000
AXPZ20 KNHC 210341
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU JAN 21 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...
AXIS ALONG 03N78W TO 06N90W TO 03N105W TO 08N125W TO 07N140W.
SCATTERED MODERATE CONVECTION WITHIN 90 NM OF AXIS W OF 116W.

...DISCUSSION...
NARROW UPPER LEVEL TROUGH EXTEND FROM NW NICARAGUA TO SMALL BUT 
WELL DEFINED CYCLONE AT 01N133W MAINTAINS DRY W ZONAL FLOW S AND 
E OF AXIS.  MODERATE TO STRONG SUBSIDENCE DRIES AIR MASS W OF 
AXIS N OF 10N AS VERY STRONG JET CORE OVER CREST OF UPSTREAM 
RIDGE MOVES OVER NW PART OF BASIN.  JET SPEEDS OVER 200 KT 
SLIP BETWEEN RIDGE AND DEEP LAYER CYCLONE...AND ITS ATTENDANT 
NEGATIVELY TILTED TROUGH...N OF BASIN BRINGS ACTION PACKED 
ENERGY IN SUPPORT OF INCOMING COLD FRONT WITH GALE FORCE WINDS 
ON BOTH SIDES OF BOUNDARY N OF 25N.  GALES SPREAD E AND CONTINUE 
THROUGH ENTIRE FORECAST PERIOD.    

UPPER LEVEL WIND FLOW EXPECTED TO ALLOW SERIES OF SHORTWAVES TO 
MOVE SE INTO NORTHERN BAJA CALIFORNIA AS PROGRESSION OF COLD 
FRONTS MOVE SE ACROSS EPAC INTO CALIFORNIA COAST.  MOST 
INGREDIENTS AVAILABLE FOR MAJOR PRECIPITATION EVENT N OF BAJA 
CALIFORNIA...BUT LACK OF MOISTURE EXPECTED TO CURTAIL EFFECTS S 
OF BORDER.  STILL STRONG WINDS SHOULD BUFFER COASTAL AREAS IN 
ADDITION TO LARGE LONG PERIOD SWELLS AND THEIR BREAKERS.     

GALES SWEEP ACROSS BASIN N OF 25N DURING NEXT 12 TO 48 HOURS 
WILL GENERATE LARGE LONG PERIOD NW SWELLS PROPAGATING SE THROUGH 
ENTIRE AREA.  SEAS ABOVE 30 FT EXPECTED THROUGH THU NEAR NW 
PORTION OF BASIN DECAYING TO 12-15 FT ALONG 110W.     

GAP WINDS 
FRESH NE TO E WINDS CONTINUE THROUGH GULF OF PAPAGAYO EXPECTED 
TO DIMINISH BELOW 20 KT BY LATE THU.

MODERATE TO STRONG N WIND ACROSS GULF OF PANAMA DIMINISH BELOW 
20 KT EARLY THU.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
WALLY BARNES