East Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 140951
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED JAN 14 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0815 UTC.

...ITCZ...

ITCZ IS CENTERED ALONG 06N77W TO 06N95W TO 08N110W TO 09N122W TO 
05N140W. ISOLATED MODERATE CONVECTION CAN BE FOUND WITHIN 90 NM 
S AND 120 NM N OF AXIS E OF 87W WHILE SCATTERED MODERATE 
CONVECTION LIES WITHIN 90 NM OF AXIS W OF 134W.

...DISCUSSION...

NEAR SHORE...
THE ASCAT PASS FROM 0410 UTC SHOWS WINDS TO 45 KT IN THE GULF OF 
TEHAUNTEPEC...BUT CONSIDERING THE ASCAT RUNS ON THE LOW SIDE FOR 
HIGH WIND EVENTS...A STORM FORCE WINDS ARE EXPECTED TO CONTINUE 
THROUGH THIS MORNING.  WINDS WILL DIMINISH TO A MINIMAL GALE WED 
EVENING THROUGH THU MORNING.  ANOTHER SURGE OF ARCTIC AIR WILL 
MAKE ITS WAY THROUGH THE ISTHMUS OF TEHAUNTEPEC THU AFTERNOON... 
INCREASING THE WINDS BACK TO STORM FORCE OVERNIGHT THU NIGHT.

TO THE SOUTH...PAPAGAYO CONTINUES TO SEE THE BLEED THROUGH OF 
EASTERLY TRADE WIND FLOW FROM THE CARIBBEAN.  THE QUIKSCAT PASS 
FROM 2344 UTC SHOWS WINDS IN THE 20 TO 25 KT RANGE WITH A FEW 
RETURNS REACHING 25 TO 30 KT. THESE CONDITIONS WILL LAST FOR THE 
FORESEEABLE FUTURE.

IN THE GULF OF CALIFORNIA...WINDS ARE FINALLY EXPECTED TO 
SUBSIDE BELOW 20 KT THU AFTERNOON AFTER A LONG PERIOD OF 
ELEVATED WINDS INCLUDING GALE CONDITIONS. 


ELSEWHERE...
THE DEEP LAYER RIDGE AXIS CENTERED APPROXIMATELY 300 NM OFF THE 
COAST OF BAJA CALIFORNIA IS EXPECTED TO BREAK DOWN THU/FRI AS 
MID TO UPPER LEVEL LOW BREAKS OFF FROM THE TROUGH OVER THE SW 
U.S. AND MIGRATES WEST INTO FAR NE WATERS.  THIS LOW WILL HELP 
SHOVE THE MID TO UPPER LEVEL HIGH OFF THE CA COAST FARTHER 
NORTHWARD...HELPING TO BREAK DOWN THE DEEP LAYER RIDGING OVER N 
WATERS.  HOWEVER...THE RIDGE WILL NOT SHIFT ENOUGH OVER THE 
FORECAST PERIOD TO ALLOW THE NEXT LONGWAVE TROUGH UPSTREAM TO 
MOVE INTO NW WATERS.  ONLY THE SWELL FROM THIS SYSTEM IS 
EXPECTED TO MOVE INTO NW WATERS BY THU.  

FARTHER SOUTH...THE EASTERLY FLOW AT THE SURFACE AROUND THE 
RIDGE IS CURRENTLY BEING BROKEN DOWN OVER W WATERS BY A MID 
LEVEL LOW CENTERED NEAR 17N135W.  TRADE WIND FLOW HAS DIMINISHED 
TO 20 KT OVER W WATERS BETWEEN 05N AND 20N AND IS EXPECTED TO 
FURTHER DIMINISH BELOW 20 KT ON THU MORNING. 

A WEAK UPPER TROUGH FROM 20N120W TO 00N115W WILL CONTINUE TO 
BREAK DOWN AS IT MOVES EASTWARD.  UPPER LEVEL DIFFLUENCE ON THE 
EAST SIDE OF THE TROUGH MAY SUPPORT SOME CONVECTION IN THE 
VICINITY OF THE ITCZ WHERE MOISTURE IS READILY AVAILABLE OVER 
THE NEXT FEW DAYS.

$$
SCHAUER CLARK