000
AXPZ20 KNHC 210322
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON DEC 21 2009

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE FLUCTUATES FROM 05N TO 08N E 
OF 108W THEN EXTENDS NW TO 10N120W AND CONTINUES W TO 09N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 90 
NM OF 07N85W AND 09N93W. ISOLATED MODERATE CONVECTION IS  
DISSIPATING NEAR 10N135W.

A CLUSTER OF STRONG CONVECTION IS OBSERVED WITHIN 90 NM OF 
12N90.5W.

...DISCUSSION...

AN UPPER TROUGH DOMINATING EASTERN N AMERICA EXTENDS INTO THE 
AREA ALONG 32N96W TO 22N103W TO A BASE IN THE DEEP TROPICS AT 
02N104W. DRY UPPER AIR IS INDICATED WITHIN 240 NM OF THE TROUGH 
AXIS. AN UPPER ANTICYCLONE CENTERED AT 06N124W HAS A RIDGE 
EXTENDING N THROUGH 22N123W TO WELL BEYOND 32N121W. CONVECTION 
WAS ENHANCED EARLIER ALONG THE ITCZ BETWEEN 130W AND 140W WITH 
THE DEBRIS MOISTURE ADVECTED N BETWEEN 130W AND 140W TO BEYOND 
32N WITH SOME OF THE MOISTURE ALSO TURNING NE OVER THE 
SUBTROPICAL PACIFIC SPILLING ACROSS THE RIDGE AXIS OVER THE SW 
CONUS AND NORTHWESTERN OLD MEXICO. AN UPPER ANTICYCLONE OVER 
COLOMBIA HAS A RIDGE EXTENDING NW ACROSS CENTRAL AMERICA TO A 
CREST OVER OLD MEXICO AT 22N102W. DEBRIS MOISTURE ORIGINATING 
FROM ITCZ CONVECTION E OF 100W IS ADVECTED NE ACROSS CENTRAL 
AMERICA AND THE GULF OF MEXICO AND THE WESTERN CARIBBEAN.    

AT THE LOW LEVELS...A STATIONARY FRONT EXTENDS FROM 32N129W TO 
25N140W. A WEAK SURFACE HIGH PRES IS NEAR 31N127W. 

GAP WINDS...N TO NE WINDS OF 20 TO 25 KT ARE OCCURRING THROUGH 
THE GULF OF TEHUANTEPEC AND ARE EXPECTED TO INCREASE TO 20 TO 30 
KT LATE TONIGHT THROUGH MON NIGHT THEN DIMINISH TO LESS THAN 20 
KT MIDDAY TUE.

GAP NE TO E WINDS OF 20 TO 25 KT ARE OCCURRING IN THE GULF OF 
PAPAGAYO AND ARE FORECAST TO DIMINISH BELOW 20 KT MON. NORTHERLY 
WINDS ARE EXPECTED TO INCREASE TO 20 TO 25 KT OVER THE WATERS N 
OF 09N BETWEEN 89W AND 93W INCLUDING THE GULF OF FONSECA ON MON 
THEN DIMINISH EARLY TUE. 

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