000
AXPZ20 KNHC 272210
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED OCT 27 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
AXIS FROM 08N84W TO 1010 MB LOW PRES AT  10N92W TO 09N102W TO 
13N116W TO 08N133W TO 08N140W.  SCATTERED MODERATE WITHIN 90 NM 
OF AXIS E OF 92W AND 120 NM N OF AXIS FROM 05W TO 109W.

...DISCUSSION...
UPPER LEVEL PATTERNS REMAINS JUST AS COMPLEX ALBEIT COMPLETELY 
DIFFERENT CONFIGURATION THAN YESTERDAY.  LARGE AMPLITUDE DEEP 
LAYER POSITIVE TILT TROUGH ENTERS CROSSES 140W EASTWARD EXTEND 
FROM 32N139W TO 10N130W AND CONNECT TO CYCLONIC VORTEX AT 
05N125W.  THIN SWATH OF TROPICAL MOISTURE ROUNDS TROUGH BASE AND 
ADVECTS N ON 55 KT JET CORE BUT IS TRAPPED BETWEEN TWO LARGE 
AREAS OF DRY SUBSIDING AIR MASSES.  NEVERTHELESS IT MAY REACH 
FAST MOVING COLD FRONT NOW ENTERING 30N140W AND SUPPLY SOME 
ENERGY IT BOUNDARY.  

DOWNSTREAM RIDGE BEING SQUEEZED BY ABOVE MENTIONED VORTEX AND 
ANOTHER TROUGH OVER BAJA CALIFORNIA.  MAIN FEATURE IN RIDGE IS 
THE SMALL AREA OF DIVERGENT FLOW ALOFT JUST NE OF SURFACE TROUGH 
AND EMBEDDED LOW PRES 1011 MB WHICH SEEM TO ENHANCE CONVECTION W 
OF TROUGH.  WEAK RIDGE OVER YUCATAN PENINSULA BRINGS TROPICAL 
MOISTURE FROM SOUTH AMERICA ALONG ITCZ AND TO LOW PRES 1010 MB 
AT 10N92W.  SCATTERED MODERATE ISOLATED TSTMS ACTIVE ALONG THAT 
STRETCH OF ITCZ WITH DRY AIR MASS CURTAILING ANY OTHER 
SIGNIFICANT DEVELOPMENT.  

ELSEWHERE AT THE SURFACE...
STRONG PACIFIC COLD FRONT ASSOCIATED WITH DEEP UPPER TROUGH 
EXTENDS FROM 32N134W TO 29N140W MOVE TO ALONG 32N131W TO 26N136W 
TO 25N140W THU WITH FRESH NW BREEZE...FOLLOWED BY NEW TRAIN OF 
LARGE LONG PERIOD NW SWELLS...UP TO 15 FT AS PER LATEST NWW3 
MODEL GUIDANCE.

WEAK LOW PRES AT 11N120W 1011 MB DO NOT SEEM TO BE ABLE TO 
DEVELOP IN SPITE OF UPPER LEVEL DIVERGENT FLOW ENHANCING ITS 
CONVECTION AS WATERS REMAIN COOL AND SURROUNDING ENVIRONMENT 
DRY.  FRESH MONSOONAL SW FLOW BRINGS WARM MOIST AIR TO COASTS OF 
COLOMBIA...PANAMA AND COSTA RICA...BUT EVENTUALLY WEAKENS AS LOW 
PRES WEAKENS AND DRIFTS NW.

GAP WINDS...
ONSET OF NEXT GALE EVENT THROUGH GULF OF TEHUANTEPEC EXPECTED 
THU NIGHT AS HIGH PRES SURGES SE ACROSS MEXICO IN WAKE OF GULF 
OF MEXICO COLD FRONT.  GALE FORCE N WINDS BEGIN WITHIN 90 NM 
FROM GULF COAST...EXPANDING TO WITHIN 30 NM OF LINE FROM 16N95W 
TO 14N96W BY 48 HOURS WITH SEAS BUILDING UP TO 13 FT.

$$
WALLY BARNES