000 AXPZ20 KNHC 100345 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON DEC 10 2012 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0330 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS W FROM THE COAST OF COLOMBIA AT 08N77W ACROSS THE SOUTHERN COASTS OF PANAMA AND COSTA RICA TO 08N89W...WHERE LOW LEVEL WINDS SUGGEST THAT AN ITCZ AXIS BEGINS AND REACHES TO 09N96W WHERE IT ENDS. A SURFACE TROUGH EXTENDS FROM 12N96W TO 06N100W. THE ITCZ AXIS RESUMES AT 07N102W...AND CONTINUES NW TO 12N113W WHERE IT AGAIN ENDS. ANOTHER SURFACE TROUGH IS NOTED FROM 14N113W TO 11N118W. THE ITCZ RESUMES AT 12N120W...AND CONTINUES TO 08N130W TO 08N140W. ISOLATED MODERATE TO STRONG CONVECTION IS FLARING UP INTERMITTENTLY ON THE FIRST TROUGH WITHIN 45 NM OF 10N97W. MODEL GUIDANCE CONTINUES TO SUGGEST THAT A SURFACE LOW WILL DEVELOP ALONG THE FIRST TROUGH THAT EXTENDS ALONG 12N96W TO 06N101W AS WAS CONFIRMED BY THE 1856 UTC OSCAT PASS FROM THIS AFTERNOON. THE LOW IS FORECAST BY THE GLOBAL MODELS TO TRACK WNW BEFORE IT DISSIPATES IN THE VICINITY OF 10N106W ON WED UNDER A VERY UNFAVORABLE UPPER LEVEL WIND FLOW. MODEL WIND GUIDANCE INDICATES THAT THIS FEATURE IS LIKELY TO GENERATE ONLY NE-E-SE WINDS AT 15-20 KT...MAINLY IN ITS NRN PERIPHERY WITH SEAS OF ABOUT 5-7 FT. ...DISCUSSION... ALOFT...A LONGWAVE UPPER RIDGE DOMINATES THE EASTERN N PACIFIC. AN UPPER SHORTWAVE TROUGH DISSECTS N AMERICA CONTINUING INTO THE DISCUSSION AREA ALONG 32N114W AND SW TO A SMALL CYCLONE MOVING SW AT 26N127W AND TO ANOTHER ONE MOVING W AND BECOMING DIFFUSE AT 26N141W. THE UPPER TROUGH IS MERGING WITH THE REMNANTS OF ANOTHER UPPER TROUGH OVER THE ENTIRE AREA N OF 10N BETWEEN 116-130W. BROAD RIDGING IS EVIDENT OVER THE S CENTRAL AND SW PORTIONS TO THE S OF THE TROUGH WITH A MEAN RIDGE AXIS EXTENDING FROM 07N129W NW TO 15N136W...AND THEN NE TO A CREST AT 23N134W. UPPER DEBRIS MOISTURE...ORIGINATING FROM THE ITCZ RELATED CONVECTION DESCRIBED BETWEEN 131W-140W...AND CONVECTION W OF 140W IS BEING ADVECTED NE BUT MOST OF THE MOISTURE REMAINS WITHIN THE ANTICYCLONIC ENVELOPE TO THE S OF 22N W OF 122W. A WEAK TROUGH IS E OF THE ANTICYCLONIC FLOW FROM NEAR 21N118W SE TO NEAR 12N111W. MODEST RIDGING IS TO THE E TROUGH...BUT SHIFTING ENE. A DENSE MOISTURE PLUME CONSISTING OF SCATTERED TO BROKEN HIGH CLOUDS IS OBSERVED OVER THE NE PORTION OF THE DISCUSSION AREA WITHIN 60 NM OF A LINE FROM 25N127W ENE TO ACROSS CENTRAL BAJA CALIFORNIA...AND CONTINUING TO OVER NRN MEXICO AND FARTHER ENE TO ACROSS THE NORTHERN GULF OF MEXICO AND SE CONUS. IN CONTRAST...THE UPPER LEVELS APPEAR VERY DRY OVER THE DISCUSSION AREA S OF 17N E OF 102W INCLUDING THE IMMEDIATE ENVIRONMENT OF THE TROUGH ALONG 12N96W 06N100W...CONTINUING TO SUPPRESS CONVECTION EXCEPT FOR THE ACTIVITY DESCRIBED ABOVE UNDER ITCZ/MONSOON TROUGH. AT THE LOW LEVELS...A COLD FRONT OVER THE SW U.S. WILL PUSH SE THROUGH THE GULF OF CALIFORNIA TONIGHT INTO MON. THE PRES GRADIENT IN ITS WAKE WILL RESULT IN WINDS BECOMING N-NE 10-15 KT ALONG THE W COAST OF THE BAJA PENINSULA TONIGHT INTO MON. LIGHT AND VARIABLE WINDS CURRENTLY OVER THE NRN GULF OF CALIFORNIA WILL BECOME NW 20-25 KT BEHIND THE FRONT TONIGHT...THEN DIMINISH TO 15-20 KT BY MON NIGHT AND TO 15 KT TUE. EXPECT SEAS MAY BUILD TO 5-8 FT BRIEFLY IN THE NRN GULF WATERS MON IN THE AREAS OF LONG NW FETCH...AND 3-6 FT IN THE SOUTHERN GULF WATERS BY LATE MON NIGHT. THESE NW WINDS SHOULD DIMINISH TO 10-15 KT OVER THE WATERS S OF 29N ON TUE NIGHT...AND BECOME LIGHT AND VARIABLE OVER THE WATERS N OF 29N. OVER THE PACIFIC A SURFACE RIDGE EXTENDS FROM 32N135W TO 16N103W. NELY WINDS OF 15-20 KT SURFACE WINDS ARE OBSERVED W OF LINE FROM 32N121W TO 08N140W...WITH COMBINED SEAS 6-9 FT IN A NE SWELL...EXCEPT FOR SEAS TO 10 FT N OF 28N AND BETWEEN 126W-136W. THE GRADIENT WILL RELAX ON MON AND TUE WITH A COLD FRONT EXPECTED TO MOVE INTO THE N CENTRAL WATERS ON TUE NIGHT...ACCOMPANIED BY A 15-20 KT SW-W-NW WIND SHIFT. SEAS WILL BUILD TO AROUND 9 FT BEHIND THE FRONT. GAP WINDS... GULF OF TEHUANTEPEC...A COLD FRONT WILL ENTER THE NW GULF OF MEXICO MON MORNING. THE ASSOCIATED NLY WINDS WILL SURGE AT 15-20 KT THROUGH THE CHIVELA PASS TUE NIGHT...GRADUALLY INCREASING TO MINIMAL GALE CONDITIONS MID WEEK AROUND LATE WED INTO THU. SEAS ARE EXPECTED TO BUILD WITH THIS EVENT. GULF OF PAPAGAYO...NE WINDS WILL CONTINUE TO PULSE AT 10-15 KT WITH AN OCCASIONAL SURGE TO 15-20 KT AS CONFIRMED BY ASCAT/OSCAT PASSES FROM TODAY...IN AND DOWNSTREAM OF THE GULF OF PAPAGAYO THROUGH THE MIDDLE OF THE UPCOMING WEEK...WITH GUIDANCE SUGGESTING AN INCREASE TO 20-25 KT BEGINNING LATE WED NIGHT. $$ AGUIRRE