000
AXPZ20 KNHC 120236
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC SUN APR 12 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0100 UTC. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              

THE ITCZ AXIS WAS ANALYZED FROM 05N87W TO 03N104W TO 04N110W TO 
03N115W TO 05N123W TO 03N131W TO 04N140W. ISOLATED MODERATE 
CONVECTION WAS WITHIN 120 NM S OF THE AXIS BETWEEN 87W AND 93W.

...DISCUSSION... 

ENERGY WITHIN A SHARP...POSITIVELY TILTED SOUTHERN STREAM UPPER 
TROUGH FROM THE U.S. FOUR CORNERS THROUGH ENSENADA MEXICO TO 
24N121W REFLECTS A 1016 MB LOW PRES SYSTEM AT THE SURFACE NEAR 
25N122W. A TROUGH EXTENDS NW OF THE LOW TO 30N129W AND A 
DISSIPATING COLD FRONT EXTENDS SW OF THE LOW THROUGH 22N123W TO 
18N133W. WINDS NEAR THIS SYSTEM HAVE DIMINISHED BELOW THE 
ADVISORY CRITERIA OF 20-25 KT...BUT THE SEAS CONTINUE TO BE IN 
THE 8-9 FT RANGE IN NW SWELL W OF THE SURFACE BOUNDARY IN THE 
AREA FROM 21N-28N W OF 124W. THE SEAS WILL SUBSIDE BELOW 8 FT 
SUN MORNING AS THE SURFACE SYSTEM DISSIPATES. 

THIS SYSTEM ALOFT WILL SWING INTO NW MEXICO...DRAGGING A MID 
LEVEL TROUGH THROUGH BAJA CALIFORNIA SUR AND THE SOUTHERN GULF 
OF CALIFORNIA LATE TONIGHT THROUGH SUN MORNING. THIS WILL 
ENHANCE THE SURFACE TROUGHING OVER THE REGION JUST AS THE 
SUBTROPICAL RIDGE BUILDS BEHIND THE AFOREMENTIONED DISSIPATING 
SURFACE BOUNDARY OFFSHORE. NW TO N WINDS AROUND 20-25 KT WILL 
BUILD SEAS TO 8 FT JUST SW OF THE BAJA CALIFORNIA PENINSULA 
EARLY SUN. WINDS WILL ALSO PICK UP TO ADVISORY CRITERIA IN THE 
SOUTHERN GULF OF CALIFORNIA AROUND SUNRISE BEFORE DIMINISHING AS 
THE TROUGH PROGRESSES INLAND. CURRENTLY...SCATTERED MODERATE 
CONVECTION AHEAD OF THE TROUGH LIES WITHIN 120 NM N AND S OF A 
LINE FROM 24N117W TO 29N112W...INCLUDING OVER THE CENTRAL BAJA 
CALIFORNIA PENINSULA AND THE GULF OF CALIFORNIA...AND EXTENDS 
INLAND INTO NW MAINLAND MEXICO. THESE SHOWERS AND THUNDERSTORMS 
SHOULD MAKE THEIR WAY S ALONG THE PENINSULA AND CONTINUE TO 
SPREAD E INTO MAINLAND MEXICO THROUGH THE REMAINDER OF THE 
WEEKEND. 
 
WATER VAPOR IMAGERY SHOWS A SHARP UPPER LEVEL TROUGH EXTENDING 
FROM WESTERN CUBA ACROSS HONDURAS AND NICARAGUA THROUGH A LOW 
NEAR 02N92W TO BEYOND THE GALAPAGOS ISLANDS IN THE SOUTHERN 
HEMISPHERE NEAR 11S93W. THIS RARE CROSS-EQUATORIAL TUTT IS PART 
OF A HIGHLY AMPLIFIED MERIDIONAL FLOW PATTERN BETWEEN 75W AND 
105W IN THE DEEP TROPICS. SPEED DIFFLUENCE ALOFT ON THE E SIDE 
OF THE UPPER LOW IS ENHANCING VERTICAL MOTION AND DEEP 
CONVECTION ALONG THE ITCZ AXIS E OF 93W. THIS CONVECTION IS 
DESCRIBED IN THE SECTION ABOVE.

$$
SCHAUER