000 AXPZ20 KNHC 081531 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN FEB 08 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 1400 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...THE LAST GASP OF 20-25 KT WINDS IN THE GULF OF TEHUANTEPEC SHOULD DIMINISH THIS MORNING AS THE NORTHERLY FLOW FUNNELING THROUGH CHIVELA PASS IS TURNED OFF. THE 0814 UTC RAPIDSCAT PASS SHOWS WINDS ARE TURNING MORE SOUTHEASTERLY IN THE SW GULF OF MEXICO AHEAD OF A DEEP LAYERED TROUGH CURRENTLY OVER THE U.S. SOUTHERN PLAINS. BY LATE MON NIGHT...THE TROUGH SHOULD BRING A NEW ROUND OF NORTHERLY FLOW THROUGH THE WESTERN GULF AND CHIVELA PASS. WINDS WILL RAPIDLY INCREASE IN THE GULF OF TEHUANTEPEC AND ARE EXPECTED TO BECOME GALE FORCE BY THE END OF THE FORECAST PERIOD AROUND SUNRISE TUE MORNING. FAR NW WATERS GALE WARNING...A POTENT NORTHERN STREAM TROUGH IS RIDING A POWERFUL SOUTHWESTERLY UPPER JET THROUGH THE NORTH EASTERN PACIFIC WATERS PRIMARILY N OF THE AREA. THE COLD FRONT ASSOCIATED WITH THIS TROUGH LIES ACROSS FORECAST WATERS FROM 32N129W TO 23N140W. WHILE THE LATEST SCATTEROMETER DATA IS OVER 5 HOURS OLD...IT SHOWED GALE FORCE WINDS AS FAR S AS 27-28N AND THERE WERE INDICATIONS THAT THE FORECAST GUIDANCE WAS TOO WEAK WITH THE WINDS BEHIND THE FRONT. THE GALE WARNING WAS EXTENDED FOR 6 HOURS BASED ON THIS INFORMATION. THE FRONT WILL WEAKEN TODAY AND IS EXPECTED TO DISSIPATE MON AS THE IMPETUS UPPER TROUGH RACES AWAY FROM THE AREA. A SWATH OF NW SWELL WITH SEAS OVER 8 FT IS ALREADY IN PLACE W OF A LINE FROM 32N117W TO 06N136W TO 06N140W. SEAS AS HIGH AS 22 FT LIE IN THE GALE WARNING AREA. THE LEADING EDGE OF THE AREA OF NW SWELL WITH SEAS OVER 8 FT WILL CONTINUE TO PROPAGATE SOUTHEASTWARD...SPREADING S ALONG THE COAST OF BAJA CALIFORNIA NORTE TODAY...BUT MAXIMUM SEAS WILL BEGIN TO SUBSIDE AFTER THE GALE WARNING EXPIRES. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 09N84W TO LOW PRES NEAR 04N90W 1011 MB TO 03N96W. THE ITCZ AXIS WAS ANALYZED FROM 03N96W TO 06N118W TO 04N131W TO 05N140W. SCATTERED MODERATE CONVECTION WAS OVER FORECAST WATERS FROM 02N TO 10N BETWEEN 81W AND 94W. SCATTERED MODERATE CONVECTION WAS WITHIN 240 NM N OF THE AXIS BETWEEN 116W AND 124W. ...DISCUSSION... A 1021 MB SURFACE HIGH NEAR 27N122W EXTENDS A RIDGE AXIS SOUTHEASTWARD TO 14N110W AND ANOTHER SOUTHWESTWARD TO BEYOND 18N140W. THIS HIGH IS EXPECTED TO WEAKEN AND MERGE WITH HIGH PRESSURE W OF THE AREA BEHIND THE COLD FRONT OVER NW WATERS MON. THE MERGED HIGH WILL BE FORCED EASTWARD BY A VAST...DEEP LAYERED TROUGH OVER THE N CENTRAL PACIFIC. THIS WILL INCREASE THE PRESSURE GRADIENT BETWEEN THE EASTERN RIDGE AXIS AND TROUGHING OVER NW MEXICO. NW TO N WINDS ARE EXPECTED TO INCREASE TO A FRESH TO STRONG BREEZE ALONG THE COAST OF BAJA CALIFORNIA NORTE N OF 28N MON EVENING THROUGH THE END OF THE PERIOD TUE MORNING. TO THE W...TRADE WINDS WILL REMAIN A MODERATE TO FRESH BREEZE THROUGH TUE MORNING. AN UPPER LEVEL LOW LIES NEAR 08N125W. A BROAD UPPER JET LIES ON THE E SIDE OF THE LOW. ASCENT ASSOCIATED WITH THE LEFT FRONT QUADRANT OF THIS JET IS LIFTING TROPICAL MOISTURE AND ENHANCING CONVECTION ALONG THE MONSOON TROUGH BETWEEN 116W AND 124W. THIS CONVECTION IS DESCRIBED IN THE SECTION ABOVE. THE UPPER LOW IS FORECAST TO SHIFT NORTHEASTWARD AND PHASE WITH THE DEEP LAYERED TROUGH THAT IS SUPPORTING THE COLD FRONT CURRENTLY OVER NW WATERS. GAP WINDS.... GULF OF PAPAGAYO...TRADE WINDS IN THE WESTERN CARIBBEAN HAVE BEEN DISRUPTED BY TROUGHING...CUTTING OFF THE NE FLOW THROUGH THE GULF OF PAPAGAYO. WINDS IN THE GULF OF PAPAGAYO SHOULD DIMINISH BELOW THE ADVISORY CRITERIA OF 20-25 KT BEFORE MIDDAY AS THE NOCTURNAL MOUNTAIN DRAINAGE FLOW WANES. $$ SCHAUER