Interesting 10:45 San Juan AFD

[*StOrmsPr*]

Area forecast discussion
National Weather Service San Juan PR
1045 PM AST Wednesday Oct 8 2003


Small vorticity center embedded within upper level trough...which is now
across the local area...has pulled northward across western Puerto
Rico to enhance evening convection across the west and SW of p.R. And
is now enhancing convection moving from the leewards into the Virgin
Islands. St Croix ASOS reporting north wind gust of 30 knots at 0153z
in a tstorm...and more activity increasing in coverage across the
usvi at this time. Sent an evening update to include thunderstorms across SW p.R.
And dropped rain chances eastern p.R. Through sunrise...expecting a
short lived subsident trend ahead of approaching tropical wave.
However...likely should have increased rain chances across the usvi
and east coast of p.R.


Global model guidance has continued to converge on the passage of a
weak low level cyclonic center passing somewhere across the Virgin
Islands/eastern p.R. Area Thursday evening then moving northwest across
p.R. And into the Atlantic through Friday. GFS has continued to show
an organized surface center...and focusing best moisture and low
level convergence on the east and NE semi circles. This scenario would
focus highest rain accumulations across the Leeward Islands...U.S.
And British Virgin Islands...and the adjacent waters Thursday
through Friday morning. However...this contingent on organization of
wave occurring. Late afternoon satellite imagery suggested some weak
cyclonic curling just to the north-northeast of Barbados...and imagery through
this hour suggests that a middle level circulation center may be
currently organizing in vicinity of 15n and 60w. The forecast with this
system thus looks to be very interesting next 48 hours for the NE
Caribbean region.

For residents and mariners of the Leeward Islands...U.S. And British
Virgin Islands...and Puerto Rico...scattered to numerous squalls and
thunderstorms will spread from southeast to northwest across the leewards into
vi/Puerto Rico area overnight through Thursday evening...with
potential for 24 hour rain totals of 4 to 8 inches...and strong wind
gusts of 35 to 50 knots in squalls and thunderstorms. Presently there is
little evidence of a surface low yet developing...but should further
organization continue overnight through Friday morning...winds of 25
knots and potentially higher could be realized on the east and
northeast side of this wave...which will rapidly deteriorate local
marine conditions. Small craft across the region are suggested to
batten down and reef sails for the next 24 to 36 hours.