000
AXPZ20 KNHC 020309
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN AUG 02 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.

...TROPICAL WAVES...
PORTION OF TROPICAL WAVE S OF ITCZ ALONG 87W REMAINS UNDER 
CONVERGING MODERATE NE SHEARING WINDS ALOFT WHICH CURTAILS 
DEVELOPMENT OF CONVECTION.  NRN HALF OF AXIS STILL OVER LAND AND 
DIFFLUENT FLOW ALOFT ENHANCING SCATTERED MODERATE CONVECTION 
OVER WRN COAST OF CENTRAL AMERICA.  WAVE MOVES INTO MORE HOSTILE 
UPPER ENVIRONMENT WITHIN NEXT 48 HRS AND NOT EXPECTED TO BECOME 
BETTER ORGANIZED.

TROPICAL WAVE FROM 03N-16N ALONG 112W MOVING W 15-20 KT PULLING 
AWAY FROM ADVERSE SHEAR ALOFT INTO AREA OF DIFFLUENT FLOW AND 
ABUNDANT TROPICAL MOISTURE AS EVIDENCED BY ITS BURST OF 
SCATTERED DEEP CONVECTION FROM 11N-14N BETWEEN 108W-115W.  MODEL 
GUIDANCE STRENGTHENS WAVE INTO 1010 MB LOW PRES CENTER AT 
09N107W IN 24 HRS AND NEAR 10N112W WITHIN 48 HRS WITH STRONGEST 
WINDS IN SE QUADRANT OF CENTER REACHING STRONG BREEZE.  

TROPICAL WAVE FROM 06N-19N ALONG 131W MOVING W 10-15 KT.  WAVE 
COMING UNDER INFLUENCE OF MID-UPPER LEVEL CYCLONIC VORTEX WITH 
CONFLUENT WIND FLOW ALOFT IN ITS PATH.  DIMINISHED ABILITY TO 
SPIN CONVECTION DOOMS THIS WAVE TO LITTLE MORE THAN A PRODUCER 
OF MODERATE TO FRESH BREEZE WITHIN NEXT 48 HRS.

...ITCZ...
AXIS ALONG 08N78W TO 11N111W TO 09N121W 12N131W TO 07N140W.  
SCATTERED MODERATE CONVECTION WITHIN 120 NM OF AXIS FROM 98W TO 
102W.  SCATTERED MODERATE CONVECTION WITHIN 90 NM OF AXIS W OF 
133W.

...DISCUSSION...
DEEP LAYERED CYCLONIC VORTEX N OF BASIN HAS UPPER LEVEL TROUGH 
EXTEND INTO E PAC FROM 32N125W TO SECOND UPPER LEVEL CIRCULATION 
AT 13N122W.  TROUGH AXIS MAINTAINS AIR MASS WITHIN 600 NM VERY 
DRY AND STABLE AND ALLOWS MID-UPPER LEVEL RIDGE TO MAINTAIN 
ANTICYCLONIC CIRCULATION W OF TROUGH AXIS N OF 12N.  

SECOND UPPER LEVEL RIDGE OVER NRN MEXICO HAS WEAK EXTENSION TO 
17N112W JUST N OF ABOVE MENTIONED TROPICAL WAVE.  RIDGE 
CIRCULATION CONTRIBUTES TO DIFFLUENT FLOW JUST AHEAD OF WAVE 
ENHANCING DEVELOPMENT OF DEEP CONVECTION AND BOOSTING ITS 
PROBABILITY OF STRENGTHENING.  MODEL GUIDANCE PRESENTS THIS 
SCENARIO AS PROBABLE SOLUTION.

FRESH NE BREEZE W OF 138W IS ALL THAT IS LEFT WITHIN E PAC BASIN 
FROM T.S. LANA.  EXPECT THESE TO DIMINISH WITHIN NEXT 12 HRS.  
FOR FURTHER INFORMATION ON T.S. LANA...SEE LATEST PUBLIC 
ADVISORY FROM THE CENTRAL PACIFIC HURRICANE CENTER UNDER 
AWIPS/WMO HEADERS MIATCPEP1/WTPZ31.

GULF OF PAPAGAYO CONDITIONS REMAIN RELATIVELY UNCHANGED THROUGH 
NEXT 48 HRS AS TROPICAL WAVE ALONG 86W PUSHES W PAST AREA.  WIND 
DIMINISHES AFTER WAVE MOVES W AND TRADE WINDS OVER SW CARIBBEAN 
DIMINISH.

CROSS EQUATORIAL LONG PERIOD SW SWELLS WITH SIGNIFICANT WAVE 
HEIGHTS TO 8 FT ENCROACH INTO SRN CENTRAL PORTION OF BASIN S OF 
08N THROUGH FORECAST PERIOD.

$$
WALLY BARNES