000 AXPZ20 KNHC 160918 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SUN MAR 16 2008 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 0900 UTC. ...ITCZ... ITCZ AXIS 3N78W 4N90W 1N100W EQUATOR AT 110W 8N130W 6N140W. ISOLATED LIGHT TO MODERATE WITHIN 60 NM EITHER SIDE OF 11N BETWEEN 110W AND 112W. SCATTERED MODERATE WITHIN 60 NM OF 7.5N BETWEEN 136W AND 139W. SCATTERED MODERATE FROM EQUATOR AND 1N BETWEEN 104W AND 106W. ...DISCUSSION... E OF 110W... WATER VAPOR IMAGERY SHOWS AN UPPER RIDGE CENTERED OVER THE CENTRAL CARIBBEAN NEAR 13N73W...EXTENDING WEST TO AROUND 100W. ASSOCIATED DIVERGENCE ALOFT OF THIS UPPER RIDGE WAS EARLIER ENHANCING SCATTERED MODEST CONVECTION JUST N OF THE ITCZ AROUND 90W BUT WHAT REMAINS IS ON A DOWNWARD TREND. PREVIOUS CONVECTION IN THIS AREA PRODUCED WHAT APPEARS TO BE A WEAK SURFACE TROUGH BETWEEN 5N AND 10N NOW APPROACHING 105W. CLOUD-TRACKED WINDS AND WATER VAPOR IMAGERY ALSO DEPICT WHAT IS LIKELY A WEAK SHORT WAVE TROUGH MOVING NE THROUGH THE SUBTROPICAL JET OVER CENTRAL MEXICO NEAR 102W. A STRONGLY CONFLUENT FLOW ALOFT BETWEEN THE CARIBBEAN RIDGE AND THE SHORTWAVE TROUGH IS FAVORING STRONG SUBSIDENCE OVER THE REGION...WHICH IS INHIBITING CONVECTIVE DEVELOPMENT. ELSEWHERE...EARLIER QSCAT/ASCAT IMAGERY REVEALED A WEAK 1013MB SURFACE HIGH NEAR 9N94W AND A LIGHT WIND REGIME ACROSS THE REGION WITH SEA HEIGHTS GENERALLY 3 TO 5 FT IN ALL AREAS E OF 110W. LOOKING AHEAD...WINDS OVER THE CARIBBEAN SHOULD PICK UP LATE THIS WEEKEND AND EARLY NEXT WEEK...PROMPTING A FRESH ELY FLOW THROUGH THE GULF OF PAPAGAYO STARTING AS SOON AS MON MORNING. W OF 110... AN IMPRESSIVE UPPER-LEVEL TROUGH...EXTENDING FROM THE GREAT BASIN OF THE CONUS TO NEAR 28N140W...IS DIGGING FARTHER SOUTH AND PUSHING AN ASSOCIATED...STRONG COLD FRONT FROM NORTHWEST MEXICO TO NEAR 27N116W. TO THE WEST OF THE WESTERN CONUS TROUGH....AN AMPLIFIED UPPER-LEVEL RIDGE CENTERED NEAR 34N148W IS FORECAST TO MOVE EAST DURING THE NEXT DAY OR TWO...CAUSING AN ASSOCIATED 1038MB SURFACE RIDGE CURRENTLY NEAR 37N140W TO SHIFT SE AND SLOWLY WEAKEN. AS A RESULT...ALREADY STRONG NLY SURFACE FLOW DOWN THE CALIFORNIA AND NRN BAJA COASTS WILL INCREASE TO 25 TO 30 KT TODAY. THE STRONG SURFACE HIGH WILL ALSO MAINTAIN FRESH TO STRONG TRADES MAINLY FROM SOUTHWEST OF THE SOUTHERN TIP OF THE BAJA PENINSULA TO NEAR 5N140W. A FEW SHIP OBS AND NOAA WAVEWATCH III MODEL GUIDANCE INDICATE SEA HEIGHTS BUILDING TO 10 TO 15 FT OFF THE BAJA COAST IN NW SWELL. GIVEN THE FETCH AND THE DURATION OF THE NLY FLOW...MODEL GUIDANCE SHOWS COMBINED SEAS RANGING FROM 12 TO AS HIGH AS 19 FT N OF 24N BETWEEN 114W AND 130W BY EARLY MON. THE FRESH TO STRONG TRADES BLOWING SOUTH OF THE SURFACE RIDGE OVER THE TROPICAL EASTERN PACIFIC WILL ALSO CAUSE WAVE HEIGHTS TO CREST AT 10 TO 14 FT IN NE SWELL BY EARLY MON N OF 8N E OF 125W. EXPECT THE STRONG NLY WINDS OFF OF BAJA TO ABATE BY TUE...AS THE STORM SYSTEM OVER THE SW CONUS HEADS EAST. HOWEVER...THE FRESH TO STRONG TRADES W OF 125W SHOULD PERSIST INTO AT LEAST MIDWEEK....WITH NE SWELL PROPAGATING INTO THE EXTREME SRN PART OF THE BASIN. FINALLY...FARTHER S...AN CUTOFF UPPER CYCLONIC CIRCULATION NEAR 8N124W HAS BEEN ENHANCING MODERATE TO STRONG CONVECTION OVER THE ITCZ AS DESCRIBED ABOVE. ALTHOUGH THIS ACTIVITY IS GRADUALLY DISSIPATING...THE PERSISTENT ENHANCED TRADE WIND CONVERGENCE ALONG THE ITCZ WILL KEEP SMALL POCKETS OF CONVECTION ACTIVE W OF 120W THROUGH THE REMAINDER OF THE WEEK. SCATTERED MODERATE TO STRONG CONVECTION HAS ALSO RECENTLY ERUPTED JUST NORTH OF THE ITCZ BETWEEN 104W AND 106W IN A REGION OF STRONGLY DIFFLUENT FLOW ALOFT BUT SHOULD BE ON THE DECREASE LATER THIS MORNING. $$ KIMBERLAIN/CHRISTENSEN