000 AXPZ20 KNHC 181602 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON MAY 18 2015 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 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH IS NOT PRESENTLY EVIDENT DEFINED AT THE PRESENT TIME. THE ITCZ AXIS EXTENDS FROM 05N103W TO 05N112W TO 07N120W TO 05N127W. IT RESUMES AT 04N131W TO 04N140W. SCATTERED MODERATE/ISOLATED STRONG IS WITHIN 180 NM S OF THE ITCZ BETWEEN 112W-118W...AND ALSO BETWEEN 121W-130W. ...DISCUSSION... BROAD UPPER TROUGHING COVERS THE AREA N OF 26N E OF 124W...WHILE WEAKENING MID/UPPER RIDGING IS TO THE W OF 124W N OF 22N. A SUBTROPICAL JET STREAM ENTERS THE AREA AT 20N140W...AND CONTINUES TO STRETCH ENE ACROSS THE BASE OF THE TROUGH TO 23N120W...AND ENE ACROSS SOUTHERN BAJA CALIFORNIA...AND TO INLAND N CENTRAL MEXICO. THIS JET STREAM SEPARATES THE AREA BETWEEN THE AFOREMENTIONED TROUGHING AND BROAD SCALE RIDGING TO ITS S E OF 135W. THE ANTICYCLONE ASSOCIATED WITH THE RIDGING IS LOCATED NEAR 12N119W. SCATTERED TO BROKEN HIGH ARE SEEN STREAMING ENE WITHIN 180 NM S OF THE JET STREAM. A MID LEVEL TROUGH IS W OF THE ANTICYCLONE FROM 14N137W TO NEAR 05N133W. WATER VAPOR SHOWS A SWATH OF MODERATE SUBSIDENCE FROM 21N TO 32N W OF 127W...AND ALSO FROM 25N TO 32N E OF 127W. THIS IS KEEPING THE ATMOSPHERE RATHER STABLE ACROSS THOSE AREA WITH ONLY SCATTERED TO BROKEN STRATOCUMLUS NOTED MOVING TO THE SSW THERE. OVER THE FAR EASTERN PORTION A RATHER LARGE UPPER TROUGH STRETCHES FROM SE GULF OF MEXICO SSW TO A SMALL UPPER LOW A 09N93W...AND CONTINUES SSE TO S OF THE EQUATOR AT 93W. UPPER DIVERGENCE E OF THE TROUGH IS ALLOWING FOR SMALL CLUSTERS OF SCATTERED TSTMS TO PERSIST FROM 04N TO 10N E OF ABOUT 96W. AT THE SURFACE...A COLD FRONT EXTENDS FROM A WEAK 1016 MB LOW N OF THE AREA AT 34N130W SW TO 28N131W AND TO 25N140W. THIS COLD FRONT WILL CONTINUE TO WEAKEN AS IT DRIFTS SLOWLY SE THROUGH EARLY TUE BEFORE DISSIPATING. WINDS OVER FORECAST WATERS ARE NOT EXPECTED TO REACH 20 KT NEAR THE FRONT AND SEAS TO 8 FT SHOULD REMAIN CONFINED N OF 31N BEHIND THE FRONT. A WEAK RIDGE EXTENDS FROM 26N130W ESE TO NEAR 24N114W. THE RIDGE WILL REMAIN OVER THE NORTHERN WATERS THROUGH WED. THE PRES GRADIENT BETWEEN THE HIGH RIDGE AND LOWER PRES TO THE S ASSOCIATED WITH THE ITCZ IS GENERATING MODERATE TO FRESH TRADES MAINLY BETWEEN 09N-20N W OF 120W. THE FRESH TRADES ARE HELPING TO MAINTAIN SEAS IN THE 8-9 FT RANGE FROM 10N TO 14N W OF 135W...AND WITHIN 60 NM EITHER SIDE OF LINE FROM 15N125W TO 10N131W TO 10.5N135W. A TROUGH IS ANALYZED FROM 14N126W TO 04N128W. MODELS SUGGEST THAT THE TROUGH WILL MOVE WESTWARD TO ALONG A POSITION FROM NEAR 15N129W TO 07N130W BY EARLY TUE...AND FROM NEAR 14N131W TO NEAR LOW PRES OF 1009 MB BY EARLY ON WED. THE GRADIENT NEAR THE TROUGH IS EXPECTED TO SUPPORT NE TO E 20-25 KT WINDS WITH SEAS OF 8 FT FROM 15N TO 18N BETWEEN 124W AND 127W BY EARLY ON TUE...AND DIMINISH TO 20 KT OR LESS BY EARLY IN WED WITH SEAS TO 8 FT IN MIXED NE AND NW SWELL. THE PRESSURE GRADIENT BETWEEN THE EASTERN RIDGE AND LOWER PRESSURE ACROSS BAJA CALIFORNIA AND NW MEXICO IS PRODUCING A MODERATE NORTHWESTERLY BREEZE ALONG MOST OF THE PACIFIC COASTAL WATERS OF THE BAJA CALIFORNIA PENINSULA. THE PRESSURE GRADIENT IS EXPECTED TO TIGHTEN SLIGHTLY THIS AFTERNOON AND EVENING AND AGAIN TUE AFTERNOON AS THE AFOREMENTIONED UPPER TROUGH SWINGS THROUGH THE BAJA CALIFORNIA PENINSULA AND INCREASES SURFACE TROUGHING. THIS SHOULD ALLOW FOR NW WINDS TO BRIEFLY REACH 20-25 KT EARLY THIS EVENING N OF 26N WITHIN 60 NM OF THE COAST OF BAJA CALIFORNIA...AND AGAIN TUE EVENING WITH SEAS TO NEAR OR AT 8 FT. GAP WINDS... GULF OF PAPAGAYO...WINDS WILL CONTINUE TO PULSE OVER THE GULF OF PAPAGAYO THROUGH EARLY ON TUE WITH NE TO E WINDS IN THE 20-25 KT RANGE ENHANCED WITH THE ADDED COMPONENT OF NOCTURNAL DRAINAGE FLOW. THESE WINDS WILL THEN DIMINISH TO 15-20 KT BY EARLY TUE AFTERNOON AND INTO THE EARLY EVENING HOURS. LOOKING AHEAD...ANOTHER STRONG SOUTHERN HEMISPHERIC SW SWELL WILL MOVE INTO THE REGIONAL WATERS LATE IN THE WEEK. SEAS WILL BUILD TO 8 FT AND GREATER ALONG THE EQUATORIAL WATERS BY THU MORNING. THIS PULSE OF LONG PERIOD SWELL IS EXPECTED TO REACH THE COASTLINES OF CENTRAL AMERICA BY LATE FRI...AND COULD BRING ROUGH SEA STATE CONDITIONS TO THOSE AREAS. $$ AGUIRRE