000
AXPZ20 KNHC 311559
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN JAN 31 2010

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...ITCZ...

THE ITCZ AXIS IS ANALYZED ALONG 06N77W TO 03N90W TO 05N108W TO 
04N120W TO 03N140W. NO SIGNIFICANT CONVECTION.  

...DISCUSSION...

AT THE UPPER LEVELS...A BROAD FLAT MIDDLE/UPPER LEVEL RIDGE 
DOMINATES THE MAJORITY OF THE FORECAST AREA WITH STRONG UPPER 
LEVEL WESTERLY FLOW NOTED N OF 15N. THIS CONTINUES TO INDUCE A 
NEGATIVE TILTED TROUGH EXTENDING FROM ANOTHER IN A SERIES OF 
STRONG SOUTHERN STREAM CYCLONIC CIRCULATIONS LOCATED JUST SW OF 
EL PASO TEXAS SSE ALONG THE WEST COAST OF MEXICO TO JUST WEST OF 
THE ISTHMUS OF TEHUANTEPEC...THEN CONTINUING ACROSS THE EPAC TO 
NEAR 08N95W. WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE 
OVER A VAST AREA S OF 22N W OF 100W WHICH IS SUPPRESSING 
CONVECTION ALONG THE ITCZ. SOME MID/UPPER LEVEL MOISTURE IS SEEN
N OF 25N W OF 120W. 

AT THE SURFACE...A WEAK 1016 MB HIGH IS LOCATED NEAR 33N125W AND 
IS FORECAST TO MOVE SE TO NEAR 30N124W IN 24 HOURS. THE PRESSURE 
GRADIENT TO THE S OF THIS WEAK RIDGE IS PRODUCING AN AREA OF 
NORTHEAST TRADE WINDS IN THE 20 KT RANGE FROM 04N TO 12N W OF 
130W. A RECENT ASCAT PASS CONFIRMS THESE WIND SPEEDS. EXPECT 
GRADIENT TO SLIGHTLY RELAX IN 24 HOURS BUT WILL INCREASE AGAIN 
BY 48 HOURS. WEAK SURFACE TROUGHS EMBEDDED WITHIN THE ITCZ ARE 
LOCATED ALONG 108W/109W AND ALONG 127W/128W...BOTH S OF 8N. NO 
SIGNIFICANT CONVECTION IS NOTED ALONG THESE TROUGHS. A COLD 
FRONT IS ENTERING THE FAR NW PORTION OF THE AREA FROM 30N137W TO 
27N140W. S TO SW WINDS OF 20 KT WERE NOTED N OF 29N E OF THE 
FRONT. THIS FRONT IS FORECAST TO MOVE TO A POSITION FROM 30N131W 
TO 24N140W IN 24 HOURS. THE FRONT WILL DISSIPATE IN ABOUT 48 
HOURS.

REGIONAL SEAS CONTINUE TO BE DOMINATED BY NWLY SWELL...AND ARE 
RUNNING IN THE 8 TO 12 FOOT RANGE N OF 20N W OF 125W. A NEW 
BATCH OF NW SWELL WILL PROPAGATE THROUGH THE AREA IN THE WAKE OF 
THE AFOREMENTIONED COLD FRONT.

GAP WINDS...
A MUCH EARLIER HIGH RESOLUTION ASCAT DATA SHOWED GALE FORCE 
WINDS OF 35 KT THROUGH THE GULF OF TEHUANTEPEC WHERE A GALE 
WARNING REMAINS IN EFFECT. WINDS ARE EXPECTED TO DIMINISH BELOW 
GALE FORCE IN ABOUT 24 HOURS. GAP WINDS IN THE GULF OF PAPAGAYO 
ARE 20 TO 25 KNOTS AND WILL PULSE UP AND DOWN OVER THE NEXT 48 
HOURS...WHILE NLY FLOW THROUGH THE GULF OF PANAMA WILL PULSE UP 
AND DOWN BELOW 20 KT THROUGHOUT THE NEXT FEW DAYS. 

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

$$
COBB