000
AXPZ20 KNHC 191021
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N84W 11N95W 8N103W 12N119W 11N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM 
EITHER SIDE LINE 8N77W 7N101W 5N110W 12N120W 7N133W.

...DISCUSSION...

AN UPPER CYCLONE IS NEAR 50N128W SHIFTING NE AND TRAILING A 
SHORTWAVE TROUGH S THROUGH A SMALL UPPER CYCLONE AT 31N126W WITH 
THE TROUGH CONTINUING SW TO BASE NEAR 21N134W. 

AN UPPER ANTICYCLONE IS CENTERED AT 22N116W WITH A RIDGE 
EXTENDING E TO CREST OVER OLD MEXICO AT 26N105W. JUST TO THE N 
OF THE RIDGE OVER N CENTRAL OLD MEXICO...A TROUGH IS NOTED 
EXTENDING S ACROSS THE CENTRAL CONUS FROM A PARENT CYCLONE OVER 
THE UPPER MIDWEST CONUS.

A BAND OF VERY DRY UPPER AIR IS INDICATED WITHIN 60 NM EITHER 
SIDE OF LINE 28N124W 23N137W...AND IS SURROUNDED BY RELATIVELY 
DRY AIR OVER THE DISCUSSION AREA NW OF LINE 11N140W 21N126W 
22N109W 27N99W.

A SMALL MID TO UPPER CYCLONE THAT SPUN OFF FROM TROPICAL CYCLONE 
MIRIAM IS STILL EVIDENT NEAR 17N126W AND CONTINUES WESTWARD.

AN INVERTED UPPER TROUGH THAT APPEARS TO HAVE CUT OF FROM AN 
ATLC TUTT IS STILL EVIDENT ALONG 17N103W 11N114W AND ACROSS THE 
EQUATOR AT 125W. TO THE E...A LARGE ANTICYCLONE IS CENTERED OVER 
THE N CENTRAL GULF OF MEXICO. ITS ENVELOPE OF ANTICYCLONIC FLOW 
DOMINATES THE DISCUSSION AREA N OF 13N E OF THE INVERTED TROUGH 
TO ABOUT 90W.

A LARGE UPPER ANTICYCLONE IS OVER S AMERICA NEAR 11S61W WITH A 
RIDGE EXTENDING NW ACROSS THE EQUATOR AT 77W TO A CREST AT 
9N85W.

ELSEWHERE AT THE SURFACE A RIDGE EXTENDS ALONG 32N138W 18N122W. 

$$
NELSON