000
AXPZ20 KNHC 250931
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON SEP 25 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...ITCZ...
INTERTROPICAL CONVERGENCE ZONE...8N78W 9N104W 9N130W 11N135W 
9N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION WITHIN 
30 NM EITHER SIDE OF A LINE FROM 6N88W TO 7N98W AND FROM 6N106W 
TO 10N116W. ISOLATED MODERATE NEAR 10N123W 14N132W AND 9N139W.

OTHER CONVECTION NEAR THE COAST...ISOLATED STRONG NEAR THE 
PANAMA COAST AT 8N80W. ISOLATED MODERATE NEAR COSTA RICA COAST 
AT 10N86W. SCATTERED MODERATE WITHIN 45 NM OF 14N95W. SCATTERED 
STRONG NEAR MEXICAN COAST FROM 15N99W TO 17N103W.

TROPICAL LOW...
NONE.

...DISCUSSION...

IN THE MID LEVELS TONIGHT A LARGE CLOSED LOW WAS LOCATED NEAR 
33N125W. WATER VAPOR IMAGERY SHOWS THE SYSTEM REMAINS FAIRLY DRY 
ALOFT AND DRIFTING NE. A PERSISTENT MID LEVEL RIDGE CONTINUES 
OVER MEXICO W AND SW TO 22N120W. WATER VAPOR SHOWS THE RIDGE 
LOADED WITH CONVECTIVE MOISTURE..PARTICULARLY OVER THE LAND 
AREAS. ON THE SURFACE TONIGHT THE PACIFIC RIDGE IS QUITE WEAK 
AND NE TRADES ARE CONFINED TO BETWEEN 10N AND 20N W OF 115W. A 
WEAK LOW WAS EMBEDDED IN THE RIDGE NEAR 31N129W DRIFTING W. GAP 
WINDS REMAIN LIGHT AS WELL AS NW WINDS ALONG THE BAJA COAST. 
CROSS EQUATORIAL SLY WINDS S OF 5N WERE MOSTLY 15 TO 20 KT 
ACROSS THE ENTIRE FORECAST AREA WITH SLY SWELL 9 TO 10 FT 
BETWEEN 100W AND 125W.  

LATER DAY 1 IT APPEARS THE TWO MID LEVEL FEATURES ARE IN A 
STANDOFF WITH NEITHER WANTING TO BUDGE. THE CUTOFF LOW ALOFT IS 
TRYING TO MOVE NE TO NEAR 34N126W. THE MID LEVEL RIDGE OVER 
MEXICO CONTINUES TO BULGE NW OVER AZ EFFECTIVELY BLOCKING THE 
PROGRESS OF THE CUTOFF. ON THE SURFACE LATER DAY 1 THE WEAK LOW 
SKIRTING THE NRN BORDER CONTINUES WWD TO NEAR 31N132W. LITTLE 
CHANGE TO THE PACIFIC RIDGE AND NE TRADES CHANGE LITTLE. WEAK 
HIGH PRESSURE BUILDS OVER THE WRN GULF OF MEXICO AND THERE ARE 
SOME INDICATIONS OF NE WINDS TO 20 KT WORKING THEIR WAY THROUGH 
TEHUANTEPEC. CROSS EQUATORIAL SLY WINDS STRENGTHEN BETWEEN 105W 
AND 125W S OF 10N. SLY SWELL OF 9 TO 10 FT CONTINUE IN THIS 
AREA.

FOR DAY 2 THE MID LEVEL RIDGE OVER MEXICO STRENGTHENS SOME WITH 
IT'S AXIS EXTENDING SW TO NEAR 15N140W. THE CUTOFF LOW JUST N OF 
THE REGION BEGINS TO GET SHEARED AS WESTERLIES INCREASE WITH A 
NEW SHORTWAVE TROUGH MOVING TO 140W. ON THE SURFACE DAY 2 A WEAK 
HIGH CELL 1020 MB DEVELOPS NEAR 30N124W MAINTAINING NE TRADES TO 
20 KT BETWEEN 12N AND 20N W OF 115W. WINDS ALONG THE BAJA COAST 
REMAIN NWLY 10 TO 15 KT. GFS MODEL SHOWS NE WINDS OF 20 KT 
THROUGH TEHUANTEPEC WITH WEAK HIGH PRESSURE TO THE N. CROSS 
EQUATORIAL SLY WINDS CHANGE LITTLE DAY 2 WITH STRONGEST WINDS TO 
20 KT BETWEEN 100W AND 140W S OF 5N. LONG PERIOD SLY SWELL OF 9 
TO 10 FT WILL CONTINUE BETWEEN 95W AND 120W NWD TO 12N. 

$$
RRG