000
AXPZ20 KNHC 131603
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JUL 13 2011

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.

...ITCZ/MONSOON TROUGH...
DISCONTINUOUS MONSOON TROUGH AXIS FROM 13N88W TO 17N105W TO 
20N108W...THEN RESUMES FROM 18N119W TO 07N133W...THEN ITCZ TO 
06N140W. SCATTERED MODERATE CONVECTION WITHIN 60 NM OF AXIS 
BETWEEN 88W AND 100W. 

...DISCUSSION...
E OF 110W...SCATTEROMETER AND TOGA BUOY DATA SHOW SOLID SW TO W 
W WINDS MAINLY E OF 105W CONVERGING INTO THE MONSOON TROUGH THAT 
PARALLELS THE COASTLINE FROM NW NICARAGUA TO OFF SOUTHERN 
MEXICO. THE TOGA BUOYS AND REPORTS FROM SHIP WTDH SHOW THE SW TO 
W WINDS AROUND 15 TO 20 KT. AN EARLIER ALTIMETER PASS FROM 08Z 
SHOWED SEAS OF 8 TO 10 FT IN THIS AREA AS WELL...AN INDICATION 
THAT SW SWELL CONTINUES TO BE PRESENT IN THE AREA. SCATTERED 
MODERATE CONVECTION LINGERS BETWEEN THE COAST THE THE MONSOON 
TROUGH...MAINLY OFF EL SALVADOR AND SOUTHERN MEXICO. THIS IS 
DIMINISHING MAINLY DUE TO WEAKENING DRAINAGE FLOW OFF THE LAND. 
THE MAIN FORECAST ISSUE FOR THE NEXT SEVERAL DAYS WILL BE THE 
STRENGTH OF THE SW FLOW INTO CENTRAL AMERICA. THE GFS IS 
BECOMING MORE OF AN OUTLIER...SHOWING VERY STRONG 40 KT FLOW 
INTO A LOW DEVELOPING OVER WESTERN PANAMA BY FRI. THIS IS LIKELY 
CONVECTIVE FEEDBACK. THE OTHER MAJOR GLOBAL MODELS DO NOT SHOW A 
LOW DEVELOPING IN THIS AREA...AND CONCENTRATE LOW PRES FORMATION 
MAINLY S OF TEHUANTEPEC. THE ECMWF AND UKMET SHOW MORE MODEST 
LOW DEVELOPMENT...WITH THE NOGAPS ALSO SHOWING CONVECTIVE 
FEEDBACK AND OVERDEVELOPING THE LOW. EVEN WITH NO DEEP LOW 
DEVELOPING...THE FRESH TO STRONG SW FLOW WILL TRANSPORT ABUNDANT 
TROPICAL MOISTURE INTO CENTRAL AMERICA AND SOUTHERN 
MEXICO...SETTING UP A POTENTIALLY DANGEROUS SITUATION FOR 
CENTRAL AMERICA AND SOUTHERN MEXICO WITH PROLONGED HEAVY 
RAINFALL WHICH WILL LEAD TO FLASH FLOODING AND MUDSLIDES... 
ESPECIALLY OVER HILLY AND MOUNTAINOUS TERRAIN. 

W OF 110W...A 05Z ASCAT PASS SHOWED 15 TO 20 KT OF NW TO N WINDS 
OFF THE COAST OF NORTHERN BAJA. THESE WINDS WILL PERSIST ALONG 
THE COAST BETWEEN HIGH PRES NEAR 31N135W AND TROUGHING OVER THE 
NORTHERN GULF OF CALIFORNIA. SEAS WILL BUILD TO 8 FT BY THU WITH 
THE PERSISTENT NW FLOW. WINDSAT PASS AT 0200 UTC SHOWED WINDS 
LESS THAN 15 KT AROUND THE REMNANT LOW OF CALVIN. THIS 
DISTURBANCE WILL BE ABSORBED INTO THE LARGER MONSOON CIRCULATION 
AND DISSIPATE LATER TODAY. ELSEWHERE...TRADE WINDS REMAIN LIGHT.

$$
CHRISTENSEN