000
AXPZ20 KNHC 311533
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE JUL 31 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 106W MOVING W 15 KT. SCATTERED SHOWERS
AND ISOLATED TSTMS ARE LOCATED WITHIN 60 NM W AND 180 NM E OF 
THE WAVE AXIS. A ROBUST MID-LEVEL CIRCULATION IS BARELY EVIDENT 
AT THE SURFACE IN ASCAT PASS AT 0436 UTC. THE WAVE WILL CONTINUE 
MOVING W NORTH OF THE ITCZ AND SLOWLY WEAKEN. THE SYSTEM LACKS 
CYCLONIC VORTICITY ASSOCIATED WITH WSW WINDS S OF THE CONVERGENCE
ZONE...AND THEREFORE TROPICAL CYCLOGENESIS IS UNLIKELY TO OCCUR.

A TROPICAL WAVE ALONG 88W MOVING THROUGH CENTRAL AMERICA EXTENDS 
S TO AROUND 10N. SCATTERED SHOWERS AND TSTMS ARE LOCATED ALONG 
THE ITCZ AXIS WITHIN 180 NM E OF THE WAVE AXIS. ASCAT DATA AT 
0256 UTC SHOWED A BROAD AREA OF 20 KT WINDS W OF NICARAGUA IN 
RESPONSE TO THE WAVE AND BACKGROUND GAP WIND FLOW THROUGH THE 
GULF OF PAPAGAYO GAP WIND EVENT. THIS WAVE IS EXPECTED TO WEAKEN 
AS IT MOVES AWAY FROM THE MONSOON TROUGH ENVIRONMENT. GLOBAL 
MODELS INDICATE TROPICAL CYCLOGENESIS IS NOT LIKELY TO OCCUR.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

ITCZ AXIS EXTENDS FROM 08N78W TO 09N89W TO 08N96W TO 10N107W TO 
09N120W TO 10N140W. SCATTERED MODERATE CONVECTION WITHIN 120 NM 
N OF AXIS BETWEEN 83W AND 105W.

...DISCUSSION...

NEARLY STATIONARY SUBTROPICAL HIGH 1027 MB CENTERED NW OF THE 
AREA NEAR 36N140W WITH A RIDGE EXTENDING SE TO 23N119W. PRES 
GRADIENT BETWEEN THE RIDGE AND LOWER PRES ASSOCIATED WITH THE 
ITCZ IS PRODUCING AN AREA OF FRESH E-NE TRADES W OF 130W... WITH 
SEAS TO 9 FT W OF 135W. THE SYNOPTIC PATTERN IS NOT LIKELY TO 
CHANGE SIGNIFICANTLY OVER THE NEXT SEVERAL DAYS BUT WINDS WILL 
GRADUALLY DIMINISH...AND THE AREA OF SEAS 8 FT OR MORE WILL 
STEADILY CONTRACT IN AREAL EXTENT.

GAP WINDS OCCASIONALLY TO 20 KT ARE EXPECTED TO CONTINUE THROUGH 
THE GULF OF PAPAGAYO THIS AFTERNOON AND TONIGHT THEN DIMINISH AS 
THE TROPICAL WAVE ALONG 88W MOVES FURTHER AWAY.

CROSS-EQUATORIAL S-SW SWELL WITH SEAS TO 7-8 FT IS LOCATED S OF 
05N BETWEEN 105W AND 130W. AN ACTIVE PROGRESSIVE PATTERN OF MID 
LATITUDE STORM SYSTEMS IN THE SOUTHERN HEMISPHERE WILL CONTINUE 
TO GENERATE LONG-PERIOD SWELL REACHING THE NORTHERN HEMISPHERE 
OVER THE NEXT SEVERAL DAYS...WITH FREQUENT EPISODES OF SEAS IN 
EXCESS OF 7-8 FT EXPECTED IN THE EQUATORIAL REGION E OF 130W.

$$
MUNDELL