000
AXPZ20 KNHC 112158
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU NOV 11 2010

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 
2100 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 08N87W 
TO 05N92W TO LOW PRES NEAR 10N104W TO 10N120W TO 08N135W TO 
06N140W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 120 NM S 
OF THE AXIS BETWEEN 111W AND 116W AND ALSO BETWEEN 127W AND 135W.

...DISCUSSION...

A DEEP LAYER LARGE AMPLITUDE TROUGH EXTENDS FROM SOUTHERN 
ARIZONA NEAR 32N111W TO 17N120W. VERY DRY AIR IS NOTED ACROSS 
THE WATERS N OF 20N AND E OF 122W. A WIDE SWATH OF ABUNDANT 
TROPICAL MOISTURE EXISTS WITHIN 300-400 NM E OF THE TROUGH AXIS 
AND IS BEING ADVECTED FROM THE ITCZ TO ACROSS CENTRAL MEXICO. A 
DOWNSTREAM UPPER CARIBBEAN RIDGE IS MAINTAINING DRY CONDITIONS 
OVER THE EXTREME E PART OF BASIN S OF 20N AND E OF 100W. 
MODERATE DIVERGENT FLOW ALOFT CONTINUES TO ENHANCE CONVECTION 
ALONG THE ITCZ W OF 100W.

AT THE SURFACE...1032 MB HIGH PRES IS CENTERED JUST N OF THE 
AREA NEAR 34N137W. A RIDGE EXTENDS FROM THE HIGH CENTER TO NEAR 
17N108W. FRESH TO MODERATE NE TRADES ARE PRESENT N OF 10N W OF 
125W. THESE TRADES WILL EXPAND TO W OF 113W WHILE INCREASING TO 
20 TO 25 KT IN 24 HOURS AS THE RIDGE TIGHTENS WITH THE HIGH 
STRENGTHENING TO 1037 MB.

WEAK 1009 MB LOW PRES IS POSITIONED NEAR 09N86W. NO SIGNIFICANT 
DEEP CONVECTION IS NOTED WITH THIS LOW WITH ONLY SCATTERED 
SHOWERS OCCURRING IN THE VICINITY OF THE LOW CENTER. A MORE 
PREVALENT 1009 MB LOW IS CENTERED NEAR 10N104W AND IS DRIFTING 
W. A 1700 UTC ASCAT PASS CAPTURED WINDS OF 20 KT OCCURRING 
WITHIN 120 NM IN THE NE QUADRANT OF THE LOW ALONG WITH SCATTERED 
MODERATE CONVECTION WHICH IS WITHIN 120 NM IN THE NE SEMICIRCLE 
OF THE LOW. ADDITIONAL DEVELOPMENT OF THIS FEATURE IS NOT 
ANTICIPATED DURING THE NEXT 48 HOURS.

NW SWELL WITH PEAK WAVE PERIODS OF 16 TO 17 SECONDS CONTINUES TO 
DOMINATE THE MAJORITY OF THE WATERS W OF 110W. THIS SWELL IS 
COMMINGLING WITH CROSS-EQUATORIAL SW SWELL AND SHORTER PERIOD NE 
SWELL OVER THE AREA S OF 20N. THE SOUTHERLY SWELL WILL GRADUALLY 
DECAY DURING THE NEXT 48 HOURS WHILE NEW SETS OF NORTHERLY SWELL 
CONTINUES TO PROPAGATE DOWN THROUGH THE AREA.

GULF OF CALIFORNIA...
A TIGHT PRES GRADIENT EXISTS OVER THE GULF OF CALIFORNIA REGION 
WITH A STRENGTHENING RIDGE OF HIGH PRES OVER THE N WATERS AND  
INVERTED TROUGHING ALONG AND JUST OFFSHORE OF THE BAJA 
CALIFORNIA PENINSULA. NW TO N WINDS OF 20 KT HAVE ALREADY BEEN 
REPORTED AT NEAR-SHORE LAND BASED STATION SAN FELIPE IN BAJA 
CALIFORNIA. NW TO N WINDS OF 20 TO 25 KT WILL SPREAD S THROUGH 
THE GULF OF CALIFORNIA DURING THE NEAR 24 HOURS THEN WILL BEGIN 
TO DIMINISH AND RETREAT NORTHWARD BY 48 HOURS.

GAP WINDS...
LAND BASED OBSERVATIONS AT IXTEPEC IN THE STATE OF OAXACA MEXICO 
HAVE BEEN REPORTING N WINDS OF 20 TO 25 KT FOR SEVERAL HOURS AND 
EXPECT THESE WINDS TO BE SURGING INTO THE GULF OF TEHUANTEPEC 
ROUGHLY WITHIN 30 NM OF A LINE FROM 16N95W TO 15N95W THROUGH THE 
NEXT 24 HOURS WITH WINDS DIMINISHING THEREAFTER.

$$
LEWITSKY