000
AXPZ20 KNHC 012139
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN MAY 01 2011

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 05N77W TO 
09N95W TO 05N110W TO 03N130W TO 03N140W. NO SIGNIFICANT 
CONVECTION. A TROUGH IS WITHIN THE ITCZ AND EXTENDS FROM 09N114W 
TO 02N117W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS 
AHEAD OF TROUGH AXIS FROM 06N TO 09N BETWEEN 118W AND 121W.   

...DISCUSSION...
AN UPPER-LEVEL CYCLONE IS NEAR 29N130W WITH AN UPPER TROUGH 
EXTENDING S TO 24N133W THEN SE TO 00N113W. SWLY FLOW ALOFT ON 
THE EASTERN SIDE OF TROUGH IS TRANSPORTING MID TO UPPER LEVEL 
MOISTURE NORTHEASTWARD PRIMARILY N OF THE ITCZ BETWEEN 110W AND 
130W. AN UPPER LEVEL ANTICYCLONE IS CENTERED AT 08N100W WITH A 
RIDGE TO THE N OVER SE MEXICO INTO THE GULF OF MEXICO. E OF THE 
UPPER ANTICYCLONE...THE TAIL END OF DEEP LAYER TROUGH EXTENDS SW 
FROM WESTERN CARIBBEAN TO ACROSS COSTA RICA INTO THE EPAC TO  
NEAR 6N98W. A DIFFLUENT PATTERN ALOFT AHEAD OF THE TROUGH AXIS 
IS SUPPORTING A FEW SHOWERS NEAR THE ITCZ E OF 95W. 

AT THE SURFACE...A 1031 MB HIGH LOCATED NEAR 36N132W EXTENDS A 
RIDGE OVER THE FORECAST WATERS TO NEAR 20N110W. THE NORTHERLY 
FLOW ALONG THE W COAST OF THE BAJA CALIFORNIA PENINSULA HAS 
DIMINISHED TO 10 TO 15 KT BASED ON THE 1800 UTC ASCAT PASS. 
N TO NE WINDS OF 15 TO 20 KT AND SEAS 8 TO 11 FT IN N AND NE 
SWELL ARE NOTED OVER THE PACIFIC WATERS N OF 20N W OF 115W.  
WINDS AND SEAS ARE EXPECTED TO DIMINISH SOME OVER THE NEXT 24 
HOURS...BUT THEN RESTRENGTHEN AGAIN MON NIGHT INTO TUE AS A 
STRONG HIGH PRES SETTLES N OF AREA. 

GULF OF CALIFORNIA...TIGHT PRESSURE GRADIENT IS SUPPORTING NW 
WINDS 20 TO 25 KT OVER THE NORTHERN GULF AND EXPECTED TO 
INCREASE TO 20 TO 30 KT AND SPREAD S OVER THE SOUTHERN WATERS 
TONIGHT. SEAS WILL BUILD TO NEAR 8 FT IN CENTRAL WATERS IN THE 
AREA OF THE LONGEST NW FETCH. THE GRADIENT WILL BEGIN TO RELAX 
EARLY TUE.

GAP WINDS...
GULF OF PAPAGAYO...NE TO E WINDS AT 20 TO 25 KT WILL CONTINUE TO 
PULSE THROUGH THE GULF OF PAPAGAYO OVER THE NEXT COUPLE OF DAYS. 
THE WINDS ARE GREATEST DURING THE OVERNIGHT AND EARLY MORNING 
HOURS WITH THE AID OF THE DRAINAGE FLOW.

GULF OF TEHUANTEPEC...ALL THE ATTENTION REMAINS FOCUSED ON THE 
NEXT GULF OF TEHUANTEPEC WIND EVENT FORECAST TO BE A STRONGER 
ONE. NORTHERLY WINDS AT 20 KT WILL BEGIN TO SURGE INTO THE AREA 
TUE MORNING AND QUICKLY INCREASE TO GALE FORCE LATE TUE. A GALE 
WARNING WILL BE POSTED WITH THE ISSUANCE OF THE NEXT PACKAGE. 
THIS WILL BE A LATE SEASON GAP WIND EVENT THAT MAY REACH NEAR 
STORM FORCE TUE NIGHT OR EARLY WED. SINCE RECORDS WERE KEPT IN 
1999...ONLY FOUR GALE FORCE WIND EVENTS...WINDS IN THE 35-40 KT 
RANGE...HAVE OCCURRED IN THE MONTH OF MAY.  

$$
GR