000 AXPZ20 KNHC 170945 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON DEC 17 2007 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0930 UTC. ...ITCZ... INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 7N78W 5N87W 6N100W 8N110W 9N120W 9N130W 9N140W. NO SIGNIFICANT CONVECTION IS NOTED. ...DISCUSSION... MID/UPPER LEVEL TROUGH EXTENDS CENTRAL CALIFORNIA SW INTO THE REGION THROUGH 32N122W AND CONTINUES THROUGH 26N130W TO 22N140W. MODERATE SUBSIDENCE AND ASSOCIATED DRY IS WITHIN 200 NM EITHER SIDE OF THE TROUGH W OF 125W. BROAD SCALE UPPER LEVEL ANTICYCLONIC FLOW IS PUSHING SWD INTO REGION IN THE WAKE OF THE TROUGH. A RATHER STRONG AND PROMINENT SUBTROPICAL JTST BRANCH ENTERS THE REGION THROUGH 18N140W...AND CONTINUES ENE THROUGH 21N130W 26N120W AND NE ACROSS THE BAJA PENINSULA AND TO ACROSS NRN MEXICO AND CENTRAL TEXAS. SATELLITE-DERIVED WINDS FROM GOES-11 SHOWED MAXIMUM WINDS IN THE RANGE OF 90-120 KT ASSOCIATED WITH THE JTST. ABUNDANT UPPER LEVEL DEEP MOISTURE WITHIN 600-700 NM S OF THE JTST IS BEING ADVECTED NEWD ACROSS THE E PACIFIC TO OVER MUCH OF THE BAJA PENINSULA AND NORTHERN MEXICO...NOW INTO THE FAR WRN SECTION OF THE GULF OF MEXICO. THE UPPER LEVEL FLOW IS ANTICYCLONIC OVER THE DEEP TROPICS S OF THE JTST W OF 125W...AND ALSO E OF ABOUT 118W. BOTH AREAS OF ANTICYCLONIC FLOW ARE SEPARATED BY A NARROW AND WEAK MID/UPPER SHEAR AXIS THAT EXTENDS S TO A WEAK MID/UPPER LEVEL CYCLONIC CIRCULATION NEAR 1N118W. MODERATE SUBSIDENCE DOMINATES THE AREA S OF THE JTST MOISTURE. A MID/UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 13N101W...WHILE ANOTHER ONE IS E OF THE REGION OVER THE GULF OF HONDURAS. DEEP CONVECTION IS NON-EXISTENT OVER THE ENTIRE AREA INCLUDING THE ITCZ DUE TO SUPPRESSION ASSOCIATED WITH THE SUBSIDENCE FOUND S OF THE JTST. DRY SINKING AIR IS BEING CHANNELED AROUND THE ERN PERIPHERY OF THE CARIBBEAN ANTICYCLONE SWD TOWARDS COSTA RICA AND SRN NICARAGUA. AT THE SURFACE...A 1023 MB HIGH CENTER IS ANALYZED NEAR 27N128W ...WITH A RIDGE EXTENDING SE THROUGH 25N120W TO 21N112W. HIGH PRES COVERS THE REGION N OF 13N W OF 110W. RESULTANT GRADIENT SUPPORTS NE-E TRADES IN THE RANGE OF 20-25 KT FROM 10N-19N W OF 130W WITH LITTLE CHANGE EXPECTED OVER THE NEXT 48 HOURS AS HIGH OVER THE NRN PORTION OF THE REGION HOLDS IN PLACE. A COLD FRONT EXTENDING FROM 32N130W TO 30N140W WHERE WILL CONTINUE TO MOVE EWD AND WEAKEN THROUGH THE NEXT 24-36 HRS AS IT MOVES TOWARDS CALIFORNIA HAVING LITTLE EFFECT ON THE HIGH CENTER...HOWEVER LARGE NW SWELLS IN THE RANGE OF 9-13 FT PER NWW3 MODEL GUIDANCE WILL OVERSPREAD THE NRN SECTION THROUGH THE NEXT 24-36 HRS...AND THEN MIX WITH SWELLS IN THE TRADE AREA GOING IN THE END OF THE WEEK. ISOLATED WEAK CONVECTION IN THE FORM OF SMALL CELLS MOVING W 10-15 KT DUE TO A WEAK MID/UPPER INVERTED TROUGH ALONG 85W FROM 4N-11N ARE SEEN ALONG AND TO WITHIN 150 NM W OF COSTA RICA. SIMILAR ACTIVITY IS OVER THE GULF OF PANAMA. THE TROUGH WILL LOSE ITS IDENTITY BY TONIGHT. BROKEN TO OVERCAST STRATOCUMULUS CLOUDS MOVING WSW WITH POSSIBLE ISOLATED SHOWERS ARE PRESENT FROM 12N-27N W OF 121W. GAP WINDS... GALE CONDITIONS ARE PRESENTLY IN PLACE IN THE GULF OF TEHUANTEPEC ...AND GULF OF PAPAGAYO NE 20-25 KT WINDS HAVE ALSO BEGUN AS STRONG HIGH PRES CONTINUES TO BUILD SWD IN THE GREAT BASIN AND E OF THE SIERRA MADRE IN MEXICO. A 1030 MB HIGH CENTER IS ANALYZED OVER SE TEXAS AT 0600 UTC. AN ASCAT PASS FROM LATE LAST NIGHT SHOWED N WINDS OF UP TO 35 KT IN THE GULF OF TEHUANTEPEC. THESE WINDS ARE FORECAST TO MAX OUT AT 45 KT TODAY...THEN DROP TO 30-35 KT TONIGHT AND TO LESS THAN GALE STRENGTH TUE AFTERNOON AS ADVERTISED BY WINDS GUIDANCE FROM BOTH THE GFS AND NAM MODELS. EXPECT SEAS TO BUILD UP TO 15 FT...BEFORE SUBSIDING TUE. GULF OF PAPAGAYO WINDS SHOULD LAST THROUGH WED EVENING...THEN DIMINISH AS HIGH PRES OVER THE E GULF OF MEXICO AND NW CARIBBEAN SEA WEAKENS. $$ AGUIRRE