000
AXPZ20 KNHC 260349
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU NOV 26 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 
0315 UTC.

...ITCZ...

AXIS ANALYZED FROM 09N79W TO 08N88W TO 07N89W TO 07N113W TO 
08N140W. ISOLATED MODERATE CONVECTION WAS NOTED WITHIN 150 NM S 
OF THE ITCZ AXIS BETWEEN 79W AND 86W AND ALSO WITHIN 60 NM S OF 
THE ITCZ AXIS BETWEEN 112W AND 115W. SCATTERED MODERATE AND 
ISOLATED STRONG CONVECTION WAS NOTED WITHIN 120 NM EITHER SIDE 
OF THE ITCZ AXIS BETWEEN 115W AND 134W. 

...DISCUSSION...

AN UPPER ANTICYCLONE NEAR 15N144W HAS A SHORTWAVE RIDGE 
EXTENDING NE TO A CREST NEAR 37N128W. THE MID AND UPPER LEVELS 
ARE DRY N OF 12N W OF 118W ALTHOUGH MOISTURE IS BEGINNING TO 
INCREASE OVER THE FAR W PORTION OF THE DISCUSSION AREA AHEAD OF 
AN UPPER TROUGH EXTENDING FROM 37N147W JUST TO THE NW OF THE 
HAWAIIAN ISLANDS. AN UPPER LEVEL LOW IS CENTERED NEAR 23N117W 
JUST W OF THE S BAJA PENINSULA. STRONG SW FLOW EXTENDING FROM 
THE ITCZ TO THE NE AROUND THE LOW IS ADVECTING MOISTURE ALOFT 
ACROSS THE BAJA AND INTO N CENTRAL MEXICO. 

A TROPICAL ANTICYCLONE IS ESTIMATED NEAR 12N103W WITH 
VERY DRY AIR AND SUBSIDENCE ALOFT S OF 15N TO THE EQUATOR 
BETWEEN 90W AND 105W HELPING TO SUPPRESS ANY CONVECTION ACROSS 
THIS AREA AND ALONG THE ITCZ AXIS. ANOTHER UPPER LEVEL TROUGH IS 
SWINGING E ACROSS THE CENTRAL GULF OF MEXICO. CONVERGENT FLOW 
BETWEEN THE BASE OF THIS TROUGH IN THE NW CARIBBEAN AND STRONG 
ANTICYCLONIC FLOW ACROSS THE REMAINDER OF THE CARIBBEAN WAS 
ENHANCING CONVECTION OVER CENTRAL AMERICA AND TO THE W ALONG THE 
ITCZ IN THE E PACIFIC E OF 91W ALTHOUGH THAT ACTIVITY IS NOW 
DIMINISHING WITH THE LOSS OF DAYTIME HEATING.

AT THE SURFACE...HIGH PRESSURE CONTINUES TO DOMINATE THE AREA W 
OF 110W. NE TO E TRADES IN THE 20 TO 25 KT RANGE PERSIST ALONG 
AND W OF THE RIDGE TO 140W. STRONGER HIGH PRESSURE WILL PASS N 
OF THE AREA THU NIGHT THROUGH FRI EXPANDING THE AREA OF NE 
TRADES. SEAS OF 8 TO 12 FT ARE ALSO CURRENTLY NOTED SW OF THE 
RIDGE WITH NW SWELLS COVERING THE ENTIRE AREA W OF 115W. ANOTHER 
SET OF LONG PERIOD NW SWELLS IS EXPECTED TO MOVE INTO THE NW 
PORTION OF THE FORECAST AREA BEGINNING LATE TONIGHT WITH SEAS 
BUILDING TO 15 FT. 

...GAP WINDS...
A 0000 UTC SYNOPTIC SURFACE OBSERVATION AT SALINA CRUZ MEXICO ON 
THE COAST OF THE GULF OF TEHUANTEPEC REPORTED 35 KT NORTHERLY 
WINDS AND THUS GALE CONDITIONS ARE NOW LIKELY OCCURRING OVER THE 
GULF OF TEHUANTEPEC. WINDS WILL INCREASE FURTHER TO MINIMAL 
STORM FORCE BY EARLY FRI.

STRONG HIGH PRESSURE OVER THE NW CONUS COMBINED WITH A LOW 
PRESSURE TROUGH ALONG THE BAJA CALIFORNIA PENINSULA IS 
MAINTAINING A TIGHT PRESSURE GRADIENT RESULTING IN STRONG 
NORTHERLY WINDS IN THE NORTHERN GULF OF CALIFORNIA N OF 28N.
THE GRADIENT WILL GRADUALLY DECREASE OVER THE NEXT 18 HOURS 
DIMINISHING THE WINDS TO BELOW 20 KT.

EASTERLY TRADES IN THE W CARIBBEAN WILL CONTINUE TO MAINTAIN NE 
TO E WIND SURGES OF 20 TO 25 KT IN AND DOWNSTREAM OF THE GULF OF 
PAPAGAYO FOR THE NEXT FEW DAYS. 

$$

LEWITSKY