415 
axpz20 knhc 082158
twdep 
Tropical weather discussion  
NWS TPC/National Hurricane Center Miami FL
2205 UTC sun Nov 08 2009
Tropical weather discussion for the eastern Pacific Ocean from 
the Equator to 32n...east of 140w. 
Based on 1800 UTC surface analysis and satellite imagery through 
2145 UTC.
...Tropical lows...
.Low pres is centered near 13n89w estimated at 1008 mb is  
stationary over the Pacific coast of San Salvador. The 
circulation is mostly a swirl of low level clouds lacking deep 
convection but rain accumulations may result in localized 
flooding.
.Low pres is centered near 11n121w estimated at 1008 mb and is 
moving slowly W. The surface low is under an upper ridge and the 
associated upper diffluence enhances intermittent convection 
which attempts to band.
.Low pres is centered near 11n110w estimated at 1008 mb. 
Convection is currently flaring within 60 nm over the E 
semicircle.   
...ITCZ...
The ITCZ axis extends from 10n85w to 06n95w to 11n110w to 
08n129w to 08n140w. Scattered moderate isolated strong 
convection is noted N of 07n between 78w and 82w and also within 
120 nm either side of a line from 09n107w to 11n118w to 09n125w 
to 11n137w.
...Discussion...
A broad upper ridge dominates the discussion area S of a line 
from 00n132w to 27n114w to 00n107w. Debris moisture from 
convection between 114w and 138w is streaming NE under the ridge 
with the plume now narrowing and crossing the southern Gulf of 
California but mostly evaporates before reaching western Mexico. 
ITCZ convection is also enhanced between 105w and 112w but 
remains in roughly the same area.
An upper trough is noted over the subtropics to the NW of the 
previously described ridge...from 21n132w to 14n140w. The upper 
flow has become zonal elsewhere in the subtropics. A plume of 
moisture originating in the central Pacific is streaming E over 
the discussion area N of 27n. 
An upper cyclone is near 32n103w with a trough extending S
along 20n99w to to a base near 10n90w. A band of dry upper air 
is sweeping E across the discussion area from 24n to 27n between 
145w and 120w...then the dry air turns se through the upper 
trough and continues to push se right into the trough base in 
deep tropical Pacific.
An upper anticyclone is over the SW Caribbean near 16n82w with a 
ridge extending SW to near 08n87w. Scattered convection is 
enhanced under the ridge over NW Colombia and also over most of 
Panama and Costa Rica...and the debris moisture is now spreading 
SW over the discussion area NE of a line from 01n80w to 10n86w.
At the low levels high pres is centered at 32n134w 1022 mb with 
a ridge extending se to near 14n105w. N to NE to E winds are 
generally 15 to 20 kt through the ridge. Large NW swells are 
spreading se across the area W of 1052 through Tue.
Gap winds...
N winds at 20 expected to resume in the Gulf of Tehuantepec 
early Mon and increase to gale force Tue morning.
$$
Nelson

		

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