000
AXPZ20 KNHC 210934
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT JAN 21 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

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

THE MONSOON TROUGH IS ALONG 04N77W TO 09N85W TO 03N104W. THE 
INTERTROPICAL CONVERGENCE ZONE EXTENDS FROM 03N104W TO 06N116W 
TO 04N140W. SCATTERED MODERATE CONVECTION IS WITHIN 240 NM N OF 
THE ITCZ W OF 135W.

...DISCUSSION...

A SHARP UPPER LEVEL TROUGH EXHIBITING STRONG DEFORMATION EXTENDS 
FROM NORTHERN BAJA CALIFORNIA SW TO NEAR 20N122W THEN TO BEYOND 
08N140W. SW FLOW E OF THE TROUGH AXIS IS ADVECTING ABUNDANT MID 
TO HIGH LEVEL CLOUDINESS FROM ITCZ CONVECTION NORTHEASTWARD TO 
ACROSS SOUTHERN BAJA CALIFORNIA AND NORTHERN MEXICO. SCATTERED 
MODERATE AND ISOLATED STRONG CONVECTION IS ALSO WITHIN 30-60 NM 
EITHER SIDE OF A LINE FROM 24N112W TO 13N124W.

A PAIR OF AREAS OF SURFACE HIGH PRES ARE IN THE NW WATERS WITH A 
1023 MB HIGH NEAR 26N126W AND A 1022 MB HIGH NEAR 24N135W. A 
RIDGE AXIS EXTENDS FROM THE EASTERN HIGH TO NEAR 20N121W. THE 
PRESSURE GRADIENT BETWEEN THE HIGHS AND A TROUGH OF LOW PRES 
ACROSS FAR NW MEXICO INTO SOUTHERN CALIFORNIA IS PRODUCING FRESH 
NW WINDS JUST WEST OF NORTHERN BAJA CALIFORNIA. IN ADDITION... 
THE PRES GRADIENT BETWEEN THE HIGHS AND LOWER PRES IN THE 
VICINITY OF THE ITCZ IS PRODUCING FRESH TO STRONG TRADE WINDS 
FROM 05N TO 18N W OF 130W AND FROM 06N TO 15N BETWEEN 116W AND 
130W. WINDS WILL WEAKEN ALONG THE BAJA CALIFORNIA COAST SUN 
AFTERNOON...WHILE THE AREA OF TRADES PERSISTS.

A WEAK COLD FRONT HAS ENTERED THE FAR NW PORTION REACHING FROM 
30N134W TO 28.5N140W. SEAS TO 9 FT IN NW SWELL ARE BEHIND THE 
FRONT WITH PEAK WAVE PERIODS OF 15 SECONDS. THE FRONT WILL
DISSIPATE LATER TODAY WHILE THE SET OF NW SWELL BUILDS TO 15 FT 
BY THIS AFTERNOON. THE SWELL WELL CONTINUE TO PROPAGATE TO THE 
SE WHILE GRADUALLY DECAYING...COVERING THE AREA N OF 20N AND W 
OF A LINE FROM 27N114W TO 20N120W BY SUN NIGHT.

...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 SUN 
EVENING...THOUGH WINDS WILL DIMINISH SLIGHTLY SAT NIGHT. THE 
STRONGEST WINDS WILL OCCUR DURING THE LATE NIGHT AND EARLY 
MORNING HOURS WITH THE ADDED COMPONENT OF NOCTURNALLY DRIVEN 
KATABATIC WINDS.

GULF OF PANAMA...FRESH WINDS FROM THE SW CARIBBEAN ARE ALSO 
FUNNELING ACROSS THE ISTHMUS OF PANAMA DOWNWIND ACROSS THE GULF 
OF PANAMA. THESE WINDS WILL DIMINISH TO LESS THAN 20 KT BY THIS 
AFTERNOON AS WINDS IN THE SW CARIBBEAN BEGIN TO DIMINISH.

$$
LEWITSKY