000
AXPZ20 KNHC 200959
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT MAR 20 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...
AXIS ALONG 03N77W TO 03N111W TO 06N121W TO 03N131W TO 04N140W.  
ISOLATED MODERATE CONVECTION WITHIN 180 NM N OF AXIS FROM 
93W-103W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 
180 NM OF AXIS FROM 110W-122W.

...DISCUSSION...
UPPER LEVEL ANTICYCLONE NEAR 08N122W HAS E-W RIDGE EXTEND ALONG 
08N THROUGH SOUTH AMERICA.  MINOR DIFFLUENT FLOW ALOFT IN RIDGE 
ENHANCING CONVECTION OVER WEAK SURFACE TROUGH RUNNING ALONG ITCZ 
NEAR 120W.  TROPICAL MOISTURE FROM ITCZ NOW EXTENDS TO 13N 
INTRUDING INTO DRY AIR MASS.  WEAK UPPER LEVEL TROUGH ALONG 108W 
N OF 15N ALLOW MOISTURE TO APPROACH SOUTHERN MEXICO...BUT NO 
RAIN EVENT EXPECTED AS LITTLE MECHANISMS FOR UPLIFT IS FORESEEN 
IN AREA.

DEEP LAYER CYCLONE WELL NORTH OF REGION HAS UPPER LEVEL TROUGH 
EXTEND SW W OF BASIN BUT ASSOCIATED COLD FRONT HAS ENTERED NW 
CORNER AND IS IN THE PROCESS OF DIFFUSING AS IT BUMPS INTO WELL 
ANCHORED HIGH PRES RIDGE.  CYCLONE LIFTS NE PULLING SUPPORT OUT 
OF ADVANCING FRONT AND LETTING IT DIE.

ELSEWHERE AT THE SURFACE...
SURFACE HIGH PRES 1022 MB AT 30N128W WEAKENS AS IT COLLIDES WITH 
COLD FRONT BUT REBUILDS BY SUN INCREASING FRESH BREEZE TRADES W 
OF 125W FROM 07N-15N.  WEAK SURFACE TROUGH ALONG 120W TIGHTENING 
GRADIENT ENOUGH TO PRODUCE FRESH NE NW OF ITS AXIS EXPECTED TO 
DIMINISH LATE TODAY OR SUN. 

HIGH PRES WELL N OF AREA MAINTAINING LONG FETCH W OF COLD FRONT 
PROMPTING LARGE LONG PERIOD NW SWELL PROPAGATE THROUGH MOST OF E 
PAC W OF 110W THROUGH FORECAST PERIOD.  HIGH PRES ALSO BRINGING 
FRESH NW BREEZE INTO GULF OF CALIFORNIA LATE SAT AND SUN...BUT 
SHOULD DIMINISH LATE SUN.

GAP WINDS...
COLD FRONT ACROSS GULF OF MEXICO FORCING STRONG WINDS ACROSS 
ISTHMUS INTO GULF OF TEHUANTEPEC BY MID SUN.  MODEL GUIDANCE 
INDICATE ALE FORCE WINDS OUGHT TO BE SHORT LIVED AS GULF OF 
MEXICO HIGH PRES MOVES QUICKLY E AND WINDS VEER SE.  

STATIONARY FRONT ALONG 75W IN WESTERN CARIBBEAN IS INCREASING 
FRESH NE WINDS INTO GULF OF PANAMA THROUGH LATE SAT THEN 
DIMINISH SUN AS FRONT WEAKENS AND BECOMES DIFFUSE.  GULF OF 
PAPAGAYO STRONG NE-E WINDS SHOULD ALSO DIMINISH ACCORDINGLY. 

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

$$
WALLY BARNES