000
AXPZ20 KNHC 061004
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT JUN 06 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.

...TROPICAL WAVE...
THE TROPICAL WAVE THAT WAS ALONG 89W N OF 04N TO 12N89W HAS BEEN 
DROPPED FROM THE 06Z SURFACE MAP AS IT HAS BECOME INCREASINGLY 
DIFFICULT TO DETECT...AND HAS NOT SHOWN A SURFACE SIGNAL IN 
SEVERAL DAYS. WEAK ELONGATED CYCLONIC TURNING CONTINUES ACROSS 
THE TROPICAL EPAC ALONG 09-10N BETWEEN 90W AND COLOMBIA 
ASSOCIATED WITH THE CLIMATOLOGICAL MONSOON CIRCULATION. THE ITCZ 
HERE REMAINS VERY ACTIVE UNDER EXCELLENT DIVERGENCE ALOFT. A 
1010 MB SURFACE LOW HAS BECOME APPARENT NEAR 07N 85.5W AND WAS 
DRIFTING W. TOTAL PRECIPITABLE WATER ANIMATIONS OF THE PAST FEW 
DAYS SUGGEST THE WAVE MAY HAVE FRACTURED...WITH A NORTH PORTION 
MOVING ACROSS THE SRN CARIB AND THEN MORE NW ACROSS THE SW AND W 
CARIB THE PAST TWO DAYS...WHILE WE HAVE FOLLOWED A WEAK 
SIGNATURE ALOFT MOVING SLOWLY W ACROSS THE EPAC. VISIBLE IMAGERY 
TODAY MAY YIELD MORE DECISIVE CLUES.

...ITCZ...
AXIS EXTENDED FROM COASTAL COLOMBIA WWD ACROSS PANAMA AND COSTA 
RICA TO THE GULF OF PAPAGAYO...AND THEN W ALONG 10N TO 09N96W TO 
A 1010 MB LOW NEAR 07N85.5W TO 08N89W TO 08N110W TO 11.5N128W TO 
09N140W. SCATTERED TO LOCALLY NUMEROUS MODERATE CONVECTION WAS 
OCCURRING WITHIN 240 NM EITHER SIDE OF AXIS E OF 90W. ISOLATED 
MODERATE CONVECTION WAS LOCATED WITHIN 45 NM OF AXIS BETWEEN 
115W AND 108W. SCATTERED CONVECTION WAS ALSO WITHIN 90 NM N OF 
AXIS W OF 122W.

...DISCUSSION...
E OF 110W...
A BROAD UPPER RIDGE IS CENTERED NEAR 15N106W. NORTHERLY 
MID/UPPER LEVEL FLOW ON THE EAST SIDE OF THE UPPER ANTICYCLONE 
AND SW OF A SHARP MID TO UPPER TROUGH ACROSS THE E AND SE U.S. 
IS PRODUCING CONVERGENT FLOW AND DEEP LAYERED DRY SINKING AIR 
ACROSS SRN MEXICO. THIS UPPER FLOW IS ENCOUNTERING SE 
FLOW OFF COLOMBIA...REPRESENTING A LARGE DEFORMATION ZONE IN THE 
UPPER PATTERN OVER CENTRAL AMERICA E OF 90W...AS WELL AS THE 
IMMEDIATE ADJACENT WATERS OF THE EPAC AND THE SW CARIBBEAN.  
ASSOCIATED DIVERGENCE ALOFT IS CONTINUING TO ENHANCE A WIDE AREA 
OF CONVECTION ALONG AND NEAR THE ITCZ. DUE TO PERSISTENT UPPER 
DIVERGENCE...CONVECTION WILL CONTINUE TO FLARE OVER THIS AREA 
DURING THE NEXT COUPLE OF DAYS. GLOBAL MODELS SLOWLY LIFT THE 
ITCZ NWD INTO THE CARIBBEAN OVER THE WEEKEND...AND DEVELOP A 
BROAD AND ELONGATED CYCLONIC CIRCULATION FROM THE W COAST OF 
COSTA RICA NE INTO THE SW CARIBBEAN...AND SLOWLY DRIFT THIS 
FEATURE NWD THROUGH WED. THIS WOULD REPRESENT A VERY WET PATTERN 
FOR THE REGION IF THIS EVOLVES AS FORECAST...POSSIBLY MORE 
SIGNIFICANT ON THE CARIBBEAN SIDE.  

FURTHER NORTH...SATELLITE IMAGERY AND A RECENT PARTIAL QUIKSCAT 
PASS CONTINUE TO SUGGEST NORTHERLY FLOW THROUGH THE GULF OF 
TEHUANTEPEC...STILL NEAR 20 KT OVERNIGHT. THIS FLOW IS EXPECTED 
TO SHUT DOWN BY TONIGHT AS SELY FLOW DEVELOPS ACROSS THE GULF OF 
MEXICO. 

W OF 110W...
A BROAD UPPER TROUGH CONTINUES FROM CENTRAL CALIFORNIA SW 
THROUGH 19N140W TO S OF HAWAII. SA SURFACE RIDGE EXTENDS FROM 
1026 MB HIGH PRES CELL NEAR 32N145W WITH A SURFACE RIDGE 
EXTENDING THROUGH 24N112W. WINDS ARE LIKELY REACH NEAR 20 KT 
ALONG THE W COAST OF THE BAJA...BETWEEN THE RIDGE AXIS AND 
THE TERRAIN...ALTHOUGH THIS MAY BE TRENDING DOWN AS THE RIDGE 
WEAKENS. A WEAK COLD FRONT IS MIGRATING THROUGH THE NORTHERN 
GULF OF CALIFORNIA. MORNING DRAINAGE FLOW ALONG WITH STRONG MID 
LEVEL FLOW MAY ALLOW W WINDS TO REACH 20 KT IN THE EARLY MORNING 
HOURS OVER THE FAR NORTHERN GULF OF CALIFORNIA. FURTHER 
SOUTH...A WEAK TROUGH WAS INDICATED ALIGNED SW TO NE THROUGH THE 
ITCZ NEAR 130W. THE PRESSURE GRADIENT BETWEEN THE SURFACE RIDGE 
AND THIS TROUGH WAS PRODUCING A SWATH OF 20 KT WINDS TO THE W OF 
THE TROUGH S OF 17N TO THE ITCZ AND W BEYOND 140W...WHERE SEAS 
WERE RUNNING 8 FT IN MIXED S SWELL AND NE WIND WAVES.

MODEST LONG PERIOD SSW SWELL FROM THE SOUTHERN HEMISPHERE 
CONTINUES TO PROPAGATE NEWD THROUGH THE ENTIRE AREA...WITH A NEW 
PULSE CURRENTLY APPROACHING THE GALAPAGOS ISLANDS THAT WILL 
REACH THE CENTRAL AMERICAN COASTLINES SUN MORNING. GLOBAL MODELS 
ARE DEVELOPING A VERY TIGHT PRESSURE GRADIENT BETWEEN A SRN HEMI 
GALE CENTER AND A HIGH TO ITS W AND SW...EFFECTING A RELATIVELY 
LONG AND SUSTAINED FETCH SUN THROUGH TUE. THIS WILL GENERATE 
LARGE SW SWELL THAT WILL AFFECT THE ENTIRE PACIFIC W COAST OF 
THE AMERICAS N OF 10S. LARGE AND POWERFUL SURF SHOULD BE 
EXPECTED ALL ALONG THE EXPOSED PACIFIC COASTS OF SOUTH AND 
CENTRAL AMERICA...THU THROUGH SAT.   

$$
STRIPLING