000 AXPZ20 KNHC 140952 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU NOV 14 2013 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 FEATURE... GULF OF TEHUANTEPEC...A RECENT SCATTEROMETER PASS DETECTED N-NW WINDS AT 30 KT OVER THE EASTERN GULF OF TEHUANTEPEC SUGGESTING MUCH STRONGER WINDS TO THE W IN THE CENTRAL GULF WATERS. AN ALTIMETER PASS MEASURED 12 FT SEAS DOWNSTREAM OF THE GULF AT 14N96W. THE RECENT SCATTEROMETER PASS ALSO DETECTED N-NW WINDS AT 30-35 KT N OF THE AREA IN THE S-CENTRAL BAY OF CAMPECHE WITH THE AREA OF NORTHERLY GALE WINDS EXTENDING AT LEAST 150 NM FURTHER TO THE N. THIS STRONG FLOW WILL SQUEEZE THROUGH THE CHEVILA PASS TONIGHT...AND CONTINUE TO SUPPORT STORM FORCE WINDS WITH SEAS TO 21 FT...THROUGH SUNRISE TODAY. THE WINDS WILL THEN QUICKLY DIMINISH BELOW GALE STRENGTH TONIGHT AND BELOW 20 KT LATE FRI. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W-SW ACROSS THE SW CARIBBEAN FROM THE NW COAST OF COLOMBIA AT 10N75W TO ACROSS NORTHERN PANAMA AND SOUTHERN COSTA RICA TO THE PACIFIC COAST OF COSTA RICA AT 09N84W...THEN DIPS SW TO 08N92W...THEN TURNS NW THROUGH A 1009 MB EMBEDDED SURFACE LOW PRESSURE AT 09N104W WITH THE MONSOON TROUGH CONTINUING W TO 09N110W TO 08N122W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ AXIS. THE ITCZ THEN WIGGLES W TO BEYOND 08N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED ALONG THE COLOMBIAN COAST WITHIN 30 NM OF 04N78W...AND IN THE COASTAL PACIFIC WATERS OF PANAMA AND 09N91W. SIMILAR CONVECTION IS NOTED TO THE N OF THE SURFACE LOW AT 09N104W ROUGHLY WITHIN 150 NM OF LINE FROM 10N101W TO 15N105W...AND ALSO ALONG THE MONSOON TROUGH AND ITCZ WITHIN 60 NM EITHER SIDE OF A LINE FROM 05N117W TO 09N127W. SCATTERED MODERATE ISOLATED STRONG IS NOTED WITHIN 75 NM EITHER SIDE OF A LINE FROM 10N115W TO 21N106W AND WITHIN 30 NM OF LINE FROM 14N106W TO 17N104W...AND WITHIN 75 NM OF LINE FROM 12N99W TO 07N122W TO 08N131W. BROKEN TO OVERCAST LOW/MID LEVEL CLOUDS...WITH ONLY EMBEDDED WEAK SHOWERS...IS NOTED ACROSS THE DEEP TROPICS ELSEWHERE FROM 10N TO ALONG 01N FROM THE S AMERICAN COAST WESTWARD TO ALONG 110W...AND FROM 03-09N BETWEEN 110-140W. ...DISCUSSION... AN UPPER LEVEL ANTICYCLONE IS CENTERED AT 18N135W WITH A RIDGE EXTENDING NE TO BEYOND 32N123W WITH ITS ANTICYCLONIC ENVELOPE COVERING THE DISCUSSION AREA W OF 117W. DENSE UPPER MOISTURE... ORIGINATING W OF THE AREA...IS STREAMING NE ALONG THE W PERIPHERY OF THE RIDGE...WITHIN 300 NM EITHER SIDE OF A LINE FROM 23N145W TO 35N132W. SOME OF THE MOISTURE RETURNS BACK SE OVER THE DISCUSSION AREA TO THE N OF 25N BETWEEN 125-135W. UPPER LEVEL SUBSIDENCE S OF THIS LARGE ANTICYCLONE IS SUPPRESSING CONVECTION TO ONLY THE SMALL CLUSTERS PREVIOUSLY DESCRIBED ALONG THE ITCZ. A UPPER TROUGH OVER THE SW CONUS CONTINUES SW ACROSS NORTHERN OLD MEXICO THROUGH AN ILL-DEFINED UPPER CYCLONE NEAR THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA...WITH THE TROUGH CONTINUING SW TO A BASE OVER THE DEEP TROPICAL PACIFIC AT 08N119W. THIS UPPER TROUGH EFFECTIVELY SEPARATES THE UPPER ANTICYCLONIC FLOW OVER THE DISCUSSION AREA. DRY UPPER AIR IS INDICATED N OF 22N W OF THE TROUGH TO ALONG 126W...AND FROM 11- 22N W OF THE TROUGH AXIS TO ALONG 135W...MOSTLY DUE TO UPPER ANTICYCLONIC FLOW PREVIOUSLY MENTIONED. AN UPPER ANTICYCLONE HAS SHIFTED E TO OVER PUERTO RICO WITH AN UPPER RIDGE EXTENDING W-SW ACROSS CENTRAL AMERICA TO A CREST OVER THE DEEP TROPICAL PACIFIC AT 12N109W. UPPER DIFFLUENCE ALONG THE SOUTHERN PERIPHERY OF THIS RIDGE IS ENHANCING CONVECTION ALONG THE LOWER LEVEL MONSOON TROUGH AS PREVIOUSLY MENTIONED. THE DEBRIS MOISTURE FROM THIS CONVECTION IS ADVECTED NE ACROSS THE TROPICAL PACIFIC N OF 10N BETWEEN 95-110W... CONTINUING NE ACROSS SE OLD MEXICO...THEN TURNING E ACROSS THE GULF OF MEXICO AND SOUTHERN FLORIDA. WESTERN BAJA CALIFORNIA PENINSULA...NW 10-15 KT WINDS WITH SEAS 3-5 FT...PRIMARILY IN MIXING LONG PERIOD NW AND LONG PERIOD CROSS EQUATORIAL S SWELL...ARE CURRENTLY OBSERVED ACROSS THESE PACIFIC COASTAL WATERS. THE GRADIENT WILL FURTHER RELAX TODAY SUPPORTING ONLY 5-10 KT WINDS BY LATE THIS MORNING. THESE LIGHT WINDS WILL BACK TO THE SW-W AT 10 KT ON FRI NIGHT INTO EARLY SAT...AHEAD OF A COLD FRONT MOVING E ACROSS THE PACIFIC WATERS N OF 23N BETWEEN 113-120W ON FRI NIGHT AND SAT...FOLLOWED BY NW WINDS AT 15-20 KT...WITH SEAS BUILDING 6-9 FT LATE FRI NIGHT...AND CONTINUING THROUGH SAT MORNING. EXPECT NW WINDS AT 10 KT/SEAS 3-5 FT TO SET UP ALONG THE ENTIRE PACIFIC COAST OF THE BAJA PENINSULA ON SUN...WITH LITTLE CHANGE THROUGH TUE. GULF OF CALIFORNIA...LIGHT AND VARIABLE 5-10 KT WINDS WILL BECOME SOUTHERLY AT 10-15 KT TONIGHT...EXCEPT INCREASING TO 20- 25 KT OVER THE FAR NORTHERN GULF WATERS ON FRI IN ADVANCE OF A COLD FRONT ARRIVING LATE FRI NIGHT. LIGHT SOUTHERLY WINDS EXPECTED ACROSS THE ENTIRE GULF WATERS ON SUN...THEN GRADUALLY BECOMING LIGHT NORTHERLY WINDS ON SUN INTO MON. GULF OF PAPAGAYO...NE 5-10 KT WINDS ARE EXPECTED...EXCEPT INCREASING BRIEFLY TO 15-20 KT LATE EACH NIGHT THROUGH SUNRISE EACH MORNING...WITH THIS PATTERN CONTINUING THROUGH THE UPCOMING WEEKEND. GUIDANCE SUGGESTS THE NOCTURNAL EVENT WILL ONLY BE 10-15 KT ON SUN NIGHT INTO MON...AND ON MON NIGHT INTO TUE. ELSEWHERE AT THE SURFACE...A SURFACE RIDGE IS STRENGTHENING ACROSS THE DISCUSSION AREA N OF 12N W OF 115W WITH NE TRADES AT 15-20 KT/SEAS 6-9 FT CURRENTLY ACROSS THE TROPICS FROM 10-22N BETWEEN 118-140W. NORTHERLY WINDS AT 20-25 KT ARE EXPECTED ACROSS THE PACIFIC WATERS N OF 28N BETWEEN 120-130W LATER TODAY...WITH ASSOCIATED SEAS BUILDING 8-12 FT. THE GRADIENT WILL BEGIN TO RELAX ON FRI NIGHT WITH LIGHT N WINDS ACROSS THE ENTIRE AREA N OF 20N W OF 108W BY LATE SAT NIGHT. $$ NELSON