000 AXPZ20 KNHC 011005 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI APR 01 2011 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 0945 UTC. ...ITCZ... AXIS CENTERED ALONG 7N81W 2N98W 4N113W TO 5N127W 3N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 118W-120W...AND WITHIN 120 NM S OF THE AXIS BETWEEN 131W-134W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 92W-95W...AND 60 NM S OF THE AXIS BETWEEN 135W-138W. ...DISCUSSION... AN UPPER LEVEL CUT-OFF CYCLONIC CIRCULATION NEAR 24N137W IS MOVING SLOWLY EASTWARD WITH A TROUGH TO SW OF THE AREA THROUGH 17N140W. THE CIRCULATION IS TRAPPED BETWEEN A VERY LARGE RIDGE OVER THE EASTERN PORTION OF THE AREA WITH AN ANTICYCLONE MOVING SOUTHEASTWARD OVER BAJA CALIFORNIA...AND AN EVEN LARGER RIDGE SHIFTING EASTWARD ACROSS THE N CENTRAL PACIFIC. LATEST SATELLITE IMAGERY ALONG WITH THE 0600 UTC PRES ANALYSIS SHOWS THAT A SURFACE TROUGH HAS DEVELOPED IN THE VICINITY OF THE CYCLONIC CIRCULATION...AND EXTENDS FROM 22N135.5W TO 17N139W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM OF THE TROUGH. THE PRES DIFFERENCE BETWEEN THE TROUGH AND STRONG HIGH PRES CENTERED N OF THE AREA AT 34N139W IS BRINGING A SWATH OF 20 KT WINDS TO THE WATERS N OF 27N AND W OF 131W. SEAS THERE ARE 8-11 FT IN A NW SWELL. THESE WINDS WILL WEAKEN OVER THE NEXT 12-18 HOURS...BUT ANOTHER ROUND OF N-NE 20 KT WILL BEGIN TO IMPACT THE N CENTRAL WATERS ON SAT AS THE PRES GRADIENT BETWEEN THE HIGH TO THE N AND BROAD LOW PRES OVER THE WESTERN U.S. LEADS TO THE THESE. ALONG WITH THESE WINDS...YET ANOTHER BATCH OF LONG PERIOD N SWELLS WILL BEGIN TO INVADE THE FAR NORTHERN WATERS SAT WITH SEAS UP TO 12 FT...AND BUILD MORE UP TO POSSIBLY 14 OR 15 FT ALONG 30N BY LATE SUN. A DIFFLUENT FLOW PATTERN E OF THE UPPER LEVEL CYCLONIC CIRCULATION IS ALLOWING FOR THE UPPER FLOW TO ADVECT BROKEN HIGH CIRRUS CLOUDS NORTHWARD AND NORTHEASTWARD E OF THE CIRCULATION TO A LINE FROM 30N125W T0 20N115W BEFORE THEY ERODE IN A DRY AND STABLE ENVIRONMENT UNDER MODERATE SUBSIDENCE. THE UPPER LEVEL CYCLONIC CIRCULATION WILL GET PICKED UP A BY AN UPPER TROUGH CURRENTLY JUST NW OF THE REGION ON SAT...AND QUICKLY BECOME ABSORBED BY IT AS IT MOVES TOWARDS SOUTHERN CALIFORNIA AND THE LARGE RIDGE BEHIND IT OVER THE N CENTRAL PACIFIC SHIFTS E TO JUST NW OF THE AREA BY LATE SAT NIGHT. A TROUGH LEFT BEHIND BY THE UPPER LEVEL CIRCULATION WILL THEN PINCH OF ANOTHER UPPER LEVEL CUT-OFF CYCLONIC CIRCULATION OVER NW PORTION NEAR 23N135W BY SAT NIGHT. THIS CIRCULATION WILL THEN BECOME LARGER AND DEEPEN THROUGH SUN AS IT ALSO BEGINS TO LIFT NORTHEASTWARD UNDER A BROAD RIDGE JUST NE OF THE REGION. A MID/UPPER LEVEL TROUGH IS TO THE SE OF THE UPPER LEVEL CYCLONIC CIRCULATION ROUGHLY ALONG 124W S OF 20N...AND ANOTHER EXTENDS FROM 30N126W SE TO 20N121W. THE FLOW IS GENERALLY SW TO W W OF THE FIRST RIDGE...AND NW OF E OF THE SECOND RIDGE. OVER THE FAR EASTERN PORTION OF THE AREA A SMALL AND ELONGATED UPPER LEVEL CYCLONIC CIRCULATION MOVING SE IS NEAR 21N107W WITH A TROUGH SW TO 11N107W AND TO NEAR 1N107W. ONLY SLIGHT ENHANCEMENT TO ITCZ CONVECTION BY THE TROUGH IS NOTED. TO ITS SE...THE MID/UPPER FLOW IS SLY AROUND THE WESTERN PERIPHERY OF A MID/UPPER RIDGE THAT STRETCHES FROM VENEZUELA NW TO CENTRAL MEXICO. THIS FLOW...CONSISTING OF S TO SW WINDS...CONTINUES TO PUMP UPPER LEVEL MOISTURE IN THE FORM OF BROKEN CIRRUS BLOW OFF CLOUDS FROM ITCZ CONVECTION N AND NE TO ACROSS MOST OF CENTRAL AMERICA AND SOUTHEASTERN MEXICO...AND INTO THE FAR WESTERN CARIBBEAN SEA. OVERALL CONVECTIVE ACTIVITY REMAINS MINIMAL ACROSS THE REGION... WITH MOST OF THE LOW LEVEL CONVERGENCE BEING CROSS-EQUATORIAL TO THE W OF 115W...WITH A MORE ACTIVE ITCZ EVIDENT IN THE SOUTHERN HEMISPHERE. A WEAK SURFACE TROUGH ALONG 8N124W 2N129W IS MOVING W AT 10-15 KT. SCATTERED SHOWERS AND TSTMS ARE JUST RECENTLY DEVELOPING WITHIN 120 NM W OF THE TROUGH IN THE VICINITY OF THE ITCZ. THE TROUGH WILL CONTINUE ON WESTWARD OVER THE NEXT 48 HOURS WITH LITTLE IN THE WAY OF ANY SIGNIFICANT CONVECTION EXPECTED TO DEVELOP. THE WAVEWATCH WAVE MODEL GUIDANCE SUGGESTS THAT ELSEWHERE W OF A LINE FROM 30N120W TO 17N127W TO 3N140W A SURGE OF LONG PERIOD 17-18 SEC NW SWELLS WITH MAX SEAS OF 8-12 FT WILL LAST THROUGH THE NEXT 48 HOURS AND BEYOND. $$ AGUIRRE