000 AXPZ20 KNHC 030323 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON APR 03 2006 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...ITCZ... ITCZ AXIS ALONG 3N78W 6N85W 4N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 90 NM OF AXIS FROM 92W TO 102W AND FROM 112W TO 127W. ...DISCUSSION... THE NE PAC IS DOMINATED BY A LONGWAVE TROUGH WITH AN EMBEDDED DEEP LAYERED CYCLONE NEAR 45N135W. A SHORTWAVE TROUGH IS SWINGING SE ALONG 34N133W 23N140W ATTM ACCOMPANIED BY A BAND OF DRY UPPER AIR WITHIN 30 NM OF LINE 32N130W 28N140W. ANOTHER SHORTWAVE TROUGH OVER THE CENTRAL CONUS EXTENDS SW INTO THE DISCUSSION AREA FROM 32N94W TO A BASE NEAR 22N106W. AN UPPER CYCLONE HAS CUTOFF NEAR 4N120W. SQUEEZED BETWEEN THESE TROUGHS...AN EMBEDDED SHORTWAVE RIDGE ORIGINATES FROM AN ANTICYCLONE NEAR 2N163W...AND EXTENDS NE INTO THE AREA ALONG 16N140W 28N122W TO AN AMPLIFYING CREST OVER NEVADA NEAR 40N117W. A DEEP LAYERED TROUGH HAS DEVELOPED S OF 12N ALONG 130W WITH UPPER DIFFLUENCE NOTED ON CLOUD MOTION VECTORS. CONVECTION IS FLARING WITHIN 120 NM E OF THE ASSOCIATED LOW LEVEL TROUGH...EXTENDING FROM 3N TO 13N ALONG 131W...AND ALONG THE ITCZ BETWEEN 128W AND 113W. THE RESULTANT DEBRIS MOISTURE IS SPREADING NE TO NEAR 17N110W THEN EVAPORATES. AN INTENSE MOISTURE PLUME THAT BEGINS NEAR THE ANTICYCLONE AT 7N167W LIES ALONG THE SHORTWAVE RIDGE AXIS AND CONTINUES ACROSS NW OLD MEXICO AND SOUTHERN CALIFORNIA INTO THE WESTERN CONUS. A BAND OF VERY DRY AIR IS NOTED WITHIN THE SHORTWAVE TROUGH OVER OLD MEXICO...ROUGHLY TO THE N OF 23N BETWEEN 111W AND 98W...AND IS SHIFTING E WITH TIME. UPPER ANTICYCLONES IS CENTERED OVER N COLOMBIA AND N VENEZUELA WITH A COLLAPSING RIDGE EXTENDING NW ACROSS THE W CARIBBEAN WHERE THE UPPER FLOW HAS BECOME ZONAL. ANOTHER UPPER ANTICYCLONE IS ESTIMATED NEAR 4N90W WITH A RIDGE EXTENDING NNE ACROSS THE W GULF OF MEXICO AND CONTINUING NE ACROSS THE SE CONUS. UPPER DIFFLUENCE UNDER THIS RIDGE IS ENHANCING CONVECTION ALONG THE ITCZ BETWEEN 101W AND 89W. THE RESULTANT UPPER DEBRIS MOISTURE IS SPREADING NE ACROSS CENTRAL AMERICA AND MERGING INTO THE ZONAL UPPER FLOW DOMINATING MOST OF THE CARIBBEAN. OTHERWISE DRY UPPER AIR DOMINATES THE DISCUSSION N OF THE ITCZ E OF 108W. AT THE SURFACE...HIGH PRES 1020 MB IS QUASI STATIONARY NEAR 29N119W AND IS BLOCKING A WEAKENING FRONTAL TROUGH THAT LIES ALONG 32N123W 22N130W. THE APPROACHING UPPER TROUGH HAS A SURFACE COLD FRONT ALONG 32N129W 26N140W THAT WILL BRING ANOTHER TRAIN OF LARGE NW SWELLS INTO THE DISCUSSION AREA. GULF OF PAPAGAYO...LATEST SSMI DATA INDICATE NE WINDS 20 KT WITHIN 60 NM EITHER SIDE LINE 8N94W 11N87W. MODEL GUIDANCE FLUCTUATES NE 20 KT WINDS THROUGH 48 HOURS. $$ NELSON