000 AXPZ20 KNHC 171551 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU JUL 17 2014 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDING FROM 17N113W TO 1011 MB LOW 07N114W IS REPRESENTED WELL IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE IN GOES HIGH DENSITY WIND DATA. THE GFS AND ECMWF ARE IN GOOD AGREEMENT INITIALIZING IT IN THE LOWER TO MID LEVELS AS WELL. A 04 UTC ASCAT SATELLITE PASS INDICATED THE WAVE AT THE SURFACE WITH 23 KT WINDS NEAR 12N112W ALONG THE WAVE AXIS BETWEEN THE LOWER PRES NEAR THE ITCZ AND A PERSISTENT SURFACE RIDGE TO THE NORTH. A CONCURRENT ALTIMETER SATELLITE PASS INDICATED ENHANCED SEAS 7 FT IN THIS AREA AS WELL. THE WAVE IS DRIFTING TOWARD A MUCH DRIER AND STABLE AREA ON THE WEST SIDE OF AN UPPER LOW CENTERED NEAR 21N115W WITH NO SIGNIFICANT CONVECTION N OF THE ITCZ. DESPITE THE LACK OF SUSTAINING CONVECTION...THE WAVE IS EXPECTED TO PERSIST AS IT MOVES WESTWARD AT 15 TO 20 KT SOUTH OF A RIDGE OVER THE NEXT TWO TO THREE DAYS BUT BECOME LESS AMPLIFIED. ANOTHER TROPICAL WAVE IS MOVING WESTWARD OFF THE COAST OF NORTHERN CENTRAL AMERICA AND IS APPROACHING 90W N OF 14N. A FEW SHOWERS AND THUNDERSTORMS ARE NOTED NEAR 10N90W POSSIBLY ASSOCIATED WITH THE WAVE. THIS TROPICAL WAVE PRESENTS POORLY IN THE LIMITED AVAILABLE DATA...POSSIBLY DUE TO THE FACT THE WAVE IS SITUATED IN AN AREA OF NORTHERLY MID TO UPPER LEVEL FLOW ON THE EAST SIDE OF AN UPPER ANTICYCLONE CENTERED OVER SOUTH CENTRAL MEXICO. GLOBAL MODELS SHOW LITTLE TO NO AMPLITUDE IN THE LOWER TO MID LEVELS RELATED TO THIS WAVE OVER THE NEXT SEVERAL DAYS AND SIGNIFICANT SENSIBLE WEATHER AT THE SURFACE IS NOT LIKELY. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 09N84W TO LOW PRES NEAR 07N101W 1011 MB TO 08N108W. THE ITCZ EXTENDS FROM 08N108W TO LOW PRES NEAR 07N114W 1011 MB TO 07N120W TO 13N135W TO BEYOND 13N140W. NUMEROUS MODERATE TO STRONG CONVECTION IS OBSERVED WITHIN 150 NM S OF MONSOON TROUGH W OF 83W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED WITHIN 180 NM S OF MONSOON TROUGH BETWEEN 91W AND 97W. NUMEROUS MODERATE TO ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 120 NM N AND 180 S OF ITCZ W OF 135W. ...DISCUSSION... A LARGE AREA OF STRONG CONVECTION COVERS THE GULF OF PANAMA N OF 04N THIS MORNING. WHILE THERE MAY BE SOME CONTRIBUTION OF MODERATE SW FLOW INTO THE MONSOON TROUGH IN THIS AREA...THE MAIN SUPPORT THESE THUNDERSTORMS IS PROVIDED BY A SHARP UPPER TROUGH REACHING FROM HISPANIOLA ACROSS THE SW CARIBBEAN THROUGH PANAMA. THE UPPER TROUGH IS EXPECTED TO WEAKEN THROUGH TONIGHT ALLOWING THE CONVECTION TO DIMINISH. AN ASCAT SATELLITE PASS FROM 02 UTC INDICATED GAP WINDS IN EXCESS OF 20 KT IN THE GULF OF PAPAGAYO...LIKELY DUE TO ENHANCED TRADE WIND FLOW OVER THE SW CARIBBEAN. THESE WINDS HAVE LIKELY STARTED TO DIMINISH SINCE PEAKING AROUND SUNRISE. ANOTHER PULSE TO 20 KT IS LIKELY TONIGHT. SEAS TO 7 FT CAN BE EXPECTED NEAR 11N87W DOWNSTREAM OF THE GAP EVENT. AN UPPER CYCLONE IS CENTERED NEAR 21N115W AND IS DRIFTING NW. THIS FEATURES APPEARS TO BE WEAKENING...BUT IS STILL ENHANCING SMALL CLUSTERS OF MODEST CONVECTION WITHIN 300 NM NORTH OF A 1011 MB LOW PRES AREA EMBEDDED IN THE ITCZ NEAR 07N103W. THERE MAY BE A LOWER TO MID LEVEL TROUGH IN THIS AREA OF CONVECTION CONNECTED TO THE LOW PRES...BUT THIS WILL LIKELY NOT BE SUSTAINED VERY LONG BEYOND 24 HOURS AS THE LOW DRIFTS WEST AND AWAY FROM MORE FAVORABLE LIFT AND MOISTURE ON THE SOUTHEAST SIDE OF THE WEAKENING UPPER LOW. FRESH TO STRONG TRADE WINDS PERSIST FROM 13N TO 17N W OF 137W ASSOCIATED WITH AN AREA OF LOW PRES ALONG THE ITCZ WEST OF 140W. SEAS AREA REACHING 9 FT IN THIS AREA. THE WINDS AND SEAS WILL DIMINISH THROUGH TONIGHT AS THE LOW WEAKENS AND SHIFTS FARTHER WEST. A WEAK 1015 MB LOW PRES AREA PERSISTS NEAR 31N130W ASSOCIATED WITH A BROAD UPPER TROUGH ARCING OVERHEAD. THE LOW PRES IS EXPECTED TO DIMINISH OVER THE NEXT 24 HOURS...ALLOWING A SURFACE RIDGE TO BUILD ALONG ROUGHLY 20N. THE GFS IS STILL INDICATING THE POTENTIAL FOR A BRIEF SPATE OF 20 TO 25 KT WINDS ALONG THE CENTRAL COAST OF THE BAJA PENINSULA ON FRI. THIS IS BASED IN PART ON THE GFS DEPICTION OF DEEP 999 MB LOW PRES OVER N CENTRAL MEXICO GOING INTO THE WEEKEND. THE FORECAST FOLLOWS SLIGHTLY MORE CONSERVATIVE ECMWF AND UKMET DEPICTIONS INDICATING THE POTENTIAL FOR 20 KT FLOW ALONG THE CENTRAL BAJA COAST. $$ CHRISTENSEN