge the long-range potential
impacts of Joaquin in the United States.  The environmental steering
currents are complex and are not being handled in a consistent
manner by the forecast models.  A wide range of outcomes are
possible and it is simply too soon to say what impacts, if any,
Joaquin will have on the United States.


INIT  30/0300Z 25.8N  71.7W   60 KT  70 MPH
 12H  30/1200Z 25.5N  72.4W   70 KT  80 MPH
 24H  01/0000Z 25.2N  73.3W   75 KT  85 MPH
 36H  01/1200Z 24.8N  74.1W   80 KT  90 MPH
 48H  02/0000Z 24.9N  74.5W   85 KT 100 MPH
 72H  03/0000Z 26.7N  74.0W   90 KT 105 MPH
 96H  04/0000Z 31.3N  72.5W   85 KT 100 MPH
120H  05/0000Z 35.5N  72.0W   80 KT  90 MPH

Forecaster Brown