000 AXPZ20 KNHC 130405 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC WED DEC 13 2006 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 0345 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG...7N78W 8N88W 6N100W 6N110W 7N119W 6N126W 6N140W. SCATTERED MODERATE/ISOLATED CONVECTION IS WITHIN 120 NM NORTH OF THE AXIS BETWEEN 113W-117W...AND BETWEEN 119W-121W. SIMILAR ACTIVITY IS WITHIN 30 NM EITHER SIDE OF AXIS BETWEEN 124W-130W. SCATTERED MODERATE CONVECTION IS WITHIN 30 NM EITHER SIDE OF THE AXIS BETWEEN 87W-90W. ...DISCUSSION... A MID/UPPER LEVEL TROUGH STRETCHES FROM WELL NORTHEAST OF THE REGION SOUTHWESTWARD ACROSS NORTHWEST MEXICO AND NORTHERN BAJA CALIFORNIA RESEMBLING MORE OF A SHEAR AXIS THROUGH 27N120W TO 24N130W WELL BEYOND THE REGION AT 19N140W. TO THE NORTH OF THE TROUGH THE FLOW HAS INCREASED TO MODERATE TO STRONG NORTH- WESTERLY...WHILE TO THE SOUTH OF THE TROUGH THE FLOW IS RATHER BROAD AND WESTERLY. A SUBTROPICAL JET STREAM BRANCH RUNS EAST-NORTHEAST ALONG THE SOUTHERN PERIPHERY OF THE TROUGH EXTENDING NORTHEASTWARD ACROSS MEXICO AT 22N106W AND CONTINUING NORTHEAST TO ACROSS THE NORTH/CENTRAL GULF OF MEXICO. SATELLITE DERIVED WINDS OF 60-90 KT ARE NOTED WITHIN 240 NM SE OF THE TROUGH EAST OF 115W. A WEAK MID/UPPER LEVEL TROUGH EXTENDS FROM 13N116W TO SOUTHWEST TO 9N120W. MID/UPPER LEVEL ANTICYCLONIC CIRCULATIONS ARE LOCATED NEAR 6N130W AND NEAR 9N105W. MID/UPPER LEVEL RIDGING EXTENDS ALONG 7N ON EITHER WEST OF THE WEAK TROUGH. STRONG STRONG UPPER LEVEL SUBSIDENCE AND ASSOCIATED DRY IS NOTED ON SATELLITE WATER VAPOR IMAGERY WITHIN 350 NM EITHER SIDE OF LINE 20N140W TO 23N125W TO 24N120W AND NORTHEASTWARD TO ACROSS BAJA CALIFORNIA AND NORTHWEST MEXICO. A WEAK MID TO UPPER TROUGH FROM 10N99W TO 5N98W IS MOVING WESTWARD ABOUT 17 KT. ITS SURFACE REFLECTION IS ANALYZED AS A WEAK TROUGH MOVING WESTWARD ABOUT 15 KT ALONG 95.5W FROM 3N-7.5N. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM W OF THE TROUGH FROM 6N-7N PRIMARILY ASSOCIATED WITH THE ITCZ. WEAK MID/UPPER ANTICYCLONIC FLOW IS OVER THE SOUTHWESTERN CARIBBEAN SEA EXTENDING WESTWARD TO 94W GENERALLY FROM 7N-15N. ITCZ CONVECTION EAST OF 85W IS BEING ENHANCED UNDERNEATH THIS AREA OF ANTICYCLONIC FLOW IN COMBINATION WITH WEAK MID TO UPPER LEVEL DIFFLUENT EAST OF THE MID TO UPPER LEVEL ALONG 10N99W 5N98W. SATELLITE WATER VAPOR IMAGERY INDICATES MODERATE TO STRONG SUBSIDENCE COVERING THE AREA SOUTHEAST OF A LINE FROM 20N105W TO 10N115W EAST TO ACROSS CENTRAL AMERICA AND INTO THE CARIBBEAN SEA WITH VERY LIMITED MOISTURE OUTSIDE ITCZ RELATED CLOUDS AND CONVECTION. AT THE SURFACE...STRONG HIGH PRESSURE WITH A CENTER OF 1031 MB IS ANALYZED NEAR 30N132W...WITH HIGH PRESSURE COVERING THE AREA NORTH OF 15N WEST OF 114W. THE RESULTANT STRONG PRESSURE GRADIENT CONTINUES TO MAINTAIN STRONG EASTERLY TRADE WINDS GENERALLY IN THE RANGE OF 20-25 KT FROM ABOUT 5N-26N WEST OF 122W. LARGE NLY SWELLS UP TO 15 FT WILL CONTINUE TO SPREAD SOUTH OVER MUCH OF THE WESTERN AND CENTRAL SECTIONS OF THE DISCUSSION THROUGH THURSDAY SUBSIDING TO THE RANGE OF 9-13 FT BY FRI OVER THE WESTERN SECTION. SCATTERED TO BROKEN STRATOCUMULUS CLOUDS WITH POSSIBLE EMBEDDED ISOLATED SHOWERS MOVING QUICKLY WEST- SOUTHWEST IN THE STRONG EASTERLY FLOW ARE SEEN NORTH OF 9N WEST OF 124W. NEXT COLD FRONT IS EXPECTED TO ENTER THE NORTHWEST CORNER THURSDAY AFTERNOON WITH WINDS SHIFTING TO NLY AND INCREASING TO 20-30 KT BEHIND THE FRONT WITH YET ANOTHER SURGE OF INCREASING SWELLS MOVING INTO THE NORTHWEST PART OF THE DISCUSSION AREA. GAP WINDS... N-NE WINDS OF 20-25 KT ACROSS THE GULF OF TEHUANTEPEC...ARE EXPECTED TO REMAIN AT THIS RANGE THROUGH THE NEXT 48 HOURS. WINDS ACROSS THE GULF OF PAPAGAYO HAVE DIMINISHED TO LESS THAN 20 KT BASED ON A QUIKSCAT PASS FROM 2348 UTC LAST NIGHT. STRONG PRESSURE GRADIENT THAT MATERIALIZED OVER NORTHERN BAJA CALIFORNIA AND NORTHWEST MEXICO IS PRODUCING NW WINDS IN THE 20-25 KT RANGE OVER THE SEA OF CALIFORNIA. THESE WINDS ARE FORECAST TO DIMINISH TO LESS THAN 20 KT EARLY THURSDAY. $$ AGUIRRE