334 axpz20 knhc 220339 twdep

Tropical weather discussion
NWS TPC/National Hurricane Center Miami FL
0405 UTC sun Nov 22 2009
Tropical weather discussion for the eastern Pacific Ocean from 
the Equator to 32n...east of 140w. 
Based on 0000 UTC surface analysis and satellite imagery through 
0215 UTC.
...ITCZ...
axis extends from 07n77w to 06n79w to 06n96w to 07n103w to 
06n110w to 09n124w to 08n135w to 06.5n140w.  Scattered moderate 
to strong within 240 nm N and 120 nm S of axis W of 124w.  
Scattered moderate within 90 nm of axis between 100w and 110w... 
and along 81w.
...Discussion...
broad mid-upper level ridge persists along 10n between 150w and 
110w...and continues to maintain a blocking effect across the 
epac while continuing to ventilate moderate to strong cnvtn 
along the ITCZ W of 120...which is occurring across the nrn 
fringes of a tongue of anomalously warm surface and sub surface 
waters. Broad zonal flow across the top of this ridge extends N 
to 25/26n...where a narrow mid-upper trough extends from the 
central Baja California peninsula wwd in a TUTT like fashion to 
an upper low N of Hawaii along 154w. These wly's N of the ridge 
are transporting upper level moisture sheared off from ITCZ 
cnvtn S through se of the  Hawaiian islands NE then E...across 
Mexico and into the srn Gulf of Mexico...effecting the famed 
pineapple express. A significant srn stream upper trough 
sweeping across the Hawaiian islands tonight is forecast to move 
E across the epac over the next several days and begin to erode 
portions of this blocking tropical ridge by mid week. In fact 
this upper trough is forecast to dig deep into the tropical epac 
and move E across the baja and into Mexico Thu-Fri and 
significantly alter the low level pattern.
E of this ridge...a mid to upper level trough extends from a mid 
level low just off the E coast of Nicaragua...SW across Central 
America to an elongated mid-upper low terminating near 03n110w. 
Upper convergence dominates most of this region E of 118w and is 
leading to dry and very stable conditions across most of this 
area...except in the vicinity of these upper lows.   
At the surface...
a 1026 mb high centered at 33n141w has a ridge extending se to 
offshore of baja...behind a now diffuse front...continuing se to 
14n105w...and is maintaining fresh to strong trades due S of the 
ridge...W of 120w.  Large long period NW swell continues to 
propagate se...covering most of epac...with another pulse now 
crossing 20n. W of 120w...seas remain confused at 10-13 ft in a 
broad mix of nely wind swell...N to NW swell...and very long 
period srn hemi swell from the SW. Similar mixed and merging 
long period swell dominated the equatorial belt south and ewd.
Moderate gap winds continue to flow through Gulf of papagayo 
this evening and are expected to increase and expand SW Sunday. 
Nly flow from Gulf of Mexico has initiated another pulse of gap 
winds through the Gulf of Tehuantepec today...presently 20-25 
kt...that will likely increase a bit overnight through Sunday 
morning before gradually diminishing through Sunday afternoon 
and evening...then quickly diminish Mon.   
$$
Stripling







« Back to the Tropical Weather Page