000 AXPZ20 KNHC 171004 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED JUN 17 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 0945 UTC. ...SPECIAL FEATURE... A SMALL LOW PRES CENTER OF 1008 MB IS NEAR 15N106W...OR ABOUT 350 MILES SSW OF MANZANILLO MEXICO MOVING WNW 7 KT. THE LOW IS PART OF AN ESTABLISHED MONSOON TROUGH CIRCULATION OCCURRING BETWEEN 101W AND 116W. SATELLITE IMAGERY DURING YESTERDAY AND EARLY THIS MORNING HAS REVEALED OTHER SIMILAR SMALL LOW LEVEL CENTERS ROTATING CYCLONICALLY WITHIN THE TROUGH. THE LOWS HAVE APPEARED INTERMITTENTLY ALONG THE NRN EDGE OF SPORADIC CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION PRIMARILY TO THE S OF THE LOW AND TROUGH. RECENT SATELLITE IMAGERY SHOWS A STRONG TSTM CLUSTER INCREASING IN SIZE JUST OVER THE W SIDE OF THE THE LOW CENTER WITHIN ABOUT TO THE 75 NM. ITS APPEARS THAT NE UPPER LEVEL WINDS EARLIER RESPONSIBLE FOR THE NE SHEAR THAT INHIBITED CONVECTION FROM DEVELOPING TO ITS N HAS NOW DECREASED. A HIGH RESOLUTION QUIKSCAT PASS FROM AROUND 0124 UTC THIS MORNING REVEALED S-SW WINDS OF 20 TO 25 KT WITHIN 220 NM IN THE SE QUADRANT OF THE LOW...AND ALONG THE SRN PERIPHERY OF THE TROUGH WITH SE-S WINDS OF MAINLY 20 KT WITHIN 150 NM IN THE NE QUADRANT. FURTHER DEVELOPMENT OF THIS SYSTEM IS POSSIBLE AS LOW CLOUD LINES ARE EVIDENT UNDER THE DEVELOPING CONVECTION ARE EVIDENT ON IR SHORTWAVE SATELLITE IMAGERY SPIRALING CYCLONICALLY INWARD TOWARDS THE LOW CENTER. THE LOW IS FORECAST TO GENERALLY MOVE WNW DURING THE NEXT COUPLE OF DAYS WITH THE POTENTIAL TO BECOME A TROPICAL DEPRESSION AS THERE IS A HIGH CHANCE...GREATER THAN 50 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N77W 8N90W 12N102W 10N115W 7N125W 6N140W. SCATTERED STRONG CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 108W-114W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM S OF THE AXIS W OF 127W...AND WITHIN 60 NM OF THE AXIS BETWEEN 96W-102W. ...DISCUSSION... A SHARPENING DEEP LAYER EXTENDS FROM NORTHERN BAJA CALIFORNIA SW INTO THE AREA THROUGH 32N121W...AND CONTINUES SW TO 22N123W WHERE IT BECOMES A SHEAR AXIS TO 19N131W AND TO A LOW MOVING WWD NEAR 16N136W. A TROUGH THEN EXTENDS FROM THE LOW S TO 8N136W TO 3N136W. MODERATE TO STRONG SUBSIDENCE INDICATING VERY DRY AND SUPPRESSES ATMOSPHERIC CONDITIONS IS NOTED WITHIN 220 NM EITHER SIDE OF THE TROUGH FROM 22N TO 25N...AND FROM 18N TO 23N BETWEEN 123W AND 131W...AND ALSO FROM 12N TO 23N W OF 131W. AN AREA OF WIDESPREAD UPPER LEVEL MOSITURE N OF THE REGION CONTINUES TO SPILL SWD INTO THE NE PORTION OF THE AREA AS IT WORKS AROUND A LARGE UPPER ANTICYCLONE CENTERED JUST N OF THE AREA NEAR 33N137W WITH A RIDGE SE TO 23N125W. AT THE SURFACE...THE ASSOCIATED SURFACE HIGH IS ANALYZED W OF THE AREA NEAR 32N145W WITH A PRES OF 1026 MB. A RIDGE EXTENDS FROM THE HIGH SE TO 29N131W TO 26N120W. THE PRES GRADIENT AT THE SOUTHERN PERIPHERY OF THIS RIDGE IS ALLOWING FOR NE TRADE WINDS TO 20 KT TO BE CONFINED FROM 9N TO 19N W OF 134W AS CONFIRMED BY A QUIKSCAT PASS FROM 0300 UTC THIS MORNING. THIS AREA OF WINDS IS FORECAST TO SHIFT NWD IN 24 HOURS FROM 14N TO 27N W OF 135W...AND TO NW OF A LINE FROM 30N122W TO 23N130W TO 18N140W IN 48 HOURS. LATEST SATELLITE IMAGERY SHOWERS SCATTERED TO BROKEN STRATOCUMULUS CLOUDS ARE MOVING SSW N OF 20N AND W OF 120W IN RESPONSE TO LOW-LEVEL FLOW DUE TO THE RIDGE. TO THE E OF THE DEEP LAYER TROUGH...A SMALL UPPER ANTICYLONE IS E OF THE AREA OVER SRN TEXAS WITH A RIDGE EXTENDING SW TO 23N106W TO 19N110W TO 17N113W. A SMALL UPPER LEVEL LOW IS JUST ALONG THE COAST OF MEXICO NEAR 18N103W. A SMALL AREA OF DIVERGENCE ALOFT BETWEEN THE LOW AND AND THE RIDGE IS PRODUCING SCATTERED MODERATE CONVECTION ALONG THE MEXICAN COAST FROM 18N TO 20N W TO 106.5W. THE RIDGE IS EXPECTED TO SHIFT N AND WEAKEN SLIGHTLY OVER THE NEXT FEW DAYS AS THE UPPER LOW BEGINS TO MOVE NW. THE DEEP LAYER TROUGH IS FORECAST TO MOVE INLAND THE NORTHERN BAJA CALIFORNIA THROUGH FRI AS A CUT-OFF UPPER LOW FORMS OVER NORTHERN NORTHERN BAJA CALIFORNIA LATE BY THU...THEN LIFTS NE TOWARDS THE SW U.S. FRI AND SAT. THE PRES GRADIENT BETWEEN THE HIGH MENTIONED ABOVE AND LOWER PRES OVER MEXICO IS RESULTING IN AN AREA OF NW WINDS TO 20 KT ALONG A PORTION OF THE BAJA CALIFORNIA COAST FROM 23N TO 27N E OF 116W. THESE WINDS ARE EXPECTED TO CHANGE IN 24 HOURS...THEN DIMINISH TO LESS THAN 20 KT BY 48 HOURS. IN REFERENCE TO MARINE ISSUES...LONG PERIOD S TO SW SWELLS OF 14-15 SECONDS WITH WAVE HEIGHTS OF 3 TO 5 FT IS MOVING INTO PORTIONS OF THE SOUTHERN MEXICAN AND NORTHERN CENTRAL AMERICAN PACIFIC COASTLINES...BUT SHOULD DIMINISH THIS MORNING AND THROUGH THE AFTERNOON. THIS SHOULD RESULT IN MODERATE SURF ALONG EXPOSED COASTLINES...AS WELL AS STRONG RIP CURRENTS WITHIN THE SURF ZONE. $$ AGUIRRE