East Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 230327
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON NOV 23 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 WAS ANALYZED FROM 06N77W TO 06N95W TO 07N106W TO 06N117W TO 
09N130W TO 06N140W.  ISOLATED TO SCATTERED MODERATE CONVECTION 
WAS OCCURRING WITHIN 120 NM OF AXIS E OF 83W. SCATTERED MODERATE 
CONVECTION WAS OCCURRING WITHIN 120 NM S AND 240 NM N OF AXIS 
FROM 127W TO 135W...ASSOCIATED WITH A LOW LEVEL TROUGH ALONG 
131W. 

...DISCUSSION...
A BROAD MID TO UPPER LEVEL RIDGE ALONG 09-10N COVERS THE 
TROPICAL EPAC S OF 22N FROM 148W TO 100W. ANTICYCLONIC FLOW OVER 
THIS AREA CONTINUES TO ADVECT ABUNDANT TROPICAL MOISTURE FROM 
CONVECTIVE DEBRIS ALONG ITCZ W OF 125W NE THEN E ACROSS MEXICO 
AND INTO THE GULF OF MEXICO.  

N OF THE RIDGE...AN UPPER LEVEL TROUGH EXTENDS FROM CENTRAL 
TEXAS TO 25N115W...AND IS HELPING TO MAINTAIN SUBSIDENCE AND 
STABLE AIR N OF 22N...DUE TO UPPER CONVERGENCE. A SECOND UPPER 
LEVEL TROUGH WAS E OF THE RIDGE...EXTENDING FROM A MID LEVEL LOW 
OFF THE NE COAST OF NICARAGUA TO 02N96W. WLY WINDS ALOFT 
ASSOCIATED WITH THE RIDGE WERE DIVING INTO THE W SIDE OF THIS 
TROUGH...PRODUCING CONVERGENCE...AND STABLE ATMOSPHERIC 
CONDITIONS N OF THE ITCZ FROM 100W TO 84W.

A 1026 MB HIGH CENTERED NEAR 33N136W CONTINUES TO MAINTAIN A  
TIGHT PRESSURE GRADIENT ACROSS MUCH OF AREA N OF ITCZ AND W OF 
115W...WITH LOW PRES OVER SRN CALIFORNIA HELPING TO INCREASE 
N-NW WINDS ALONG THE W COAST COASTAL WATERS...WHICH WERE 
SPREADING S TO OFFSHORE OF THE BAJA PENINSULA W COAST. THESE 
TRADE WINDS INCLUDE A  LARGE AREA OF 20-25 KT NE-E WINDS S OF 
25N AND W OF 125W...WITH SEAS 9 TO 14 FT IN MIXED NE WIND SWELL 
AND LONG PERIOD NW SWELL. THESE TRADES ARE FORECAST TO GENERALLY 
PERSIST THROUGH THE FORECAST PERIOD...SHRINKING SLIGHTLY IN 
AREAL COVERAGE. THE HIGH IS FORECAST TO MOVE E AND IS EXPECTED 
TO INCREASE WINDS N OF 28-29N IN GULF OF CALIFORNIA WITHIN 30 
HOURS. ELSEWHERE W OF 115W...LARGE NWLY SWELL CONTINUES TO 
DOMINATE THE WATERS AND WILL FADE MODESTLY THROUGH EARLY 
WEDNESDAY BEFORE ANOTHER STRONG PULSE OF NW SWELL ARRIVES. ALONG 
THE ITCZ AND UNDERNEATH THE UPPER RIDGE...AN ELY WAVE WAS ALONG 
ABOUT 131W...EMBEDDED IN ABUNDANT TROPICAL MOISTURE. THIS 
FEATURE WILL CONTINUE TO MOVE W OVER THE NEXT FEW DAYS AND 
REMAIN ACTIVE CONVECTIVELY N OF 11N UNDER THE INFLUENCE OF 
STRONG CONVERGENCE FROM THE TRADES. E OF 115W...SEAS REMAIN IN 
THE 4 TO 7 FT RANGE ACROSS THE OFFSHORE WATERS...DOMINATED BY A 
MERGING MIX OF NW...SW...AND S SWELL.

NLY GAP WINDS THROUGH THE GULF OF TEHUANTEPEC SHOULD DIMINISH 
SLIGHTLY DURING THE NEXT 24 HOURS AS A COLD FRONT AND ASSOCIATED 
HIGH PRES BEHIND IT MOVE FURTHER E...VEERING WINDS TO THE SE. 
HOWEVER...A SMALL PLUME OF NEAR 20 KT N WINDS IS FORECAST TO 
PERSIST THROUGH 36 HOURS. FRESH NELY TRADES THROUGH THE GULF OF 
PAPAGAYO AND DOWNSTREAM SOME 300 MILES SHOULD CONTINUE THROUGH 
MONDAY BEFORE GRADUALLY BEGINNING TO WEAKEN THROUGH 48 HOURS. 
OTHER SMALL PLUMES OF OFFSHORE GAP WIND FLOW WERE NOTED IN 
RECENT SCATTEROMETER IMAGERY...THROUGH THE GULF OF FONSECA...AND 
ALONG THE GUATEMALA-EL SALVADOR BORDER.   

$$

STRIPLING