000 AXPZ20 KNHC 080935 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT OCT 08 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0745 UTC. ...SPECIAL FEATURES... HURRICANE IRWIN CENTERED NEAR 14.4N 121.1W AT 08/0900 UTC MOVING NW OR 315 DEG AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 980 MB. MAXIMUM SUSTAINED WIND SPEED IS 80 KT WITH GUSTS TO 100 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. IRWIN IS EXPECTED TO MOVE LITTLE OVER THE NEXT 24 HOURS. THEREAFTER IRWIN IS FORECAST TO MOVE E NE IN THE GENERAL DIRECTION OF W CENTRAL MEXICO THROUGH 120 HOURS. IRWIN IS FORECAST TO MAINTAIN ITS CURRENT INTENSITY THROUGH 36 HOURS. THE SYSTEM IS THEN FORECAST TO GRADUALLY WEAKEN BUT MAINTAIN HURRICANE STRENGTH THROUGH WED. NUMEROUS MODERATE TO STRONG CONVECTION LIES WITHIN 120 NM W SEMICIRCLE AND 30 NM E SEMICIRCLE OF IRWIN WITH SCATTERED MODERATE CONVECTION ELSEWHERE WITHIN 180 NM W SEMICIRCLE. TROPICAL STORM JOVA CENTERED NEAR 15.9N 110.4W AT 08/0900 UTC MOVING N OR 05 DEG AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 996 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. JOVA IS EXPECTED TO BEGIN MOVING E NE TOWARD W CENTRAL MEXICO TODAY. THE CURRENT FORECAST TAKES JOVA INLAND ON TUE. ADDITIONAL STRENGTHENING IS FORECAST UNTIL POSSIBLE LANDFALL...WITH JOVA FORECAST TO REACH HURRICANE STRENGTH OVERNIGHT TONIGHT. NUMEROUS MODERATE TO STRONG CONVECTION LIES WITHIN 120 NM N SEMICIRCLE AND 180 NM S SEMICIRCLE OF JOVA WITH SCATTERED MODERATE CONVECTION ELSEWHERE WITHIN 300 NM SW SEMICIRCLE. 1008 MB LOW PRES CENTERED NEAR 11N96.5W HAS BEEN DRIFTING WEST AROUND 5 KT OVER THE LAST 12 HOURS...BUT THE LOW IS EXPECTED TO SLOW TODAY AND BEGIN MOVING EASTWARD TONIGHT THROUGH MON. SCATTERED MODERATE CONVECTION SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 45 NM AND 75 NM S SEMICIRCLE OF THE LOW PRES CENTER. UPPER LEVEL WINDS APPEAR SOMEWHAT CONDUCIVE FOR ADDITIONAL DEVELOPMENT OF THIS SYSTEM...AND IT MAY BECOME A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS LIES FROM 11N85W TO LOW PRES NEAR 11N96.5W THEN RESUMES FROM 13N125W TO 08N137W. ITCZ AXIS FROM 08N137W TO 08N140W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS E OF 89W AS WELL AS WITHIN 150 NM N AND 75 NM S OF THE AXIS BETWEEN 128W AND 133W. ...DISCUSSION... 1029 MB HIGH PRES IS CENTERED N OF THE AREA NEAR 35N136W WITH A RIDGE AXIS EXTENDING SE TO NEAR 19N114W. THE PRES GRADIENT BETWEEN THIS RIDGE AND LOWER PRES ASSOCIATED WITH HURRICANE IRWIN AND TROPICAL STORM JOVA IS PRODUCING FRESH TRADES FROM 17N TO 25N W OF 117W AS DEPICTED BY THE 0524 UTC ASCAT PASS. THESE TRADES WILL NOT CHANGE MUCH OVER THE NEXT 24 HOURS...BUT ARE EXPECTED TO SHRINK W AS THE SUBTROPICAL HIGH REORGANIZES NW OF THE AREA AFTER A PROGRESSIVE COLD FRONT IMPINGES UPON IT FROM THE N. IN ADDITION...THE PRES GRADIENT BETWEEN THE RIDGE AND TROUGHING OVER INLAND MEXICO IS MAINTAINING FRESH NW TO N WINDS OVER THE GULF OF CALIFORNIA N OF 25N WHICH WILL PERSIST THROUGH THE NEXT 48 HOURS AS WELL AS WITHIN 120 NM OF THE W COAST OF BAJA CALIFORNIA. WINDS OFF THE BAJA WERE CAPTURED BY THE 0524 UTC ASCAT PASS AND ARE EXPECTED TO DIMINISH BY THIS TIME TOMORROW AS THE SUBTROPICAL HIGH BEGINS TO SHIFT WESTWARD. NW SWELL IS CONTINUING TO PROPAGATE THROUGH THE NORTHERN FORECAST WATERS AND IS MEETING THE 15-17 PERIOD CROSS-EQUATORIAL SW SWELL OVER CENTRAL WATERS INCLUDING THE AREA NEAR JOVA AND IRWIN. SEAS ARE AS HIGH AS 12 FT IN MERGING SW AND NW SWELL. THIS SWELL IS CONTRIBUTING TO THE CONFUSED SEA STATE ACROSS CENTRAL WATERS THAT IS EXPECTED TO PERSIST THROUGH THE WEEKEND. A NEW BATCH OF NW SWELL WILL PROPAGATE INTO THE FORECAST AREA BY EARLY SUN...WITH SEAS EXPECTED TO BUILD TO 8 FT OVER N CENTRAL FORECAST WATERS. SW MONSOON FLOW HAS BECOME FRESH OVER SE WATERS WHERE THE PRES GRADIENT BETWEEN HIGH PRES OVER THE EASTERN SOUTH PACIFIC AND BROAD LOW PRES OVER MUCH OF CENTRAL AMERICA AND COLOMBIA IS STRONGEST. SHIP BATFR53 REPORTED SW WINDS AT 21 KT AT 0500 UTC NEAR 06N83W. THIS AREA OF FRESH WINDS IS EXPECTED TO SHIFT NW AND MERGE WITH THE AREA OF LOW PRES DISCUSSED IN THE SPECIAL FEATURES SECTION AS PRESSURES FALL ALONG THE MONSOON TROUGH AND AROUND THIS LOW. $$ SCHAUER