000 AXPZ20 KNHC 212136 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC FRI MAY 21 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ..TROPICAL WAVES... TROPICAL WAVE EXTENDING FROM FAR EPAC NEAR 04N83W NE INTO SW CARIBBEAN TO NEAR 12N77W IS CURRENTLY MOVING THROUGH THE COLOMBIAN CYCLONIC GYRE...INFLUENCING THE NE TO SW HORIZONTAL TILT. SELY LOW TO MID LEVEL FLOW ACROSS THE WRN CARIBBEAN IS ADVECTING MOISTURE ASSOCIATED WITH THIS LOW TOWARD THE NW AND WILL LIKELY LEAD TO SOME FRACTURING OF THE N PORTION OF THIS WAVE AS IT MOVES TOWARDS THE N COAST OF HONDURAS OVER THE NEXT FEW DAYS...WHILE THE REMAINDER OF THE WAVE DRIFTS W TO WNW. ACTIVE CONVECTION IS EXPECTED TO CONTINUE TO PULSE ON THE E SIDE OF THIS WAVE AS IT REMAINS IN A FAVORABLE UPPER ENVIRONMENT FOR TSTM DEVELOPMENT. TROPICAL WAVE ALIGNED SW TO NE FROM 04N90W TO 11N85W....MOVING NW 5 TO 10 KT PAST 24 HOURS. MID LEVEL VORTEX NEAR 08N88W APPEARED A FEW DAYS AGO ACROSS INTERIOR COLOMBIA AND HAS BECOME MORE EVIDENT AGAIN IN THE PAST 24 HOURS. SCATTERED MODERATE TO STRONG CONVECTING WAS OCCURRING FROM 05N TO 10N BETWEEN 86W AND 90W. A LOW TO MID LEVEL CYCLONIC GYRE CONTINUES ACROSS THE EPAC E OF 92W AND HAS SIGNIFICANTLY ALTERED TYPICAL WWD SPEED AND MOTION OF THIS WAVE THE PAST FEW DAYS. TROPICAL WAVE FROM 04N113W TO 11.5N110W. ALONG 117W S OF 12N MOVING W AT 10 KT HAS WEAKENED CONSIDERABLY WITH SCATTERED MODERATE CONVECTION WITHIN 90 NM E OF AXIS BETWEEN 08N AND 10N. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 10N86W TO 09N104W TO 07N121W TO 07.5N132W TO 06N140W. SCATTERED TO LOCALLY NUMEROUS MODERATE TO STRONG CONVECTION WITHIN 150 NM EITHER SIDE OF AXIS BETWEEN 92W AND 101W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM N OF AXIS AND 60 NM S OF AXIS BETWEEN 101W AND 108W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM N OF AXIS BETWEEN 126W AND 131W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM EITHER SIDE OF AXIS W OF 131W. ...DISCUSSION... A BROAD RIDGE CENTERED ON A 1031 MB HIGH NEAR 33N144W DOMINATES THE SURFACE PATTERN N OF 15N AND W OF 110W. THERE IS A TIGHT PRES GRADIENT IN PLACE BETWEEN THIS RIDGING AND TROUGHING FROM THE SW U.S. THROUGH CENTRAL MEXICO....PRODUCING FRESH TO STRONG NW TO N WINDS FROM OFFSHORE OF CENTRAL CALIFORNIA...WHERE AN AREA OF GALE FORCE WINDS IS FOUND...TO ALONG THE W COAST OF BAJA CALIFORNIA. THIS STRONG PRES GRADIENT OVER NE WATERS WILL BE MAINTAINED THE NEXT FEW DAYS AS THE GENERAL PATTERN BECOMES LESS PROGRESSIVE...WITH A MEAN TROUGH OVER THE WESTERN U.S. AND RIDGING OVER THE CENTRAL N PACIFIC. LOOK FOR NE TRADE WINDS BETWEEN THE HIGH AND THE ITCZ...CURRENTLY IN THE 20-25 KT RANGE ACCORDING TO THE 1534 UTC ASCAT PASS...TO REMAIN IN PLACE GENERALLY W OF 120W THROUGH SUN EVENING. SEAS IN THIS REGION OF FRESH TRADES WILL GROW TO 9-10 FT BY SAT MORNING IN NE WIND WAVES AND A MIX OF LONG PERIOD NW AND S SWELL. AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 14.5N94W. THE ASSOCIATED RIDGE EXTENDS SOUTHWESTWARD TO 06N115W AND NE INTO THE W CARIBBEAN. ACTIVE CONVECTION ALONG THE ITCZ AND NEAR TROPICAL WAVES MOVING THROUGH THE COLOMBIAN CYCLONIC GYRE WILL MAINTAIN THIS UPPER RIDGING. MEANWHILE...A 40-50 KT W-SW UPPER JET PARALLELS THE RIDGE AXIS WITH ITS JET CORE WITHIN 5 DEG NW OF THIS RIDGE. A 1010 MB LOW PRES CENTER IS EMBEDDED IN THE ITCZ NEAR 08N132W. LARGE CROSS-EQUATORIAL LONG PERIOD SW SWELL HAS REACHED MUCH OF THE PACIFIC COASTLINE WITHIN THE FORECAST AREA WITH WAVE HEIGHTS IN THE 6-8 FT RANGE AT 15 TO 16 SECONDS. THE EXCEPTION TO THIS BEING THE W COAST OF BAJA CALIFORNIA WHERE NW WIND WAVES HAVE DRIVEN SEAS UP TO 8-13 FT. A NEW PULSE OF S-SW SWELL HIT THE COAST OF CENTRAL AMERICA THIS MORNING AND WILL DRIVE TO 9-10 FT AT 16-17 SECONDS BY SAT MORNING. THIS WILL GENERATE VERY LARGE AND POWERFUL SURF ALONG THE COASTLINES...REEFS AND SHOALS FROM BAJA CALIFORNIA TO PERU...MAKING FOR EXTREMELY DANGEROUS SURF CONDITIONS. THESE SWELLS WILL BEGIN TO FADE BY SUNDAY NIGHT. $$ AL/STRIPLING