000
AXPZ20 KNHC 121606
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT JAN 12 2008

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1600 UTC.
 
...ITCZ...

INTERTROPICAL CONVERGENCE ZONE...5N78W 4N90W 6N100W 7N110W 8N120W
7N130W 6N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS 
WITHIN 60 NM EITHER SIDE OF THE AXIS BETWEEN 109W-112W...AND 
BETWEEN 118W-121W. SCATTERED MODERATE CONVECTION IS WITHIN 180 
NM N OF THE AXIS BETWEEN 109W-113W.

...DISCUSSION...

MID/UPPER TROUGH EXTENDS FROM NRN MEXICO SW TO 18N105W. A 
PERSISTENT NEARLY STATIONARY MID/UPPER LEVEL CYCLONIC CIRCULATION
IS EVIDENT NEAR 13N131W. MID/UPPER LEVEL RIDGING IS PRESENT N OF 
BOTH THE TROUGH AND CYCLONIC CIRCULATION. THE COMBINATION OF 
THESE FEATURES IS RESULTING IN MODERATE SUBSIDENCE AND ASSOCIATED
DRY AIR TO BE CHANNELED S AND SE INTO THE TROPICAL ZONE W OF 
ABOUT 135W AND AROUND AND INTO THE CYCLONIC CIRCULATION. A RATHER
AMPLIFIED DIFFLUENT PATTERN IS NOTED TO THE E OF THE CIRCULATION
RESULTING IN AN AREA OF OVERCAST MULTILAYERED MOSTLY BROKEN 
CLOUDINESS WITH EMBEDDED SCATTERED SHOWERS AND OCCASIONAL 
ISOLATED TSTMS JUST N OF THE ITCZ FROM 8N-13N BETWEEN 108W-113W. 
CONVECTION IS ALSO ENHANCED ALONG THE ITCZ BETWEEN 109W-120W.

THE CYCLONIC CIRCULATION IS FORECAST TO BEGIN TO DIP S IN ABOUT 
24-36 HRS THEN MOVE EASTWARD EARLY NEXT WEEK. A MID/UPPER LEVEL 
TROUGH IS EVIDENT ALONG 15N104W 12N100W 7N96W. MODERATE 
SUBSIDENCE SURROUNDING THE TROUGH IS INHIBITING AND SIGNIFICANT 
CONVECTION FROM DEVELOPING E OF 100W INCLUDING ALONG THE ITCZ. 
UPPER LEVEL RIDGING EXTENDS NW FROM S AMERICA TO ACROSS CENTRAL 
AMERICA AND SE MEXICO...ALSO KEEPING CONVECTION THERE TO A 
MINIMUM.

AT THE SURFACE...A STATIONARY 1025 MB HIGH CENTER IS ANALYZED 
NEAR 32N132W WITH AN ASSOCIATED RIDGE SE THROUGH 25N125W TO 
20N120W. HIGH PRES COVERS THE REGION N OF 17N AND W OF 117W WITH 
GENERALLY MODERATE TRADES FROM 9N-21N W OF 125W. N WINDS ARE 
FORECAST TO INCREASE THROUGH THE GULF OF TEHUANTEPEC ON SUN AS 
HIGH PRES RIDGING BUILDS S OVER MEXICO. NLY WINDS MAY ALSO 
INCREASE ACROSS THE GULF OF CALIFORNIA LATE SAT INTO EARLY NEXT 
WEEK AS THIS SAME RIDGE INTERACTS WITH LOW PRES TROUGHING ALONG 
THE W COAST OF MEXICO INTO SRN CALIFORNIA. CONVECTION SHOULD 
CONTINUE TO BE FAIRLY ACTIVE E OF THE MID/UPPER CIRCULATION TO 
ABOUT 120W...INCLUDING THE ITCZ THROUGH SUN. 

ON THE WAVE FRONT...WAVEWATCH III MODEL GUIDANCE IS CONSISTENT 
IN SHOWING ANOTHER GROUP OF LARGE NW SWELL ENTERING THE NW 
PORTION OF THE AREA BEGINNING THIS AFTERNOON...AND SPREADING 
EASTWARD N OF MAINLY N OF 20N THROUGH SUN BEFORE SUBSIDING LATE 
SUN INTO MON.

AGUIRRE