000 AXPZ20 KNHC 120956 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI JUL 12 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W FROM THE NW COAST OF COLOMBIA AT 10N76W ACROSS THE CARIBBEAN ALONG 11N TO THE COAST OF NORTHERN COSTA RICA AT 10N86W...AND CONTINUES W TO 11N90W AND TO 11N106W WHERE LOW LEVEL WINDS AND PREVIOUS SCATTEROMETER WINDS INDICATE A TRANSITION TO AN INTERTROPICAL CONVERGENCE ZONE. THE ITCZ THEN EXTENDS TO 12N113W TO 10N120W TO 06N131W AND TO BEYOND 07N140W. SCATTERED STRONG CONVECTION IS WITHIN 120 NM S OF THE ITCZ AXIS BETWEEN 111W-115W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM N OF THE TROUGH AXIS BETWEEN 90W- 93W....AND ALSO WITHIN 180 NM S OF THE ITCZ AXIS BETWEEN 116W- 118W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS LOCATED S OF THE MONSOON TROUGH WITHIN 45 NM OF 07N89W. ...DISCUSSION... A NEGATIVELY-TILTED UPPER TROUGH EXTENDS FROM AN ELONGATED UPPER LOW NW OF THE AREA NEAR 36N1423W SE THROUGH 32N134W AND TO NEAR 23N130W. AN UPPER ANTICYCLONE W OF THE AREA OVER THE DEEP TROPICS NEAR 16N147W EXTENDS A RIDGE NE JUST TO THE S OF THE TROUGH...AND TO ANOTHER UPPER ANTICYCLONE MOVING E AT 23N125W. RIDGING PREVAILS THROUGHOUT MUCH OF THE AREA N OF ABOUT 18N AND W OF 118W WHERE SATELLITE WATER VAPOR IMAGERY SHOWS ABUNDANT MODERATE TO STRONG SUBSIDENCE MAINTAINING RELATIVELY DRY AND STABLE ATMOSPHERIC CONDITIONS THROUGHOUT THIS PORTION OF THE AREA...WITH ONLY STRATOCUMLUS CLOUDS MOVING SSW NOTED. A BROAD INVERTED UPPER TROUGH...ACCOMPANIED BY DRY AIR ALOFT... DOMINATES THE DEEP TROPICS S OF 07N BETWEEN 111W-138W WITH THE PATTERN SHIFTING W WITH TIME. THE UPPER FLOW REMAINS SLIGHTLY DIFFLUENT S OF THE PREVIOUSLY MENTIONED SUBTROPICAL UPPER RIDGE AND TO THE N OF THIS BROAD TROUGH. IT IS ENHANCING THE ISOLATED CONVECTION PREVIOUSLY DESCRIBED BETWEEN 113W-140W. THE RESULTANT DEBRIS MOISTURE APPEARS VERY THIN...AND IS BEING ADVECTED WESTWARD ACROSS THE TROPICS FROM 10N-16N BETWEEN 115W-140W. A SMALL UPPER ANTICYCLONE IS CENTERED NEAR 22N117W WITH AN UPPER RIDGE STRETCHING SE TO A BASE AT 12N111W. UPPER DEBRIS CLOUDINESS FROM THE ITCZ CONVECTION IS BEING ADVECTED WWD OVER THE SOUTHERN PORTION OF THE RIDGE. AN UPPER CYCLONE IS STATIONARY OVER CENTRAL OLD MEXICO AT 23N100W WITH AN UPPER TROUGH EXTENDING SW TO A BASE NEAR 13N109W. AN UPPER ANTICYCLONE IS OVER NICARAGUA WITH ITS ENVELOPE OF ANTICYCLONIC FLOW DOMINATING THE TROPICAL PACIFIC E OF THE JUST DESCRIBED UPPER TROUGH. THE ASSOCIATED DIFFLUENCE IS ENHANCING THE CONVECTION ACROSS THE WATERS E OF 108W. THE RESULTANT DEBRIS MOISTURE FROM THIS CONVECTION HAS MOISTENED THE UPPER LEVELS OF THE ATMOSPHERE N OF 02N BETWEEN 73W-103W. AT THE SURFACE...A RIDGE ASSOCIATED WITH A 1032 MB HIGH CENTER NW OF THE REGION AT 40N149W STRETCHES SE THROUGH 32N140W...AND FURTHER SE TO 16N111W. A WEAK TROUGH IS ALONG A POSITION FROM 12N124W TO 08N127W. THE PRES DIFFERENCE BETWEEN BOTH OF THESE FEATURES IS JUST ENOUGH TO ALLOW FOR NE TRADES AT AROUND 15 KT...TO AT TIMES 20 KT...OVER THE AREA FROM 10N TO 17N AND W OF 130W WITH SEAS OF 5-7 FT. LITTLE CHANGE IS EXPECTED IN THESE CONDITIONS THROUGH THE NEXT 24-48 HRS. SOUTHERLY CROSS EQUATORIAL SWELLS WITH COMBINED SEAS OF 6-8 FT ARE LINGERING ACROSS THE TROPICAL WATERS FROM 06N TO 08N BETWEEN 94W AND 110W...AND ALSO FROM 04N TO 09N BETWEEN 110W AND 120W. WITH THE SWELL ENERGY JUST ABOUT SPENT FROM AFTER SEVERAL DAYS OF IT IMPACTING THE SOUTHERN WATERS...THE 6-8 FT SEAS ARE FORECAST TO LOWER TO LESS THAN 8 FT BY THIS EVENING. $$ AGUIRRE