000
AXPZ20 KNHC 270346
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED DEC 27 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 
0315 UTC.

...ITCZ...
AXIS 6N78W 6N85W 5N97W 7N122W 
7N140W. SCATTERED MODERATE CONVECTION WITHIN 60 NM OF AXIS 
BETWEEN 80W AND 84W. SCATTERED LIGHT TO MODERATE WITHIN 30 NM N 
OF AXIS W OF 130W.

...DISCUSSION...
UPPER TROUGH...THE TRAILING END OF AN UPPER LOW MOVING INTO THE 
OREGON COAST...IS STALLING ALONG 138W MAINLY N OF 20N. BLOCKING 
UPPER RIDGE TO THE E OF THIS ALONG 120W. FURTHER E...UPPER 
TROUGH OVER THE CENTRAL GULF OF MEXICO EXTENDS SW ACROSS SRN 
MEXICO...BRINGING DRY AND STABLE AIRMASS OVER COASTAL MEXICO. 
BROAD 1027 MB SURFACE HIGH PRES IS CENTERED NEAR 25N132W...AHEAD 
OF WEAK COLD FRONT ASSOCIATED WITH UPPER TROUGH TO THE NW. 
QUIKSCAT AND SHIP OBSERVATIONS ARE SHOWING PERSISTENT FRESH TO 
STRONG TRADES S OF THE RIDGE AXIS GENERALLY BETWEEN 5N AND 20N W 
OF 110W. LIGHT ANTICYCLONIC FLOW IS EVIDENT ALONG THE SURFACE 
RIDGE AXIS AT 25N. MEANWHILE...MORNING QUIKSCAT SHOWED STRONG 
GALE CONDITIONS CONTINUING OVER GULF OF TEHUANTEPEC IN RESPONSE 
TO 1029 MB HIGH OVER S TEXAS. UPPER RIDGE CENTERED NEAR 10N115W 
IS ENHANCING CONVECTION OVER THE ITCZ AS NOTED ABOVE. TIGHT 
GRADIENT ON THE EASTERN SIDE OF THE HIGH PRES IS PROMOTING FRESH 
NLY WINDS ALONG SRN GULF OF CALIFORNIA...ALTHOUGH THIS WILL 
DIMINISH TONIGHT AS HIGH PRES WEAKENS AND GRADIENT RELAXES.

LOOKING AHEAD...UPPER TROUGH ALONG 138W WILL LIFT OUT WITH 
ASSOCIATED SURFACE FRONT RETREATING NWD. RIDGE AXIS OVER 120W 
WILL ERODE IN RESPONSE TO THE TROUGH LIFTING TO THE N. 
HOWEVER...RIDGE WILL BUILD ALONG 135W AHEAD OF DEEPENING TROUGH 
IN THE CENTRAL PACIFIC...MAINTAINING SURFACE HIGH PRES W OF 
118W. THIS WILL KEEP FRESH TO STRONG TRADE WIND FLOW S OF THE 
RIDGE OVER THE NEXT COUPLE OF DAYS. GALES OVER TEHUANTEPEC WILL 
DIMINISH OVER THE NEXT 24 HOURS AS RIDGE OVER THE GULF OF MEXICO 
WEAKENS AND SHIFTS E...AND RETURN FLOW BECOMES ESTABLISHED OVER 
THE WESTERN GULF OF MEXICO. SURGE OVER THE CARIBBEAN WILL BRING 
FRESH ELY FLOW INTO THE GULF OF PAPAGAYO...EXTENDING ALONG 
GENERALLY ALONG 10N TO 100W.

$$
CHRISTENSEN