000 AXPZ20 KNHC 121533 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1515 UTC. ...SPECIAL FEATURES... TROPICAL STORM JOVA IS CENTERED NEAR 20.6N 105.0W AT 12/1500 UTC MOVING N OR 360 DEG AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. NUMEROUS MODERATE AND ISOLATED STRONG CONVECTION IS OCCURRING WITHIN 150 NM OF THE EASTERN QUADRANT AND SOUTHERN SEMICIRCLE AND WITHIN 90 NM ELSEWHERE OF CENTER. JOVA IS FORECAST TO REMAIN INLAND AND CONTINUE WEAKENING ON A NORTHWARD TRACK. THE OFFICIAL NHC FORECAST CALLS FOR JOVA TO DIMINISH TO A TROPICAL DEPRESSION BY THURSDAY MORNING. VERY HEAVY RAINFALL AMOUNTS OF 6-12 INCHES WITH ISOLATED AMOUNTS TO 20 INCHES 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 TODAY. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP5/WTPZ35 KNHC AND THE FULL FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. TROPICAL STORM IRWIN IS CENTERED NEAR 16.0N 110.7W AT 12/1500 UTC MOVING E-NE OR 065 DEG AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE CONVECTION IS OCCURRING WITHIN 75 NM OF THE CENTER OF IRWIN. THE LATEST NHC FORECAST DIMINISHES IRWIN TO A DEPRESSION BY THURSDAY MORNING AS IT CONTINUES EASTWARD THROUGH 72 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 15.1N 93.6W AT 12/1500 UTC MOVING N OR 360 DEG AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. NUMEROUS MODERATE AND ISOLATED STRONG CONVECTION IS OCCURRING FROM 12N TO 17N BETWEEN 90W AND 97W. THE LATEST NHC FORECAST INTENSIFIES THE SYSTEM TO A TROPICAL STORM BY THIS EVENING AND MOVES THE SYSTEM INLAND INTO FAR SOUTHERN MEXICO OVERNIGHT TONIGHT. RAINFALL ACCUMULATIONS OF 5 TO 10 INCHES WITH ISOLATED AMOUNTS OF 15 INCHES ARE EXPECTED OVER SOUTHERN MEXICO AND WESTERN GUATEMALA. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP2/ WTPZ32 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS IS ALONG 13N115W TO 08.5N130W TO 09N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 90 NM OF 04N78W AND WITHIN 60 NM OF 07N121.5W. ...DISCUSSION... THE 1021 MB SUBTROPICAL HIGH PRES IS CENTERED JUST N OF THE AREA NEAR 34N132W WITH A RIDGE AXIS EXTENDING SE TO 22N113W. TO THE SE 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.S. JOVA...AND T.D. TWELVE-E. THIS RIDGE CONTINUES TO BE ERODED AS IRWIN AND JOVA TRACK GENERALLY TO THE E-NE. TRADES HAVE DIMINISHED AS A RESULT OF THE WEAKENING RIDGE... 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 AND IRWIN WEAKEN. FRESH SOUTHWESTERLY MONSOON FLOW DOMINATES THE AREA S OF THE THREE SPECIAL FEATURES NOTED ABOVE. EARLIER MORNING ASCAT PASSES AROUND 12/0356 UTC AND 0536 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. THE 12/0536 UTC ASCAT PASS ALSO INDICATES A BROAD AREA OF LOW PRES TRYING TO ORGANIZE ALONG THE MONSOON TROUGH AROUND 128W. A NEW LOW PRES SYSTEM IS EXPECTED TO DEVELOP HERE ALONG THE MONSOON TROUGH BY THURSDAY AND WILL TRACK NORTHEASTWARD. 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 20N 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 08N 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 AS IT MAKES ITS WAY INTO CENTRAL WATERS. $$ HUFFMAN