000 AXPZ20 KNHC 152201 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC MON SEP 15 2008 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 2145 UTC. ...TROPICAL WAVES... TROPICAL WAVE OVER THE FAR ERN PACIFIC ALONG 84W AND N OF 4N IS MOVING W 10-15 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 240 NM E OF THE WAVE FROM 3N-7N. THIS CONVECTION IS SUPPORTED BY UPPER LEVEL RIDGING THAT EXTENDS FROM THE WRN CARIBBEAN WSW INTO THE FAR E PACIFIC WATERS S OF 15N. THIS WAVE IS MORE ACTIVE OVER THE E PORTIONS OF HONDURAS AND NICARAGUA... AND WATERS OF THE WRN CARIBBEAN SEA WHERE UPPER LEVEL ANTICYCLONIC FLOW IS MOST PRONOUNCED. GLOBAL MODELS HINT AT POSSIBLE LOW PRES FORMING ALONG OR NEAR THE E SIDE OF HONDURAS OR NICARAGUA TUE OR WED...AND EVENTUALLY DRIFT NW DURING THE NEXT FEW DAYS. TROPICAL WAVE ALONG 106W FROM 04N-17N IS MOVING W 10 KT. THE WAVE IS EMBEDDED WITHIN BROAD SW MONSOON FLOW THROUGHOUT THIS AREA. IT ALSO DISSECTS THE ITCZ AXIS. A POSSIBLE WEAK MID-LEVEL CYCLONIC CIRCULATION IS OBSERVED JUST NE OF THE WAVE NEAR 17N105W. ONLY ISOLATED SHOWERS ARE E OF THE WAVE WITHIN 45 NM OF 13N105W. THE WAVE IS ALSO SLIGHTLY ENHANCING ITCZ CONVECTION IN ITS VICINITY. ...ITCZ... ITCZ AXIS IS CENTERED FROM 6N77W 10N85W TO 9N95W TO 11N106W TO 10N115W TO 12N124W TO 08N140W. SCATTERED MODERATE CONVECTION IS WITHIN 300 NM N OF THE AXIS BETWEEN 96W-100W...AND ALSO WITHIN 180 NM S AND 120 NM N OF THE AXIS BETWEEN 111W-117W. ...DISCUSSION... E OF 120W... AN UPPER LEVEL ANTICYCLONE OVER THE WRN CARIBBEAN SEA NEAR 17.1N82W HAS A RIDGE EXTENDING SW ACROSS SRN HONDURAS AND SW TO NEAR 12N94W. TO ITS NW...A WEAK MID/UPPER LEVEL TROUGH EXTENDS SW ACROSS SE MEXICO FROM AN ELONGATED MID/UPPER LEVEL CYCLONIC CIRCULATION OVER THE CENTRAL GULF OF MEXICO. UPPER LEVEL DEBRIS MOSITURE FROM NUMEROUS STRONG CONVECTION OVER THE WRN CARIBBEAN SEA IS BEING CHANNELED N AROUND THE RIDGE AXIS...THEN IS CAUGHT UP IN NE FLOW BETWEEN THE RIDGE AND MID/UPPER TROUGH ALLOWING FOR IT TO SPREAD NEWD INTO THE ERN GULF OF MEXICO. AN ELONGATED MID/UPPER LEVEL RIDGE EXTENDS ALONG 23N/24N. MODERATE TO STRONG NE-E FLOW S OF THE RIDGE IS ADVECTING ABUNDANT MID/UPPER MOISTURE WSW TO W OF 120W. THE UPPER FLOW BECOMES RATHER ZONAL N OF THE RIDGE WITH STRONG SUBSIDENCE AND ASSOCIATED STABLE CONDITIONS NOTED IN THAT PORTION OF THE AREA. A WEAK MID/UPPER RIDGE IS JUST N OF THE ERN PORTION OF THE AREA ALONG 115W N OF 32N. ISOLATED SHOWERS AND TSTMS UNDER SLIGHT DIFFLUENT FLOW ALOFT ARE NOTED FROM 11N-14N BETWEEN 100W AND THE WAVE ALONG 105W. WEAK UPPER LEVEL TROUGH OVER NRN MEXICO HAD SET OFF ISOLATED WEAK CONVECTION JUST W OF THE MEXICAN COAST FROM 20N-22N E OF 108W. GAP WINDS...A COLD FRONT PRESENTLY PUSHING S THROUGH NRN AND CENTRAL MEXICO IS EXPECTED TO USHER IN N WINDS OF 20-25 KT INTO THE GULF OF TEHUANTEPEC BEGINNING TUE AFTERNOON...AND CONTINUE INTO POSSIBLY THU EVENING. SEAS ARE FORECAST TO BUILD TO 9 FT. W OF 120W... A HIGHLY AMPLIFIED PATTERN PREVAILS THROUGHOUT THIS AREA AS DENOTED BY A RATHER PERSISTENT MID/UPPER LEVEL ANTICYCLONE MOVING E ABOUT 10 KT NEAR 26N135W. ITS ASSOCIATED RIDGE AXIS EXTENDS TO N OF THE AREA AT 32N137W AND REACHES A CREST TO WELL N OF THE DISCUSSION AREA NEAR 40N137W. A MID/UPPER LEVEL TROUGH EXTENDS SW INTO THE AREA THROUGH 32N124W TO 29N125W TO 22N126W WHERE A COL REGION IS IDENTIFIED ON WATER VAPOR IMAGERY. TO THE S OF THE COL...MID/UPPER LEVEL RIDGING IS ALONG 20N124W 14N124W TO 9N122W. WATER VAPOR IMAGERY SHOWS ABUNDANT MODERATE TO STRONG SUBSIDENCE EXISTING THROUGHOUT WITH ASSOCIATED STABLE CONDITIONS...WITH THE EXCEPTION BEING WITH MOISTURE PRESENT ALONG AND NEAR THE ITCZ. A WEAK SURFACE TROUGH MOVING W 10-15 KT IS ALONG 12N129W 9N130W. ISOLATED SHOWERS AND WEAK TSTMS ARE WITHIN 30 NM OF 12N129W. ELSEWHERE...PATCHES OF SCATTERED TO BROKEN STRATOCUMULUS CLOUDS MOVING W WITH ISOLATED SHOWERS ARE PREVALENT TO THE N OF 24N BETWEEN 120W-133W...AND N OF 145 W OF 133W. A SURFACE RIDGE EXTENDS FROM 32N133W TO 22N122W. RELATIVELY WEAK HIGH PRES COVERS THE AREA N OF 17N. $$ AGUIRRE