000
AXPZ20 KNHC 132201
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN AUG 13 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 86W N OF 6N MOVING W 15 KT HAS LOST MUCH OF 
ITS CONVECTION W OF AXIS DUE TO ADVERSE UPPER ENVIRONMENT.  
SCATTERED MODERATE CONVECTION E OF AXIS OVER CENTRAL AMERICA 
MAINLY DUE TO MASS CONVERGENCE OF MOIST TROPICAL AIR AND DAYTIME 
HEATING OVER MOUNTAINOUS REGION. 

TROPICAL WAVE ALONG 101W N OF 5N MOVING W 15 KT HAS GOOD BURST 
OF MODERATE CONVECTION UNDER FAVORABLE UPPER WINDS AND GOOD 
AMOUNT OF AVAILABLE MOISTURE.  ENVIRONMENT ALOFT JUST AHEAD OF 
WAVE NOT SO AMIABLE AND DRY AIR INTRUSION LIKELY TO ARREST ANY 
SIGNIFICANT DEVELOPMENT.

TROPICAL WAVE ALONG 118W ALSO PRESENTLY HAVING A BURST OF 
CONVECTION DUE TO WELL DEFINED ANTICYCLONIC CIRCULATION ON ITS 
NRN HALF OF AXIS.  CONDITIONS REMAIN SIMILAR FOR NEXT 24 HRS 
WITH ADVERSE CONDITIONS MEETING WAVE AXIS NEAR 123W. 

TROPICAL WAVE ALONG 134W FROM 5N TO 17N MOVING W TO 15 KT.
AIR MASS BECOMING DRIER AND WAVE IS UNABLE TO DEVELOP ANY 
SIGNIFICANT CONVECTION IN SPITE OF FAVORABLE WINDS ALOFT. 

...ITCZ...
ITCZ AXIS ALONG 8N78W 9N86W 11N100W 10N107W 12N117W 10N125W 
10N140W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 
300 NM S OF AXIS FROM 92W TO 97W AND WITHIN 180 NM OF AXIS FROM 
100W TO 103W.   SCATTERED MODERATE CONVECTION WITHIN 180 NM OF 
AXIS FROM 114W TO 129W.  

...DISCUSSION...
N OF 15N...
MID/UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED AT 17N132W 
CONTROL AIR FLOW OVER AREA W OF 127W.  SHARP UPPER LEVEL TROUGH 
FROM 32N123W TO 15N124W CUTS OFF RIDGE EASTWARD EXTENSION 
BRINGING VERY DRY SUBSIDING AIR MASS WITHIN 120 NM OF AXIS.  
SMALL ANTICYCLONIC CIRCULATION AT 16N119W SHOULD BE PUSHED TO 
MERGE WITH LARGER RIDGE OVER SW CONUS WHILE DOWNSTREAM CYCLONIC 
VORTEX DEEPENS.  TO THE EAST...LARGE RIDGE OVER GULF OF MEXICO 
DIGS SW TO 16N94W BRINGING DRY AIR GULF AND YUCATAN PENINSULA. 

S OF 15N...
ITCZ MOISTURE SWATH INTERLACED WITH AREAS OF DRY AIR MASS 
BROUGHT S BY UPPER FEATURES MENTIONED ABOVE.  PRETTY DRY S OF 8N 
ALL ACROSS BASIN.  

AT THE SURFACE...
TRADES DIMINISHING IN STRENGTH AND COVERAGE AS 1034 MB HIGH PRES 
CENTER WEAKENS AND REMAINS N OF 40N.  SIMILARLY N WINDS AND SEAS 
ALONG COAST OF CALIFORNIA ABATING RAPIDLY. 

MODERATE TO STRONG CROSS EQUATORIAL S-SW WINDS BRINGING 8 FT 
SEAS S OF 9N BUT LACKING ENOUGH MOISTURE TO OVERCOME POOR 
UPLIFTING CONDITIONS S OF ITCZ.

$$
WALLY BARNES