000
AXPZ20 KNHC 050954
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT MAR 05 2011

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...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 01N80W TO A 
WEAK 1007 MB LOW PRESSURE CENTERED AT 06N95W...THEN DIPS SW 
CROSSING THE EQUATOR AT 102W TO 04S108W...TURNS NW CROSSING THE 
EQUATOR AT 119W TO 07N129W...THEN TURNS WESTWARD TO BEYOND 
06N140W. BROKEN TO OVERCAST LOW AND MID LEVEL CLOUDS...WITH 
OCCASIONAL SMALL CLUSTERS OF MODERATE CONVECTION FLARING...ARE 
OBSERVED S OF 10N E OF 108W...AND S OF 11N W OF 108W WITH  
SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 120 
NM EITHER SIDE OF A LINE FROM 07N131W TO 05N140W.

...DISCUSSION...

AN ILL DEFINED UPPER LEVEL CYCLONE IS OVER THE TROPICS NEAR 
14N139W AND IS MOVING W WITH TIME. AN UPPER ANTICYCLONE IS NOTED 
JUST TO THE N AT 22N136W WITH AN UPPER RIDGE EXTENDING NE OVER 
THE SUBTROPICAL PACIFIC CRESTING NEAR 36N130W. A LONG WAVE UPPER 
TROUGH DOMINATES CENTRAL N AMERICA...CONTINUING SW INTO THE 
DISCUSSION AREA ALONG 32N108W TO 23N109W...TURNING S AND INTO AN 
UPPER CYCLONE AT 12N118W. AN UPPER LEVEL ANTICYCLONE IS QUASI 
STATIONARY NEAR 14N101W WITH A RIDGE EXTENDING W TO 15N117W. THE 
RIDGE IS EXPECTED TO CONTINUE TO WEAKEN ALLOWING THE UPPER 
TROUGH TO CONTINUE E AND THE UPPER ANTICYCLONE OVER THE WESTERN 
PORTION TO AMPLIFY FURTHER N ALONG THE WEST COAST OF N AMERICA. 

IN THE MEANTIME...ITCZ DEBRIS MOISTURE IS NOTED FROM 03N TO 10N 
BETWEEN 122W AND 140W BUT SEEMS TO REMAIN IN THE SAME AREA. A 
WELL DEFINED PLUME OF UPPER MOISTURE...ORIGINATING IN THE 
CENTRAL PACIFIC NEAR 15N163W...STREAMS NE ACROSS THE WESTERN 
UPPER RIDGE...ROUGHLY N OF 23N W OF 117W...WITH SOME MOISTURE NOW
SPREADING SE ACROSS THE NORTHERN BAJA CALIFORNIA PENINSULA. 
OTHERWISE THE UPPER LEVELS ARE RELATIVELY DRY...AND SUPPRESSING 
CONVECTION ESPECIALLY ALONG THE ITCZ E OF 120W.
  
AT THE SURFACE...HIGH PRESSURE CENTERED NEAR 31N128W IS FORECAST 
TO DROP A LITTLE SW WITH THE GRADIENT WEAKENING OVER THE NW 
PORTION ALLOWING A COLD FRONT TO ENTER THE AREA TONIGHT.
THE FRONT IS EXPECTED TO REACH ALONG 32N130W TO 28N140W 
SUN...THEN SLOW AND WEAKEN...WASHING OUT SUN NIGHT OVER THE 
PACIFIC WATERS...BUT CONTINUING E ACROSS THE NORTHERN GULF OF 
CALIFORNIA SUN NIGHT INTO EARLY MON. HIGH PRESSURE WILL REBUILD 
MON WITH THE ENHANCED TRADES OF 20 KT OVER THE TROPICS S OF THE 
RIDGE SPREADING N OVER THE AREA FROM 06N TO 24N W OF 125W MON. 
NORTHERLY WINDS ALONG THE W COAST OF THE BAJA CALIFORNIA 
PENINSULA ARE AT 15 TO 20 KT TODAY...BUT SHOULD DIMINISH 
TONIGHT...INCREASING AGAIN SUN NIGHT.    

GULF OF CALIFORNIA...NW WINDS AT 20 TO 25 KT ARE OBSERVED OVER 
THE GULF WATERS S OF 29N...AND EXPECTED TO WEAKEN TO 20 KT 
SUN...AND FURTHER WEAKEN SUN NIGHT...EXCEPT FOR A BRIEF 20 KT SW 
TO NW WIND SHIFT OVER THE NORTHERN WATERS AS THE FRONT PASSES.

GULF OF TEHUANTEPEC...LIGHT SOUTHERLY WINDS EXPECTED TILL A COLD 
FRONT MOVES INTO THE BAY OF CAMPECHE TONIGHT. NORTHERLY WINDS 
WILL INCREASE TO 20 KT IN THE GULF OF TEHUANTEPEC AFTER 
MIDNIGHT...FURTHER INCREASING TO A MINIMAL GALE SUN AFTERNOON 
CONTINUING THROUGH SUNRISE MON...THEN WINDS WILL QUICKLY ABATE.

GULF OF PAPAGAYO...NE TO E WINDS WILL CONTINUE TO PULSE AT 15 TO 
20 KT THROUGH TONIGHT...THEN DIMINISH SOME SUN...RETURNING AGAIN 
MON.

.GULF OF PANAMA...NORTHERLY WINDS AT 15 TO 20 KT OVER THE AREA N 
OF 06N BETWEEN 79W AND 81W WILL DIMINISH TO 10 TO 15 KT LATE 
TONIGHT AND SUN.

$$
NELSON