000
AXPZ20 KNHC 020957
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON FEB 02 2009

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 
0945 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 03N77W TO 08N88W TO 04N106W TO 
06N122W TO 04N140W. THUNDERSTORMS RECENTLY FORMED ALONG THE 
COAST OF COLOMBIA. OTHERWISE...CLUSTERS OF WEAK SHOWERS WERE 
NOTED FROM 07N TO EQUATOR BETWEEN 80W AND 140W. 

...DISCUSSION...

A QUASI STATIONARY UPPER ANTICYCLONE IS CENTERED OVER THE 
TROPICS NEAR 13N112W WITH A RIDGE EXTENDING W NW THROUGH ANOTHER 
NEW ANTICYCLONIC CENTER DEVELOPING NEAR 14N123W TO A GENTLE 
CREST ALONG POINTS 21N140W TO 27N120W WHERE THE RIDGE BECOMES 
FLAT CONTINUING E ACROSS OLD MEXICO TO NEAR 26N97W. TO THE N OF 
THIS RIDGE...A UPPER TROUGH IS MOVING SE ACROSS W TEXAS AND THE 
NORTHERN GULF OF CALIFORNIA INTO AN UPPER CYCLONE AT 28N128W 
WITH A TROUGH CONTINUING SW TO 23N140W. SOME UPPER MOISTURE IS 
NOTED WITH 90 NM OF THE UPPER CYCLONE WHICH APPEARS TO BE 
WEAKENING AS IT DRIFT S OVER THE DISCUSSION AREA. A MOISTURE 
PLUME...ORIGINATING FROM FORMER ITCZ CONVECTION THAT HAS 
DISSIPATED...STREAMS ALONG THE PERIPHERY OF THE RIDGE...ROUGHLY 
WITHIN 90 NM EITHER SIDE OF LINE FROM 15N137W TO 24N111W TO 
25N99W WHERE IT EVAPORATES. THERE IS A SMALL AREA OF UPPER DEBRIS
MOISTURE NEAR 06N123W AND SOME ALONG THE PACIFIC COAST OF 
COLOMBIA. THE UPPER LEVELS ARE VERY DRY OVER THE REMAINDER OF 
THE DISCUSSION AREA SUPPRESSING CONVECTION ESPECIALLY ALONG THE
ITCZ.

AT THE LOW LEVELS A RIDGE EXTENDS FROM 32N132W TO 18N108W. 
SURFACE WINDS S OF 20N TO THE W OF THIS RIDGE CONTINUE AT 20 TO 
25 KT WITH SEAS TO 10 FT...HIGHEST SEAS ALONG 140W. WINDS NE OF 
THE RIDGE CONTINUE AT NW 15 TO OCCASIONALLY KT OVER THE N GULF 
OF CALIFORNIA...AND EXPECTED TO SPREAD S OVER THE GULF WATERS N 
OF 24N LATE TODAY...THEN DIMINISH TO LESS THAN 20 KT TUE.

CENTRAL AMERICAN GAPS...N WINDS EXPECTED TO INCREASE AGAIN TO 20 
TO 25 KT LATE TONIGHT IN THE GULF OF TEHUANTEPEC...THEN RAPIDLY 
INCREASE TO GALE FORCE AROUND SUNRISE TUE...AND FURTHER INCREASE 
TO STORM FORCE TUE AFTERNOON AND CONTINUE THROUGH EARLY WED 
MORNING. LATEST GUIDANCE SUGGESTS THAT THE NORTHERLY FLOW WILL 
WEAKEN BRIEFLY TO A STRONG GALE AROUND SUNSET WED...BUT A 
SECONDARY COLD FRONT OVER THE GULF OF MEXICO WILL DRIVE THE N 
WINDS BACK TO STORM FORCE WED NIGHT. WILL BACK OFF A LITTLE ON 
THE ASSOCIATED SEAS THROUGHOUT PERIOD AS COLD WATER UPWELLING 
FROM LAST STORM EVENT MOST CERTAINLY MODIFIED THE MARINE LAYER. 
NE WINDS IN AND DOWNSTREAM OF THE GULF OF PAPAGAYO HAVE ALSO 
BEEN SURGING AT 20 KT ALONG A NARROW BAND TO NEAR 09N100W. 
EXPECT THIS AREA TO BRIEFLY SHRINK E TO THE WATERS FROM 10N TO 
12N E OF 87W TONIGHT. THEN THE NEXT SURGE ARRIVES TUE WITH NE 
WINDS INCREASING 20 TO 25 KT ALL THE WAY N TO THE GULF OF 
FONSECA. 
      
$$
NELSON