000
AXPZ20 KNHC 260310
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE SEP 26 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 
0300 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N83W 7N93W 9N110W 9N130W 10N140W. 
SCATTERED MODERATE WITHIN 90-120 NM OF THE AXIS BETWEEN 106W AND 
113W. 

TROPICAL WAVES/LOW PRESSURE...
1007 MB SURFACE LOW CENTERED NEAR 14N113W IS MOVING WWD 10 KT. 
CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ARE 
INDICATED WITHIN 90-120 NM OVER THE W QUADRANT OF THE LOW. 
SHORTWAVE INFRARED SATELLITE IMAGERY REVEALS A RATHER DEFINED 
LOW LEVEL CIRCULATION SITUATED NEAR THE EDGE OF THE CLUSTER OF 
DEEP CONVECTION.  

...DISCUSSION...
BROAD MID TO UPPER LEVEL TROUGH COVERS THE NW PORTION OF THE 
DISCUSSION AREA WITH TWO EMBEDDED CYCLONIC CIRCULATION CENTERS.
THE FIRST CENTERED JUST N OF THE DISCUSSION AREA NEAR 33N126W 
WAS DRIFTING EWD. THE SECOND...AND MORE VIGOROUS CENTER WAS 
SWEEPING EWD INTO THE DISCUSSION AREA NEAR 29N141W AND WAS 
ACCOMPANIED BY AN AREA OF MID TO UPPER LEVEL MOISTURE N OF 23N W 
OF 130W. AXIS OF SUBTROPICAL JTST WAS CARVING OUT THE BASE OF 
THE TROUGH WITH SATELLITE DERIVED WINDS OF 80-100 KT NOTED. A 
BROAD MID-UPPER LEVEL RIDGE/LARGE ANTICYCLONE LIES TO THE SE OF 
THE TROUGH NOTED ABOVE OVER NORTH-CENTRAL MEXICO WITH 
RIDGING/ANTICYCLONIC FLOW  EXTENDING SWWD TO NEAR 17N120W. 
ANOTHER...BUT WEAKER NE-SW ELONGATED UPPER ANTICYCLONE IS 
CENTERED NEAR 16N125W WAS BECOMING ILL-DEFINED WITH TIME. 
A SLIGHT WEAKNESS EXISTS BETWEEN THE TWO ANTICYCLONES. THE MOST 
ACTIVE WEATHER IN THE REGION IS A FEW HUNDRED MILES TO THE S AND 
SW OF THE SRN TIP OF THE BAJA WHERE SCATTERED MODERATE TO STRONG 
CONVECTION WAS ASSOCIATED WITH THE 1007 MB LOW NOTED ABOVE. 

AT THE SURFACE...THE PACIFIC RIDGE IS RATHER WEAK DUE TO THE 
PRESENCE OF A BROAD 1013 MB LOW LOCATED NEAR 32N131W. THE 
RESULTING WEAK PRES GRAD HAS MANIFESTED ITSELF IN WEAKER THAN 
NORMAL TRADES WHICH ARE CONFINED TO THE AREA FROM 11N TO 18N W 
OF 120W. CROSS EQUATORIAL SLY WINDS S OF 6N W OF 100W ARE 
MOSTLY 15 TO 20 KT WITH SLY SWELL 8 TO 10 FT. IN THE EASTERN 
PORTION OF THE REGION...THE TAIL END OF THE GULF OF MEXICO FRONT 
EXTENDS ALONG THE E SLOPES OF THE SRN SIERRA MADRE. HIGH PRES IS 
BUILDING IN BEHIND THE FRONT...WITH A TIGHTENED SFC PRES GRAD 
PRODUCING WINDS 20 TO 25 KT ACROSS CENTRAL AND NRN MEXICO AND 
THE NW GULF. SURFACE OBSERVATIONS AROUND THE GULF OF TEHUANTEPEC 
ALSO INDICATED THAT GAP WINDS HAVE STARTED WITH THE FIRST COLD 
AIR SURGE EVENT OF THE SEASON. THIS EVENT IS EXPECTED TO BE WEAK 
WITH WINDS EVENTUALLY REACHING 20-25 KT BY 24-36 HOURS. 
   
$$
COBB