000
AXPZ20 KNHC 090930
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED JAN 9 2013

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 06N78W TO 09N84W TO 06N89W...THEN 
CONTINUES AS ITCZ TO 05N100W TO 08N140W. NO SIGNIFICANT 
CONVECTION. 

...DISCUSSION...
HIGHLY AMPLIFIED UPPER LEVEL PATTERN IN PLACE OVER THE DISCUSSION
AREA. FRESH NE TRADES WINDS ASSOCIATED WITH WEAKENING SUBTROPICAL
HIGH CENTERED NEAR 33N133W PREVAIL ACROSS MOST OF THE AREA N OF 
THE ITCZ W OF 112W...WITH 25-30 KT WINDS INDICATED W OF 136W FROM
0705 UTC ASCAT PASS. SMALL PATCH OF FRESH NW TO N WINDS ARE NOTED
FROM SCATTEROMETER DATA W OF BAJA PENINSULA FROM 23N TO 27N E OF 
118W. UNUSUALLY STRONG HIGH PRESSURE WILL DEVELOP BEHIND A COLD 
FRONT NOW APPROACHING THE WEST COAST...THEN REMAIN CENTERED NEAR 
38N140W THU MORNING THROUGH SUN. THIS WILL CREATE A VERY TIGHT 
PRES GRADIENT BETWEEN THE HIGH AND LOWER PRESSURE ALONG THE 
ITCZ...RESULTING IN A BROAD AREA OF 20 TO 30 KT NE-E WINDS AND 
BUILDING SEAS 8 TO 14 FT W OF 120W THU THROUGH SAT. THIS VERY 
STRONG 1040-1042 MB HIGH WILL INDUCE GALE FORCE NW WINDS ALONG 
THE CALIFORNIA COAST THU AFTERNOON THROUGH EARLY SAT... 
GENERATING LARGE N-NW SWELL THAT WILL SPREAD SOUTHWARD W OF THE 
BAJA PENINSULA...WITH SEAS BUILDING TO 13-15 FT N OF 27N BY FRI.

$$
MUNDELL