000
AXPZ20 KNHC 280955
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT JAN 28 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...
MONSOON TROUGH EXTENDS 05N77W TO 04N90W. ITCZ EXTENDS FROM 
05N77W TO 08N115W TO 06N140W. SCATTERED MODERATE CONVECTION IS 
NOTED WITHIN 90 NM S OF AXIS BETWEEN 95W AND 105W. SCATTERED 
MODERATE CONVECTION ALSO FROM 10N TO 13N BETWEEN 102W AND 
106W...AND FROM 08N TO 10N BETWEEN 125W AND 128W.

...DISCUSSION...
W OF 110W...A SHARP MID TO UPPER LEVEL LONG WAVE TROUGH EXTENDS 
SOUTHWARD FROM THE CENTRAL N PACIFIC ALONG 150W EAST OF HAWAII. 
A MID/UPPER LEVEL CYCLONIC CIRCULATION THAT WAS CENTERED NEAR 
15N140W 24 HOURS AGO HAS OPENED INTO A TROUGH AND IS LIFTING N 
AND COMING IN PHASE WITH THE APPROACHING LONG WAVE TROUGH. A 
MID/UPPER LEVEL RIDGE IS AMPLIFYING N OF 10N GENERALLY ALONG 
130W EAST OF THE TROUGH. ASSOCIATED 1035 MB HIGH PRES IS 
CENTERED OFF WASHINGTON STATE...WITH A SURFACE RIDGE EXTENDING 
SW TO 20N135W. SCATTEROMETER DATA OVER THE PAST SEVERAL HOURS 
SHOW PERSISTENT 20 KT N TO NE WINDS N OF 20N W OF 120W WITH 
SLIGHTLY STRONGER NW TO N WINDS PUSHING DOWN THE COAST OF 
SOUTHERN CALIFORNIA...ON THE EDGE OF THE HIGH PRES. FURTHER 
SOUTH...15 TO 20 KT TRADE WIND FLOW IS NOTED FROM THE ITCZ TO 
15N W OF 120W. DESPITE FORCING PROVIDED BY UPPER DIVERGENCE ON 
THE EAST SIDE OF THE TROUGH CONVECTION REMAINS FAIRLY MODEST N 
OF THE ITCZ BETWEEN 120W AND 130W...MOST LIKELY DUE TO COOLER 
SEA SURFACE TEMPERATURES IN THAT AREA. FURTHER E...UPPER FORCING 
PROVIDED BY A BROAD MID/UPPER TROUGH FROM 15N TO 25N ALONG 120W 
ALONG WITH MODEST TRADE WIND CONVERGENCE AND WARMER SEA SURFACE 
TEMPERATURES HAS BEEN AIDING DEVELOPMENT OF SCATTERED SHOWERS 
AND THUNDERSTORMS FROM THE ITCZ TO 15N BETWEEN 105W AND 115W. 
ALTHOUGH THIS ACTIVITY HAS DIMINISHED IN THE PAST SEVERAL 
HOURS...IT IS LIKELY TO FLARE UP AGAIN AS TROUGHING TO THE WEST 
MIGRATES OVER THE AREA. A WEAK SURFACE TROUGH IS NOTED IN 
SCATTEROMETER DATA ALONG 117W FROM 08N TO 11N. THIS WILL PERSIST 
THROUGH LATE SAT SE OF THE UPPER TROUGH...AND SHOULD ENHANCE 
IMMEDIATE TRADE WIND FLOW. MEANWHILE DECAYING NW SWELL IN EXCESS 
OF 8 FT CONTINUES TO COVER MUCH OF THE AREA N OF 05N W OF 
110W...MIXING WITH NE SWELL FROM 10N TO 20N.

GULF OF CALIFORNIA...A VIGOROUS SHORT WAVE TROUGH IS NOTED 
PUSHING SE OVER SOUTHERN CALIFORNIA AND NW MEXICO ON THE W SIDE 
OF THE AMPLIFYING MID/UPPER RIDGE. THE RESULTING DEEPENING LOW 
PRES OVER CENTRAL MEXICO AND STRONG HIGH PRES BUILDING OVER THE 
GREAT BASIN IS PROMPTING FRESH TO STRONG NW FLOW OVER THE 
NORTHERN GULF OF CALIFORNIA. OBSERVATIONS AT SAN FELIPE ALONG 
THE FAR NW COAST OF THE GULF HAVE BEEN SHOWING NW WINDS OF 20 TO 
25 KT. THE STRONG NW FLOW WILL PUSH DOWN MOST OF THE LENGTH OF 
THE GULF OF CALIFORNIA THROUGH LATE SUN.

GULF OF TEHUANTEPEC...A 0324 UTC ASCAT PASS SHOWED ONLY 20 TO 25 
KT GAP FLOW...CONFIRMING GALE CONDITIONS HAVE ENDED. STRONG 
REINFORCING HIGH PRES WILL BUILD OVER THE TEXAS SAT 
NIGHT...RESULTING IN ANOTHER...STRONGER...GALE EVENT BY EARLY 
SUN MORNING. WINDS WILL REACH AS HIGH AS 40 KT IN THE GULF OF 
TEHUANTEPEC AND ADJACENT PACIFIC WATERS...WITH SEAS BUILDING TO 
AS HIGH AS 15 FT BY SUN AFTERNOON. THE GAP WIND PLUME WILL ARC 
SW TO W WITH WINDS TO 20 KT AS FAR AS 10N105W BY MON MORNING. 
WINDS SHOULD DROP BELOW GALE CONDITIONS BY LATE MON AS HIGH PRES 
MODIFIES AND SHIFTS E OVER THE GULF OF MEXICO.

GULFS OF PAPAGAYO AND PANAMA...20 TO 25 KT GRADIENT FLOW OVER 
THE SW CARIBBEAN ALONG WITH OVERNIGHT DRAINAGE EFFECTS WILL 
SUPPORT 20 KT GAP WINDS THROUGH NICARAGUA AND THE GULF OF 
PAPAGAYO REACHING AS FAR AS 88W...MAINLY DURING THE OVERNIGHT 
HOUR AND EARLY MORNING HOURS THROUGH EARLY NEXT WEEK. 
SIMILARLY...N FLOW OVER THE ISTHMUS OF PANAMA WILL PUSH INTO THE 
GULF OF PANAMA PERSISTING THROUGH EARLY NEXT WEEK. 

$$
CHRISTENSEN