000
AXPZ20 KNHC 241536
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1430 UTC.

...SPECIAL FEATURES...
A 1007 MB LOW PRESSURE SYSTEM REMAINS EMBEDDED IN THE MONSOON 
TROUGH NEAR 10N117W. THIS LOW IS INTERACTING WITH A TROPICAL 
WAVE EXTENDING FROM 15N102W TO 07N103W. MOST OF THE DEEP 
CONVECTION ASSOCIATED WITH THIS SYSTEM IS TO THE S OF THE LOW 
LEVEL CENTER. SATELLITE IMAGERY SHOWS NUMEROUS MODERATE TO 
STRONG CONVECTION WITHIN 210 NM S SEMICIRCLE 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. 
THERE IS CURRENTLY A HIGH 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 CONTINUES TO SUGGEST 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 14N 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 MOST RECENT 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 08N92W. ITCZ AXIS IS 
FROM 10N120W TO BEYOND 07N140W. NUMEROUS MODERATE TO STRONG 
CONVECTION IS N OF 04N E OF 81W TO THE COAST OF COLOMBIA... 
INCLUDING THE GULF OF PANAMA. SCATTERED MODERATE ISOLATED STRONG 
WITHIN 120 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 127W AND 
132W. 

...DISCUSSION...
1036 MB HIGH PRESSURE CENTERED NW OF THE FORECAST AREA NEAR 
42N146W EXTENDS A RIDGE SE 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 125W AS DEPICTED BY THE MOST 
RECENT 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 1ON117W 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 11N131W 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.  

WEAK 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 
OCCASIONALLY 25 KT DURING THE OVERNIGHT AND EARLY MORNING HOURS 
WITH THE AID OF NOCTURNALLY DRIVEN DRAINAGE FLOW. 

$$
GR