000 AXPZ20 KNHC 081005 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT MAR 07 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...HIGH RESOLUTION RAPIDSCAT DATA FROM LATE LAST NIGHT DEPICTED GALE FORCE N TO NE WINDS OF 35-45 KT ACROSS THE GULF OF TEHUANTEPEC WHILE IZTEPEC LOCATED ON THE NORTHERN END OF THE GULF REPORTED N WINDS WITH GUSTS TO 30 KT. LAST OBSERVATION FROM THAT SITE SHOWED THAT THE WINDS HAVE DIMINISHED TO JUST UNDER 30 KT. THE PERSISTENT STRONG HIGH PRES CELL OVER NE MEXICO FROM THE PAST FEW DAYS HAS WEAKENED AS IT SHIFTS SOUTHWARD. THE ASSOCIATED TIGHT PRES GRADIENT HAS RESPONDED TO THIS WEAKENING TREND. THE WINDS WILL LOWER TO MINIMAL GALE FORCE DURING THE MORNING...AND JUST BELOW GALE FORCE WINDS BY EARLY THIS AFTERNOON. THE WINDS WILL FURTHER DIMINISH ON MON WITH NORTHERLY WINDS OF 15-20 KT BY MON AFTERNOON. LOOKING AHEAD...THE NEXT TEHUANTEPEC GAP WIND EVENT IS EXPECTED TO BEGIN WITH 20-25 KT NORTHERLY WINDS LATE TUE NIGHT AS REINFORCING HIGH PRES BUILDS SWD IN THE WAKE OF A WESTERN GULF OF MEXICO COLD FRONT. MODEL GUIDANCE HAS BEEN CONSISTENTLY FORECASTING THESE WINDS TO INCREASE TO MINIMAL GALE FORCE LATE WED NIGHT INTO THU MORNING. GULF OF PAPAGAYO GALE WARNING...OBSERVATIONS FROM NORTHERN COSTA RICA STATION LIBERA (MRLB) INDICATE THAT E WINDS THERE HAVE DIMINISHED TO JUST UNDER 30 KT WITH ASCAT DATA FROM LATE LAST SHOWING SIMILAR WINDS JUST TO THE W AND NW OF THE GULF. ANOTHER SHORT PULSE OF MINIMAL NE GALE FORCE WINDS IS EXPECTED TO DEVELOP DURING THE MAXIMUM DRAINAGE FLOW BEFORE 12Z BUT ONLY LAST TILL LATE THIS MORNING...AND MATERIALIZE AGAIN LATE TONIGHT INTO EARLY MON MORNING. THE ASCAT DATA ALSO REVEALED THAT NE WINDS OF 20-25 KT WERE OCCURRING ALONG THE COAST OF NICARAGUA TO THE GULF OF FONSECA...AND W FROM THERE TO NEAR 89W. A NE SURGE OF 20-25 KT WINDS WAS NOTED ALONG THE EL SALVADOR AND GUATEMALA BORDER...AND SW FROM THERE FOR ABOUT 60 NM. WINDS ARE FORECAST TO DIMINISH BRIEFLY TO 15-20 KT EARLY MON NIGHT THEN INCREASE TO 20-25 KT LATE MON NIGHT. SEAS JUST W OF THE GULF WILL PEAK TO 12 KT THIS MORNING...AND TO 13 FT FROM 08N TO 11N BETWEEN 90W AND 93W EARLY THIS AFTERNOON BEFORE SUBSIDING TO 10 FT LATE TONIGHT...TO 9 FT IN NE SWELLS BY MON NIGHT...AND TO 6-7 FT BY LATE MON NIGHT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS EXTENDS FROM 02N85W TO 03N100W TO 02N110W TO 04N120W. A SECOND ITCZ AXIS IS NOTED S OF THE EQUATOR AND W OF THE FORECAST AREA. THE CLIMATOLOGICAL PATTERN OF THE ITCZ DURING THE MONTHS OF MARCH AND APRIL TYPICALLY EXHIBITS DUAL AXES...ONE N OF THE EQUATOR AND THE OTHER ONE TO THE S OF THE EQUATOR AS PRESENTLY OBSERVED. SATELLITE IMAGERY SHOWS NO SIGNIFICANT CONVECTION WITH BOTH ITCZ FEATURES. ...DISCUSSION... A LARGE STATIONARY UPPER LEVEL CYCLONIC VORTEX IS TO THE NW OF THE AREA NEAR 36N151W WITH BROAD SCALE MID/UPPER RIDGING OBSERVED TO ITS SE. A VERY ACTIVE SUBTROPICAL JET STREAM BRANCH ROUNDS THE CREST OF THE RIDGING ENTERING THE AREA THROUGH 28N140W...AND CONTINUES TO 30N131W...THEN DIVES SEWD WHERE IT ROUNDS THE BASE OF AN UPPER TROUGH OVER THE NE PART OF THE AREA. THE JET THEN STRETCHES NEWD TO ACROSS NW MEXICO...AND TO THE SW U.S. SATELLITE IMAGERY SHOWS EXTENSIVE...MOSTLY OVERCAST... MID/UPPER LEVEL CLOUDS WITHIN 480 NM S OF THE JET BEING ADVECTED EWD INTO THE AREA REACHING AS FAR E AS 122W. SOME INDICATIONS OF BROKEN LOW CLOUDS SEEN ON THE IMAGERY ALONG THE SOUTHERN PERIPHERY OF THE MID/UPPER CLOUDS. SIMILAR CLOUDS ARE MOST LIKELY UNDER THE MID/UPPER CLOUDS AS WELL. TO THE E OF 122W... THE CLOUDS...ABOUT 360 NM S OF THE JET...CONTINUE EWD TO ACROSS SOUTHERN BAJA CALIFORNIA...AND TO WELL INLAND NORTHERN MEXICO AND TO ACROSS MOST OF TEXAS. SCATTERED SHOWERS AND ISOLATED TSTMS ARE POSSIBLE UNDERNEATH THESE CLOUDS WITH GREATER LIKELIHOOD OF THEM IN THE VICINITY OF THE RRQ OF THE JET LOCATED TO THE W OF 135W. MAINLY ISOLATED SHOWERS ARE POSSIBLE ELSEWHERE UNDER THESE CLOUDS. BROAD RIDGING ALOFT IS TO THE SW OF THE AFOREMENTIONED JET STREAM. OVER THE FAR EASTERN PORTION...AN UPPER TROUGH STRETCHES FROM NEAR MANZANILLO MEXICO SW TO 09N110W TO THE EQUATOR AT 116W. NO DEEP MOISTURE IS NOTED WITH THIS TROUGH AS ITS SURROUNDING ENVIRONMENT CONTINUES TO BE DOMINATED BY STRONG SUBSIDENCE AND DRY SINKING AIR ALOFT. A THE SURFACE...A RIDGE EXTENDS FROM 32N128W SEWD TO NEAR 18N111W. HIGH PRES COVERS THE AREA N OF 15N AND W OF 111W. THE GRADIENT BETWEEN THE RIDGE AND THE LOWER PRES OF THE TROPICS IS RESULTING IN NE TRADES OF 20-25 KT FROM 04N TO 16N BETWEEN 114W AND 128W...AND ALSO FROM 13N TO 16N BETWEEN 128W AND 134W WITH GENERATED SEAS IN THE RANGE OF 9-10 FT. THE GRADIENT WILL GRADUALLY RELAX OVER THE NEXT COUPLE OF THE DAYS AS THE RIDGE BREAKS DOWN IN RESPONSE TO A FRONTAL SYSTEM THAT MOVES INTO THE FAR WESTERN PART OF THE AREA. BY LATE MON NIGHT...NE TO E 20-25 KT WINDS ARE FORECAST FROM 07N TO 10N W OF 134W WITH SEAS OF 9- 11 FT. REINFORCING NE SWELL...ORIGINATING FROM PREVIOUS GULF OF TEHUANTEPEC STORM FORCE WINDS...AND STRONG TO GALE FORCE WINDS IN THE GULF OF PAPAGAYO WILL CONTINUE TO PROPAGATE WSW INTO THE TROPICAL WATERS S OF ABOUT 13N...AND SPREAD WWD ACROSS THE WATERS BETWEEN 94W-120W OVER THE NEXT 24-48 HRS. CROSS EQUATORIAL SOUTHERLY SWELLS ARE FORECAST TO REACH THE SOUTHERN PORTION BY EARLY MON AS PROJECTED BY WAVEWATCH MODEL GUIDANCE. WHAT WAS RECENTLY A COLD FRONT OVER THE NW PORTION OF THE AREA IS ANALYZED AS A DISSIPATING STATIONARY FRONT FROM 30N139W TO 25N140W. SE-S WINDS OF 20-25 KT ARE NOTED PER SCATTEROMETER DATA AHEAD OF THE FRONT DUE A TIGHT PRES GRADIENT BETWEEN THE FRONT AND THE ABOVE MENTIONED RIDGE. THESE WINDS ARE ROUGHLY WITHIN 300 NM E OF THE FRONT AND N OF 28N WITH INDUCED SEAS IN THE RANGE OF 8-10 FT. THE REMNANT MOISTURE OF THE FRONT WILL DRIFT BACK TO THE W THIS AFTERNOON AND TONIGHT...AND COMBINE INTO ANOTHER FRONT THAT APPROACHES 140W ON MON. THE PRES GRADIENT E OF THIS FRONT WILL RESPOND SIMILARLY TO THE PRESENT ONE AND PRODUCE SE-S WINDS OF 20-25 KT N OF 22N W OF 138W WITH SEAS OF 8-11 FT...AND LAST INTO MON NIGHT WHEN THE FRONT REACHES 140W N OF 24N AS A COLD FRONT. A TOUGH EXTENDS ALONG THE COAST OF COLOMBIA FROM 05N77W TO 01N81W. SCATTERED SHOWERS ARE POSSIBLE NEAR THIS TROUGH. GAP WINDS... GULF OF PANAMA...FRESH TO STRONG N WINDS ARE FUNNELING INTO THE GULF OF PANAMA FROM THE CARIBBEAN SEA. WINDS ARE IN THE 20-25 KT RANGE...AND ARE FORECAST TO BRIEFLY REACH 30 KT AROUND DAYBREAK THIS MORNING AS THE WINDS SPREAD S TO NEAR 04N BETWEEN 79W AND 82W BEFORE DECREASING BACK TO 20-25 KT THIS AFTERNOON. SEAS ARE UP TO 8 FT...AND SHOULD REACH THE RANGE OF 8-10 FT LATER THIS MORNING. SEAS WILL THEN LOWER TO 9 FT EARLY TONIGHT...AND TO LESS THAN 8 FT BY EARLY MON NIGHT AS WINDS DIMINISH TO 15-20 KT. $$ AGUIRRE