000
AXPZ20 KNHC 141545
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI MAY 14 2010

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 
1500 UTC.

...TROPICAL WAVES...

A WEAK TROPICAL WAVE IS ALONG 87W FROM 03N TO 08N MOVING W AT 10 
KT. THE WAVE COINCIDES WITH A MAXIMUM IN TOTAL PRECIPITABLE 
WATER IMAGERY. CONVECTION ASSOCIATED WITH THE WAVE IS MOSTLY 
ALONG THE ITCZ.

...ITCZ...

THE ITCZ AXIS IS ALONG 07N78W TO 07N90W TO 08N104W TO 08N120W TO 
07N140W. SCATTERED MODERATE TO ISOLATED STRONG IS ALONG THE 
COAST OF COLOMBIA FROM 02N TO 07N E OF 80W. SCATTERED MODERATE 
ISOLATED STRONG FROM 06N TO 09N BETWEEN 84W AND 88W. SIMILAR 
CONVECTION IS WITHIN 60 NM OF AXIS BETWEEN 97W AND 115W.  

...DISCUSSION...

ALOFT...A DEEP LAYER TROUGH EXTENDS ACROSS THE N WATERS FROM THE 
SW U.S. TO 20N BETWEEN 100W AND 130W. MODERATE TO STRONG 
SUBSIDENCE IS NOTED N OF THE TROUGH.

AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 10N105W WITH A BROAD 
RIDGE EXTENDING EWD TO NEAR 85W. THIS RIDGE ALSO DOMINATES SE 
MEXICO AND NORTHERN CENTRAL AMERICA. A JETSTREAM BRANCH WITH 
CORE WIND SPEEDS OF 70-90 KT LIES BETWEEN THE AFOREMENTIONED 
TROUGH AND THIS ANTICYCLONE ENTERING THE FORECAST NEAR 18N140W 
AND CONTINUING E-NE ACROSS SOUTHERN BAJA PENINSULA INTO MAINLAND 
MEXICO. THE RIDGE IS HELPING TO INDUCE CONVECTION ALONG THE 
ITCZ. A DIFFLUENT PATTERN ALOFT IS ENHANCING CONVECTION ALONG 
THE PACIFIC COAST OF COLOMBIA AND PANAMA.

AT THE SURFACE...A 1026 MB HIGH PRES CENTER NEAR 31N139W EXTENDS 
A RIDGE ACROSS THE DISCUSSION AREA TO 16N105W. NE TRADES OF 20 
TO 25 KT ARE ON THE SOUTHERN PERIPHERY OF THE RIDGE COVERING A 
LARGE AREA FROM 10N TO 21N W OF 124W. THE AERIAL EXTENT AND 
STRENGTH OF THE TRADES WILL DECREASE DURING THE NEXT 48 HOURS AS 
THE HIGH AND RIDGE WEAKEN. PRESSURE GRADIENT BETWEEN THE HIGH 
AND LOWER PRESSURE OVER THE SW CONUS IS ALSO PRODUCING AN AREA 
OF NORTHERLY WINDS OF 20 KT N OF 28N BETWEEN 120W AND 125W. 
THESE WINDS SHOULD DIMINISH TO LESS THAN 20 KT WITHIN THE NEXT 
24 HOURS AS THE PRES GRADIENT IN THAT AREA WEAKENS. A 1009 MB 
LOW WITH ASSOCIATED CONVECTION IS NOTED ON THE ITCZ NEAR 08N111W 
AS DEPICTED BY THE 0514 UTC WINDSAT IMAGERY. THE LOW IS DRIFTING 
W. 
ELSEWHERE...THE GFS COMPUTER MODEL SUGGESTS THAT A COLD FRONT 
WILL REACH THE FAR NW CORNER OF THE AREA BY SUN.  

THE REGIONAL SEAS ARE DOMINATED BY NE WIND WAVES DUE TO THE 
TRADE WINDS AND LONG PERIOD...16-18 SECONDS...CROSS EQUATORIAL 
SW SWELLS. THESE SWELLS WILL GRADUALLY DECAY TO LESS THAN 8 FT 
OVER THE MAJORITY OF THE DISCUSSION AREA DURING THE NEXT 48 
HOURS.

GAP WINDS...NE TO E WINDS AT 20 KT ARE SURGING THROUGH THE GULF 
OF PAPAGAYO DOWNWIND TO 90W. THESE WINDS ARE EXPECTED TO 
DIMINISH TO LESS THAN 20 KT IN ABOUT 30 HOURS.

$$
FORMOSA