000
AXPZ20 KNHC 280926
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT OCT 28 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.

...SPECIAL FEATURES...
LOW PRES 1010 MB...REMNANT OF TROPICAL DEPRESSION 18 E...NEAR 
16N106W MOVING W 10 KT. WITHIN 90 NM OF CENTER WINDS 20 TO 25 KT 
SEAS 8 TO 10 FT. ISOLATED MODERATE CONVECTION ON N SIDE OF 
CIRCULATION..OTHERWISE ONLY BROKEN TO OVERCAST LOW AND MID 
CLOUDS REMAIN.

A GALE WARNING THIS MORNING N OF 14N BETWEEN 94W AND 96W 
INCLUDING THE GULF OF TEHUANTEPEC WITH N WINDS INCREASING TO 30 
TO 35 KT AND SEAS BUILDING 8 TO 10 FT. 

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N78W 9N97W 10N116W 9N128W 12N140W. 
SCATTERED STRONG CONVECTION NEAR 4N78W 4N80W AND 6N82W. 
SCATTERED MODERATE ALONG A LINE FROM 6N89W TO 12N99W TO 12N101W 
TO 9N103W. ISOLATED MODERATE NEAR 12N113W 11N115W AND 7N140W. 
SCATTERED MODERATE TO STRONG CONVECTION WITHIN 90 NM OF 8N134W.

...DISCUSSION...

IN THE MID LEVELS TONIGHT A RIDGE LIES ALONG 20N AND HAS BEEN 
MOVING SLOWLY WWD THE PAST 36 HR. CENTER OF THE RIDGE IS NEAR 
20N115W. WHATS LEFT OF TROPICAL DEPRESSION 18E IS MOVING WWD 
ALONG THE SRN SIDE OF THE RIDGE. NW OF THE RIDGE A STRONG SWLY 
FLOW HAS DEVELOPED AS AN OLD CUTOFF LOW OPENED UP LAST NIGHT AND 
IS MOVING NE JUST N OF THE REGION ALONG 32N. ON THE SURFACE 
TONIGHT THE PACIFIC RIDGE EXTENDS OVER THE AREA N OF 10N W OF 
110W. NE AND E TRADES HAVE DECREASED SOME AS AN OLD TROUGH SW OF 
THE RIDGE MOVED W OF 140W. STILL WINDS OF 20 KT ARE EVIDENT W OF 
130W. A COLD FRONT OVER THE SW GULF OF MEXICO WILL MOVE E AS 
HIGH PRESSURE BUILDS S AND WINDS INCREASE THROUGH 
TEHUANTEPEC..THUS A GALE WARNING IS POSTED FOR THAT AREA AND 
WINDS ARE EXPECTED TO INCREASE THIS MORNING TO GALE FORCE. WINDS 
ALONG THE BAJA COAST ARE MOSTLY NWLY 10 TO 15 KT. CROSS 
EQUATORIAL WINDS W OF 105W ARE SELY TO 20 KT AND E OF 105W S TO 
SW TO 20 KT. 

LATER DAY 1 THE MID LEVEL RIDGE CONTINUES TO MOVE SLOWLY WWD 
ALONG 20N. THE OLD CUTOFF THAT OPENED UP LAST NIGHT CONTINUES 
MOVING NE TOWARD THE CENTRAL CA COAST. A NEW DEEP SHORTWAVE NW 
OF THE REGION AND IS RESPONSIBLE FOR KICKING THE CUTOFF NE. ON 
THE SURFACE LATER DAY 1 GALE FORCE WINDS RUSH THROUGH 
TEHUANTEPEC AND SEAS BUILD TO 8 TO 12 FT. OTHERWISE NE AND E 
TRADES W OF 125W ARE MOSTLY TO 20 KT WHILE WINDS ALONG THE BAJA 
COAST WEAKEN TO MOSTLY 10 KT. CROSS EQUATORIAL WINDS REMAIN 
ABOUT THE SAME WITH SLY SWELL TO 8 FT. 

FOR DAY 2 THE MID LEVEL FLOW N OF 25N BECOMES MORE ZONAL WITH 
THE OLD SHORTWAVE MOVING E OVER THE SW U.S.  THE NEXT SHORTWAVE 
MOVES TO 145W AND BEGINS TO LOWER MID LEVEL HEIGHTS W OF 135W. 
THE MID LEVEL RIDGE SHIFTS SW TO ALONG 17 TO 20N WHILE COVERING 
THE AREA FROM CENTRAL MEXICO W TO 140W. ON THE SURFACE DAY 2 
GALE CONDITIONS CONTINUE N OF 13N BETWEEN 94W AND 96W INCLUDING 
THE GULF OF TEHUANTEPEC WITH SEAS TO 13 FT. THE PACIFIC RIDGE 
CONTINUES OVER THE REGION N OF 12N W OF 110W WITH NW WINDS ALONG 
THE BAJA COAST OF 10 KT. WINDS INCREASE N OF 25N W OF 137W WITH 
APPROACH OF A COLD FRONT. THE FRONT IS ASSOCIATED WITH THE 
STRONG SHORTWAVE. CROSS EQUATORIAL WINDS REMAIN ABOUT THE SAME.

$$
RRG