000
AXPZ20 KNHC 250311
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED JUL 25 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

...SPECIAL FEATURES...
A 1006 MB LOW PRESSURE SYSTEM REMAINS EMBEDDED IN THE MONSOON 
TROUGH NEAR 11N121W. THIS LOW IS SITUATED AT THE SOUTHERN EXTENT 
OF A TROPICAL WAVE EXTENDING FROM 17N119W TO THE LOW. MOST OF 
THE DEEP CONVECTION ASSOCIATED WITH THIS SYSTEM IS TO THE SE OF 
THE LOW LEVEL CENTER WHICH HAS BEEN RELOCATED FURTHER TO THE 
WEST THIS EVENING. THIS RELOCATION COMBINED WITH MARGINAL 
ENVIRONMENTAL CONDITIONS FOR ADDITIONAL DEVELOPMENT SUGGESTS 
THAT THE CURRENT MEDIUM PROBABILITIES OF TROPICAL CYCLOGENESIS 
MAY BE REDUCED TO LOW PROBABILITIES LATER TONIGHT OR TOMORROW. 
INFRARED SATELLITE IMAGERY SHOWS SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 180 NM IN THE SE QUADRANT OF THE LOW CENTER. 
THE 1756 UTC HIGH RESOLUTION ASCAT PASS CONTINUED TO INDICATE 30 
KT WINDS IN AN AREA WELL REMOVED FROM THE CENTER. UPPER LEVEL 
SHEARING WINDS CONTINUE TO KEEP ANY FURTHER DEVELOPMENT FROM 
OCCURRING AT THIS TIME. 

...TROPICAL WAVES...
A TROPICAL WAVE EXTENDS FROM 16N104W TO 08N107W AND WILL 
CONTINUE TO MOVE WWD OVER THE NEXT COUPLE OF DAYS. THE WAVE IS 
WELL DEPICTED IN THE CIMSS TPW PRODUCT. SCATTERED MODERATE 
CONVECTION IS NOTED FROM 12N TO 16N WITHIN 90 NM W AND 180 NM E 
OF THE TROPICAL WAVE AXIS. AN AREA OF 20 KT WINDS WAS INDICATED 
FROM 12N TO 16N BETWEEN 103W AND 107W PER A 1615 UTC 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 09N90W TO 10N100W. ITCZ AXIS 
IS FROM 09N124W TO BEYOND 07N140W. SCATTERED TO NUMEROUS STRONG 
WITHIN 90 NM N AND 180 NM W OF OF THE ITCZ AXIS BETWEEN 133W AND 
140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 90 NM EITHER 
SIDE OF THE MONSOON TROUGH BETWEEN 86W AND 91W...AND FROM 10N TO 
12N BETWEEN 95W AND 99W. 

...DISCUSSION...
1035 MB HIGH PRESSURE CENTERED NW OF THE FORECAST AREA NEAR 
41N147W 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 
11N121W 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 11N134W TO 07N136W. THIS 
TROUGH IS EMBEDDED WITHIN THE ITCZ AND WILL MOVE WWD AROUND THE 
SOUTHERN PERIPHERY OF THE RIDGE. THIS TROUGH IS THE FOCUS FOR 
SCATTERED TO NUMEROUS MODERATE STRONG CONVECTION WITHIN 180 NM 
OF THE INTERSECTION OF THE TROUGH AND THE ITCZ. 

FRESH 20 KT GULF OF PAPAGAYO GAP WINDS CONTINUE. 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. 
BY 48 HOURS THE FORCING FOR THIS GAP WIND EVENT WILL BE LIMITED 
TO THE TIMES OF NOCTURNALLY DRIVEN DRAINAGE FLOW.

$$
COBB