000
AXPZ20 KNHC 212210
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI DEC 21 2007

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...
INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG...INTERTROPICAL 
CONVERGENCE ZONE...5N77W 6N95W 9N110W 7N120W  9N140W. SCATTERED 
MODERATE CONVECTION FROM 9N TO 11N FROM 109W TO 114W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WITHIN 75 NM OF 9N121W. 
SCATTERED MODERATE TO STRONG CONVECTION WITHIN 90 NM EITHER SIDE 
OF AXIS W OF 139W.

...DISCUSSION...
FAIRLY AMPLIFIED PATTERN SETTING UP AS UPPER RIDGE BUILDS 
ROUGHLY ALONG 138W TO THE E OF A DEEP LONG WAVE TROUGH THROUGH 
THE HAWAIIAN ISLANDS. DIVERGENCE ALOFT ON THE SE SIDE OF THE 
TROUGH ALONG WITH DECENT LOW LEVEL CONVERGENCE ARE TOGETHER 
AIDING IN PRODUCTION OF PROLIFIC MODERATE TO STRONG CONVECTION 
ALONG THE ITCZ AS MENTIONED ABOVE. E OF THE UPPER RIDGE...AN 
UPPER SHORT WAVE TROUGH ALOFT EXTENDS FROM NRN BAJA TO 23N126W 
IS DIGGING SE...COMING INTO PHASE WITH TROUGH FROM 23N126W TO 
12N127W. VERY MODEST WEAKENING CONVECTION IS EVIDENT ON THE SE 
SIDE OF THIS UPPER TROUGH AS WELL ALONG THE ITCZ. 

A SURFACE HIGH PRES AREA ASSOCIATED WITH THE UPPER RIDGE IS 
CENTERED NEAR 32N135W AND WILL REMAIN STATIONARY FOR THE NEXT 
SEVERAL DAYS. FRESH TO STRONG TRADES ARE EVIDENT IN 
SCATTEROMETER AND SHIP OBSERVATIONS S OF THE SURFACE 
HIGH...GENERALLY W OF 115W...BUT INCLUDING THE AREA JUST ALONG 
THE NRN BAJA COAST AND THROUGH THE GULF OF CALIFORNIA. 

BOTH GFS AND ECMWF GLOBAL MODELS SHOW THE AMPLIFIED PATTERN 
REMAIN IN PLACE THROUGH EARLY NEXT WEEK...THEN BECOMING MORE 
ZONAL THROUGH MID WEEK. THIS WILL TRANSLATE TO LITTLE CHANGE IN 
PRESENT CONDITIONS THROUGH AT LEAST EARLY NEXT WEEK...THEN 
GRADUALLY DIMINISHING WINDS THEREAFTER. LARGE NLY SWELL WILL 
GRADUALLY DECAY OVER MUCH OF THE AREA E OF 110W...ALTHOUGH A NEW 
BATCH OF NWLY SWELL IS EXPECTED OFF THE BAJA COAST BY MIDWEEK. 
IN ADDITION...WINDS ARE EXPECTED TO PICK UP EARLY NEXT WEEK. 
OVER THE GULF OF TEHUANTEPEC DUE A COLD FRONT IN THE GULF OF 
MEXICO...AND IN THE GULF OF PAPAGAYO DUE TO FRESH TO STRONG ELY 
FLOW IN THE CARIBBEAN. 

$$
CHRISTENSEN