000 AXPZ20 KNHC 290325 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN NOV 29 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0300 UTC. ...ITCZ... AXIS ANALYZED ALONG 06N78W TO 08N92W TO 06N101W TO 06N105W TO 12N122W TO 10N125W TO 09N140W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 150 NM S OF THE AXIS BETWEEN 80W AND 86W AND WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 135W AND 140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION WAS WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 89W AND 99W. ...DISCUSSION... SURFACE HIGH PRES OF 1031 MB IS CENTERED NEAR 38N133W WITH A SURFACE RIDGE AXIS EXTENDING FROM THE HIGH TO NEAR 26N125W TO 21N118W. A TIGHT PRES GRADIENT REMAINS IN PLACE BETWEEN THE HIGH TO THE N AND LOWER PRES ASSOCIATED WITH THE ITCZ. AN 1845 UTC ASCAT PASS INDICATED NORTHEASTERLY TRADES IN THE 20 TO 30 KT RANGE...WITH GALE FORCE WINDS JUST N OF THE DISCUSSION AREA. MEANWHILE LONG PERIOD SWELL UP TO 17 FT (AS CAPTURED BY A 2115 UTC JASON ALTIMETER PASS) CONTINUES TO PROPAGATE THROUGH THE NORTHERN WATERS REACHING ALL THE WAY TO THE EQUATOR. SEAS ARE FORECAST TO PEAK AROUND 18 FT ALONG THE NE BORDER OF THE AREA OVERNIGHT TONIGHT...THEN WILL GRADUALLY SUBSIDE AND DECAY BY THE EARLY PART OF NEXT WEEK. UPPER LEVEL LOW PRES IS CENTERED NEAR 36N115W WITH AN UPPER LEVEL TROUGH EXTENDING FROM THE LOW ACROSS THE ARIZONA/NEW MEXICO BORDER TO THE S-SW ACROSS OVER THE NORTHERN BAJA PENINSULA THEN WESTWARD ALONG 28/29N. A COLD FRONT ASSOCIATED WITH THIS FEATURE IS REFLECTED AT THE SURFACE JUST AHEAD OF THE TROUGH. AN EARLIER 1700 UTC ASCAT PASS CAPTURE 20 TO 25 KT W-SW AHEAD OF THE FRONT OVER THE N GULF OF CALIFORNIA WHICH WILL DIMINISH AND VEER TO THE NW-N FOLLOWING FRONTAL PASSAGE. ANOTHER UPPER LEVEL TROUGH EXTENDS FROM THE U.S. LOWER MISSISSIPPI VALLEY DOWN OVER THE W GULF OF MEXICO...ACROSS CENTRAL MEXICO... TO NEAR 08N108.5W WITH DRY AIR AND SUBSIDENCE IN PLACE N OF THE TROUGH AXIS. BETWEEN THESE TWO TROUGHS AND OVER THE REMAINDER OF THE DISCUSSION AREA W OF 109W A BROAD RIDGE OF HIGH PRES IS IN PLACE. TO THE E A VERY BROAD AND FLAT TROPICAL UPPER RIDGE COVERS THE CARIBBEAN...NORTHERN S AMERICA...AND THE EPAC E OF THE LOWER TROUGH AXIS...AND WAS CONTINUING TO VENTILATE CONVECTION ALONG THE ITCZ FROM COLOMBIA TO 105W. OTHERWISE A WEAK 1006 MB AREA OF LOW PRES WAS ALONG THE ITCZ NEAR 06.5N102.5W...INDUCING SCATTERED MODERATE CONVECTION MAINLY IN THE N SEMICIRCLE...ALONG WITH 20 TO 25 KT WINDS. A 2022 UTC JASON ALTIMETER PASS INDICATED SEAS TO 9 FT IN THE VICINITY OF THE LOW. THIS LOW IS FORECAST TO CONTINUE TO MOVE TO THE W AROUND 10 KT DURING THE NEXT 48 HOURS...WHILE WEAKENING TO AROUND 1010 MB BY MON AFTERNOON AND THEN DISSIPATING THEREAFTER. ...GAP WINDS... HIGH PRES IN THE GULF OF MEXICO HAS WEAKENED TO 1020 MB AND HAS MOVED INLAND OVER THE SOUTHEAST U.S. STATES. AS A RESULT NORTHERLY AIR FLOW ACROSS THE ISTHMUS OF TEHUANTEPEC AND DOWNSTREAM WATERS OF THE GULF OF TEHUANTEPEC HAS DIMINISHED TO BELOW GALE FORCE AND WILL CONTINUE TO EASE TO LESS THAN 20 KT WITHIN 24 HRS. EASTERLY TRADES IN THE W CARIBBEAN WILL CONTINUE TO FUNNEL WINDS THROUGH THE GULF OF PAPAGAYO AND DOWNSTREAM WATERS TO NEAR 91W THROUGH MON WHICH WILL MAINTAIN FRESH TO STRONG BREEZE...AND RESULTANT SHORT PERIOD SEAS WILL REMAIN 7 TO 8 FT. A TIGHT PRES GRADIENT BETWEEN HIGH PRES OVER THE CENTRAL U.S. A LOW PRES TROUGH ALONG THE E COAST OF THE GULF OF CALIFORNIA AND A RIDGE OF HIGH PRES W OF THE BAJA PENINSULA WILL BECOME ESTABLISHED DURING THE NEXT 36 HOURS...WITH N TO NW WINDS OF 20 TO 25 KT N OF 26.5N EXPECTED IN THE GULF OF CALIFORNIA BY MON EVENING. $$ LEWITSKY