000
AXPZ20 KNHC 310933
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN JAN 31 2010

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...

THE ITCZ AXIS IS ANALYZED ALONG 06N77W TO 03N90W TO 05N104W TO 
04N120W TO 03N140W. NO SIGNIFICANT CONVECTION.  

...DISCUSSION...

ALOFT...A BROAD MIDDLE/UPPER LEVEL RIDGE DOMINATES THE MAJORITY 
OF THE FORECAST AREA. A STRONG UPPER LEVEL WLY FLOW IS NOTED N 
OF 15N. THIS CONTINUES TO INDUCE A NEGATIVE TILTED TROUGH 
ROUGHLY EXTENDING ALONG THE WEST COAST OF MEXICO TO NEAR 
ACAPULCO...THEN CONTINUING ACROSS THE EPAC TO NEAR 08N100W. 
WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE OVER A VAST AREA 
S OF 22N W OF 105W WHICH IS SUPPRESSING CONVECTION ALONG THE 
ITCZ. ABUNDANT MID/UPPER LEVEL MOISTURE IS SEEN N OF 22N W OF 
125W. 

AT THE SURFACE...A 1018 MB HIGH IS LOCATED NEAR 31N128W AND IS 
FORECAST TO MOVE SE TO NEAR 30N124W IN 24 HOURS. THE PRESSURE 
GRADIENT TO THE S OF THIS WEEK RIDGE IS PRODUCING AN AREA OF 
NORTHEAST TRADE WINDS IN THE 20 TO 25 KT RANGE PARTICULARLY 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 IN 48 HOURS. SURFACE TROUGHS/PERTURBATIONS 
EMBEDDED WITHIN THE ITCZ ARE LOCATED ALONG 105W/106W AND ALONG 
126W/127W...BOTH S OF 8N. NO SIGNIFICANT CONVECTION IS NOTED 
ALONG THESE TROUGHS. A COLD FRONT IS ENTERING THE FAR NW PORTION 
OF THE AREA. S TO SW WINDS OF 20 TO 25 KT ARE BLOWING AHEAD OF 
THE FRONT THAT IS FORECAST TO MOVE TO A POSITION FROM 30N132W TO 
26N140W 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...
BOTH...A WINDSAT PASS AND HIGH RESOLUTION ASCAT DATA SHOW GALE 
FORCE WINDS OF 35 KT THROUGH THE GULF OF TEHUANTEPEC WHERE A 
GALE WARNING CONTINUES IN EFFECT. MINATITLAN...IN THE ENTRANCE 
OF THE GAP REGION IS REPORTING SUSTAINED WINDS OF 20 KT WITH 
GUSTS OF UP TO 30 KT. WINDS ARE EXPECTED TO DIMINISH BELOW GALE 
FORCE IN ABOUT 36 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 AT OR BELOW 20 KT THROUGHOUT THE NEXT FEW DAYS. 

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

$$
GR