000
AXPZ20 KNHC 150356
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT AUG 15 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...SPECIAL FEATURES...

AT 0300 UTC...HURRICANE GUILLERMO AT LOCATED 18.3N 130.3W OR 
ABOUT 1120 NM W-SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA... 
MOVING TOWARD THE WEST OR 285 DEG AT 14 KT. MAXIMUM SUSTAINED 
WINDS ARE 85 KT WITH GUSTS TO 105 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS ESTIMATED AT 972 MB. GUILLERMO IS EXPECTED TO WEAKEN 
GRADUALLY AS IT MOVES SLOWLY WESTWARD OVER THE NEXT COUPLE OF 
DAYS.  SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. 

...TROPICAL WAVES...

A TROPICAL WAVE WAS ANALYZED ALONG 80W N OF 04N MOVING WEST AT 
15 KT. CONVERGENCE AHEAD OF THE WAVE WAS ENHANCING CONVECTION 
ALONG THE ITCZ BETWEEN 85W AND 90W.

A TROPICAL WAVE WAS ANALYZED ALONG 90W N OF THE ITCZ WITH 
WESTWARD MOTION ESTIMATED AT 15 TO 20 KT.

A TROPICAL WAVE IS ANALYZED 107W AND HAS BEEN MOVING W AT 20 
KT...CHASING AN UPPER LOW MOVING SLOWLY WEST THROUGH 17N110W. 
THIS WILL LIKELY HELP CONVECTION FLARE ALONG THE TROPICAL WAVE 
IN THE NEXT SEVERAL HOURS. 

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG 09N84W TO 
10N113W TO 17N127W TO 10N140W. SCATTERED MODERATE CONVECTION 
WITHIN 180 NM S OF AXIS BETWEEN 85W AND 90W. SCATTERED MODERATE 
CONVECTION WITHIN 180 NM S OF AXIS BETWEEN 105W AND 110W. 

...DISCUSSION...

E OF 115W...A BROAD UPPER ANTICYCLONE IS CENTERED OVER SOUTHERN 
MEXICO NEAR 18N95W. SUBSIDENT NORTHERLY FLOW ALOFT IS 
SUPPRESSING THROUGH HONDURAS AND INTO THE EASTERN PACIFIC OFF 
NICARAGUA. HOWEVER...ACTIVE CONVECTION PERSISTS ALONG THE ITCZ E 
OF 100W AIDED BY LOWER LEVEL CONVERGENCE AHEAD OF THE TROPICAL 
WAVE ALONG 92W. FURTHER WEST...AN UPPER LOW IS CENTERED NEAR 
17N111W. DIVERGENT FLOW ALOFT SE OF THE UPPER LOW WAS ENHANCING 
CONVECTION FROM 10N TO 15N BETWEEN 100W AND 110W. MOST OF THIS 
IS DIMINISHING CURRENTLY HOWEVER...BUT MAY REIGNITE BY EARLY 
MORNING. A SCATTEROMETER PASS FROM 12Z SHOWED A SMALL AREA OF 20 
KT WINDS THROUGH THE GULF OF TEHUANTEPEC. THE TROPICAL WAVE 
MOVING THROUGH 90W MAY KEEP WINDS TO 20 KT THROUGH TEHUANTEPEC 
INTO SAT. SIMILARLY GAP WIND FLOW THROUGH THE GULF OF PAPAGAYO 
HAD DIMINISHED BELOW 20 KT...BUT EARLY MORNING DRAINAGE FLOW MAY 
EXCEED 20 KT OVER THE NEXT COUPLE OF DAYS.

W OF 115W...AN UPPER ANTICYCLONE IS CENTERED NEAR 
26N124W...PROVIDING VENTILATION TO CONVECTION OVER GUILLERMO 
MOVING WESTWARD TO THE SW OF THE UPPER ANTICYCLONE. ASCAT DATA 
FROM AROUND 19Z SHOWED AN AREA OF 20 KT SOUTHERLY WINDS 
CONVERGING NORTHWARD TOWARD GUILLERMO N OF 05N BETWEEN 125W AND 
130W. FURTHER TO THE WEST...THE REMNANT LOW OF T.D. NINE-E 
CONTINUES TO SPIN NEAR 11N139W WITH AN ESTIMATED PRESSURE OF 
1009 MB. CONVECTION HAS FLARED OVER THE PAST SEVERAL HOURS NEAR 
THE CENTER OF THIS LOW...LIKELY DUE TO DIVERGENT SOUTHERLY FLOW 
ALOFT BETWEEN UPPER ANTICYLONE AT 26N124W AND AN UPPER TROUGH NE 
OF HAWAII. THIS FEATURE IS NEARLY STATIONARY...BUT WILL SLOWLY 
MEANDER WESTWARD OVER THE NEXT COUPLE OF DAYS WITH A LOW 
PROBABILITY THAT IT WILL RE-INTENSIFY.

$$
CHRISTENSEN