000 AXPZ20 KNHC 231612 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN MAY 23 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0730 UTC. ...TROPICAL WAVES... TROPICAL WAVE WAS ANALYZED ALONG ITCZ 118/199W. LITTLE EVIDENCE EXISTS THIS MORNING OF CYCLONIC TURNING IN THIS AREA AND CONVECTION HAS DECREASED OVERNIGHT AND HAD BECOME ISOLATED IN THIS AREA. LOW LEVEL FLOW APPEARED TO BECOME DIFFLUENT TO THE W OF THIS AREA...AND THIS FEATURE WILL HAVE TO BE REEVALUATED FOR THE 18Z MAP. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 08N81W TO 10N101W TO 08N118W TO 07N140W. SCATTERED TO LOCALLY NUMEROUS MODERATE TO STRONG CONVECTION WAS WITHIN 150 NM OF AXIS E OF 95W. SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 90 NM EITHER SIDE OF AXIS BETWEEN 101W AND 112W. SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION WAS WITHIN 90 NM S AND 180 NM N OF AXIS W OF 121W. ...DISCUSSION... A LARGE RIDGE DOMINATES THE EPAC S OF 40N W OF 115W...CENTERED ON A 1034 MB HIGH PRES CENTER NEAR 34N150W. THERE IS A TIGHT PRES GRADIENT IN PLACE BETWEEN THIS RIDGE AND LOW PRES ACROSS THE DESERT SW OF THE U.S. FRESH NW TO N WINDS HAVE EXPANDED OUT TO BEYOND 500 NM OF THE W COAST OF BAJA CALIFORNIA IN THE 20-25 KT RANGE...ACCORDING TO THE 0532 UTC ASCAT PASS. SHIP ZCDT7 REPORTED NW WINDS OF 25 KT NEAR 24N112W AT 09OO UTC. THE STRONG PRES GRADIENT OVER NE WATERS WILL BE MAINTAINED THE NEXT FEW DAYS WITH THE MAIN PATTERN CHANGE BEING A SHIFT E IN THE PRES GRADIENT...ALLOWING THE 20-25 KT WINDS TO GRADUALLY CONTRACT E TOWARD THE COAST. THE EASTWARD SHIFTING GRADIENT SHOULD ALSO INCREASE THE NW TO N WINDS IN THE GULF OF CALIFORNIA TO 20-25 KT BY EARLY MON MORNING. LOOK FOR NE TRADE WINDS BETWEEN THE RIDGE AND THE ITCZ...CURRENTLY IN THE 20-25 KT RANGE ACCORDING TO THE 0530 UTC ASCAT PASS...TO REMAIN IN PLACE GENERALLY W OF 128W FOR THE NEXT TWO DAYS. A 60-80 KT SOUTHERN STREAM UPPER JET LIES FROM 17N131W TO 23N120W THEN E THROUGH MAZATLAN MEXICO. THE DIFFLUENT RIGHT REAR QUADRANT OF THIS UPPER JET IS ENHANCING DEEP CONVECTION ALONG THE ITCZ W OF 125W. SOME CONVECTIVE BLOW OFF FROM THE ITCZ IS BEING TRANSPORTED TO THE NE BY THIS JET. S OF THIS JET AND BROAD SW TO WLY FLOW ALOFT DOMINATING MOST OF THE AREA...PULSING MODERATE TO STRONG ITCZ CONVECTION ALONG THE ITCZ CONTINUES TO MAINTAIN AN UPPER RIDGE ALONG ABOUT 11/12N BETWEEN 95W AND 125W. A BROAD LOW LEVEL CYCLONIC GYRE PERSISTS FROM COLOMBIA W TO 94W WITH A LOW TO MID LEVEL CYCLONIC CIRCULATION HAVING DEVELOPED OVER NICARAGUA AND HONDURAS AND THE ADJACENT WATERS OF THE PAST 2 DAYS. WIDESPREAD CONVECTION...MUCH OF IT MODERATE TO STRONG... WILL PERSIST ACROSS THIS PORTIONS OF CENTRAL AMERICA FOR THE NEXT COUPLE OF DAYS AS ABUNDANT MOISTURE CONTINUES TO CONVERGE ACROSS THIS AREA...ASSOCIATED WITH THIS LATTER CYCLONIC CIRCULATION. THIS LOW IS FORECAST TO DRIFT VERY SLOWLY SW OF THE NEXT FEW DAYS AND WILL CONTINUE TO FORCE ITCZ CONVECTION INTO THE W COASTS OF COSTA RICA AND WRN PANAMA. LARGE CROSS-EQUATORIAL LONG PERIOD SW SWELL CONTINUES TO IMPACT MUCH OF THE PACIFIC COASTLINE WITHIN THE FORECAST AREA. DEEP WATER WAVE HEIGHTS ARE IN THE 8-10 FT RANGE AT 14-17 SECONDS PER WAVEWATCH GUIDANCE. OFFSHORE OF BAJA CALIFORNIA THESE LONG PERIOD SWELL ARE MIXING WITH NW WIND WAVES THAT HAVE DRIVEN SEAS UP TO 14 FT. THE SW SWELLS WILL BEGIN TO FADE BY TONIGHT... REACHING 6-8 FT IN 12-14 SECOND PERIODS BY MON NIGHT. A NEW PULSE OF LONG PERIOD CROSS-EQUATORIAL SWELL WILL MOVE INTO S WATERS MON. $$ STRIPLING 000 AXPZ20 KNHC 231612 CCA TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN MAY 23 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1515 UTC. ...TROPICAL WAVES... TROPICAL WAVE WAS ANALYZED ALONG ITCZ 118/199W. LITTLE EVIDENCE EXISTS THIS MORNING OF CYCLONIC TURNING IN THIS AREA AND CONVECTION HAS DECREASED OVERNIGHT AND HAD BECOME ISOLATED IN THIS AREA. LOW LEVEL FLOW APPEARED TO BECOME DIFFLUENT TO THE W OF THIS AREA...AND THIS FEATURE WILL HAVE TO BE REEVALUATED FOR THE 18Z MAP. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 08N81W TO 10N101W TO 08N118W TO 07N140W. SCATTERED TO LOCALLY NUMEROUS MODERATE TO STRONG CONVECTION WAS WITHIN 150 NM OF AXIS E OF 95W. SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN 90 NM EITHER SIDE OF AXIS BETWEEN 101W AND 112W. SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION WAS WITHIN 90 NM S AND 180 NM N OF AXIS W OF 121W. ...DISCUSSION... A LARGE RIDGE DOMINATES THE EPAC S OF 40N W OF 115W...CENTERED ON A 1034 MB HIGH PRES CENTER NEAR 34N150W. THERE IS A TIGHT PRES GRADIENT IN PLACE BETWEEN THIS RIDGE AND LOW PRES ACROSS THE DESERT SW OF THE U.S. FRESH NW TO N WINDS HAVE EXPANDED OUT TO BEYOND 500 NM OF THE W COAST OF BAJA CALIFORNIA IN THE 20-25 KT RANGE...ACCORDING TO THE 0532 UTC ASCAT PASS. SHIP ZCDT7 REPORTED NW WINDS OF 25 KT NEAR 24N112W AT 09OO UTC. THE STRONG PRES GRADIENT OVER NE WATERS WILL BE MAINTAINED THE NEXT FEW DAYS WITH THE MAIN PATTERN CHANGE BEING A SHIFT E IN THE PRES GRADIENT...ALLOWING THE 20-25 KT WINDS TO GRADUALLY CONTRACT E TOWARD THE COAST. THE EASTWARD SHIFTING GRADIENT SHOULD ALSO INCREASE THE NW TO N WINDS IN THE GULF OF CALIFORNIA TO 20-25 KT BY EARLY MON MORNING. LOOK FOR NE TRADE WINDS BETWEEN THE RIDGE AND THE ITCZ...CURRENTLY IN THE 20-25 KT RANGE ACCORDING TO THE 0530 UTC ASCAT PASS...TO REMAIN IN PLACE GENERALLY W OF 128W FOR THE NEXT TWO DAYS. A 60-80 KT SOUTHERN STREAM UPPER JET LIES FROM 17N131W TO 23N120W THEN E THROUGH MAZATLAN MEXICO. THE DIFFLUENT RIGHT REAR QUADRANT OF THIS UPPER JET IS ENHANCING DEEP CONVECTION ALONG THE ITCZ W OF 125W. SOME CONVECTIVE BLOW OFF FROM THE ITCZ IS BEING TRANSPORTED TO THE NE BY THIS JET. S OF THIS JET AND BROAD SW TO WLY FLOW ALOFT DOMINATING MOST OF THE AREA...PULSING MODERATE TO STRONG ITCZ CONVECTION ALONG THE ITCZ CONTINUES TO MAINTAIN AN UPPER RIDGE ALONG ABOUT 11/12N BETWEEN 95W AND 125W. A BROAD LOW LEVEL CYCLONIC GYRE PERSISTS FROM COLOMBIA W TO 94W WITH A LOW TO MID LEVEL CYCLONIC CIRCULATION HAVING DEVELOPED OVER NICARAGUA AND HONDURAS AND THE ADJACENT WATERS OF THE PAST 2 DAYS. WIDESPREAD CONVECTION...MUCH OF IT MODERATE TO STRONG... WILL PERSIST ACROSS THIS PORTIONS OF CENTRAL AMERICA FOR THE NEXT COUPLE OF DAYS AS ABUNDANT MOISTURE CONTINUES TO CONVERGE ACROSS THIS AREA...ASSOCIATED WITH THIS LATTER CYCLONIC CIRCULATION. THIS LOW IS FORECAST TO DRIFT VERY SLOWLY SW OF THE NEXT FEW DAYS AND WILL CONTINUE TO FORCE ITCZ CONVECTION INTO THE W COASTS OF COSTA RICA AND WRN PANAMA. LARGE CROSS-EQUATORIAL LONG PERIOD SW SWELL CONTINUES TO IMPACT MUCH OF THE PACIFIC COASTLINE WITHIN THE FORECAST AREA. DEEP WATER WAVE HEIGHTS ARE IN THE 8-10 FT RANGE AT 14-17 SECONDS PER WAVEWATCH GUIDANCE. OFFSHORE OF BAJA CALIFORNIA THESE LONG PERIOD SWELL ARE MIXING WITH NW WIND WAVES THAT HAVE DRIVEN SEAS UP TO 14 FT. THE SW SWELLS WILL BEGIN TO FADE BY TONIGHT... REACHING 6-8 FT IN 12-14 SECOND PERIODS BY MON NIGHT. A NEW PULSE OF LONG PERIOD CROSS-EQUATORIAL SWELL WILL MOVE INTO S WATERS MON. $$ STRIPLING