000
AXPZ20 KNHC 220339
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN JAN 22 2012

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 09N85W TO 06N88W. THE ITCZ 
EXTENDS FROM 06N88W TO 03N97W TO 06N118W TO BEYOND 04N140W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 180 NM N AND 90 
NM S OF ITCZ BETWEEN 116W AND 123W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION WAS NOTED WITHIN 120 NM N AND 60 NM S OF AXIS 
W OF 123W.

...DISCUSSION...

HIGH PRESSURE 1025 MB IS CENTERED NEAR 30N130W WITH RIDGE 
EXTENDING TO NEAR 19N108W. THE PRESSURE GRADIENT BETWEEN THIS 
AREA OF HIGH PRESSURE AND LOWER PRESSURE IN THE VICINITY OF THE 
ITCZ IS MAINTAINING FRESH TO STRONG TRADEWINDS FROM 05N TO 20N W 
OF 125W AND FROM 05N TO 14N BETWEEN 115W AND 120W. THIS 
EXTENSIVE AREA OF FRESH TO STRONG TRADEWINDS IS EFFECTIVE AT 
OBTAINING ENERGY FROM THE SEA AS IT FLOWS INTO THE ITCZ. THE 
CONVERGENCE OF THIS AIR WITH RELATIVELY HIGHER ENERGY INTO THE 
ITCZ IS RESULTING IN A BROAD AREA OF CONVECTION AS MENTIONED 
ABOVE. AN UPPER LEVEL TROUGH EXTENDS FROM 27N114W TO 11N140W. SW 
WIND FLOW ON THE E SIDE OF THIS TROUGH AXIS IS HELPING ADVECT 
ABUNDANT MID AND UPPER LEVEL MOISTURE FROM THIS ITCZ CONVECTION 
ACROSS THE SOUTHERN HALF OF BAJA CALIFORNIA AND ACROSS CENTRAL 
AND NORTHERN MEXICO.

THE PRESSURE GRADIENT BETWEEN THE AREA OF HIGH PRESSURE 
MENTIONED ABOVE AND LOWER PRESSURE OVER MEXICO IS MAINTAINING 
FRESH NW FLOW OFF THE NORTHERN COAST OF BAJA CALIFORNIA. WITH 
HIGH PRESSURE EXPECTED TO PREVAIL OVER THE N PART OF THE AREA 
THE NEXT COUPLE OF DAYS...THE AREA OF TRADEWINDS AND WINDS OFF 
THE COAST OF BAJA CALIFORNIA ARE EXPECTED TO CONTINUE. 

NW SWELL WITH HEIGHTS REACHING NEAR 15 FT AND PERIODS NEAR 15 
SECONDS ALONG THE LEADING EDGE OF THE SWELL PREVAILS OVER THE NW 
PART OF THE AREA. THE SWELL WILL CONTINUE TO SHIFT SE ACROSS THE 
AREA WHILE WEAKENING...MIXING WITH THE NE TRADEWIND SWELL IN THE 
REGION OF STRONG TRADES MENTIONED ABOVE. 

...GAP WINDS...
GULF OF PAPAGAYO...FRESH TO STRONG WINDS OVER THE SW CARIBBEAN 
CONTINUE TO FUNNEL THROUGH THE GAPS IN THE TOPOGRAPHY OF 
NICARAGUA AND COSTA RICA ACROSS THE GULF OF PAPAGAYO. THESE NE 
TO E WINDS ARE FORECAST TO PERSIST THROUGH AT LEAST MON...THOUGH 
WINDS WILL DIMINISH SLIGHTLY OVERNIGHT. THE STRONGEST WINDS WILL 
OCCUR DURING THE LATE NIGHT AND EARLY MORNING HOURS WITH THE 
ADDED COMPONENT OF NOCTURNALLY DRIVEN KATABATIC WINDS.

$$
AL