000
AXPZ20 KNHC 172136
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI NOV 17 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 
2115 UTC.

...SPECIAL FEATURE...

TROPICAL STORM SERGIO IS CENTERED NEAR 14.0N 102.6W...OR 235 NM 
SW OF ACAPULCO MEXICO...AT 17/2100 UTC MOVING N 1 KT. MAXIMUM 
SUSTAINED WIND SPEED HAS DECREASED TO 40 KT WITH GUSTS TO 50 KT. 
ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. THE LOW-LEVEL 
CENTER OF SERGIO HAS BECOME COMPLETELY EXPOSED UNDER THE EFFECTS 
OF STRONG W/SWLY SHEAR...AND THE DEEP CONVECTION IS ABOUT 50 NM 
E OF THE CENTER. SCATTERED MODERATE CONVECTION FROM 11N-16N 
BETWEEN 100W-102W. SEE LATEST NHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. 

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N84W 14N100W 10N120W 7N140W. 
SCATTERED MODERATE/STRONG CONVECTION WITHIN 120 NM EITHER SIDE 
OF THE AXIS BETWEEN 105W-118W. 

...DISCUSSION...

LARGE-SCALE MID/UPPER RIDGE PATTERN CONTINUES OVER THE 
SUBTROPICAL E PACIFIC WATERS EXCEPT THAT NOW THERE ARE TWO 
EMBEDDED CUT-OFF LOWS/TROUGHS. ONE TROUGH EXTENDS FROM 30N130W 
TO 17N140W AND IS SURROUNDED BY AN AREA OF MODERATE/STRONG 
SUBSIDENCE...AND THE OTHER (AN UPPER LOW) IS CENTERED NEAR 
20N116W ALSO SURROUNDED BY ABUNDANT DRY AIR. A SURFACE HIGH IS 
PLANTED BENEATH THESE FEATURES NEAR 30N135W WITH GENERALLY 
BENIGN WEATHER N OF 20N.

THE ITCZ IS QUITE LINEAR AND NOT VERY CONVECTIVE W OF 120W WITH 
THE ABSENCE OF ANY DEEP UPPER TROUGHS IN THE VICINITY. E OF 120W 
HOWEVER...THE UPPER LOW NEAR 20N116W IS PRODUCING A HIGHLY 
DIFFLUENT ENVIRONMENT SW OF THE MEXICAN COAST. A 1008 MB LOW IS 
EMBEDDED ALONG THE ITCZ NEAR 11N115W AND HAS ACQUIRED A GOOD 
AMOUNT OF DEEP CONVECTION...WITH SCATTERED MODERATE/STRONG 
WITHIN 150 NM S SEMICIRCLE. UPPER FLOW EMANATING AWAY FROM THIS 
AREA OF CONVECTION IS SCREAMING EWD RIGHT OVER T.S. SERGIO AND 
CONTRIBUTING TO THE CYCLONE'S DEMISE. ANOTHER AREA OF LOW 
PRESSURE...1009 MB...IS STILL LOCATED SW OF THE NICOYA PENINSULA 
OF COSTA RICA NEAR 8N88W BUT HAS MINIMAL CONVECTION.

THE GALE EVENT OVER THE GULF OF TEHUANTEPEC HAS ENDED FOR THE 
TIME BEING...BUT IT APPEARS LIKELY THAT ANOTHER GALE WILL BEGIN 
IN ABOUT 48 HRS (OR SUN EVENING) AS ANOTHER PUSH OF COLD AIR 
SURGES THROUGH THE GULF OF MEXICO. THIS EVENT LOOKS AS THOUGH IT 
COULD BE STRONGER THAN THE PREVIOUS EVENT...POSSIBLY CLOSE TO 
STORM FORCE.

$$
BERG