000 AXPZ20 KNHC 160345 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC THU SEP 16 2010 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 0315 UTC. ...ITCZ... AXIS ALONG 15N94W 12N104W 11N116W 10N125W 9N129W 10N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM N OF THE AXIS BETWEEN 121W-125W...AND 60 NM S OF THE AXIS BETWEEN 126W-128W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 102W-107W. ...DISCUSSION... ALOFT... A VERY SHARP UPPER LEVEL TROUGH ENTERS THE FAR NE PORTION OF THE AREA FROM SOUTHERN CALIFORNIA SW TO NEAR 27N126W. A RIDGE IS FOLLOWING IN ITS WAKE TO THE N OF 29N BETWEEN 120W-128W. WATER VAPOR IMAGERY SHOWS MODERATE SUBSIDENCE AND VERY STABLE AIR COVERING THE AREA TO THE S OF THE TROUGH AND RIDGE TO NEAR THE ITCZ REGION. THE TROUGH IS FORECAST TO MOVE INLAND ACROSS THE WESTERN U.S. OVERNIGHT AS THE RIDGE SLIDES TO THE NE PORTION. AN ELONGATED ANTICYCLONE IS LOCATED OVER BAJA CALIFORNIA NEAR 26N112W WITH A RIDGE SW TO NEAR 18N120W. ANOTHER ANTICYCLONE IS OVER E CENTRAL MEXICO NEAR 22N99W WITH A RIDGE WNW TO 23N107W. A SHEAR ZONE BETWEEN BOTH ANTICYCLONES CONTINUES TO ADVECT AMPLE TROPICAL MOISTURE FROM THE DEEP TROPICS...MOSTLY DEBRIS CLOUDINESS FROM ITCZ CONVECTION...N AND NE TO ACROSS NORTHERN MEXICO AND INTO SECTIONS OF THE SOUTHERN U.S. THE FLOW PATTERN S OF THE ANTICYCLONES IS RATHER STRONG WHILE IT ACTS TO ADVECT EXTENSIVE OF MOISTURE WESTWARD TO A LINE FROM SOUTHERN BAJA CALIFORNIA TO 10N130W. CONVECTION WITHIN THIS MOISTURE AREA HAS INCREASED SOME DURING THE PAST 24 HOURS...BUT AT THE SAME TIME IS BEING SHEARED UNDER THE ELY FLOW. SURFACE... HIGH PRES OF 1021 MB NW OF THE AREA NEAR 28N148W EXTENDS A RIDGE E TO NEAR 123W. A WEAK FRONTAL BOUNDARY WELL N OF THE AREA APPROACHING NRN CALIFORNIA IS PRESSING THE HIGH S ALLOWING FOR THE PRES GRADIENT OVER THE FAR EASTERN PORTION OF THE AREA NEAR THE BAJA CALIFORNIA COAST TO BEGIN TO TIGHTEN SHORTLY RESULTING IN NW WINDS OF 20 KT TO FILTER ACROSS THE WATERS N OF 25N AND WITHIN 120 NM W OF THE BAJA CALIFORNIA COAST. AS THE GRADIENT WEAKENS WITHIN THE NEXT 24-36 HRS...THE WINDS WILL ALSO DIMINISH. LAST VISIBLE SATELLITE IMAGERY DEPICTED A STRONG E-W SHEAR VORTICITY FROM 10N TO 14N BETWEEN 106W AND 119W. A SURFACE LOW OF 1007 MB APPEARS TO BE POSITIONED ALONG THIS AREA OF VORTICITY ROUGHLY NEAR 12N110W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION EXISTS TO THE W OF THE LOW FROM 12N TO 14N AND BETWEEN 112W AND 115W. GLOBAL MODEL GUIDANCE SUGGESTS THAT THIS LOW...OR ANOTHER ONE POSSIBLY FORMING IN ITS VICINITY WILL DEVELOP FURTHER OVER THE NEXT 24-48 HOURS...WITH FRESH TO STRONG SW WINDS DEVELOPING IN ITS S SEMICIRCLE ALONG WITH SEAS UP TO 10 FT IN LATEST WAVEWATCH GUIDANCE. MARINE... CROSS EQUATORIAL LONG PERIOD SWELLS SPREADING NORTHWARD ARE EXPECTED TO REACH AS FAR NORTH AS 16N. LARGE SURF ALONG EXPOSED COASTS IS POSSIBLE THE NEXT FEW DAYS FROM SEAS MAYBE REACHING TO NEAR 12 FT AS INDICATED BY NOAA WAVEWATCH GUIDANCE FROM 5N TO 15N BETWEEN 101W AND 114W DUE TO SW WINDS INCREASING WITH LOW DEVELOPMENT IN THE MONSOON TROUGH. $$ AGUIRRE