000
AXPZ20 KNHC 250920
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON JAN 25 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 
0915 UTC.

...ITCZ...
AXIS ALONG 4.5N77W TO 05N80W TO 02N86W TO 05N103W TO 02N127W TO 
03N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 60 
NM EITHER SIDE OF AXIS E OF 90W. SCATTERED MODERATE CONVECTION 
WITHIN 60 NM EITHER SIDE OF AXIS BETWEEN 115W AND 118W.

...DISCUSSION...
AN UPPER LEVEL TROUGH HAS MOVED INTO THE WESTERN PORTION OF THE 
FORECAST AREA N OF 23N...WITH RIDGING PREVAILING OVER THE REST 
OF THE AREA N OF 23N. S OF 20N...AN UPPER LEVEL TROUGH PREVAILS 
ACROSS THE CENTRAL PORTION. UPPER LEVEL RIDGING REMAINS W OF 
125W...BUT HAS WEAKENED OVER THE PAST 24 HOURS DUE TO A DECREASE 
IN CONVECTION IN THE ITCZ W OF 130W. UPPER LEVEL RIDGING 
PREVAILS E OF 97W...AND IS BEING MAINTAINED BY ACTIVE CONVECTION 
IN THE ITCZ E OF 90W. 

AT THE SURFACE...A COLD FRONT RESULTING FROM THE UPPER LEVEL 
TROUGH MENTIONED IN THE PREVIOUS SECTION HAS SHIFTED INTO THE NW 
PART OF THE AREA. SURFACE HIGH PRESSURE 1022 MB CENTERED NEAR 
30N122W WITH RIDGE EXTENDING SW TO 23N140W. THIS RIDGE HAS 
HELPED MAINTAIN FRESH TO STRONG TRADEWINDS IN THE TRADEWIND BELT 
W OF 120W. THE SURFACE HIGH PRESSURE CENTER WILL SHIFT WSW AS 
THE COLD FRONT MOVES ACROSS THE N PORTION OF THE AREA...N OF 
26N. THE LOCATION OF THE SURFACE HIGH PRESSURE WILL HELP 
MAINTAIN FRESH TO STRONG TRADES ALONG THE TRADEWIND BELT W OF 
120W THROUGH THE FORECAST PERIOD. 

NW SWELLS CONTINUE TO PREVAIL ACROSS THE FORECAST AREA. THE 
SWELLS ARE MIXING WITH NE WIND WAVES IN THE REGION OF THE 
STRONGEST TRADES. THE SWELLS WILL CONTINUE TO SLOWLY SUBSIDE 
THROUGH THE FORECAST PERIOD. ANOTHER SET OF LONG PERIOD NW 
SWELLS HAS BEEN GENERATED BEHIND THE COLD FRONT IN THE NW PART 
OF THE AREA THAT WAS MENTIONED IN THE PREVIOUS SECTION. THESE 
SWELLS WILL SPREAD S AND E THROUGH THE FORECAST PERIOD...BUT ARE 
GENERALLY EXPECTED TO REMAIN N OF 16N.

FRESH BREEZE ACROSS THE GULF OF CALIFORNIA WILL DIMINISH BY TUE 
AS HIGH PRES OVER THE GREAT BASIN REGION SHIFTS EASTWARD 
WEAKENING THE PRESSURE GRADIENT. 

GAP WINDS...
FRESH N WINDS ARE EXPECTED ACROSS THE GULF OF TEHUANTEPEC 
TONIGHT AS NORTHERLY FLOW BEHIND A COLD FRONT ACROSS GULF OF 
MEXICO FUNNELS THROUGH THE ISTHMUS OF TEHUANTEPEC. WINDS WILL 
BECOME STRONG EARLY TUE.

FRESH TO STRONG NE TO E TRADES ACROSS THE SW CARIBBEAN WILL 
FUNNEL INTO THE GULF OF PAPAGAYO EARLY TUE AND WILL PERSIST AND 
SPREAD W THROUGH THE FORECAST PERIOD.

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

$$
AL