000
AXPZ20 KNHC 242157
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE JUL 24 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...SPECIAL FEATURES...
A 1009 MB LOW PRESSURE SYSTEM REMAINS EMBEDDED IN THE MONSOON 
TROUGH NEAR 10N118W. THIS LOW IS SITUATED AT THE SOUTHERN EXTENT 
OF A TROPICAL WAVE EXTENDING FROM 16N116W TO THE LOW. MOST OF 
THE DEEP CONVECTION ASSOCIATED WITH THIS SYSTEM IS TO THE S OF 
THE LOW LEVEL CENTER. SATELLITE IMAGERY SHOWS SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 240 NM IN THE SW QUADRANT OF 
LOW CENTER. THE 0520 UTC HIGH RESOLUTION ASCAT PASS PROVIDED 
OBSERVATIONS OF SOME 30 KT WIND BARBS TO THE E OF THE LOW 
CENTER. UPPER LEVEL WINDS CONTINUE TO KEEP ANY FURTHER 
DEVELOPMENT FROM OCCURRING... AND ENVIRONMENTAL CONDITIONS 
REMAIN MARGINALLY CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM 
DURING THE NEXT COUPLE OF DAYS. AS THERE IS NOW A MEDIUM  
PROBABILITY THAT THIS FEATURE WILL DEVELOP INTO A TROPICAL 
CYCLONE WITHIN THE NEXT 48 HOURS AS IT MOVES WESTWARD OR 
WEST-NORTHWESTWARD AT AROUND 10 KT. THE GFS GLOBAL MODEL IS 
BACKING OFF ON THE DEVELOPMENT OF A TROPICAL CYCLONE.

...TROPICAL WAVES...
A TROPICAL WAVE EXTENDS FROM 15N102W TO 07N103W AND WILL 
CONTINUE TO MOVE WWD OVER THE NEXT COUPLE OF DAYS. THE WAVE IS 
WELL DEPICTED IN THE MOISTURE PRODUCT. A CLUSTER OF MODERATE TO 
STRONG CONVECTION IS NOTED FROM 12N TO 15N WITHIN 180 NM E OF 
TROPICAL WAVE. AN AREA OF 20 KT WINDS IS ALSO SEEN FROM 11N TO 
15N BETWEEN 98W AND 103W BASED ON THE LAST ASCAT PASS. THE 
LATEST COMPUTER MODEL GUIDANCE DOES NOT SUGGEST TROPICAL CYCLONE 
DEVELOPMENT WITH THIS FEATURE.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 10N90W...ITCZ AXIS IS 
FROM 09N122W TO BEYOND 07N140W. SCATTERED MODERATE TO STRONG N 
OF MONSOON TROUGH TO COSTA RICA AND WITHIN 120 NM N OF TROUGH 
BETWEEN 93W AND 96W. SCATTERED TO NUMEROUS MODERATE/STRONG 
WITHIN 90 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 131W AND 140W. 
SCATTERED MODERATE ISOLATED STRONG WITHIN 240 NM EITHER SIDE OF 
ITCZ AXIS BETWEEN 122W AND 130W. 

...DISCUSSION...
1037 MB HIGH PRESSURE CENTERED NW OF THE FORECAST AREA NEAR 
41N145W EXTENDS A RIDGE SE THROUGH 30N127W TO NEAR 22N115W. THE 
PRESSURE GRADIENT BETWEEN THIS FEATURE AND LOWER PRES ALONG THE 
MONSOON TROUGH AND IN THE VICINITY OF THE ITCZ IS MAINTAINING 
FRESH TRADE WINDS FROM 09N TO 17N W OF 128W AS DEPICTED BY THE 
AN EARLY MORNING ASCAT SCATTEROMETER PASSES. THE AREA OF FRESH 
TRADES WILL SLIGHTLY DECREASE IN ABOUT 24 HOURS BUT WILL 
INCREASE AGAIN IN 48 HOURS AND THE LOW PRES CURRENTLY NEAR 
1ON118W CONTINUES TO MOVE WWD. PRES GRADIENT IS FORECAST BY THE 
COMPUTER MODELS TO INCREASE BETWEEN THIS LOW AND THE RIDGE TO 
THE N. 

A SURFACE TROUGH IS ANALYZED FROM 11N132W TO 07N133W. THIS 
TROUGH IS EMBEDDED WITHIN THE ITCZ AND WILL MOVE WWD AROUND THE 
SOUTHERN PERIPHERY OF THE RIDGE. SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION CAN BE FOUND E OF THE TROUGH AXIS AND ON 
EITHER SIDE OF THE ITCZ AS MENTIONED ABOVE. 

FRESH 20 KT GULF OF PAPAGAYO GAP WINDS CONTINUE. SHIP CALLSIGN 
DFCW2 REPORTED SUSTAINED WINDS OF 20 KT AND SEAS TO 9 FT. THIS 
WEATHER PATTERN WILL PERSIST FOR THE NEXT COUPLE OF DAYS...WITH 
OCCASIONAL BURSTS OF 25 KT WINDS DURING THE OVERNIGHT AND EARLY 
MORNING HOURS WITH THE AID OF NOCTURNALLY DRIVEN DRAINAGE FLOW. 

$$
COBB