000
AXPZ20 KNHC 101520
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC FRI APR 10 2015

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

ITCZ AXIS FROM 03N93W TO 04N105W TO 03N110W TO 05N130W...THEN  
RESUMING AT 02N132W AND CONTINUING WESTWARD TO BEYOND 02N140W. 
SCATTERED MODERATE CONVECTION NOTED WITHIN 90 NM OF ITCZ AXIS 
BETWEEN 100W AND 120W. NUMEROUS MODERATE TO ISOLATED STRONG 
WITHIN 300 NM N OF ITCZ AXES BETWEEN 120W AND 130W.

...DISCUSSION... 

E OF 120W...
A FEW SHOWERS AND THUNDERSTORMS ARE NOTED ALONG THE 
ITCZ NEAR 04N87W AND ALONG A LINE BETWEEN THE GALAPAGOS TO 
SOUTHERN COLOMBIA WHERE A SURFACE TROUGH IS ANALYZED. THESE 
SHOWERS AND THUNDERSTORMS ARE ENHANCED IN PART BY DIVERGENCE 
ALOFT ASSOCIATED WITH A SHARP UPPER TROUGH THAT REACHES FROM 
HONDURAS TO JUST N OF THE GALAPAGOS. THE TROUGH WILL WEAKEN BUT 
REMAIN IN PLACE THOUGH THE NEXT COUPLE OF DAYS...WITH AN 
ABUNDANCE OF DEEP LAYER MOISTURE OVER THE AREA E OF 85W. DESPITE 
SUBSIDENT NORTHERLY FLOW ALOFT ON THE WEST SIDE OF THE UPPER 
TROUGH...LOW LEVEL CONVERGENCE ALONG THE ITCZ IS STRONG ENOUGH 
TO SUPPORT A FEW SHOWERS AND THUNDERSTORMS WITHIN 90 NM N OF THE 
ITCZ BETWEEN 100W AND 120W. 

SCATTEROMETER DATA FROM THE PAST SEVERAL HOURS INDICATE MODERATE 
TO FRESH GAP WINDS THROUGH THE GULFS OF PAPAGAYO AND PANAMA DUE 
IN LARGE PART TO SOMEWHAT STRONG RIDGING OVER THE GULF OF 
MEXICO. SEAS ARE ESTIMATED TO BE NEAR 8 FT DOWNSTREAM IN THE 
GULF OF PAPAGAYO. THE RIDGE WILL WEAKEN THOUGH TODAY...ALLOWING 
THE GAP WINDS TO TREND WEAKER THROUGH TONIGHT LEAVING LIGHT TO 
GENTLE BREEZES OVER MUCH OF THE AREA E OF 120W TO THE CENTRAL 
AMERICAN COAST WITH 3 TO 5 FT SEAS THROUGH SUNDAY.

FARTHER NORTH...A SHIP OBSERVATION OFF SOUTHERN BAJA CALIFORNIA 
SUR INDICATED 20 KT NW WINDS...PART OF A LARGER AREA OF MODERATE 
TO FRESH WINDS NOTED IN EARLIER SCATTEROMETER SATELLITE DATA IN 
THE REGION BETWEEN 1020 MB SURFACE HIGH PRES CENTERED NEAR 
27N122W AND TROUGHING ALONG THE GULF OF CALIFORNIA. THE HIGH 
PRES WILL WEAK THROUGH TONIGHT AS IT DRIFTS EAST...ALLOWING THE 
FRESH NORTHERLY FLOW OFF BAJA CALIFORNIA AND THE SOUTHERN GULF 
OF CALIFORNIA TO DIMINISH THROUGH SAT. MEANWHILE INSTABILITY 
ASSOCIATED WITH AN ACTIVE SOUTHERN STREAM UPPER JET IS 
SUPPORTING A STREAM OF MID AND HIGH CLOUDS PROBABLY WITH A FEW 
EMBEDDED SHOWERS ACROSS BAJA CALIFORNIA SUR AND THE SOUTHERN GULF 
OF CALIFORNIA.

W OF 120W...
UPPER DIVERGENCE ON THE RIGHT FRONT ENTRANCE PORTION 
OF AN UPPER JET IS INTERACTING WITH MODEST LOW LEVEL CONVERGENCE 
ALONG THE ITCZ TO ENHANCE A BROAD AREA OF MODERATE TO STRONG 
CONVECTION MAINLY WITHIN 300 NM N OF THE ITCZ. GLOBAL MODELS 
INDICATE THIS PATTERN WILL PERSIST THROUGH SATURDAY. 

1008 MB LOW PRES CENTERED NEAR 32N133W IS MOVING SE INTO TOWARD 
THE DISCUSSION AREA. MODELS ARE IN GOOD AGREEMENT SHOWING THE 
LOW PRES WEAKENING SUBSTANTIALLY AS IT MOVES TOWARD 29N130W 
THROUGH LATE TODAY...THEN STALLING AND WEAKENING FURTHER TO A 
TROUGH SATURDAY BEFORE DISSIPATING ALTOGETHER BY SUNDAY. FOR 
NOW...STRONG WINDS ARE PUSHING S OF 30N BEHIND A COLD FRONT 
REACHING FROM 30N128W TO 24N140W. THE FRONT WILL DRIFT S AND 
BECOME DIFFUSE BY LATE TODAY AS THE LOW WEAKENS...WITH WINDS 
DIMINISHING. A RECENT ALTIMETER PASS INDICATED SEAS OF 10 TO 15 
FT IN THE STRONG FLOW W OF THE LOW PRES. VARIOUS WAVE MODELS 
SHOW SWELL OF AT LEAST 8 TO 12 FT PROPAGATING OVER THE WATERS N 
OF 20N AND W OF 125W THROUGH SATURDAY...BEFORE SUBSIDING BELOW 8 
FT SAT NIGHT.

$$
CHRISTENSEN