491
axpz20 knhc 230929
twdep
Tropical weather discussion
NWS TPC/National Hurricane Center Miami FL
0405 UTC Mon Nov 23 2009
Tropical weather discussion for the eastern Pacific Ocean from
the Equator to 32n...east of 140w.
Based on 0600 UTC surface analysis and satellite imagery through
0815 UTC.
...ITCZ...
axis was analyzed from 10n85w to 08n115w to 09n130w to 07n140w.
Isolated to scattered moderate convection was occurring within
125 nm of axis between 127w and 130w...associated with a low
level trough along 130w.
...Discussion...
The persistent convection in the ITCZ W of 120w the past couple
of days has decreased in coverage tonight as the se trades have
decreased in magnitude...and convergence has decreased. Though
there still remains isolated to moderate convection between 127
and 130w due to a weak low level perturbation.
Surface high pressure 1026 mb centered near 33.5n136w as
depicted in the 0400 UTC Quikscat pass. This has maintained
fresh to strong tradewinds across the western portion of the
forecast area N of 11n. This high pressure center will remain N
of the forecast area through the next 48 hours...with a shift E
of its current position...before starting to weaken on Wed. This
will maintain fresh to occasionally strong trades across the
area shrinking slightly in areal coverage through the forecast
period. Additionally...as the surface high shifts E over the
next 24 hours...winds in the Gulf of California N of 29n will
increase. The trade winds currently include a large area of
20-25 kt NE-E winds S of 25n and W of 125w...with seas 9 to 14
ft in mixed NE wind swell and long period NW swell. Large nwly
swell continues to dominate the waters and will fade modestly
through early Wednesday before another strong pulse of NW swell
arrives. E of 115w...seas remain in the 4 to 7 ft range across
the offshore waters...dominated by a merging mix of
NW...SW...and S swell.
Northerly gap winds through the Gulf of Tehuantepec should
diminish during the next 24 hours as the winds have veered
across the Gulf of Mexico with high pressure building behind the
front. However...a small plume of near 20 kt N winds is forecast
to persist through 24 hours. Fresh NE trades through the Gulf of
papagayo and downstream some 300 miles should continue through
tonight before gradually weakening through 48 hours.
$$
Al
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