000 AXPZ20 KNHC 011523 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU AUG 01 2013 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 1500 UTC. ...SPECIAL FEATURES... HURRICANE GIL CENTERED NEAR 14.5N 123.9W AT 01/1500 UTC MOVING W- NW OR 280 DEG AT 10 KT. MAXIMUM SUSTAINED WINDS ARE 70 KT WITH GUSTS TO 85 KT AND ESTIMATED MINIMUM SEAS PRESSURE IS 990 MB. CURRENTLY...NUMEROUS STRONG CONVECTION IS OBSERVED WITHIN 90 NM NW AND WITHIN 30 NM SE SEMICIRCLES OF CENTER. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ELSEWHERE IN A BAND WITHIN 30 NM E OF LINE FROM 14N123W TO 13N124W TO 12N125W. GIL IS MOVING ALONG THE SOUTHERN PERIPHERY OF A STRONG MID-LEVEL RIDGE EXTENDING FROM THE US/MEXICAN BORDER WEST-SOUTHWESTWARD INTO THE PACIFIC WATERS. THE INTENSITY FORECAST CALLS FOR GIL REACHING ITS MAXIMUM WINDS OF 75 KT IN ABOUT 12 HOURS. AFTER THAT TIME... A GRADUAL WEAKENING IS EXPECTED AND GIL WILL BE A TROPICAL STORM BY 48 HOURS. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTNT22 KNHC FOR ADDITIONAL DETAILS. A 1008 MB LOW PRESSURE IS CENTERED NEAR 12.5N115W AND IS MOVING W AT 10 KT. CURRENTLY A BAND OF SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 90 NM OVER THE W SEMICIRCLE OF CENTER. THIS LOW MAY DEVELOP INTO A TROPICAL CYCLONE AS IT MOVES W-NW TO NEAR 13N118W IN ABOUT 24 HOURS...AND NEAR 14N120W BY 48 HOURS. WINDS OF 20-25 KT AND SEAS TO 9FT ARE NOTED WITHIN 70 NM OF THE CENTER. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS EXTENDS FROM 09N84W TO 08N92W TO 1009 MB LOW PRESSURE AT 12.5N115W. ITCZ AXIS STRETCHES FROM 12N130W TO 10N140W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE NOTED FROM 04N TO 08N E OF 80W TO THE COAST OF COLOMBIA. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 07N TO 09N BETWEEN 83W AND 92W...FROM 07M TO 15N BETWEEN 100W AND 106W...FROM 13N TO 15N BETWEEN 112W AND 119W. SCATTERED MODERATE IS FROM 10N TO 13N BETWEEN 130W AND 134W. ...DISCUSSION... ALOFT...AN UPPER LEVEL LOW IS SPINNING OVER THE NW CORNER OF THE FORECAST AREA WITH A TROUGH EXTENDING SE TO NEAR 25N131W. A LARGE UPPER ANTICYCLONE HAS BEEN QUASI-STATIONARY NEAR THE TEXAS/MEXICO BORDER FOR THE PAST FEW DAYS WITH AN UPPER RIDGE CURRENTLY EXTENDING WWD ACROSS THE BAJA CALIFORNIA PENINSULA AND REGIONAL WATERS. DRY UPPER AIR IS INDICATED TO THE W OF THIS RIDGE AND EXTENDS W THROUGH THE ABOVE MENTIONED UPPER TROUGH. ANOTHER UPPER LEVEL LOW NEAR 24N118W HAS A TROUGH EXTENDING SE TO A THIRD UPPER CYCLONE NEAR 20.5N107W. THIS SYSTEM IS GENERATING SOME SHOWERS AND TSTMS OVER PARTS OF MICHOACAN... COLIMA AND JALISCO. ANOTHER ANTICYCLONIC CIRCULATION IS NOTED NW OF GIL NEAR 17N128W WITH A RIDGE EXTENDING EWD TO NEAR 15N105W. UPPER DIFFLUENCE ASSOCIATED WITH THIS SYSTEM IS HELPING TO SUPPORT CONVECTION ALONG THE MONSOON TROUGH AND THE ITCZ. NE TO E WIND FLOW ALOFT DOMINATES THE AREA E OF 100W. CLUSTERS OF MODERATE TO STRONG CONVECTION HAVE DEVELOPED AGAIN THIS MORNING ALONG WESTERN COLOMBIA AND REGIONAL WATERS. A DIFFLUENT PATTERN ALOFT IS HELPING TO ENHANCE THIS CONVECTIVE ACTIVITY. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS ALSO NOTED OVER PARTS OF THE GULF OF CALIFORNIA MAINLY FROM 25N TO 28N. IN ADDITION TO HURRICANE GIL AND THE LOW PRES NEAR 12.5N115W... A PAIR OF WEAK LOWS ARE SEEN ALONG THE MONSOON TROUGH BASED ON SATELLITE PICTURES AND SCATTEROMETER DATA. ONE IS NEAR 10N100W AND THE OTHER NEAR 13N131W. A SURFACE RIDGE COVERS MAINLY THE WATERS N OF 18N W OF 120W. NE TRADES AT 20-25 KT ARE ENHANCED SW OF THE RIDGE FROM 12N TO 20N W OF 130W. MIXING NE AND SW SWELL RESULT IN COMBINED SEAS OF 8- 10 FT. THESE CONDITIONS ARE FORECAST TO REMAIN IN PLACE ACROSS THE TROPICAL WATERS OVER THE NEXT 36 TO 48 HOURS. THE AREA OF SEAS HIGHER THAN 8 FT WILL INCREASE IN ADVANCE OF TROPICAL CYCLONE GIL...PARTICULARLY BETWEEN 10N AND 20N W OF 130W. $$ GR