000 AXPZ20 KNHC 110356 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE DEC 11 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 FROM THE W OF COLOMBIA TO 08N79W TO 08N93W TO LOW PRES AT 10N101W 1007 MB. LOW LEVEL SUGGEST THAT THE ITCZ BEGINS AT 07N127W AND EXTENDS TO 07N113W TO 08N120W TO 08N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM S OF THE MONSOON TROUGH BETWEEN 79W-86W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE ITCZ W OF 128W. ...DISCUSSION... A LONGWAVE TROUGH EXTENDS FROM NRN PLAINS STATES SW TO CENTRAL BAJA CALIFORNIA AND SW TO 25N124W TO A SMALL CYCLONIC CIRCULATION MOVING W AT 26N133W TO A LARGER CYCLONIC CIRCULATION W OF THE AREA AT 26N146W. THE TROUGH EXTENSION ACROSS THE N CENTRAL PORTION IS IN BETWEEN TWO AREAS OF LARGE DEEP LAYER RIDGING. THE FIRST IS TO THE N OF 27N W OF 125W...AND THE SECOND ONE COVERS THE AREA S OF THE TROUGH WITH A MEAN RIDGE AXIS ALONG 23N127W 12N119W TO THE EQUATOR AT 119W. WATER VAPOR IMAGERY SHOWS A STRONG SUBTROPICAL JET STREAM BRANCH ENTERING THE DISCUSSION AREA THROUGH 20N140W...AND CONTINUING TO 23N124W THEN ROUNDING THE BASE OF THE TROUGH TO 21N109W WHERE IT TURNS NE TO ACROSS CENTRAL MEXICO AT 22N103W. SATELLITE IMAGERY SHOWS BROKEN CIRRUS CLOUDS BEING ADVECTED EWD WITHING 400 NM EITHER SIDE OF THE JET STREAM. THE WATER VAPOR IMAGERY ALSO DEPICTS ABUNDANT MODERATE TO STRONG SUBSIDENCE ALOFT TO THE S OF THE ITCZ/MONSOON TROUGH ZONE RESULTING IN RATHER DRY AND STABLE ATMOSPHERIC CONDITIONS THERE WITH ONLY SCATTERED TO BROKEN LOW CLOUDS WITH ISOLATED SHOWERS OVER THAT PORTION OF THE AREA. OVER THE FAR SE PORTION....AN UPPER TROUGH REACHES FROM SE MEXICO TO JUST W OF THE CENTRAL AMERICA COASTLINE TO NEAR 02N86W. SATELLITE IMAGERY INDICATES VERY DRY AIR PRESENT S OF 09N AND ACROSS THE ENTIRE AREA E OF 100W WITH LIMITED CONVECTION PRESENT. AT THE SURFACE...A STRONG RIDGE DOMINATES THE NW AND N CENTRAL PORTIONS WITH AN ASSOCIATED SURFACE HIGH OF 1035 MB WELL N OF THE REGION AT 39N142W. THE TIGHT PRES GRADIENT ON ITS SRN PERIPHERY DUE TO THE IS PRODUCING NE TO E TRADES OF 20-25 KT FROM 15N TO 21N W OF 133W WITH SEAS TO 9 FT. N AREA OF MIXED NE AND NW SWELL LEADING TO SEAS OF 8 FT IS EXISTS N OF 10N AND W OF A LINE FROM 30N124W TO 10N134W. THE DEEP LAYER RIDGE WILL WEAKEN THROUGH 48 HOURS AND SHIFT WEST TO 150W BEGINNING LATER TODAY AS A MID/UPPER LEVEL SHORT WAVE TROUGH TROUGH DIGS N OF THE RIDGE OVER THE FAR NE PACIFIC. THIS WILL ALLOW THE FRESH TO STRONG TRADE WINDS IN THE DISCUSSION WATERS TO DIMINISH. FRESH TO STRONG WINDS HAVE COMMENCED THROUGH THE GULF OF CALIFORNIA N OF 25N INDUCED BY STRONG SURFACE HIGH PRES OVER THE U.S. GREAT BASIN AND THE TYPICAL INVERTED TROUGH ALONG THE W COAST OF MEXICO. WITH THE PRES GRADIENT FORECAST TO SLACKEN BY TUE NIGHT...THE WINDS WILL RESPOND BY DIMINISHING TO 20 KT OR LESS. CROSS-EQUATORIAL SE SWELL IS S OF 03N BETWEEN 120W AND 132W. THIS SWELL IS ACCOMPANIED BY FRESH TO STRONG E-SE WINDS. THE WINDS WILL DIMINISH WITHIN 24 HOURS WHILE THE SWELL PROPAGATES TO THE W W THROUGH 48 HOURS. GAP WINDS... A TIGHT PRES GRADIENT SURGE SWD OVER MEXICO BEHIND A GULF OF MEXICO WILL GRADUALLY HELP SET OFF GALE FORCE WINDS THROUGH THE CHIVELA PASS AND THROUGH THE GULF OF TEHUANTEPEC BEGINNING WED NIGHT. SEAS ARE FORECAST TO BUILD UP 9 FT EARLY WED NIGHT ...THEN BUILD FURTHER INTO THU. FOR THE GULF OF TEHUANTEPEC...A COLD FRONT WILL MOVE THROUGH THE WESTERN GULF OF MEXICO TODAY AND TOMORROW. THE ASSOCIATED NORTHERLY 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 TO 10 FT BY LATE WED WITH THIS EVENT. GULF OF PAPAGAYO...NE WINDS WILL CONTINUE TO PULSE AT 10-15 KT WITH AN OCCASIONAL SURGE TO 15-20 KT IN AND DOWNSTREAM OF THE GULF OF PAPAGAYO THROUGH WED. MODEL WIND GUIDANCE SUGGESTS THAT THESE WINDS WILL THEN INCREASE TO 20-25 KT BEGINNING LATE WED NIGHT. $$ AGUIRRE