000 AXPZ20 KNHC 160231 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE JUL 16 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. ...TROPICAL LOWS AND WAVES... A SURFACE LOW PREVIOUSLY EMBEDDED WITHIN THE MONSOON TROUGH AT 11.5N126.5W HAS BECOME DIFFICULT TO LOCATE AND HAS REMOVED FROM THE SURFACE ANALYSIS. A TROPICAL WAVE IS ANALYZED TO THE N OF 10N ALONG 101W AND IS CURRENTLY ACCOMPANIED BY ISOLATED MODERATE TO STRONG CONVECTION WITHIN 150 NM EITHER SIDE OF THE WAVE AXIS. A NE-E-SE 10-15 KT WIND SHIFT IS EXPECTED ALONG THE WAVE AXIS AS IT CONTINUES WESTWARD AT ABOUT 12 KT THROUGH TUE...THEN GUIDANCE GRADUALLY DAMPENS THE WAVE ON WED AND THU...WITH THE CIRCULATION DISAPPEARING WITHIN THE MONSOON FLOW ON THU NIGHT INTO FRI. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W FROM THE COAST OF COLOMBIA AT 06N77W CROSSING SOUTHERN TO THE COAST OF COSTA RICA AT 09N84W...THEN DIPS SW TO 08N89W...THEN NW THROUGH THE BASE OF THE TROPICAL WAVE AT 10N101W THEN SW TO 09N105W...THEN NW TO 13N123W...THEN SW TO 10N137W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN INTERTROPICAL CONVERGENCE ZONE. THE ITCZ THEN CONTINUES W ALONG 10N TO BEYOND 10N140W. ISOLATED MODERATE TO STRONG CONVECTION IS OBSERVED N OF 04N TO THE E OF 80W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED OVER AND S OF THE MONSOON TROUGH WITHIN 15 NM OF 07N86W AND WITHIN 75 NM EITHER SIDE OF A LINE FROM 09N99W TO 08N108W...FROM 07N-14N BETWEEN 120W-126W...AND WITHIN 120 NM EITHER SIDE OF A LINE FROM 10N132W-10N138W. ...DISCUSSION... AN UPPER TROUGH EXTENDS S FROM THE COAST OF CALIFORNIA AT 34N120W INTO THE DISCUSSION AREA FROM 32N122W TO 23N126W. SOUTHERLY DRY FLOW ALOFT IS INDICATED E OF THE TROUGH AXIS ACROSS THE NORTHERN BAJA PENINSULA AND SOUTHERN CALIFORNIA. AN UPPER ANTICYCLONE IS AT 18N136W WITH ITS ENVELOPE OF ANTICYCLONIC FLOW DOMINATING THE DISCUSSION AREA FROM 12N-32N BETWEEN 129W-140W. ITCZ DEBRIS MOISTURE IS ADVECTED N AROUND THE W PERIPHERY OF THE ANTICYCLONE...BUT EVAPORATES BETWEEN 17N-21N IN DRY UPPER ALOFT INDICATED TO THE N OF 17N W OF 123W. AN UPPER CYCLONE IS OVER THE DEEP TROPICS NEAR 05N119W WITH AN UPPER TROUGH EXTENDING SW TO BEYOND 00N138W. A WELL-DEFINED UPPER CYCLONE IS CENTERED AT 20N120W AND APPEARS TO BE SHIFTING W WITH TIME. AN 360 NM WIDE UPPER TROUGH EXTENDS N FROM THIS CYCLONE TO A SHARP CREST AT 28N121W WHILE THE CYCLONIC CIRCULATION EXTENDS 360 NM SW AND 480 NM SE QUADRANTS OF CENTER. THESE UPPER FEATURES COMBINED TO SET UP AN UPPER DEFORMATION ZONE OVER THE LOWER LEVEL MONSOON TROUGH AND IS ENHANCING THE ASSOCIATED CONVECTION PREVIOUSLY DESCRIBED. AN UPPER ANTICYCLONE IS CENTERED OVER NORTHERN HONDURAS WITH ITS ENVELOPE OF ANTICYCLONIC FLOW EXTENDING S OVER THE TROPICAL PACIFIC N OF 10N BETWEEN 84W-102W. A SMALL AREA OF UPPER DIFFLUENCE IS ALONG THE W PERIPHERY OF THIS RIDGE AND SUPPORTING THE CONVECTION PREVIOUSLY DESCRIBED ALONG THE THE TROPICAL WAVE. SOME OF THE DEBRIS MOISTURE IS ADVECTED N AND NE ACROSS THE CENTRAL GULF OF MEXICO AROUND AN UPPER CYCLONE NEAR 21N93W. AT THE LOW LEVELS A RIDGE EXTENDS FROM 32N135W TO 18N107W. NE TRADES ARE INCREASING TO 15-20 KT ACROSS THE TROPICS FROM 11N-22N W OF 127W WITH SEAS EXPECTED TO MAX AT 7 FT IN NE SWELL. THESE CONDITIONS WILL CHANGE LITTLE THROUGH FRI. NW WINDS CURRENTLY AT 5-10 KT ALONG THE WESTERN SHORE OF THE BAJA CALIFORNIA PENINSULA WILL PERSIST THROUGH EARLY TUE...THEN INCREASE TO 15 KT ON TUE NIGHT ACROSS THE ADJACENT WATERS TO THE N OF 28N. NW WINDS OF 15-20 KT ARE EXPECTED N OF 25N W OF THE BAJA PENINSULA TO ALONG 122W ON THU...WITH ASSOCIATED SEAS TO 7 FT. GULF OF PAPAGAYO...NE WINDS WILL INCREASE BRIEFLY TO 15-20 KT LATE EACH NIGHT AND CONTINUE UNTIL AFTER SUNRISE EACH MORNING THROUGH FRI MORNING. S SWELLS RESULTING IN COMBINED SEAS TO 8 FT WILL SOON ARRIVE ALONG THE EQUATOR BETWEEN 115W-128W. THESE CONDITIONS WILL REACH ALONG 05N BETWEEN 100W-115W ON WED...THEN BEGIN TO SUBSIDE. HOWEVER THE LONG PERIOD SW SWELL ENERGY WILL REACH THE COAST OF CENTRAL AMERICA...INCLUDING THE SOUTHERN GULF OF CALIFORNIA...AS EARLY AS WED NIGHT. $$ NELSON