000 AXPZ20 KNHC 122144 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED OCT 12 2011 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION JOVA IS CENTERED NEAR 21.4N 104.6W AT 12/2100 UTC MOVING N OR 005 DEG AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SCATTERED MODERATE CONVECTION IS OCCURRING FROM 18N TO 21N BETWEEN 105W AND 107W. JOVA IS FORECAST TO REMAIN INLAND AND WEAKEN TO A REMNANT LOW BY MIDDAY THURSDAY. VERY HEAVY RAINFALL AMOUNTS OF 6-12 INCHES WITH ISOLATED AMOUNTS TO 20 INCHES ARE STILL POSSIBLE WITH JOVA WHICH WILL RESULT IN FLASH FLOODING AND LIFE-THREATENING MUDSLIDES. LARGE AND DANGEROUS SWELLS WILL CONTINUE TO PROPAGATE TO THE W CENTRAL MEXICO COASTLINE RESULTING IN LIFE-THREATENING RIP CURRENTS THROUGH THE OVERNIGHT HOURS. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. TROPICAL STORM IRWIN IS CENTERED NEAR 16.9N 109.4W AT 12/2100 UTC MOVING E-NE OR 060 DEG AT 15 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION REMAINS LIMITED TO WITHIN 60 NM NW QUADRANT OF THE CENTER OF IRWIN. THE LATEST NHC FORECAST DIMINISHES IRWIN TO A DEPRESSION BY THURSDAY AFTERNOON AS IT CONTINUES EASTWARD THROUGH 48 HOURS WITH TURN BACK TO THE WEST THEREAFTER AS IRWIN GRADUALLY DISSIPATES. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. TROPICAL DEPRESSION TWELVE-E IS CENTERED NEAR 16.3N 94.3W AT 12/2100 UTC MOVING N OR 350 DEG AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SCATTERED MODERATE CONVECTION IS OCCURRING FROM 14N TO 17N BETWEEN 90W AND 95W...MOSTLY OVER INLAND PORTIONS OF WESTERN GUATEMALA AND SOUTHERN MEXICO. GIVEN LOW-LEVEL SOUTHWESTERLY FLOW TO THE SW OF T.D. TWELVE-E... SCATTERED MODERATE CONVECTION ALSO COVERS A LARGE AREA OF THE E PACIFIC WATERS FROM 12N TO 15N BETWEEN 94W AND 102W. THE SYSTEM IS MOVING INLAND INTO FAR SOUTHERN MEXICO AND WILL CONTINUE DISSIPATING OVERNIGHT ACROSS THE ISTHMUS OF TEHUANTEPEC. RAINFALL ACCUMULATIONS OF 5 TO 10 INCHES WITH ISOLATED AMOUNTS OF 15 INCHES ARE EXPECTED OVER SOUTHERN MEXICO AND WESTERN GUATEMALA. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS IS ALONG 13N115W TO 09N125W TO 09N140W. SCATTERED MODERATE CONVECTION IS FROM 12N TO 15N BETWEEN 91W AND 106W. ...DISCUSSION... A 1021 MB SUBTROPICAL HIGH PRES IS CENTERED JUST N OF THE AREA NEAR 31N137W WITH A RIDGE AXIS EXTENDING SE TO 18N130W. TO THE EAST LIES A BROAD AREA OF LOW PRES THAT SPANS ACROSS CENTRAL AMERICA N OF NICARAGUA AND WESTERN MEXICO INTO THE ADJACENT NW CARIBBEAN AND EASTERN PACIFIC INCLUDING ALL TROPICAL CYCLONES... T.S. IRWIN...T.D. JOVA...AND T.D. TWELVE-E. AS A RESULT OF WEAK HIGH PRES OVER WESTERN PORTIONS OF THE FORECAST WATERS AND BROAD LOWER PRES OVER THE EASTERN FORECAST WATERS...TRADES REMAIN GENERALLY WEAK...HOWEVER...AND THE PRES GRADIENT BETWEEN THIS RIDGE AND LOWER PRES OVER NW MEXICO IS GENERATING A SMALL AREA OF FRESH N WINDS OVER THE N CENTRAL FORECAST WATERS AND FRESH NW WINDS OVER THE GULF OF CALIFORNIA. THESE WINDS ARE EXPECTED TO DIMINISH BY EARLY THURSDAY AS JOVA DISSIPATES OVER LAND AND IRWIN WEAKENS. FRESH SOUTHWESTERLY MONSOON FLOW DOMINATES THE AREA S OF THE THREE SPECIAL FEATURES NOTED ABOVE. EARLIER MORNING ASCAT PASSES AND A NEW PASS AROUND 12/1630 UTC SHOWED A VAST EXPANSE OF FRESH TO STRONG WINDS OVER MUCH OF THE REGION S OF THESE TROPICAL CYCLONES AND THE MONSOON TROUGH E OF 120W. THESE WINDS WILL DIMINISH GRADUALLY AND TRANSLATE EASTWARD ALONG 10N TO BETWEEN 85W AND 110W BY FRIDAY AS THE THREE TROPICAL CYCLONES WEAKEN AND SW FLOW FEEDS INTO A MONSOONAL GYRE OVER NORTHERN PORTIONS OF CENTRAL AMERICA. SEAS CONTINUE TO REMAIN CHAOTIC OVER THE CENTRAL WATERS WHERE NW SWELL FROM FRONTAL SYSTEMS TO THE N AND CROSS-EQUATORIAL SW SWELL ARE MERGING IN THE VICINITY OF T.S. IRWIN. A PULSE OF NW SWELL WITH SEAS OVER 8 FT IS CURRENTLY PROPAGATING THROUGH THE AREA GENERALLY N OF 18N E OF 125W INCLUDING THE AREA WHERE THE AFOREMENTIONED FRESH N WINDS ARE IN PLACE OVER THE N CENTRAL WATERS. A NEW NW SWELL TRAIN IS ALSO MAKING ITS WAY THROUGH THE NW WATERS WITH SEAS AS HIGH AS 11 FT. MEANWHILE...A NEW BATCH OF 16-18 SECOND PERIOD SW SWELL HAS MOVED INTO THE SOUTHERN WATERS TODAY S OF 10N AND RAISED SIGNIFICANT WAVE HEIGHTS TO THE RANGE OF 8 TO 11 FT IN AREAS S OF THE MONSOON TROUGH WHERE WINDS ARE NOT FRESH OR STRONGER. THIS SWELL WILL GRADUALLY DAMPEN BELOW A 15 SECOND PERIOD BY FRIDAY AS IT MAKES ITS WAY INTO CENTRAL WATERS. $$ HUFFMAN