000
AXPZ20 KNHC 120321
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI NOV 12 2010

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 
0300 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 08N86W 
TO LOW PRES NEAR 10N105W TO 11N117W TO 11N130W TO 09N136W. 
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS 
BETWEEN 120W AND 123W AND ALSO WITHIN 90 NM OF THE AXIS BETWEEN 
130W AND 135W.

...DISCUSSION...

A DEEP LAYER LARGE AMPLITUDE TROUGH EXTENDS FROM THE ARIZONA
NEW MEXICO BORDER NEAR 32N108W TO 17N120W. VERY DRY AIR IS NOTED 
ACROSS THE WATERS N OF 20N AND E OF 120W. 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...1033 MB HIGH PRES IS CENTERED JUST N OF THE 
AREA NEAR 35N137W. A RIDGE EXTENDS FROM THE HIGH CENTER TO NEAR 
17N111W. FRESH NE TRADES ARE PRESENT N OF 13N W OF 120W. THESE 
TRADES WILL INCREASE TO 20 TO 25 KT IN 24 HOURS AS THE RIDGE 
TIGHTENS WITH THE HIGH STRENGTHENING TO 1037 MB.

WEAK 1011 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 1012 MB 
LOW IS CENTERED NEAR 10N105W AND IS DRIFTING W. AN EARLIER 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 ALSO 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 14N95W THROUGH THE 
NEXT 18 TO 24 HOURS WITH WINDS DIMINISHING THEREAFTER.

$$
LEWITSKY