000
AXPZ20 KNHC 060934
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON AUG 06 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.

...TROPICAL WAVES...
A TROPICAL WAVE EXTENDS FROM 1010 MB LOW PRES NEAR 12N106W TO 
18N105W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS 
WITHIN 120 NM W OF THE WAVE AXIS FROM 12N TO 16N. NO DEEP 
CONVECTION IS SEEN NEAR THE LOW PRES CENTER. ENVIRONMENTAL 
CONDITIONS APPEAR CONDUCIVE FOR DEVELOPMENT...AND THIS LOW COULD 
BECOME A TROPICAL DEPRESSION DURING THE NEXT DAY OR TWO. THIS 
SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE AS IT 
MOVES WEST- NORTHWESTWARD AT AROUND 10 KT DURING THE NEXT 48 
HOURS.

A TROPICAL WAVE EXTENDS ALONG 130W FROM 10N TO 18N. ONLY 
SCATTERED SHOWERS ARE OBSERVED ON EITHER SIDE OF THE WAVE AXIS. 
THE PRES GRADIENT BETWEEN THE SURFACE TROUGHING ASSOCIATED WITH 
THE WAVE AND THE SUBTROPICAL RIDGE SHOULD BE STRONG ENOUGH FOR 
FRESH TO STRONG WINDS TO BUILD NEAR THE WAVE OVER THE NEXT FEW 
DAYS. CURRENTLY...SCATTEROMETER DATA SHOW WINDS OF MAINLY 15 KT 
IN ASSOCIATION WITH THIS WAVE. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS EXTENDS FROM 10N86W TO 1011 MB LOW PRES NEAR 
09N98W TO 1010 MB LOW PRES NEAR 12N106W TO 10N120W TO 12N128W. 
ITCZ AXIS IS FROM 10N130W TO 09N140W. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION IS NOTED FROM 06N TO 10N BETWEEN 96W 
AND 101W. SCATTERED MODERATE CONVECTION IS FROM 07N TO 11N 
BETWEEN 110W AND 117W...AND FROM 07N TO 10N BETWEEN 129W AND 
134W.

...DISCUSSION...
A WEAK SUBTROPICAL RIDGE EXTENDS OVER N WATERS WITH 1022 MB HIGH 
PRES CENTERED NEAR 31N130W. THE RIDGE WILL SLOWLY BUILD ACROSS 
THE FORECAST REGION BEGINNING TODAY AS THE SUBTROPICAL HIGH 
CONSOLIDATES NW OF THE AREA NEAR 35N140W BY TUE NIGHT. NE WINDS 
OF 15 KT ARE ALONG THE SOUTHERN PERIPHERY OF THE RIDGE AND N OF 
THE MONSOON TROUGH/ITCZ AXIS PER THE MOST RECENT ASCAT PASSES. 

CROSS-EQUATORIAL LONG PERIOD S SWELLS OF 18-20 SECONDS CONTINUE 
TO IMPACT MOST OF THE REGIONAL WATERS. HIGHEST ASSOCIATED 
SIGNIFICANT WAVE HEIGHTS ARE ACROSS THE S CENTRAL WATERS WITH 
SEAS TO 8 FT. THE SWELL WILL GRADUALLY DECAY TODAY AND TUE WITH 
SEAS SUBSIDING TO LESS THAN 8 FT BY LATE TODAY. ANOTHER SWELL 
EVENT FROM THE SOUTHERN HEMISPHERE WITH PERIODS IN THE 16-18 
SECOND RANGE IS EXPECTED TO CROSS THE EQUATOR W OF 120W THIS 
AFTERNOON. SWELLS WILL PROPAGATE ACROSS THE WATERS S OF 10N BY 
TUE.  

GAP WINDS...FRESH TO STRONG NORTHERLY WINDS ARE EXPECTED TO 
BEGIN IN THE GULF OF TEHUANTEPEC THIS MORNING AND ARE FORECAST 
TO PERSIST AT LEAST THROUGH TUE MORNING. THIS GAP WIND EVENT 
WILL BE INDUCED BY RELATIVELY HIGHER SURFACE PRESSURES OVER THE 
SW GULF OF MEXICO AHEAD OF ATLANTIC TROPICAL STORM ERNESTO AND 
LOWER PRES ASSOCIATED WITH THE MONSOON TROUGH WHICH WILL BE 
DRIFTING NORTHWARD AS ERNESTO APPROACHES CENTRAL AMERICA AND THE 
YUCATAN PENINSULA.

$$
GR