000 AXPZ20 KNHC 292205 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED APR 29 2009 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 2130 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG...4N78W 6N90W 6N100W 5N107W TO 6N120W TO 4N130W TO 4N140W. SCATTERED MODERATE TO STRONG CONVECTION EXISTS FROM 4N-9N BETWEEN 82W-87W...FROM 3N-6.5N BETWEEN 122W-133W AND WITHIN 120 NM S OF THE AXIS BETWEEN 87W-92W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 240 NM S OF THE AXIS BETWEEN 119W-122W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE AXIS W OF 136W. ...DISCUSSION... A PROGRESSIVE PATTERN IS PRESENT ACROSS THE REGION AS DENOTED BY HIGHLY AMPLIFIED FEATURES. THE FIRST IS A BROAD RIDGING AT ALL LEVELS OF THE ATMOSPHERE OVER THE CENTRAL PORTION OF THE AREA WITH A MEAN MID/UPPER RIDGE AXIS EXTENDING INTO THE AREA THROUGH 32N124W TO 18N121W TO 17N118W TO A STATIONARY ANTICYCLONE NEAR 9N117W. ANOTHER RIDGE EXTENDS FROM THE ANTICYCLONE NE TO 16N110W TO ACROSS CENTRAL MEXICO. MID/UPPER TROUGHING NE OF THE RIDGE HAS MOVED E TO OVER NRN MEXICO AND THE SW U.S. A NEARLY STATIONARY MID/UPPER LEVEL TROUGH IS OVER THE FAR ERN PORTION OF THE AREA EXTENDING FROM SE MEXICO SW TO TO A RECENTLY FORMED CUT-OFF UPPER LEVEL LOW NEAR 12N97W. BROKEN MID AND UPPER LEVEL CLOUDS ARE BEING CHANNELED NEWD ACROSS CENTRAL AMERICA E OF THE TROUGH WITH SCATTERED SHOWERS AND TSTMS INCREASING NE THROUGH SE OF THE TROUGH AND LOW...MAINLY OVER WATER ALONG AND N OF THE ITCZ BETWEEN 84W-87W UNDER AN ASSOCIATED JET STREAM BRANCH THAT EXTENDS FROM 8N91W NNE TO ACROSS HONDURAS AND INTO THE WRN CARIBBEAN SEA. THE SHOWER AND TSTM WILL CONTINUE THROUGH AT LEAST THE NEXT 48 HRS AS THE LOW AND TROUGH REMAIN ABOUT STATIONARY. A JET STREAM BRANCH WITH MAXIMUM WINDS OF 60-90 KT ENTERS THE REGION AT 15N140W...AND CONTINUES NE TO 20N135W TO 25N125W THEN DIVES SEWD OVER THE RIDGE TO 24N115W TO 16N109W. THE RIDGE IS FORECAST TO DAMPEN OUT SOME AS IT GETS NUDGED EWD TO OVER THE WRN U.S. WITHIN THE NEXT 2 DAYS BY A RATHER SHARP DEEP LAYER TROUGH W OF THE AREA PRESENTLY ALONG 144W/145W. THE TROUGH IS FORECAST TO BE ALONG 140W BY THU. ITS REFLECTION WILL BE SEEN AS WEAKENING FRONTAL BOUNDARY THAT MOVES INTO THE FAR NW WATERS WED AND BECOMES DIFFUSE AS IT PULLS NE OF THE AREA. FOR THE TIME BEING...DEEP LAYER MOISTURE CONSISTING OF BROKEN MULTILAYERED CLOUDS WITH SCATTERED SHOWERS AND TSTMS IS ADVECTING NEWD INTO THE FAR NW WATERS MAINLY AS A RESULT OF THE ABOVE JET STREAM ROUNDING THE BASE OF THE TROUGH BRINGING ADDITIONAL MOSITURE FROM THE DEEP TROPICAL PACIFIC NEWD ACROSS THE RIDGE. SOME AMPLIFICATION OF THE RIDGE IS EVIDENT AS THE JET ENERGY IS DRIVEN NE AHEAD OF THE TROUGH. BROAD/MID UPPER LEVEL RIDGING COVERING THE WRN CARIBBEAN SEA ALSO EXTENDS W ACROSS CENTRAL AMERICA TO THE E OF THE MID/UPPER LEVEL TROUGH OVER THE ERN PORTION OF THE AREA. AT THE SURFACE...HIGH PRES OF 1025 MB IS JUST N OF THE AREA NEAR 33N127W EXTENDS A RIDGE SE TO 24N118W TO 18N111W. AS THE TROUGH W OF THE AREA ADVANCES EWD THROUGH THE NEXT 48 HRS...THE RIDGE WILL ALSO SLIDE E AS WHILE LOW PRES DEEPENS OVER THE PLAINS INTO NRN MEXICO. THIS WILL ALLOW FOR THE PRES GRADIENT TO INCREASE OVER THE NE PART OF THE AREA INCREASING THE NW WINDS ALONG THE BAJA CALIFORNIA COAST REACHING W TO NEAR 121W. SE-S WINDS OF 20-25 KT E OF THE COLD FRONT WILL DIMINISH AND BECOME SW-W 20 KT IN 48 HRS AS THE FRONT DISSIPATES. A WEAK TROUGH MOVING W 15 KT EXTENDS FROM 3N129W TO 9N126W. THIS FEATURE IS ENHANCING ITCZ CONVECTION IN ITS VICINITY. GAP WINDS...NE WINDS OF 20-25 KT THROUGH THE GULF OF PAPAGAYO ARE EXPECTED TO DIMINISH TO LESS THAN 20 KT BY 48 HRS. $$ AGUIRRE