000
AXPZ20 KNHC 021607
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU AUG 02 2007

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1445 UTC.

...SPECIAL FEATURES...
TROPICAL STORM ERICK CENTERED AT 13.6N 130.2W AT 1500 UTC WITH 
CENTRAL PRESSURE OF 1006 MOVING W AT 9 KT.  MAXIMUM SUSTAINED 
WINDS 30 GUSTS TO 40 KT.  ERICK CONTINUES ALONG ITCZ AROUND SRN 
PERIPHERY OF BROAD.  ANY NWD INTRUSION WOULD SPELL ITS DEMISE 
DUE TO THE VERY DRY AIR MASS N OF SYSTEM.  ERICK IS UNDER ELY 
SHEAR ALOFT WHICH KEEPS ITS CONVECTION SEPARATED FROM ITS CENTER 
OF CIRCULATION.  IT HAS PEAKED IN INTENSITY AND EXPECTED TO 
REMAIN AT PRESENT STRENGTH FOR 48 HRS BEFORE FURTHER ADVERSE 
CONDITIONS MARK ITS DOWNTURN.  SEE LATEST NHC FORECAST/ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR ADDITIONAL 
DETAILS.

...TROPICAL WAVE...
TROPICAL WAVE ALONG 115W FROM 8N TO 21N MOVING W 10 KT.  MOST 
CONVECTION STILL EMBEDDED IN ITCZ AXIS HAS NO ORGANIZATION AT 
THIS TIME.  WAVE HAS PLENTY OF MOISTURE AVAILABLE AND NOT AN 
ADVERSE ENVIRONMENT ALOFT WHICH MIGHT TURN MORE FAVORABLE NEXT 
24-36 HRS AS SYSTEM CONTINUES W.  SCATTERED CONVECTION WITHIN 
180 NM W OF AXIS FROM 13N-16N AND WITHIN 210 NM E OF AXIS FROM 
15N17N.

SECOND TROPICAL WAVE S OF HONDURAS TO 7N86W MOVING W AT 20 KT. 
WAVE SHOWS NO SIGNS OF ORGANIZATION AND IS APPROACHING HOSTILE 
ENVIRONMENT ALOFT WITHIN NEXT 12-24 HRS.  UNDER THESE CONDITIONS 
NO DEVELOPMENT IS EXPECTED AT THIS TIME.  

...ITCZ...
ITCZ AXIS ALONG...11N86W  10N99W  15N113W  14N127W  9N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM S OF 
AXIS FROM 94W-103W. SCATTERED MODERATE TO STRONG CONVECTION 
WITHIN 120 NM OF AXIS FROM 110W-120W ALSO ASSOCIATED WITH 
TROPICAL WAVE MENTIONED ABOVE.  SCATTERED MODERATE WITHIN 60 NM 
OF AXIS W OF 136W.

...DISCUSSION...
BROAD MID-UPPER LEVEL RIDGE CENTERED AT 22N136W COVERS MW 
SECTION OF BASIN AND MAINTAINS DRY AIR MASS N OF ITCZ W OF 125W. 
WEAK UPPER LEVEL TROUGH DOWNSTREAM EXTEND FROM 32N127W TO 
20N124W WITH DRY AIR MASS REACHING TO 120W N OF 23N.  GLOBAL 
MODELS HAVE APPROACHING UPPER LEVEL SHORTWAVE TROUGH WELL N OF 
AREA WHICH WOULD HELP LIFT WEAK TROUGH NE IN 24-48 HRS ALLOWING 
RIDGE OVER SW CONUS TO BUILD W INCREASING MOISTURE ADVECTION 
FURTHER W AND EXTENDING LIFE OF TROPICAL WAVE NOW ALONG 115W.

UPPER LEVEL CYCLONIC VORTEX OVER CARIBBEAN SEA AT 15N81W HELPS
DIFFLUENT PATTERN ALONG SRN CENTRAL AMERICA WITH CONVECTION 
DEBRIS CARRIED INTO E PAC FEEDING ITCZ.  

ON THE SURFACE...TRPCL ST0RM ERICK IS E PAC MAIN SPECIAL FEATURE 
AND DISCUSSED ABOVE.  OTHERWISE...WEAK HIGH PRES 1027 MB AT 
37N142W MAINTAINS MODERATE TRADES N OF 29N W OF 120W.  

$$
WALLY BARNES