000
AXPZ20 KNHC 301535
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU DEC 30 2010

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 
1500 UTC.

...ITCZ...

ITCZ AXIS ALONG 05N82W TO 08N119W TO 08N140W. SCATTERED MODERATE 
AND ISOLATED STRONG CONVECTION IS FROM 07N TO 10N BETWEEN 110W 
AND 117W...AND BETWEEN 120W AND 123W. A SURFACE TROUGH IS 
EMBEDDED WITHIN THE ITCZ ANALYZED FROM 11N116W TO 07N119W WITH 
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION OCCURRING 
WITHIN 120 NM EITHER SIDE OF THE SURFACE TROUGH.

...DISCUSSION...

W OF 100W...
A SHORTWAVE UPPER LEVEL TROUGH IS EVIDENT ON WATER VAPOR IMAGERY 
WITH TROUGH AXIS EXTENDING FROM ARIZONA THROUGH THE NORTHERN 
GULF OF CALIFORNIA NEAR 30N114W TO 23N127W THAT SUPPORTS A 
DISSIPATING COLD FRONT ANALYZED FROM 30N112W TO 27N114W TO 
23N123W. EARLIER MORNING ASCAT PASSES CAPTURED AN AREA OF 20 TO 
25 KT WINDS MAINLY N OF 26N E OF 127W. AS THIS WIND FIELD HAS 
ENTERED THE DISCUSSION AREA...SEAS ARE EXPECTED TO CONTINUE 
BUILDING IN WAKE OF THE FRONT TO 14 FT BY 31/1200 UTC AND BEGIN 
SUBSIDING THEREAFTER AS THE WIND FIELD GRADUALLY DIMINISHES AS 
STRONG HIGH PRESSURE LOCATED OFF TO THE NW OF THE REGION BUILDS 
IN BY LATE FRIDAY. AS THIS BOUNDARY SKIRTS THE NORTHERN GULF OF 
CALIFORNIA REGION N OF 28N...SW TO W WINDS ARE EXPECTED TO 
REMAIN BRISK THROUGH THE DAY THURSDAY...WITH SEAS NOT EXPECTED 
TO BUILD BEYOND 8 FT.

THIS SHORTWAVE TROUGH IS PART OF LARGER BROAD SCALE TROUGHING 
OVER THE AREA W OF 100W...WITH THE TROUGH AXIS EXTENDING FROM 
17N118W SW TO 10N140W. EAST OF THIS AXIS...SCATTERED MODERATE 
AND ISOLATED STRONG CONVECTION IS ENHANCED WITHIN THE ITCZ 
REGION FOCUSED ALONG A SURFACE TROUGH NEAR 118W. SOME OF THIS 
CONVECTION STRETCHES NORTHEASTWARD TO NEAR 13N105W.

ELSEWHERE...AS THE FRONT DISSIPATES OVER THE NEXT 24 HOURS...THE 
AREA OF NE TO E TRADES FROM 08N TO 19N W OF 125W IS EXPECTED TO 
BECOME SMALLER IN AREAL COVERAGE BY THE END OF THE PERIOD AS A 
1028 MB HIGH CENTERED NEAR 35N137W DIPS SOUTHEASTWARD AND 
GRADUALLY WEAKENS. GLOBAL MODELS INDICATE BY THE END OF THE 
PERIOD THAT THE PRESSURE GRADIENT IS FORECAST TO BE RELATIVELY 
WEAK WITH WINDS BELOW 20 KT AND SEAS REMAINING GENERALLY BELOW 8 
FT.
  
GAP WINDS...
N TO NE WINDS THROUGH THE GULF OF PAPAGAYO ARE EXPECTED TO 
PERSIST THROUGH THIS AFTERNOON...WITH ANOTHER POSSIBLE EVENT 
EXPECTED TO INITIATE BY EARLY FRIDAY AS STRONGER TRADES OVER THE 
WESTERN CARIBBEAN ON TOP OF MORNING DRAINAGE FLOW CONTRIBUTES TO 
ENHANCED WINDS THROUGH THE GAP.

$$
HUFFMAN