669
axpz20 knhc 231608
twdep
Tropical weather discussion
NWS TPC/National Hurricane Center Miami FL
1605 UTC Mon Nov 23 2009
Tropical weather discussion for the eastern Pacific Ocean from
the Equator to 32n...east of 140w.
Based on 1200 UTC surface analysis and satellite imagery through
1445 UTC.
...ITCZ...
axis from 06n77w to 06n107w to 07n114w to 08n134w to 05n140w.
Scattered moderate convection within 90 nm of axis E of 93w.
Isolated moderate convection within 60 nm of axis from 98w-120w.
...Discussion...
broad mid-upper level ridge from 00n115w to 32n130w maintains
anticyclonic flow across basin W of 120w and advects abundant
tropical moisture well N of ITCZ eastward into central Mexico.
Weak upper level trough from central Texas to 13n110w keep dry
air mass N of 20n from 100w-120w. Upper level diffluent flow
between trough and ridge over South America enhancing convection
E of 93w associated with low pres center 1007 mb over Colombia.
Elsewhere at the surface...
high pres 1028 mb centered at 34n134w maintain fresh to strong
tradewinds across W of 125w N of 10n. High pres remain N of
forecast area through next 48 hours then shift E...before
weakening Wed and diminishing and shrinking trades. It will
also bring tightening gradient into Gulf of California bringing
fresh N breeze N of 28n large long period NW swell still
spreading across most E pac W of 115w.
Fresh NE trades through Gulf of papagayo and downstream expected
to diminish late Tue as low pres over Colombia weakens.
$$
Wally Barnes
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