000 AXPZ20 KNHC 071521 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SAT MAY 07 2016 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 1415 UTC. ...INTERTROPICAL CONVERGENCE ZONE... A MONSOON TROUGH AXIS WAS ANALYZED FROM 13N96W TO 11N106W TO 11N113W TO 09N117WTO 09N123W TO 07N130W. THE ITCZ AXIS WAS ANALYZED FROM 07N130W TO 05N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 240 NM S OF THE AXIS BETWEEN 103W-108W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS FROM 04N-08.5N BETWEEN 111W-114W. SCATTERED MODERATE CONVECTION WAS WITHIN 180 NM N OF THE AXIS BETWEEN 114W-126W. ...DISCUSSION... ALOFT...AN ANTICYCLONE S OF ACAPULCO WILL REMAIN STATIONARY FOR THE NEXT DAY OR SO. A UPPER RIDGE EXTENDS SOUTHEASTWARD FROM THE LOW TO THE COASTAL BORDER OF NICARAGUA AND COSTA RICA AND INTO EASTERN PANAMA. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE RIDGE AXIS IS ENHANCING VERTICAL MOTION IN THIS AREA OF INCREASING LOW LEVEL MOISTURE. SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 120 NM EITHER SIDE OF A LINE FROM 04N80W TO 13N93W...JUST OFFSHORE OF CENTRAL AMERICA. THE RIDGE AXIS IS EXPECTED TO SHIFT SLIGHTLY WESTWARD LATE SUN INTO MON...TAKING THE BEST CHANCE OF PRECIPITATION A BIT FARTHER OFFSHORE. AT THE SURFACE...A 1030 MB SUBTROPICAL HIGH WAS ANALYZED NEAR 38N138W WITH A RIDGE AXIS EXTENDING SOUTHEASTWARD THROUGH 32N137W TO 18N109W. A DEEP-LAYER LOW ON THE W SIDE OF THE SUBTROPICAL HIGH WILL SHIFT SLIGHTLY NORTHEASTWARD...SENDING A WEAK COLD FRONT WITHIN 150 NM OF THE NW CORNER OF THE FORECAST AREA BY MON MORNING. THE SUBTROPICAL HIGH WILL BE FORCED NORTHWARD BY THE APPROACHING DEEP-LAYERED LOW...WITH THE RIDGE SHIFTING SLIGHTLY SOUTHWESTWARD OVER THE FORECAST AREA SUN AND MON. MODERATE TO FRESH TRADE WINDS SW OF THE RIDGE AXIS WILL GRADUALLY SHRINK IN AREA THROUGH MON MORNING AS THE HIGH MOVES AWAY AND THE PRESSURE GRADIENT WEAKENS. AN AREA OF 7-9 FT SEAS IN MIXED SWELL LIES FROM 06N-20N W OF 134W AND FROM 06N-12N BETWEEN 124W-134W. THIS AREA OF SEAS IS EXPECTED TO GRADUALLY SHRINK THROUGH MON MORNING...WITH SEAS SUBSIDING BELOW 8 FT BY THAT TIME. GAP WINDS... GULF OF CALIFORNIA...A SLOW-MOVING NORTHERN STREAM PATTERN IS IN PLACE N OF 20N. DEEP LAYER TROUGHING OVER THE GREAT BASIN AND SOUTHWESTERN UNITED STATES HAS SENT A WEAK COLD FRONT INTO THE FAR NORTHERN GULF OF CALIFORNIA. SW WINDS S OF THE FRONT WERE IN THE FRESH TO STRONG RANGE THIS MORNING AS SEEN BY THE 0512Z ASCAT PASS. THE PARENT UPPER LOW OVER THE GREAT BASIN HAS A SPOKE OF ENERGY FORECAST TO PASS INLAND FROM THE PACIFIC OVERNIGHT TONIGHT. WINDS IN THE GULF WILL BRIEFLY DIMINISH AHEAD OF THIS FEATURE...WITH SW WINDS AHEAD OF THE ASSOCIATED LOW- LEVEL BOUNDARY RETURNING TO A FRESH TO STRONG BREEZE TONIGHT AND DISSIPATE ONCE AGAIN AROUND SUNRISE SUN. THE UPPER LOW IS FORECAST TO SHIFT E SUN AND MON. GULF OF TEHUANTEPEC...A LAST GASP OF 20-30 KT WINDS PERSISTS IN THE GULF OF TEHUANTEPEC THIS MORNING AFTER AN UNSEASONABLY COOL AND DRY AIR MASS MOVED THROUGH CHIVELA PASS FRI. WINDS IN THE SW GULF OF MEXICO ARE EXPECTED TO VEER AS HIGH PRES OVER THE LOWER MISSISSIPPI VALLEY SHIFTS E INTO THE ATLC SUN. THIS WILL CUT OFF THE FLOW THROUGH CHIVELA PASS. SEAS ARE CURRENTLY TO 10 FT IN THE GULF OF TEHUANTEPEC...BUT ARE FORECAST TO SUBSIDE BELOW 8 FT WITH WINDS DIMINISHING TO A FRESH BREEZE OR LESS LATE TODAY. GULF OF PAPAGAYO...THE PRES GRADIENT BETWEEN THE AFOREMENTIONED HIGH OVER THE LOW MISSISSIPPI VALLEY AND LOWER PRES TO THE SW ASSOCIATED WITH THE MONSOON TROUGH HAVE COUPLED WITH NOCTURNAL DRAINAGE FLOW TO SUPPORT A FRESH TO STRONG NE BREEZE THROUGH THE GULF OF PAPAGAYO THIS MORNING. WINDS WILL PULSE BELOW 20-25 KT THIS AFTERNOON AND RETURN TO A FRESH TO STRONG BREEZE DOWNWIND OF THE GULF TO 88W OVERNIGHT TONIGHT BEFORE DIMINISHING AGAIN AS THE HIGH PRES MOVES EASTWARD...SLACKENING THE PRES GRADIENT. SEAS ARE FORECAST TO REMAIN BELOW 8 FT. $$ SCHAUER