000
AXPZ20 KNHC 110327
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU NOV 11 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 LOW 
PRES NEAR 08N86W TO 06N91W TO LOW PRES NEAR 09N111W TO 11N124W 
TO 07N135W TO 08N140W. SCATTERED MODERATE CONVECTION IS NOTED 
WITHIN 120 NM OF THE AXIS BETWEEN 121W AND 127W.

...DISCUSSION...

AN UPPER LEVEL TROUGH EXTENDING FROM CENTRAL MEXICO INTO THE E 
PACIFIC NEAR 23N107W EXTENDS SW TO NEAR 11N140W WITH A VERY DRY 
AIR MASS PREVALENT ACROSS THE DISCUSSION WATERS N OF THE TROUGH 
AXIS. A JET CORE WITH PEAK SPEEDS OF 60 TO 70 KT IS ADVECTING A 
SWATH OF DEEP TROPICAL MOISTURE AND CONVECTIVE DEBRIS FROM THE 
ITCZ ACROSS CENTRAL MEXICO TO JUST SE OF THE TEXAS COAST. 
MODERATE DIVERGENT FLOW ALOFT IS ENHANCING CONVECTION ALONG
THE ITCZ MAINLY W OF 100W.

AT THE SURFACE...NEARLY STATIONARY 1027 MB HIGH PRES IS CENTERED 
NEAR 33N137W WITH A RIDGE EXTENDING FROM THE HIGH CENTER TO NEAR 
16N106W. FRESH NE TRADES ROUGHLY FROM 12N TO 24N W OF 120W WILL 
EXPAND TO THE ENTIRE AREA N OF 11N W OF 120W BY 24 HOURS THEN TO 
N OF 06N W OF 113W BY 48 HOURS.

NW SWELL WITH PEAK WAVE PERIODS OF 14 TO 15 SECONDS DOMINATES 
THE MAJORITY OF THE WATERS W OF 100W. 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.

1009 MB LOW PRES IS POSITIONED NEAR 08N86W. CONVECTION HAS 
DIMINISHED DURING THE PAST SEVERAL HOURS ALTHOUGH SCATTERED 
SHOWERS ARE STILL OCCURRING IN THE VICINITY OF THE LOW. AN 
EARLIER ASCAT PASS INDICATED WINDS TO 20 KT NEAR THE LOW IN THE 
SE SEMICIRCLE AND RECENT SHIP OBSERVATIONS CONFIRM THE 20 KT
WINDS. EXPECT THIS LOW TO REMAIN NEARLY STATIONARY DURING THE 
NEXT 24 TO 48 HOURS WHILE WEAKENING. A WEAKER 1010 MB LOW IS
POSITIONED NEAR 09N111W. SCATTERED SHOWERS ARE OCCURRING NEAR 
THE LOW. THIS LOW IS EXPECTED TO DISSIPATE DURING THE NEXT 24 
HOURS.

GULF OF CALIFORNIA...A TIGHT PRES GRADIENT WILL BECOME 
ESTABLISHED OVER THE GULF OF CALIFORNIA REGION WITH A 
STRENGTHENING RIDGE OF HIGH PRES OVER THE N WATERS AND AN 
INVERTED TROUGH FORMING ALONG OR JUST OFFSHORE OF THE BAJA 
CALIFORNIA PENINSULA. NW TO N WINDS OF 20 TO 25 KT WILL OCCUR 
BEGINNING AROUND 12 UTC THU THEN WILL PERSIST THROUGH AT LEAST 
48 HOURS WHILE EXPANDING SOUTHWARD TO 24N BY 00 UTC SAT.

GAP WINDS...BOTH THE OPERATIONAL GFS AND ECMWF HI-RES CONTINUE 
TO INDICATE A WEAK GULF OF TEHUANTEPEC EVENT OCCURRING BETWEEN 
30 AND 48 HOURS MAINLY DUE TO NOCTURNAL DRAINAGE FLOW THROUGH 
THE CHIVELAS PASS WITHIN 30 NM OF A LINE FROM 16N95W TO 15N95W.

$$
LEWITSKY