000 AXPZ20 KNHC 120317 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN APR 12 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 5N78W 7N90W 3N105W 2N115W 2N125W 3N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM S OF THE AXIS W OF 135W. ...DISCUSSION... LATEST SATELLITE WATER VAPOR IMAGERY SHOWS THE STRONG SHORTWAVE TROUGH THAT 24 HRS PUSHED A TROUGH THROUGH THE NE PORTION OF THE AREA AND WAS FOLLOWED BY STRONG NW WINDS HAS NOW MOVED FAR INLAND OVER THE WRN U.S...AND CONTINUES TO PULL FURTHER E AWAY FROM THE DISCUSSION AREA. ITS AXIS STRETCHES SSW ACROSS NRN MEXICO SW TO 25N111W TO 19N118W TO NEAR 12N127W. CONFLUENT FLOW INTO THE BACK SIDE OF THE TROUGH IS RESULTING IN AN AREA OF MODERATE SUBSIDENCE AND RATHER STABLE CONDITIONS FROM 17N-28N AND E OF 131W. SCATTERED HIGH CLOUDS E OF THE TROUGH FROM 18N-21N E OF 108W MOVING NE ACROSS NRN MEXICO. ACROSS THE MARINE ENVIRONMENT...NW WINDS OF 20-25 KT ARE N OF ABOUT 25N E OF 125W WITH SEAS 8-12 FT. ELSEWHERE N OF 23N BETWEEN 115W AND 130W WINDS ARE LESS THAN 20 KT WITH SEAS 8 TO 11 FT IN NW TO N SWELL. SEAS WITHIN THIS AREA MAY SUBSIDE SLIGHTLY OVER THE NEXT 24-46 HRS THEN INCREASE AGAIN IN 48 HRS AND BEYOND AS YET ANOTHER SWELL TRAIN COMPOSED OF LARGE SEA HEIGHTS (UP TO 10 OR 11 FT) MIGRATES SWD INTO THE NE PART OF THE AREA AS AGREED BY ALL WAVE MODEL GUIDANCES. TO THE W OF THE TROUGH...A LONGWAVE RIDGE HAS MOVED INTO THE AREA...AND IS ROUGHLY ALONG 138W N OF 15N. UPPER LEVEL MOISTURE FROM THE DEEP TROPICAL CENTRAL PACIFIC IS RIDING NE UP ACROSS THE RIDGE AND THEN SPILLING SE INTO THE FAR WRN PORTION OF THE AREA N OF 13N W OF 129W. TO THE E AND SE OF THE TROUGH...BROAD UPPER RIDGING WITH A NEARLY STATIONARY ANTICYCLONE MOVING W NEAR 6N102W CONTINUES TO MAINTAIN RATHER DRY AND STABLE CONDITIONS OVER THE SE PORTION OF THE AREA. TO THE SW OF THE TROUGH...THE ERN PERIPHERY OF BROAD MID/UPPER RIDGING OVER THE S/CENTRAL PACIFIC EXTENDS E INTO THE AREA TO NEAR 136W. A SMALL UPPER LEVEL CYCLONIC CIRCULATION NEAR 1N129W MOVING WSW 13 KT IS PRODUCING ISOLATED SHOWERS WITHIN 45 NM OF LINE 4N124W TO 3N128W. AT THE SURFACE...A STATIONARY 1029 MB HIGH CENTER IS NEAR 31N124W WITH A RIDGE EXTENDING SE THROUGH 27N125W TO 22N115W TO 17N107W. HIGH PRES COVERS THE AREA N OF 14N W OF 107W. LATEST VISIBLE SATELLITE IMAGERY SHOWS A WEAK TROUGH DISPLAYING SOMEWHAT OF AN INVERTED-V SHAPE PATTERN OVER THE LOCATION FROM 5N125W TO 12N122W. ISOLATED SHOWERS AND SPORADIC SMALL TSTM CELLS ARE WITHIN 30 NM OF THE TROUGH. ANOTHER WEAK TROUGH EXTENDS ALONG 135W S OF 6N MOVING W ABOUT 15 KT. THIS TROUGH CONTINUES TO LOSE THE DISTINCT SATELLITE SIGNATURE IT HAD FROM 24 HRS AGO INCLUDING THE SMALL VORTICITY MAXIMUM THAT WAS ALSO NOTED. IT IS JUST CLOSE ENOUGH TO THE SRN TIP OF THE UPPER TROUGH DESCRIBED ABOVE TO ALLOW FOR INCREASING SCATTERED SHOWERS AND TSTMS WITHIN 120 NM EITHER SIDE OF ITS AXIS. THE COMBINATION OF THESE TROUGHS WITH THE SURFACE RIDGE TO THE N IS RESULTING IN NE TRADES OF 20 KT FROM 6N TO 21N W OF 120W WITH SEAS 8-10 FT PRIMARILY IN NE SWELL. THESE MARINE CONDITIONS ARE EXPECTED TO EXPAND E TO 118W IN 24 HRS...THEN DECREASE IN AREAL COVERAGE TO W OF 130W IN 48 HRS WITH SEAS STILL AROUND THE 8-10 FT RANGE IN NE SWELL. NW WINDS OF 20 KT ARE OVER AN AREA BOUNDED FROM 17N-21N E OF 108W TO THE COAST OF MEXICO WITH SEAS TO 8 FT. THIS AREA WILL EXPAND N TO 23N IN 24 HRS...THEN DIMINISHING IN ABOUT 36 HRS. PATCHES OF CELLULAR SHAPE MOSTLY BROKEN STRATOCUMULUS CLOUDS MOVING SW TO W WITH POSSIBLE ISOLATED SHOWERS ARE PRESENT N OF 19N...AND ARE BEING STEERED BY THE GENERAL SYNOPTIC WIND FLOW AROUND THE RIDGE THAT EXTENDS INTO THE REGION DESCRIBED ABOVE. $$ AGUIRRE