000
AXPZ20 KNHC 031445
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE MAY 03 2011

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1445 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED ALONG 05N77W 
TO 04N87W TO 06N100W TO 04N118W TO 03N140W. SCATTERED MODERATE 
TO STRONG WITHIN 90-120 NM OF THE AXIS BETWEEN 123W AND 133W. 
SCATTERED MODERATE ISOLATED STRONG WITHIN 180 NM OF THE AXIS 
BETWEEN 103W AND 111W...AND WITHIN 90 NM OF THE AXIS BETWEEN 
111W AND 120W.  

...DISCUSSION...
AN UPPER LEVEL CYCLONE IS FILLING NEAR 28N131W WITH A NEGATIVE 
TILT TROUGH AXIS EXTENDING SE THROUGH ANOTHER CYCLONIC 
CIRCULATION NEAR 21N122W TO A BASE NEAR 06N107W. MIDDLE TO UPPER 
LEVEL MOISTURE IS NOTED WITHIN 480 NM NE OF THE TROUGH AXIS 
SPILLING OVER MOST OF THE GULF OF CALIFORNIA AND MEXICO. WATER 
VAPOR IMAGERY INDICATES FAIRLY DRY CONDITIONS ON THE BACK SIDE 
OF THE TROUGH FROM 08N TO 22N BETWEEN 115W AND 130W. AN UPPER 
LEVEL ANTICYCLONE IS CENTERED NEAR THE ISTHMUS OF TEHUANTEPEC...
14N95W WITH A RIDGE EXTENDING TO THE NW AND CRESTING NEAR 
30N122W. UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER TROUGH AND 
THIS RIDGE IS ENHANCING ISOLATED MODERATE CONVECTION IN THE DEEP 
TROPICS S OF 12N BETWEEN 103W AND 111W. THIS SYNOPTIC PATTERN 
SHOULD SHIFT SLIGHTLY NORTHEASTWARD OVER THE NEXT 24 HOURS. THE 
UPPER LEVELS APPEAR VERY DRY ELSEWHERE S OF 17N E OF 100W.

AT THE LOW LEVELS...FLOW IS DOMINATED BY A 1031 MB SURFACE HIGH 
WELL NORTH OF OUR AREA NEAR 45N135W WITH A MODERATE GRADIENT ON 
THE EQUATORWARD SIDE CAUSING 20 KT NE TRADEWINDS MAINLY W OF 
128W. ACCOMPANYING THIS ARE HIGH SEAS OF UP TO 10 FT IN MIXED NE 
WIND WAVES AND NW SWELL. IN 48 HOURS...THE GRADIENT WEAKENS AND 
A LARGE PORTION OF THE 20 KT NE TRADEWINDS WILL LOCATE W OF 
140W...HOWEVER A SMALL AREA FROM 13N TO 26N W OF 135W WILL 
CONTINUE AND PROVIDE SEAS TO 8 FT.

GULF OF CALIFORNIA...A TIGHT PRESSURE GRADIENT OVER NW MEXICO IS 
SUPPORTING NW WINDS IN THE RANGE OF 20 TO 25 KT N OF 24N. AN 
ASCAT PASS FROM AROUND 03/0452 UTC SHOWED A SMALL SWATH OF 25 TO 
30 KT WINDS IN THE VICINITY OF 26N111W. ALL NWP MODELS SUGGEST 
THE WINDS HAVE ALREADY PEAKED AND ARE FORECAST TO DROP BELOW 20 
KT BY THIS EVENING. 
   
GULF OF PAPAGAYO...NE TO E WINDS AT 20 TO 25 KT WILL CONTINUE TO 
PULSE THROUGH WEDNESDAY IN THE AREA FROM 10N TO 12N E OF 90W.  
WINDS AND SEAS HIGHEST LATE NIGHT AND EARLY MORNING HOURS.

GULF OF TEHUANTEPEC...NORTHERLY WINDS SHOULD BEGIN TO SURGE INTO 
THE NORTHERN GULF WITHIN THE NEXT SEVERAL HOURS AT SPEEDS OF 20 
TO 25 KT BUT QUICKLY INCREASE TO GALE FORCE BY LATE THIS 
AFTERNOON. THIS GAP WIND EVENT IS EXPECTED TO PEAK OVERNIGHT 
TONIGHT AND EARLY WEDNESDAY MORNING WITH GALE CONDITIONS WILL 
CONTINUE THROUGH EARLY THURSDAY MORNING. THERE IS THE POTENTIAL 
FOR THESE NORTHERLY WINDS TO BRIEFLY REACH MINIMAL STORM FORCE. 
IN ANY EVENT THE FORECAST WINDS OF 35 TO 45 KT WOULD MAKE THIS 
GAP WIND EVENT THE STRONGEST FOR THE MONTH OF MAY IN THE PERIOD 
BEGINNING IN 1999. 

$$
COBB