000 AXPZ20 KNHC 160920 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED SEP 16 2015 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS FROM 18N102W TO 09N104W. SCATTERED MODERATE ISOLATED STRONG C0NVECTION IS NOTED ON EITHER SIDE OF THE WAVE AXIS FROM 09N TO 18N BETWEEN 100W AND 107W. THIS WAVE WILL CONTINUE TO SHIFT W-NW OVER THE NEXT FEW DAYS...AND STRENGTHEN THE SE SURFACE WINDS OFFSHORE OF THE MEXICAN COAST FROM ACAPULCO TO MANZANILLO TO AROUND 20 KT TODAY AND TONIGHT WHERE SEAS WILL BUILD TO 7-8 FT. A SHIP CALL SIGN SBLI LOCATED NEAR THE NORTHERN END OF THE WAVE AXIS IS ALREADY REPORTING SE WIND OF 20 KT AND COMBINED SEAS OF 6 FT. WIDESPREAD CONVECTION WILL ALSO ACCOMPANY THIS WAVE...AND GENERALLY SHIFT W-NW WITH THE WAVE THAT COINCIDES WITH AN AREA OF DEEP TROPICAL MOISTURE AS NOTED ON TOTAL PRECIPITABLE WATER SATELLITE IMAGERY. A TROPICAL WAVE IS ALONG 111W WITH AN EMBEDDED 1008 MB LOW PRES NEAR 15.5N111W. SCATTERED MODERATE TO STRONG CONVECTION IS OBSERVED MAINLY AHEAD OF THE WAVE AXIS FROM 14N TO 18N BETWEEN 111W AND 114W. AN EARLIER SCATTEROMETER PASS SHOWED THE CYCLONIC CIRCULATION ASSOCIATED WITH THE LOW AND THE WIND SHIFT RELATED TO THE WAVE AXIS. THE WAVE IS EVIDENT IN THE LATEST GFS 700 MB STREAMLINES AND 850 VORTICITY ANALYSIS AS WELL AS IN TOTAL PRECIPITABLE WATER SATELLITE IMAGERY WHERE A NORTHWARD BULGE OF DEEP TROPICAL MOISTURE IS SEEN. THIS WAVE IS EXPECTED TO MOVE SLOWLY WWD DURING THE NEXT FEW DAYS AND EVOLVE INTO AN ELONGATED LOW LEVEL NE TO SW ALIGNED CYCLONIC CIRCULATION. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 09N85W TO 10N89W TO A LOW PRES LOCATED NEAR 15.5N111W TO 11N123W...WHERE IT TERMINATES. SCATTERED MODERATE CONVECTION IS OVER THE GULF OF PANAMA N OF 07N...FROM 06N TO 09N BETWEEN 94W AND 97W...AND FROM 05N TO 08N BETWEEN 101W AND 104W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 10N TO 13N BETWEEN 114W AND 119W. ...DISCUSSION... GULF OF CALIFORNIA...A TROUGH EXTENDING FROM 32N114W TO 30N115W CONTINUES TO SUPPORT S-SW WINDS OF 15-20 KT ACROSS THE WATERS N OF 30N. LITTLE CHANGE IS EXPECTED THROUGH THIS MORNING THEN THE GRADIENT WILL FURTHER WEAKEN. IN ADDITION...A RECENT ASCAT PASS PROVIDED OBSERVATIONS OF NW WINDS IN THE 15-20 KT RANGE JUST OFFSHORE THE BAJA CALIFORNIA PENINSULA FROM 25N TO 27N. THE REMNANT TROUGH OF LINDA CONTINUES TO WEAKEN AND IS ALONG FAR N PORTIONS OF THE COAST OF BAJA CALIFORNIA NORTE...ALONG 116W. EXPECT THIS WEAKENING TROUGH TO MOVE E AND INLAND ACROSS BAJA CALIFORNIA NORTE TODAY. CLOUDINESS ASSOCIATED WITH THIS FEATURE IS ALREADY MOVING INLAND ACROSS BAJA CALIFORNIA NORTE AND COULD PRODUCE ISOLATED TO SCATTERED SHOWERS. AS THE REMNANT TROUGH OF LINDA FINALLY DISSIPATES...RIDGING WILL BUILD ACROSS THE NORTH PART OF THE FORECAST AREA BRINGING FRESH TO LOCALLY STRONG TRADE WINDS ACROSS THE WEST-CENTRAL WATERS. BY THU NIGHT INTO EARLY FRI...EXPECT NE WINDS OF 20-25 KT AND SEAS UP TO 8 FT FROM 18N TO 22N W OF 130W. A 1011 MB SURFACE LOW IS ANALYZED AT 16.5N129W MOVING W 10 KT. A TROUGH EXTENDS FROM THE LOW CENTER TO NEAR 120N128W. NIGHT CHANNEL VISIBLE IMAGES SHOW A WELL DEFINED SWIRL OF LOW CLOUDS ASSOCIATED WITH THIS LOW WHILE SCATTERED MODERATE CONVECTION IS NEAR THE NORTHERN END OF THE TROUGH. THIS LOW IS FORECAST TO WEAKEN TO AN OPEN TROUGH AND SHIFT WWD DURING THE NEXT FEW DAYS...AND MOVE OUT OF THE AREA ON FRIDAY. LONG PERIOD CROSS EQUATORIAL SW SWELL CONTINUES TO MOVE ACROSS THE TROPICS AND TOWARDS THE COAST OF MEXICO AND CENTRAL AMERICA...AND IS EXPECTED TO REACH THE COASTS THIS MORNING. WAVE HEIGHTS ACROSS THE OPEN OCEAN WILL CHANGE LITTLE WITH THE ARRIVAL OF THIS SWELL...AND WILL ACT TO MAINTAIN CURRENT OFFSHORE WAVE HEIGHTS OF GENERALLY 4-6 FT. $$ GR