000
AXPZ20 KNHC 230301
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 UTC SUN JUN 23 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

...SPECIAL FEATURES...                                           
CONVECTIVE BANDS AROUND A 1005 MB SURFACE LOW NEAR 12N103W 
CONTINUE TO BECOME MORE ORGANIZED. 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 09N85W TO 09N90W TO LOW PRES NEAR 
12N103W 1005 MB. MONSOON TROUGH IS DISCONTINUOUS AFTER 
12N103W...THEN CONTINUES FROM LOW PRES 1008 MB NEAR 14N115W TO 
10N125W. THE ITCZ STARTS AT 10N125W AND CONTINUES W OF 10N140W. 
SCATTERED MODERATE CONVECTION FROM 06N TO 08N BETWEEN 90W AND 
95W.

...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.

EARLIER SCATTEROMETER DATA INDICATED WINDS TO 20 KT THROUGH THE 
GULF OF TEHUANTEPEC. THIS IS DUE TO A TIGHTENING PRES GRADIENT 
BETWEEN A 1016 SURFACE HIGH NEAR TAMPICO MEXICO...AND THE 
OVERALL LOWERING OF PRES OVER THE EASTERN PACIFIC.

WINDS WILL ALSO INCREASE THROUGH THE GULF OF PAPAGAYO AHEAD OF A 
TROPICAL WAVE MOVING THROUGH SOUTHERN CENTRAL AMERICA INTO THE 
EASTERN PACIFIC. WINDS WILL PEAK AROUND 20 KT SUN...WITH SEAS 
INCREASING TO 8 FT...BEFORE SUBSIDING LATE SUN.

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