000 AXPZ20 KNHC 150942 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON JUN 15 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0915 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 10N85W 10N100W 6N111W 7N125W 9N133W 9N140W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 120 NM OF THE AXIS BETWEEN 95W-100W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE AXIS BETWEEN 115W-121W. ...DISCUSSION... A DEEP LAYER TROUGH EXTENDS FROM SOUTHERN CALIFORNIA SW INTO THE AREA THROUGH 32N119W...AND CONTINUES SW TO 25N124W TO 18N128W TO NEAR 11N132W. MODERATE SUBSIDENCE WITH ASSOCIATED DRY AIR UNDER NW FLOW IS PRESENT TO THE W OF THE TROUGH...EXCEPT FOR THE FAR NORTHERN PORTION OF THE AREA WHERE UPPER LEVEL MOISTURE IS SPILLING INTO THE AREA AROUND A LARGE MID/UPPER RIDGE W OF THE AREA ALONG 146W. A WEAK SURFACE TROUGH ASSOCIATED WITH THE DEEP LAYER TROUGH EXTENDS FROM 32N125W SW TO 28N128W TO 26N134W. BROKEN TO OVERCAST LOW AND MID LEVEL CLOUDS WITH POSSIBLE ISOLATED SHOWERS ARE ALONG AND TO THE NW OF THE TROUGH. TO THE SE OF THE DEEP LAYER TROUGH...AN UPPER LEVEL ANTICYCLONE OVER WESTERN MEXICO NEAR 22N104W EXTENDS A RIDGE SW TO 16N113W TO 1N117W. UPPER LEVEL DIFFLUENCE ON ITS SE PERIPHERY HAD EARLIER ENHANCED ITCZ CONVECTION BETWEEN 109W AND 114W. THIS CONVECTION HAS RECENTLY COLLAPSED DUE TO NE FLOW BETWEEN THE ANTICYCLONE OVER MEXICO AND AN UPPER LEVEL LOW JUST S OF THE COAST NEAR THE BORDER OF MEXICO AND GUATEMALA ENTRAINING A SLOT OF DRY AIR OFF SE MEXICO TOWARDS THE ITCZ. SW UPPER FLOW BETWEEN THE TROUGH AND RIDGE IS ADVECTING SOME NARROW PLUMES OF UPPER LEVEL MOISTURE IN THE FORM OF SCATTERED CIRRUS CLOUDS NEWD...BUT ARE ERODING IN A MOSTLY DRY AND STABLE ENVIRONMENT THAT EXISTS TO THE SE OF THE TROUGH AS SEEN ON SATELLITE WATER VAPOR IMAGERY. THE RIDGE IS EXPECTED TO SHIFT N AND WEAKEN SLIGHTLY OVER THE NEXT FEW DAYS AS THE AFOREMENTIONED UPPER LOW CURRENTLY MOVES SW ACROSS THE FAR E PACIFIC WATERS THROUGH TONIGHT...THEN WNW THROUGH WED. THE DEEP LAYER TROUGH IS FORECAST TO SHARPEN AS IT MOVES INLAND THE NORTHERN BAJA CALIFORNIA ON WED...WITH A POSSIBLE CUT-OFF LOW DEVELOPING OFF CENTRAL BAJA BY LATE WED. RECENT RUNS OF THE GLOBAL MODELS SUGGEST THAT BROAD LOW PRES MAY EVENTUALLY DEVELOP OVER THE EASTERN PORTION OF THE DISCUSSION AREA DURING THE WEEK IN THE VICINITY OF THE ITCZ BETWEEN 99W-105W WITH A GENERAL MOVEMENT TOWARDS THE N. AT THE PRESENT TIME IT IS UNCERTAIN AS TO WHETHER THIS SCENARIO WILL BE REALIZED. WILL SEE HOW FUTURE MODEL RUNS CONTINUE TO PORTRAY THIS SCENARIO BEFORE MAKING A DETERMINISTIC FORECAST OF A DEVELOPING LOW. A WEAK MID/UPPER LEVEL RIDGE IS OVER THE FAR WESTERN PORTION OF THE AREA FROM 6N-11N W OF 137W. A SURFACE RIDGE ENTERS THE DISCUSSION AREA THROUGH 28N140W AND STRETCHES SE TO 25N131W ...AND E TO NEAR 25N116W. THE PRES GRADIENT AT THE SOUTHERN PERIPHERY OF THIS RIDGE IS ALLOWING FOR NE TRADE WINDS TO 20 KT TO BE CONFINED FROM 10N-16N W OF 135W AS CONFIRMED BY A QUIKSCAT PASS FROM NEAR 0400 UTC THIS MORNING. THIS AREA OF WINDS IS FORECAST TO CHANGE LITTLE OVER THE NEXT 24 HOURS...THEN DIMINISH IN ABOUT 48 HOURS. THE PRES GRADIENT BETWEEN THE AFOREMENTIONED HIGH AND LOWER PRES OVER MEXICO...AS WELL AS TERRAIN VARIATIONS OVER THE BAJA PENINSULA IS CONTINUING TO PRODUCE NW WINDS OF 20 KT ALONG AND WITHIN ABOUT 150 NM OF THE BAJA CALIFORNIA COAST AS WELL AS FROM 19N-23N BETWEEN 109W-112W. WITH THE SURFACE PATTERN CHANGING VERY LITTLE OVER THE NEXT COUPLE OF DAYS EXPECT THESE NW WINDS TO CONTINUE...BUT WITH A DECREASE IN AREAL COVERAGE. LIKE YESTERDAY...SCATTEROMETER DATA FROM EARLIER THIS MORNING DEPICTED THESE WINDS PRETTY WELL. IN REFERENCE TO MARINE ISSUES...LONG PERIOD S TO SW SWELLS OF 13-15 SECONDS HAVE OVERSPREAD MUCH OF THE EASTERN PORTION OF THE AREA WITH SIGNIFICANT WAVE HEIGHTS TO NEAR 7 FT...EXCEPT UP TO 8 FT S OF THE ITCZ TO 5N BETWEEN 95W-108W. LATEST MODEL GUIDANCE OF WAVE PERIODS AND SIGNIFICANT WAVE GUIDANCES SUGGEST THAT A NEW SWELL TRAIN OF INCREASED PERIODS (IN THE RANGE OF 15-17 SECONDS) WILL EMERGE FROM THE SOUTHERN HEMISPHERE TO ACROSS THE EQUATOR...AND REACH THE COASTS OF CENTRAL AMERICA AND SE MEXICO ON TUE MORNING BEFORE GRADUALLY LETTING UP LATER TUE INTO WED. $$ AGUIRRE