000 AXPZ20 KNHC 131604 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU OCT 13 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 1545 UTC. ...SPECIAL FEATURES... IRWIN HAS BEEN UPGRADED TO A TROPICAL STORM. DEEP CONVECTIVE PRECIPITATION HAS DEVELOPED NEAR THE CENTER DURING THE LAST FEW HOURS. THE CENTER OF TROPICAL STORM IRWIN AT 13/1500 UTC IS NEAR 18.3N 107.7W. IRWIN IS MOVING EAST-NORTHEASTWARD OR 060 DEGREES 08 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 35 KT WITH GUSTS TO 40 KT. SCATTERED STRONG RAINSHOWERS ARE FROM 18N TO 19N BETWEEN 106W AND 108W AROUND THE CENTER. OTHER STRONG RAINSHOWERS ARE WITHIN 150 NM TO THE NORTHWEST OF THE CENTER. THE FORECAST TRACK SHOWS THAT IRWIN WILL MOVE SOUTHEASTWARD FOR THE FIRST 48 HOURS...AND THEN IT WILL CURVE SOUTHWESTWARD AND WESTWARD FOR THE REST OF THE FORECAST TIME PERIOD. PLEASE READ THE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC AND/OR THE PUBLIC ADVISORY UNDER MIATCPEP1/WTPZ31 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH REACHES BELIZE AND THE SOUTHERN YUCATAN PENINSULA FROM THE WESTERN CARIBBEAN SEA...AND EVENTUALLY IT REACHES THE ISTHMUS OF TEHUANTEPEC OF MEXICO. THE MONSOON TROUGH IS DISRUPTED...AND CONSEQUENTLY IT DOES NOT START AGAIN UNTIL 16N117W IN THE PACIFIC OCEAN. IT CONTINUES FROM 16N117W TO 10N128W...TO A 1008 MB LOW PRESSURE CENTER THAT IS NEAR 07N133W...AND IT CONTINUES TO 8N140W. SCATTERED MODERATE TO ISOLATED STRONG RAINSHOWERS ARE FROM 04N TO 06N BETWEEN 79W AND 81W...AND FROM 14N TO 16N BETWEEN 102W AND 105W. ISOLATED MODERATE RAINSHOWERS ARE FROM 07N TO 09N BETWEEN 122W AND 123W. THE 1007 MB REMNANT LOW PRESSURE CENTER OF TROPICAL DEPRESSION TWELVE-E IS IN THE CENTRAL ISTHMUS OF TEHUANTEPEC. SCATTERED MODERATE TO STRONG RAINSHOWERS ARE IN THE COASTAL WATERS OF CENTRAL AMERICA FROM EL SALVADOR NEAR 13N90W TO 15N94W...ABOUT 100 NM TO THE WEST OF THE SOUTHERN MEXICO/SOUTHWESTERN GUATEMALA BORDER. ...DISCUSSION... AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 20N122W. LARGE-SCALE UPPER LEVEL CYCLONIC WIND FLOW COVERS THE AREA FROM 10N TO 31N BETWEEN 110W AND 130W. UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE GULF OF MEXICO... MEXICO...CENTRAL AMERICA...THE NORTHWESTERN CARIBBEAN SEA... AND THE EASTERN PACIFIC OCEAN BETWEEN 80W AND 100W...AND CONTINUING TO THE SOUTH OF 12N BETWEEN 100W AND 120W. A COLD FRONT IS TO THE NORTHWEST OF THE FORECAST AREA. BROAD SURFACE ANTICYCLONIC WIND FLOW COVERS THE AREA THAT IS AT LEAST 900 NM AWAY FROM THE FRONT IN THE SOUTHEASTERN SEMICIRCLE. EXPECT 20 KT WINDS AND SEA HEIGHTS RANGING FROM 8 TO 11 FEET AROUND THE 7N133W LOW PRESSURE CENTER FOR THE NEXT 48 HOURS. THE LOW PRESSURE CENTER WILL MOVE NORTHEASTWARD WITH TIME. EXPECT 20 KT WINDS AND SEA HEIGHTS RANGING FROM 9 TO 11 FEET THAT WILL BE ASSOCIATED A 1009 MB LOW PRESSURE CENTER NEAR 11N126W IN 24 HOURS. WIND SPEEDS WILL REACH 20 KT AND SEA HEIGHTS WILL RANGE FROM 8 TO 11 FEET AT THE START OF THE FORECAST PERIOD...AND AFTER THE LOW CENTER DEVELOPS...FOR 48 HOURS. WIND SPEEDS WILL RANGE FROM 20 TO 30 KNOTS AND SEA HEIGHTS WILL RANGE FROM 8 TO 12 FEET TO THE NORTH OF 4N TO THE EAST OF 100W. THESE CONDITIONS WILL BE ASSOCIATED WITH THE BROAD AREA OF LOW PRESSURE AND THE PRESENCE OF THE MONSOON TROUGH THAT WILL BE IN CENTRAL AMERICA FOR THE NEXT 48 HOURS. $$ MT