000
AXPZ20 KNHC 142118
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU MAY 14 2009

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 ITCZ AXIS IS ALONG POINTS 07N77W TO 12N105W TO 04N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 
THE AREA BOUNDED FROM 03N TO 12N BETWEEN 79W AND 121W.

...DISCUSSION...

ALOFT...AN UPPER TROUGH EXTENDS W ACROSS THE N PORTION OF THE 
DISCUSSION AREA FROM 32N116W THROUGH AN UPPER CYCLONE AT 30N122W 
WITH TROUGH CONTINUING SW INTO ANOTHER CYCLONE AT 23N132W WITH 
THE TROUGH STILL CONTINUING SW TO WELL BEYOND 19N140W. AN UPPER 
ANTICYCLONE IS CENTERED AT 13N108W WITH A RIDGE EXTENDING NE 
ACROSS OLD MEXICO ALONG 20N99W WITH THE RIDGE CREST COLLAPSING 
SE OVER THE GULF OF MEXICO NEAR 27N86W. AN UPPER RIDGE EXTENDS W 
ACROSS NORTHERN VENEZUELA AND COLOMBIA TO A CREST OVER PANAMA. A 
BROAD UPPER TROUGH EXTENDS SW ACROSS THE NW CARIBBEAN ALONG 
18N77W TO 09N86W SEPARATING THE FLOW ASSOCIATED WITH THE TWO 
ANTICYCLONES.

UPPER DIFFLUENCE IS ENHANCING CONVECTION ALONG AND N OF THE  
ITCZ TO 16N BETWEEN 90W AND 115W BUT THE DEBRIS MOISTURE SEEMS 
TO REMAIN S OF 20N. HOWEVER DEBRIS MOISTURE FROM PREVIOUS 
CONVECTION BETWEEN 120W AND 140W IS STREAMING NE WITHIN 360 NM 
EITHER SIDE OF A LINE FROM 20N107W TO 12N120W. OTHERWISE DRY 
UPPER AIR IS INDICATED N OF 15N W OF 120W AND N OF 20N E OF 120W.
     
AT THE LOW LEVELS...1026 MB HIGH PRES IS CENTERED AT 32N134W 
WITH A RIDGE EXTENDING SE TO 20N108W. THE GRADIENT NE OF THE 
RIDGE IS SUPPORTING N WINDS 20 TO 25 KT NEAR 30N120W WITH THE 
SEAS EXPECTED TO MAX AT ABOUT 13 FT IN THE N SWELL TILL LATE FRI 
THEN THE GRADIENT SHOULD RELAX SOME FRI NIGHT THROUGH SAT. A 
SMALL AREA OF NE TRADES TO 20 KT ARE OBSERVED S OF THE RIDGE 
FROM 05N TO 15N W OF 132W...AND EXPECTED TO DIMINISH TONIGHT 
INTO EARLY FRI.      

GAP WINDS...N WINDS MAY INCREASE TO 20 KT IN THE GULF OF 
TEHUANTEPEC SUN MORNING.

$$
NELSON