000
AXPZ20 KNHC 290943
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN JAN 29 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 06N77W TO 05N79W TO 06N82W TO 04N100W. ITCZ 
FROM 04N100W TO 08N125W TO 04N140W. SCATTERED MODERATE 
CONVECTION WITHIN 60 NM S OF AXIS BETWEEN 85W AND 90W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION FROM 12N TO 14N BETWEEN 105W 
AND 115W.

...DISCUSSION...
THE OVERALL PATTERN REMAINS PROGRESSIVE AND FOR THE MOMENT 
HIGHLY AMPLIFIED. STARTING TO THE WEST OF THE DISCUSSION 
AREA...A SHARP MID/UPPER LEVEL TROUGH EXTENDS FROM 40N130W TO A 
CLOSED UPPER LOW NEAR 15N145W. THE NORTHERN PORTION OF THE 
TROUGH IS RAPIDLY DE-AMPLIFYING AS IT SHIFTS E DUE TO AN ACTIVE 
NORTHERN JET CUTTING EASTWARD FROM 35N TO 40N. THIS IS STARTING 
TO FLATTEN A MID/UPPER RIDGE MIGRATING E THROUGH 125W N OF 20N. 
AN ASSOCIATED 1029 MB SURFACE HIGH IS CENTERED NEAR 35N130W. 
VARIOUS SCATTEROMETER DATA FROM THE PREVIOUS 12 HOURS HAS 
INDICATED 15 TO 20 KT TRADE WINDS SOUTH OF THE SURFACE HIGH FROM 
THE ITCZ POSITION TO 20N W OF 125W. THE SURFACE HIGH PRES WILL 
WEAKEN AND SAG SOUTH THROUGH 48 HOURS AS THE UPPER RIDGE 
FLATTENS OUT...MAINTAINING A MODEST AREA OF TRADE WINDS MAINLY W 
OF 130W. MEANWHILE NW SWELL WILL DECAY TO LESS THAN 8 FT OVER 
MUCH OF THE AREA W OF 110W...AS A NEW TRAIN OF NW SWELL ENTERS 
THE AREA FROM THE N CENTRAL PACIFIC STARTING IN 24 HOURS.

FURTHER EAST...AN UPPER TROUGH EXTENDS FROM THE NORTHERN CENTRAL 
PLAINS THROUGH WEST TEXAS AND SOUTHERN BAJA CALIFORNIA TO 
20N120W. THE TIGHT PRES GRADIENT BETWEEN HIGH PRES OVER THE 
GREAT BASIN BEHIND THE TROUGH...AND A SURFACE TROUGH OVER NW 
MEXICO...IS MAINTAINING FRESH TO STRONG NW FLOW OVER THE 
NORTHERN GULF OF CALIFORNIA. WHILE NO RECENT DATA ARE 
AVAILABLE...THESE WINDS ARE LIKELY DIMINISHING AS THE TROUGH 
SHIFTS EAST...AND AS THE RIDGE TO THE NORTH WEAKENS AHEAD OF 
ADVANCE OF THE UPSTREAM JET.

TO THE SOUTH...A NEGATIVELY-TILTED MID/UPPER TROUGH SHOWS UP 
WELL IN GOES HIGH DENSITY WIND DATA FROM 13N120W TO 05N100W. 
ALTHOUGH TRADE WIND CONVERGENCE IN THE LOWER LEVELS REMAINS 
MODEST...WARM SEA SURFACE TEMPERATURES AND UPPER FORCING FROM 
THE TROUGH ARE MAINTAINING AREAS OF MODERATE TO STRONG 
CONVECTION FROM 12N TO 14N BETWEEN 105W AND 115W...AND SCATTERED 
MODERATE CONVECTION ALONG THE ITCZ BETWEEN 85W AND 90W.

GULF OF TEHUANTEPEC...A 0552 UTC OSCAT PASS SHOWED WINDS ARE 
STARTING TO REACH GALE FORCE AS STRONG 1032 MB HIGH PRES OVER 
TEXAS SHIFTS SE INTO THE NORTHERN GULF OF MEXICO. THE GALES WILL 
PERSIST MON AFTERNOON THEN DIMINISH AS THE HIGH PRES N OF THE 
AREA SHIFTS EAST. GAP WINDS TO 30 KT WILL PERSIST AT LEAST 
THROUGH MON NIGHT WITH THE AID OF DRAINAGE EFFECTS. THE PLUME OF 
GAP WINDS WILL ARC SW TO W AS FAR AS 105W THROUGH MON...WITH 
ASSOCIATED NE TO E FRESH SWELL OF 8 TO 10 FT.

GULFS OF PAPAGAYO AND PANAMA...FRESH TO STRONG TRADE WINDS OVER 
THE SW CARIBBEAN ARE SPILLING ACROSS SOUTHERN CENTRAL AMERICA 
THROUGH NICARAGUA AND THE GULF OF PAPAGAYO...AND OCCASIONALLY 
OVER THE ISTHMUS OF PANAMA. THE PAPAGAYO PLUME OF FRESH TO 
STRONG WINDS WILL BE STRONGEST DURING THE OVERNIGHT AND EARLY 
MORNING HOURS...AND REACH WEST OF 95W...MERGING WITH GAP FLOW 
AND RELATED SEAS EMERGING OUT OF TEHUANTEPEC.

$$
CHRISTENSEN