000 AXPZ20 KNHC 011525 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SAT AUG 01 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1300 UTC. ...TROPICAL WAVES... TROPICAL WAVE ALONG 84W N OF THE EQUATOR TO COAST OF SOUTHERN COSTA RICA THEN CONTINUES N INTO THE CARIBBEAN ALONG 82W MOVING W 15 KT TO 20 KT. NO SIGNIFICANT CONVECTION ASSOCIATED WITH THIS TROPICAL WAVE. TROPICAL WAVE FROM 02N TO 16N ALONG 110W MOVING W 15 KT TO 20 KT. SCATTERED MODERATE CONVECTION CAN BE FOUND WITHIN 120 NM E AND 270 NM W OF THE TROPICAL WAVE AXIS FROM 09N TO 14N IN A REGION OF UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE UPPER LEVEL RIDGE AXIS ALONG 108W N OF 10N TO THE GULF OF CALIFORNIA COAST. TO THE NORTH OF THE TROPICAL WAVE...SCATTERED MODERATE CONVECTION CAN BE FOUND WITHIN 60 NM OF THE MEXICAN COAST FROM 18N TO 21N IN ANOTHER DIFFLUENT REGION FOUND BETWEEN THE UPPER RIDGE AXIS AND AN UPPER TROUGH CENTERED ALONG THE CENTRAL MEXICAN COAST. TROPICAL WAVE FROM 04N TO 19N ALONG 127W MOVING W 10 KT TO 15 KT. ONLY ISOLATED SHOWERS ARE ALONG THE WAVE. ...ITCZ... THE ITCZ AXIS LIES ALONG A LINE FROM 08N78W TO 10N94W TO 11N125W TO 09N140W. SCATTERED MODERATE CONVECTION CAN BE FOUND WITHIN 180 NM S OF THE ITCZ AXIS BETWEEN 94W AND 98W WHILE ISOLATED MODERATE CONVECTION LIES WITHIN 180 NM S OF THE ITCZ AXIS W OF 134W. ...DISCUSSION... N OF 20N... A DEEP LAYERED LOW PRES SYSTEM N OF THE FORECAST AREA HAS A SURFACE TROUGH THAT EXTENDS SOUTH FROM 30N128W TO 27N134W. A SURFACE RIDGE AXIS LIES S OF THE TROUGH ALONG 26N W OF 123W AND CONTINUES SOUTHEASTWARD TO 17N106W. BROKEN TO OVERCAST STRATOCUMULUS CLOUDS BLANKET THE AREA N OF 20N W OF 115W WITH THE EXCEPTION OF THE FAR NW CORNER WHERE THE OVERCAST STRATOCUMULUS IS BROKEN UP NW OF THE LOW LEVEL TROUGH AXIS. SOUTHERLY FLOW ON THE EAST SIDE OF THE TROPICAL WAVE ALONG 110W HAS BROUGHT A SURGE OF HIGHER PRECIPITABLE WATER VALUES NORTHWARD INTO THE CENTRAL GULF OF CALIFORNIA. DEW POINTS IN LOS MOCHIS AND HERMOSILLO WERE BOTH 73 DEGREES FAHRENHEIT AT 1400 UTC. AFTERNOON THUNDERSTORMS ARE EXPECTED TO BECOME MORE WIDESPREAD OVER THE NEXT TWO DAYS AS THIS MOISTURE MAKES ITS WAY INTO MAINLAND NW MEXICO AND THE U.S. DESSERT SW. S OF 20N... THE EFFECTS OF T.S. LANA CONTINUE TO BE FELT OVER FORECAST WATERS W OF 137W FROM 13N TO 20N WHERE WINDS OF 20 KT AND SEAS OF 8 FT CAN BE FOUND. BOTH THE 0338 UTC QUIKSCAT AND 0716 ASCAT PASSES CONFIRM THESE WINDS. EXPECT THE IMPACTS FROM LANA TO DIMINISH BY TOMORROW MORNING AS THE SYSTEM PASSES SOUTH OF THE HAWAIIAN ISLANDS. FOR FURTHER INFORMATION ON T.S. LANA...PLEASE SEE THE LATEST PUBLIC ADVISORY FROM THE CENTRAL PACIFIC HURRICANE CENTER UNDER AWIPS/WMO HEADERS MIATCPEP1/WTPZ31. THE HIGH RESOLUTION QUIKSCAT RETRIEVALS FROM 1118 UTC SHOW THE RETURN OF 20 KT TO 25 KT WINDS IN THE GULF OF PAPAGAYO. EXPECT CONDITIONS TO REMAIN RELATIVELY UNCHANGED THROUGH TODAY AND TOMORROW MORNING AS THE TROPICAL WAVE CURRENTLY ALONG 84W PUSHES THROUGH THE AREA. WINDS WILL DIMINISH TO 20 KT ON MON AFTER THE WAVE MOVES OFF TO THE WEST AND TRADE WINDS OVER THE SW CARIBBEAN DIMINISH...DECREASING THE LOW LEVEL GAP WINDS THROUGH COSTA RICA AND NICARAGUA. LONG PERIOD SOUTHWESTERLY SWELL HAS CROSSED THE EQUATOR WITH SIGNIFICANT WAVE HEIGHTS TO 9 FT IN THE CENTRAL PORTION OF THE FORECAST AREA S OF 07N. THIS LONG PERIOD SWELL TRAIN WILL CONTINUE NORTH-NORTHEAST...REACHING THE SOUTHERN BAJA AND CENTRAL MEXICAN COASTS SUN MORN AND THE REMAINDER OF THE CENTRAL AMERICAN COAST BY MON MORN. HOWEVER...SIGNIFICANT WAVE HEIGHTS ARE NOT EXPECTED TO EXCEED 6 FT ALONG THE COAST AS THIS SWELL MOVES IN. $$ SCHAUER CLARK