000 AXPZ20 KNHC 171035 AAA TWDEP TROPICAL WEATHER DISCUSSION...UPDATED NWS NATIONAL HURRICANE CENTER MIAMI FL 1030 UTC WED JUL 17 2013 UPDATED CONVECTION 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 1015 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ANALYZED FROM 16N106W TO 10N107W MOVING W 10- 15 KT. EARLIER SCATTERED CONVECTION NOTED HAS DIMINISHED OVER THE PAST FEW HRS. LATEST SATELLITE IMAGERY SHOWS SCATTERED MODERATE CONVECTION OCCURRING WITHIN 180 NM E OF THE WAVE AXIS FROM 13N-16N. WIDELY SCATTERED SHOWERS AND TSTMS ARE ELSEWHERE WITHIN 240 NM E AND 180 NM W OF THE WAVE AXIS...WITH THE EXCEPTION OF NEW SCATTERED MODERATE/ISOLATED STRONG CONVECTIVE ACTIVITY WITHIN 45 NM OF 12N108W. SCATTEROMETER DATA FROM YESTERDAY AFTERNOON SUGGESTED THAT WINDS WERE RATHER LIGHT...IN THE 10-15 KT RANGE...ACROSS AND NEAR THE WAVE. MODELS HAVE A PRETTY GOOD HANDLE IN DEPICTING THE WAVE TO CONTINUE ON A GENERAL WESTWARD TRACK THROUGH FRI WHILE GRADUALLY BECOMING LESS DEFINED. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W FROM THE COAST OF COLOMBIA AT 10N76W...AND EXTENDS TO 08N90W TO 12N106W TO 11N120W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN INTERTROPICAL CONVERGENCE ZONE. THE ITCZ THEN CONTINUES WSW TO 10N130W AND TO BEYOND 09N140W. SCATTERED STRONG CONVECTION SEEN FROM 02N-08N E OF 80W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM S OF THE TROUGH BETWEEN 105W-110W...BETWEEN 114W-117W... ...WITHIN 120 NM S OF TROUGH BETWEEN 99W-106W AND WITHIN 120 NM S OF THE ITCZ AXIS W OF 128W. ...DISCUSSION... W OF 120W... A WELL-DEFINED UPPER LOW LIFTING NNW IS CENTERED AT 23N124W. A TROUGH EXTENDS FROM THE LOW N TO A SHARP CREST AT 29N123W WHILE THE CYCLONIC CIRCULATION EXTENDS 390 NM SW AND 270 NM SE QUADRANTS OF THE CENTER. SINCE THE LOW IS WITHIN A VERY DRY AND STABLE ENVIRONMENT AS SEEN BY THE VERY STRONG SUBSIDENCE IN WATER VAPOR IMAGERY NO CONVECTION IS OCCURRING IN CLOSE PROXIMITY TO THE LOW. A RECENTLY DEVELOPED CLUSTER OF SCATTERED STRONG CONVECTION IS WITHIN 60 NM OF 13N132W. BROKEN TO OVERCAST STRATOCUMLUS CLOUDS MOVING WSW ARE SEEN FROM 19N-24N BETWEEN 120W-130W...AND FROM 16N-27N W OF 130W. TO THE W OF THE LOW...AN UPPER ANTICYCLONE IS AT 25N131.5W WITH A RIDGE NE TO 29N126W ...AND ANOTHER RIDGE SW TO A LARGER UPPER ANTICYCLONE SW OF THE AREA AT 13N145W. WELL TO THE THE NW OF RIDGE AND ANTICYCLONES... ...A BROAD UPPER TROUGH IS NOTED WITH THE RESULTANT FLOW BETWEEN BOTH OF THESE FEATURES BEING SWLY. DRY AND STABLE ATMOSPHERIC CONDITIONS ALSO NOTED ACROSS THE REMAINDER OF THIS PORTION OF THE AREA IS SUPPRESSING ANY CONVECTION FROM DEVELOPING WITH THE EXCEPTION OF THE DEEP TROPICS NEAR AND ALONG THE ITCZ WHERE ACTIVE CONVECTION AS DESCRIBED ABOVE IS UNDERNEATH THE UPPER RIDGE. THE DEBRIS CLOUDINESS ASSOCIATED WITH THIS CONVECTION IS BEING ADVECTED SSW TO NEAR 04N DUE TO THE CLOCKWISE FLOW WITH THE RIDGE. LITTLE OVERALL CHANGES ARE EXPECTED WITH THE CURRENT UPPER PATTERN IN PLACE THROUGH FRI. THE UPPER LOW WILL MOVE MORE TO THE N TODAY AND TONIGHT BEFORE IT BECOMES ABSORBED INTO THE PREVAILING SW FLOW. AT THE SURFACE TO LOW LEVELS...STRONG HIGH PRES OF 1036 MB N OF THE AREA EXTENDS A RIDGE SE THROUGH 32N138W TO 26N117W. HIGH PRES COVERS THE AREA N OF 20N W OF 116W. A WEAK TROUGH EXTENDS FROM 13N129W TO 101N31W. THE PRES GRADEINT BETWEEN THE TROUGH AND RIDGE IS JUST TIGHT ENOUGH TO PRODUCE NE TRADE WINDS OF 15- 20 KT NW OF TROUGH TO ABOUT 21N...WITH SEAS OF 6-7 FT. THE TROUGH WILL MOVE TO NEAR 133W/134W TONIGHT...AND TO NEAR 139W/140W BY THU NIGHT. THE ASSOCIATED NE 15-20 KT WINDS WILL SHIFT WESTWARD AS WELL WITH THE TROUGH. NW WINDS OF 15-20 KT ARE EXPECTED N OF 25N W OF THE BAJA PENINSULA TO ALONG 122W ON THU...WITH ASSOCIATED SEAS TO 7 FT. E OF 120W... THE ATMOSPHERE OVER THIS PORTION OF THE AREA HAS MOISTENED OVER THE PAST 48 HRS. AN UPPER RIDGE EXTENDS FROM THE WESTERN U.S. SSE TO OVER NW AND W CENTRAL MEXICO. AN INVERTED MID-LEVEL TROUGH HELPING TO ENHANCE CONVECTION ALONG AND NEAR THE MONSOON TROUGH TO SOME EXTENT IS NOTED TO THE S OF THE RIDGE ALONG 111W FROM 12N-19N. A SMALL ANTICYCLONE OVER NORTHERN NICARAGUA EXTENDS A RIDGE SSW TO 07N87W. ANTICYCLONIC FLOW FROM THIS RIDGE...AND THE ONE FROM THE WESTERN U.S. IS TRANSPORTING ABUNDANT MID/UPPER LEVEL MOISTURE FROM THE MONSOON RELATED CONVECTION WESTWARD TO NEAR 119W BEFORE IT EVAPORATES IN DRIER AIR. OVER THE FAR NE CORNER...NW WINDS OF NW WINDS OF 15-20 KT ARE EXPECTED TO BEGIN TONIGHT N OF 27N E OF 117W. THESE WINDS THEN EXPAND WESTWARD THU AND FRI WITH SEAS THERE TO 7 FT. BROAD LOW PRES IS FORECAST BY THE NWP MODELS TO BEGIN TO MATERIALIZE ACROSS THE FAR EASTERN PORTION ON FRI. GULF OF PAPAGAYO...NE WINDS WILL INCREASE BRIEFLY TO 15 KT LATE EACH NIGHT AND CONTINUE UNTIL AFTER SUNRISE EACH MORNING THROUGH FRI MORNING. S SWELLS RESULTING IN COMBINED SEAS TO 9 FT ARE PRESENT TO THE S OF A LINE FROM 00N97W TO 07N115W TO 00N126W. THESE SWELLS WILL DIMINISH SOME IN ENERGY THROUGH THE NEXT 24-48 HRS...HOWEVER LONG PERIOD SW SWELL ENERGY WITH PERIODS OF 19-21 SEC SHOULD REACH THE COAST OF CENTRAL AMERICA...THE COAST OF MUCH OF MEXICO INCLUDING THE SOUTHERN GULF OF CALIFORNIA...TODAY AND TONIGHT THEN SLOWLY DIMINISH FRI. $$ AGUIRRE