000 AXPZ20 KNHC 091553 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON MAR 09 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. ...SPECIAL FEATURE... A MINIMAL GALE WARNING IS IN EFFECT ACROSS THE GULF OF PAPAGAYO AND EXTENDING ABOUT 120 NM TO THE SW AT SUNRISE THIS MORNING. WINDS AND SEAS WILL QUICKLY DIMINISH AND SUBSIDE THROUGHOUT THE DAY WITH ONLY REMNANT NE SWELL WELL DOWNSTREAM OF PAPAGAYO AN ISSUE BY THIS EVENING. ANOTHER ENE 20-25 KT SURGE IS EXPECTED TONIGHT LATE TONIGHT THROUGH SUNRISE ON TUE WITH THESE CONDITIONS REACHING AS FAR W AS 10N92W. THESE NOCTURNAL 20-25 KT SURGES ARE EXPECTED THROUGH NEXT WEEKEND BUT SHOULD NOT EXTEND W OF 90W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A LOW LEVEL TROUGH EXTENDS SW ALONG THE PACIFIC COAST OF COLOMBIA. SCATTEROMETER WINDS INDICATE THAT THE ITCZ FORMS NEAR 04N89W...AND EXTENDS WSW TO 03N106W...THEN WNW TO AN EMBEDDED TROUGH AT 05N133W...THEN THE ITCZ TURNS SW TO BEYOND 03N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 75 NM OF 08N133W IN ASSOCIATION WITH THE EMBEDDED LOW LEVEL TROUGH ANALYZED FROM 03N134W TO 10N133W. BROKEN TO LOCALLY OVERCAST LOW- MID LEVEL CLOUDS WITH EMBEDDED LIGHT SHOWERS ARE OBSERVED WITHIN 300 NM OF THE PACIFIC COAST OF COLOMBIA AND OVER AND WITHIN 120 NM OF THE ITCZ E OF 126W...AND ELSEWHERE S OF 10N W OF 133W. SCATTEROMETER WINDS...BUOY AND IR IMAGERY INDICATE A WEAK SOUTHERN HEMISPHERE ITCZ FROM 06S90W TO 03S113W TO 04S122W TO BEYOND 01S140W. OVERCAST LOW-MID LEVEL CLOUDS WITH EMBEDDED LIGHT SHOWERS ARE OBSERVED WITHIN 150 NM OF THIS SOUTHERN HEMISPHERE ITCZ. ...DISCUSSION... GULF OF TEHUANTEPEC...STRONG GALE CONDITIONS AT SUNRISE THIS MORNING ARE EXPECTED TO DIMINISH TO A MINIMAL GALE THIS AFTERNOON...AND FURTHER DIMINISH TO BELOW GALE FORCE THIS EVENING. MAXIMUM SEAS OF 17 FT NEAR 14N96W AT SUNRISE THIS MORNING SHOULD DIMINISH TO 12 FT OVER THE SOUTHERN WATERS OF THE GULF OF TEHUANTEPEC THIS EVENING. COLD WATER UPWELLING IS OBSERVED ON IR SATELLITE IMAGERY AS FAR S AS 12.8N96W. TONIGHTS NOCTURNAL MAXIMUM DRAINAGE SHOULD INCREASE THE NORTHERLY FLOW TO 30 KT WITH SEAS TO ABOUT 10 FT...THEN CONDITIONS WILL QUICKLY IMPROVE TO 15-20 KT ON MON AFTERNOON. THE NEXT TEHUANTEPEC EVENT IS EXPECTED TO BEGIN WITH 20-25 KT NORTHERLY WINDS DURING THE MAXIMUM DRAINAGE LATE TUE NIGHT...THEN GRADUALLY INCREASE TO A MINIMAL GALE EARLY ON WED NIGHT. LATEST GUIDANCE IS MORE AGGRESSIVE ON THIS NEXT EVENT...AND NOW SUGGESTS THE GALE CONDITIONS WILL PERSIST THROUGH SUNRISE ON FRI. ALOFT...AN UPPER LEVEL ANTICYCLONE IS OBSERVED OVER THE DEEP TROPICS AT 12N134W WITH A SHORT WAVE RIDGE EXTENDING N TO A CREST BEYOND 36N130W. TO THE W OF THIS RIDGE IS A DEEP LAYERED CYCLONE QUASI-STATIONARY AT 36N153W. SURFACE COLD FRONTS CONTINUE TO ROTATE AROUND THE CYCLONE. THE NEXT COLD FRONT WILL PASS E OF 140W THIS EVENING PRECEDED BY SOUTHERLY 20-25 KT WINDS AND SEAS OF 8-11 FT MAINLY ASSOCIATED WITH A LOW PRESSURE EXPECTED TO BRIEFLY DEVELOP W OF 140W ALONG THE FRONT LATE THIS AFTERNOON INTO THIS EVENING. THE LOW IS EXPECTED TO FILL COMPLETELY BEFORE ITS PARENT COLD FRONT PASSES E OF 140W EARLY TONIGHT. THIS WEAK FRONT WILL BE BLOCKED BY A SURFACE HIGH EXPECTED TO DEVELOP NEAR 26N125W LATE TUE...WITH THE FRONT STALLING FROM 32N131W TO 22N136W ON TUE NIGHT...AND DISSIPATING ON WED. THE SOUTHERLY FLOW AHEAD OF THE FRONT WILL DIMINISH TO 15-20 KT TONIGHT. POST-FRONTAL NW SWELLS WILL RESULT IN COMBINED SEAS OF 7-10 FT W OF THE FRONT ON TUE...THEN SUBSIDING BELOW 8 FT ON WED. TO THE E OF THE UPPER RIDGE IS AN UPPER TROUGH THAT EXTENDS S ACROSS NEW MEXICO AND OLD MEXICO TO A BASE OVER THE TROPICAL PACIFIC AT 08N107W. AN UPPER ANTICYCLONE IS OVER THE DEEP TROPICS NEAR 05N87W. DENSE DEBRIS MOISTURE...ORIGINATING FROM ITCZ CONVECTION OVER THE CENTRAL PACIFIC...IS ADVECTED NE ALONG A 900 NM WIDE PLUME INTO THE NW PORTION OF DISCUSSION AREA... THEN TURNS SE AS IT CROSS THE UPPER RIDGE AXIS NARROWING TO ABOUT 420 NM WIDE AS IT ROTATES E THROUGH THE UPPER TROUGH JUST S OF THE BAJA CALIFORNIA PENINSULA...TURNS NE ACROSS CENTRAL OLD MEXICO...AND THEN FANS OUT ACROSS THE SE CONUS. OTHERWISE...THE UPPER LEVELS APPEAR VERY DRY ACROSS THE TROPICS S OF 16N AND SUPPRESSING CONVECTION ALONG THE ITCZ...EXCEPT FOR THE SMALL CLUSTER NEAR THE LOW LEVEL TROUGH PREVIOUSLY MENTIONED NEAR 08N133W. A SURFACE RIDGE EXTENDS FROM 32N130W TO 15N105W. THE TRADES SW OF THE RIDGE ARE MOSTLY AT 15-20 KT WITH A SMALL EMBEDDED PATCHES OF 20-25 KT EXPECTED THROUGH TONIGHT WITH COMBINED SEAS OF 7-10 FT IN MIXING NE TRADES...ALONG WITH LONG PERIOD S AND NW SWELL. NE SWELL...ORIGINATING FROM A RECENT GAP EVENTS IN THE GULF OF TEHUANTEPEC...GULF OF PAPAGAYO AND GULF OF FONSECA...IS PROPAGATING WSW ACROSS THE TROPICAL WATERS TO THE S OF 12N BETWEEN 90-120W...BUT WILL GRADUALLY SUBSIDE THROUGH TUE. .GULF PANAMA...A NARROW SWATH OF NORTHERLY 15-20 KT WINDS ARE EXPECTED TO DEVELOP EACH NIGHT ALONG 80W. $$ NELSON