000 AXPZ20 KNHC 152155 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC MON JUL 15 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 2145 UTC. ...TROPICAL LOWS AND WAVES... A 1010 MB SURFACE LOW IS EMBEDDED WITHIN THE MONSOON TROUGH AT 11.5N126.5W WITH SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 90 NM EITHER SIDE OF A LINE FROM 15N122W TO 09N131W. THE LOW IS EXPECTED TO WEAKEN AND DISSIPATE WITHIN 24 HOURS. A TROPICAL WAVE IS ANALYZED TO THE N OF 10N BETWEEN 99W-100W AND IS CURRENTLY ACCOMPANIED BY ISOLATED MODERATE TO STRONG CONVECTION WITHIN 90 NM W AND WITHIN 150 NM E 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 08N78W CROSSING PANAMA TO THE COAST AT 09N84W...THEN DIPS SW TO 08N90W...THEN NW THROUGH THE BASE OF THE TROPICAL WAVE AT 10N100W THEN SW TO 09N105W...THEN NW TO 12N111W...CONTINUING W TO 12N123W THROUGH THE EMBEDDED LOW PRESSURE AT 11.5N126.5W...THEN WSW TO 10N135W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN INTERTROPICAL CONVERGENCE ZONE. THE ITCZ THEN CONTINUES W ALONG 10N TO BEYOND 10N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED S OF THE MONSOON TROUGH FROM 04N-08N TO THE E OF 80.5W TO JUST INLAND THE COAST OF COLOMBIA. A FEW LIGHTNING STRIKES ARE DETECTED ALONG THE MONSOON TROUGH AXIS OVER PANAMA. SIMILAR CONVECTION IS OBSERVED ALONG THE MONSOON TROUGH WITHIN 90 NM EITHER SIDE OF A LINE FROM 09N96W TO 07N108W...E OF THE EMBEDDED SURFACE LOW FROM 06N-12N BETWEEN 121W-125W...N OF THE MONSOON TROUGH WITHIN 120 NM OF 12N132W AND WITHIN 30 NM EITHER SIDE OF THE ITCZ AXIS. ...DISCUSSION... AN UPPER TROUGH EXTENDS S FROM THE COAST OF CALIFORNIA AT 34N120W INTO THE DISCUSSION AREA TO 26N127W. STRONG SOUTHERLY DRY FLOW IS INDICATED E OF THE TROUGH AXIS ACROSS THE NORTHERN BAJA PENINSULA AND SOUTHERN CALIFORNIA AND NOW OVER SW ARIZONA. AN UPPER ANTICYCLONE IS AT 17N135W WITH ITS ENVELOPE OF ANTICYCLONIC FLOW DOMINATING THE DISCUSSION AREA FROM 12N-32N BETWEEN 130W-140W. THE ITCZ DEBRIS MOISTURE THAT THE CIRCULATION CAPTURED YESTERDAY IS QUICKLY EVAPORATING BETWEEN 17N-21N AS THE UPPER LEVELS APPEAR VERY DRY TO THE N OF 17N W OF 123W. AN UPPER CYCLONE IS OVER THE DEEP TROPICS NEAR 04N121W WITH AN UPPER TROUGH EXTENDING SW TO BEYOND 00N140W. A WELL-DEFINED UPPER CYCLONE IS CENTERED AT 20N119W AND APPEARS TO BE SHIFTING W WITH TIME. AN 360 NM WIDE UPPER TROUGH EXTENDS N FROM THIS CYCLONE TO A SHARP CREST AT 28N120W WHILE THE CYCLONIC CIRCULATION HAS BECOME A UNIFORM 480 NM OVER ITS SOUTHERN PERIPHERY. THESE UPPER FEATURES COMBINED TO SET UP AN UPPER DEFORMATION ZONE OVER THE LOWER LEVEL MONSOON TROUGH AND ITS EMBEDDED SURFACE LOW...AND IS ENHANCING THE ASSOCIATED CONVECTION PREVIOUSLY DESCRIBED. AN UPPER ANTICYCLONE IS CENTERED OVER THE GULF OF HONDURAS WITH ITS ENVELOPE OF ANTICYCLONIC FLOW EXTENDING S OVER THE TROPICAL PACIFIC N OF 08N BETWEEN 84W-100W. 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 32N132W TO 18N107W. NE TRADES ARE EXPECTED TO INCREASE TO 15-20 KT ACROSS THE TROPICS FROM 11N-22N W OF 127W TONIGHT WITH SEAS OF 6-7 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 NW AT MOSTLY 15 KT ON TUE NIGHT ACROSS THESE 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 ARRIVE ALONG THE EQUATOR BETWEEN 115W-128W LATE TONIGHT. 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