000
AXPZ20 KNHC 200933
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI JAN 20 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 03N77W TO 04N90W. THE INTERTROPICAL 
CONVERGENCE ZONE EXTENDS FROM 04N90W TO 04N105W TO 07N120W TO 
04N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS 
WITHIN 120-180 NM N OF THE ITCZ BETWEEN 112W AND 118W. SIMILAR 
CONVECTION IS WITHIN 90 NM N OF THE ITCZ BETWEEN 125W AND 130W. 
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE
ITCZ BETWEEN 134W AND 139W.

...DISCUSSION...

A MID AND UPPER CYCLONIC CIRCULATION IS CENTERED NEAR 23N124W. 
SOUTHWESTERLY FLOW PRECEDING THIS LOW IS ADVECTING MOISTURE UP 
FROM THE ITCZ TO ACROSS SOUTHERN BAJA CALIFORNIA INTO NW MEXICO 
WITH SCATTERED MODERATE CONVECTION WITHIN 150 NM EITHER SIDE OF 
A LINE FROM 24N115W TO 12N116W. THE LOW WILL DRIFT SLOWLY E 
THROUGH THE NEXT 48 HOURS ALONG WITH THE ASSOCIATED PATCH OF 
MODERATE CONVECTION.

OTHERWISE THE PATTERN IS DOMINATED BY A 1024 MB AREA OF HIGH 
PRES CENTERED NEAR 28N126W. THE PRESSURE GRADIENT BETWEEN THIS 
HIGH AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS 
MAINTAINING FRESH TO STRONG TRADE WIND FLOW FROM 05N TO 17N W OF 
116W. HIGH PRESSURE WILL CONTINUE TO PREVAIL OVER THIS REGION 
WHILE MAINTAINING THIS COVERAGE OF FRESH TO STRONG TRADE WINDS 
THROUGH AT LEAST SAT NIGHT. A TIGHT PRESSURE GRADIENT BETWEEN 
THIS SAME HIGH AND A TROUGH OVER MEXICO IS PRODUCING FRESH NW 
WINDS N OF 28N W OF THE COAST OF NORTHERN BAJA CALIFORNIA. THESE 
WINDS ARE ALSO EXPECTED TO CONTINUE THROUGH AT LEAST SAT EVENING 
WHILE REACHING TO 25N IN 48 HOURS.

...GAP WINDS...

GULF OF TEHUANTEPEC...HIGH PRES OVER THE GULF OF MEXICO HAS 
SHIFTED E OF THE GULF WATERS. THIS HAS DIMINISHED THE PRESSURE 
GRADIENT OVER THE SW GULF OF MEXICO AND THE ASSOCIATED WINDS 
FUNNELING THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC. 
FRESH 20 KT WINDS CONTINUE OVER THE GULF OF TEHUANTEPEC THROUGH 
EARLY AFTERNOON ENHANCED BY THE ADDITION OF NOCTURNAL DRAINAGE 
FLOW.

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 
WINDS ARE FORECAST TO PERSIST THROUGH AT LEAST SAT NIGHT. THE 
STRONGEST WINDS WILL OCCUR DURING THE EARLY MORNING HOURS WITH 
THE ADDED COMPONENT OF NOCTURNALLY DRIVEN KATABATIC WINDS.

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

$$
LEWITSKY