000
AXPZ20 KNHC 222126
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
2205 UTC SAT JUN 22 2013

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

...SPECIAL FEATURES...                                           
CONVECTIVE BANDS AROUND A 1007 MB SURFACE LOW NEAR 12N103W ARE 
SLOWLY BECOMING MORE ORGANIZED. UNFAVORABLE NORTHERLY SHEAR 
ALOFT PERSISTS OVER THE LOW PRES...BUT THIS IS DIMINISHING 
ALLOWING CONVECTION TO BECOME MORE CONSISTENT. A SECOND WEAKER 
LOW PRES AREA IS CENTERED NEAR 14N115W WITH AN ESTIMATED MSLP OF 
1008 MB. THE CURRENT FORECAST CALLS FOR CONTINUED 
DEVELOPMENT...POSSIBLY TROPICAL CYCLONE DEVELOPMENT...OF THE 
EASTERNMOST LOW PRES SYSTEM. THE WESTERNMOST LOW IS EXPECTED TO 
DEVELOP FURTHER THROUGH APPROXIMATELY 24 HOURS...WITH POSSIBLE 
TROPICAL CYCLONE FORMATION DURING THAT WINDOW. THIS LOW IS THEN 
FORECAST TO GRADUALLY BECOME ENGULFED IN THE BROADER CIRCULATION 
AROUND THE LOW FURTHER E.  

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            
MONSOON TROUGH AXIS FROM 10N84W TO LOW PRES NEAR 12N103W 1007 
MB. ITCZ AXIS FROM 11N123W TO 08N140W. SCATTERED MODERATE WITHIN 
210 NM S OF MONSOON TROUGH AXIS E OF 100W.

...DISCUSSION...                                               
NORTHERLY SHEAR ALOFT ON THE EAST SIDE A BROAD UPPER ANTICYCLONE 
CENTERED NEAR 24N120W CONTINUES TO PUSH DRIER SUBSIDENT AIR 
SOUTHWARD OVER THE BAJA PENINSULA TOWARD THE LOW PRES CENTERED 
NEAR 12N103W. ONGOING CONVECTION DUE TO LOW LEVEL CONVERGENCE 
ALONG THE MONSOON TROUGH IS STARTING TO PRESENT ITS OWN OUTFLOW 
OVER THE LOW PRES HOWEVER AND THE IMPACT OF THE SHEARING IS 
DIMINISHING ALLOWING CONVECTION TO BECOME BETTER ORGANIZED. 

DESPITE OCCASIONAL BURSTS...CONVECTION REMAINS MUCH MORE LIMITED 
AND NOT AS ORGANIZED WITH THE LOW NEAR 14N115W COMPARED TO THE 
MORE EASTERN LOW PRES. THIS IS DUE IN PART BECAUSE IT IS 
SITUATED ON THE FAR WESTERN PORTION OF THE MONSOON TROUGH...AND 
THE SW FLOW INTO THE LOW IS MUCH MORE LIMITED...AS WELL AS BEING 
OVER COOLER WATER THAN THE EASTERNMOST LOW.

LINES OF CONVECTION PARALLELING THE COAST FROM EL SALVADOR TO 
SOUTHERN MEXICO WERE NOTED EARLIER THIS MORNING...DUE TO 
CONVERGENCE OF DRAINAGE FLOW WITH SW BOUNDARY LAYER FLOW 
ASSOCIATED WITH THE MONSOON TROUGH AND THE WINDS ON THE EAST 
SIDE OF THE SURFACE LOW NEAR 12N103W. THIS HAS ALMOST ENTIRELY 
DIMINISHED BUT WILL LIKELY REDEVELOP TONIGHT.

FARTHER WEST...ONLY MODERATE TO FRESH TRADE WIND FLOW IS NOTED 
IN THE LATEST SCATTEROMETER PASSES S OF 20N W OF 120W. A SMALL 
AREA OF SEAS TO 8 FT IN NE SWELL FROM 10N TO 12N W OF 138W WILL 
GRADUALLY SHIFT W OF THE DISCUSSION AREA THROUGH SUN. 

MEANWHILE A NEW ROUND OF SW SWELL OUT OF THE SOUTHERN HEMISPHERE 
WITH HEIGHTS GREATER THAN 8 FT WILL START TO PUSH N OF THE 
EQUATOR BETWEEN 120W AND 130W TONIGHT. THIS WILL EVENTUALLY 
PROPAGATE OVER MUCH OF THE AREA S OF 11N BETWEEN 100W AND 
130W...EVENTUALLY INTERACTING WITH SHORTER PERIOD ENERGY 
GENERATED AROUND THE DEVELOPING LOW NEAR 12N103W TO PRODUCE AREAS 
OF CONFUSED SEAS NEAR THE LOW BY 48 HOURS. THE LEADING EDGE OF 
THIS SWELL WILL IMPACT THE CENTRAL AMERICAN AND MEXICAN COASTS 
BY EARLY TUE. LOOKING AHEAD...THE COMBINED EFFECTS OF THE 
DEVELOPING LOW AND THE SWELL COULD BRING HAZARDOUS SURF 
CONDITIONS TO THE MEXICAN COAST BETWEEN ACAPULCO AND MANZANILLO 
TUE...SPREADING NORTHWARD TO SOUTHERN BAJA WED. 
  
$$ 
CHRISTENSEN