000
AXPZ20 KNHC 280256
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI MAY 28 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0215 UTC.

...SPECIAL FEATURE...
AN AREA OF DISTURBED WEATHER SOUTH OF THE GULF OF TEHUANTEPEC  
CHARACTERIZED BY A BROAD 1008 MB SURFACE LOW NEAR 13N95W HAS 
PRODUCED ABUNDANT TROPICAL MOISTURE OVER INLAND CENTRAL AMERICA 
FROM NICARAGUA TO SW MEXICO. SCATTERED MODERATE TO ISOLATED 
STRONG IS FROM 08N TO 14N BETWEEN 90W AND 99W. CONVECTION TENDS 
TO FOLLOW A DIURNAL PATTERN WITH CONVECTION DECREASING DURING 
THE LATE EVENING AND INCREASING AGAIN DURING THE EARLY MORNING 
HOURS. THERE IS A HIGH PROBABILITY FOR THIS SYSTEM TO DEVELOP 
INTO A TROPICAL CYCLONE OVER THE NEXT 48 HOURS. REGARDLESS OF 
THE POTENTIAL FOR DEVELOPMENT...THIS SYSTEM IS EXPECTED TO 
PRODUCE VERY HEAVY RAINFALL AND FLOODING OVER PORTIONS OF 
CENTRAL AMERICA DURING THE NEXT FEW DAYS. 

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 13N87W TO 
07N100W TO 08N110W TO 05N130W TO 06N140W. BESIDES THE CONVECTION 
MENTIONED IN THE SPECIAL FEATURE SECTION...SCATTERED MODERATE TO 
ISOLATED STRONG FROM 10N TO 17N BETWEEN 85W AND 90W. SCATTERED 
MODERATE FROM 06N TO 08N BETWEEN 99W AND 108W...FROM 05N TO 07N 
BETWEEN 112W AND 115W...AND FROM 05N TO 08N BETWEEN 133W AND 
137W.

...DISCUSSION...

THE BASE OF AN UPPER LEVEL TROUGH COVERS THE FAR N PORTION OF 
THE DISCUSSION AREA N OF 20N. A 50-70 KT SUBTROPICAL JET STREAM 
ENTERS THE AREA NEAR 17N140W AND CONTINUES E-NE TO BEYOND THE 
SOUTHERN TIP OF BAJA CALIFORNIA. 

AN UPPER LEVEL RIDGE IS FROM 01N TO 15N W OF 120W. FURTHER 
E...AN UPPER LEVEL HIGH IS CENTERED SOUTH OF MEXICO NEAR 
17N94W.  

AT THE SURFACE...A 1024 MB SURFACE HIGH LIES NEAR 29N144W. A 
RIDGE EXTENDS SOUTHEAST THROUGH FORECAST WATERS FROM 27N140W TO 
NEAR 17N113W. THE RIDGE IS PRODUCING A TIGHT ENOUGH PRES 
GRADIENT TO SUPPORT NE TO E 20-25 KT TRADE WINDS IN AN AREA FROM 
08N TO 17N W OF 130W. THE GRADIENT BETWEEN THE SAME RIDGE AND 
LOWER PRES OVER MEXICO IS PRODUCING 20-25 KT NW WINDS WITHIN 180 
NM OF THE W COAST OF BAJA CALIFORNIA. THESE WINDS WILL REMAIN 
CONFINED TO THE AREA E OF 118W TO THE BAJA CALIFORNIA COAST 
THROUGH THE NEXT 48 HOURS WITH LITTLE CHANGE IN WIND SPEED. 

$$
FORMOSA