000
AXPZ20 KNHC 192156
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE SEP 19 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 
2145 UTC.

...TROPICAL LOWS...

THE REMNANT LOW OF TROPICAL CYCLONE MIRIAM IS NEAR 22.5N115W 
1011 MB DRIFTING N AND FORECAST TO DISSIPATE BY 30 HOURS. 

LOW PRES NEAR 15N102W 1011 MB LIES UNDER AN UPPER RIDGE WITH 
UPPER DIFFLUENCE FLARING CONVECTION WITHIN 150 NM OVER THE W 
SEMICIRCLE. ANOTHER SURFACE LOW IS APPARENT IN THIS BROAD AREA 
OF LOW PRES NEAR 11N96W ESTIMATED AT 1010 MB...ALSO UNDER THE 
UPPER RIDGE. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
NOTED N OF 11N BETWEEN 90W AND 102W. SCATTERED STRONG CONVECTION 
IS OBSERVED WITHIN 120 NM 16N104W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N85W 10N98W 7N109W 10N124W 7N134W 
8N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 
NM EITHER SIDE OF LINE 5N78W 10N90W 6N120W. 

...DISCUSSION...

AN UPPER CYCLONE OVER THE NW CONUS NEAR 46N120W TRAILS A 
SHORTWAVE TROUGH INTO THE DISCUSSION AREA FROM 32N122W TO A BASE 
AT 25N131W. AN UPPER ANTICYCLONE IS CENTERED AT 24N103W WITH A 
RIDGE EXTENDING W TO CREST NEAR 26N117W. ITS ENVELOPE OF UPPER 
ANTICYCLONIC FLOW DOMINATES THE DISCUSSION AREA N OF 10N BETWEEN 
88W AND 114W. AN INVERTED UPPER TROUGH LIES ALONG 18N124W 3N137W 
AND IS SHIFTING W WITH TIME. 

DRY UPPER AIR INDICATED OVER THE DISCUSSION AREA NW OF LINE 
11N140W 20N126W 25N107W.

A LARGE UPPER ANTICYCLONE IS OVER S AMERICA NEAR 11S64 WITH A 
RIDGE EXTENDING NW ACROSS THE EQUATOR AT 71 WITH ITS CREST 
MERGING WITH THE NE FLOW ASSOCIATED WITH THE MEXICAN 
ANTICYCLONE.

ELSEWHERE AT THE SURFACE A RIDGE EXTENDS ALONG 32N138W 17N118W. 

$$
NELSON