000
AXPZ20 KNHC 042124
TWDEP 

TROPICAL WEATHER DISCUSSION                                   
NWS NATIONAL HURRICANE CENTER MIAMI FL                       
2205 UTC SUN AUG 03 2014

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

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

...SPECIAL FEATURES...

MAJOR HURRICANE ISELLE CENTERED NEAR 16.1N 137.4W AT 04/2100 UTC 
MOVING WEST OR 270 DEGREES AT 9 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 947 MB. ISELLE IS A CATEGORY FOUR HURRICANE ON THE 
SAFFIR-SIMPSON HURRICANE WIND SCALE. MAXIMUM SUSTAINED WIND 
SPEED IS 120 KT WITH GUSTS TO 145 KT. NUMEROUS STRONG CONVECTION 
IS OBSERVED WITHIN 90 NM OF THE CENTER OF ISELLE. GIVEN THE 
STRONG WINDS AND MODEST FORWARD SPEED OF ISELLE...SEAS ARE 
ESTIMATED TO BE NEAR 40 IN THE NORTH CENTRAL PORTION OF THE 
STORM. THE OFFICIAL INTENSITY FORECAST CALLS FOR ISELLE TO 
MAINTAIN HURRICANE STATUS THROUGH TUE ACROSS THE FORECAST AREA. 
ISELLE IS FORECAST TO CROSS 140W LATE TUE. PLEASE SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC 
FOR MORE DETAILS.  

TROPICAL STORM JULIO IS CENTERED NEAR 13.5N 121.6W AT 04/2100 
UTC OR ABOUT 873 NM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA 
MOVING WEST OR 270 DEGREES AT 14 KT. ESTIMATED CENTRAL PRESSURE 
IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 
60 KT. NUMEROUS MODERATE TO STRONG CONVECTION IS OBSERVED WITHIN 
180 NM IN THE W SEMICIRCLE OF THE CENTER. T.S. JULIO IS FORECAST 
TO INTENSIFY FURTHER TO HURRICANE STRENGTH BY TUE NIGHT INTO WED 
MORNING AS IT MOVES WEST ACROSS THE FORECAST AREA. PLEASE SEE 
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS.  
                           
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM FROM 10N85W TO LOW PRES NEAR 09N96W 1011 MB TO 
07N102W TO 08N107W. SCATTERED MODERATE CONVECTION IS FROM 04N TO 07N BETWEEN 
83W AND 85W.             

...DISCUSSION...

A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE N PART OF THE 
FORECAST AREA...MAINLY N OF 20N. AN UPPER-LEVEL TROUGH IS OVER 
THE NW CORNER AND EXTENDS FROM A CUT-OFF LOW NEAR 33N129W TO 
BEYOND 25N140W. AN ANTICYCLONIC CIRCULATION IS CENTERED NEAR 
21N125W WITH A RIDGE EXTENDING N-NE TO NEAR 30N118W. EAST OF THE 
RIDGE...ANOTHER UPPER-LEVEL TROUGH PERSIST..STRETCHING FROM 
31N115W TO 24N115W TO 19N122W. A SECOND ANTICYCLONE HAS 
DEVELOPED OVER N-CENTRAL MEXICO NEAR 26N104W. A GENERAL EASTERLY 
FLOW ALOFT IS NOTED S OF 20N W OF 110W. AN UPPER-LEVEL LOW IS 
OVER SE MEXICO AND THE YUCATAN PENINSULA WITH A TROUGH TO NEAR 
13N95W. THIS TROUGH IS ENHANCING SCATTERED MODERATE CONVECTION 
FROM 11N TO 15N BETWEEN 94W AND 105W...AND FROM 17N TO 20N 
BETWEEN 104W AND 110W. THE REMAINDER OF THE AREA IS UNDER THE 
INFLUENCE OF A RIDGE ANCHORED BY AN ANTICYCLONE LOCATED OVER 
NICARAGUA.
 
A SURFACE RIDGE IS N OF 20N. FAIRLY DRY CONDITIONS PERSIST 
ACROSS MOST OF THE AREA N OF 20N W OF 115W. A FAIRLY MOIST 
ENVIRONMENT IS TO THE SOUTH OF THE RIDGE DUE TO THE PRESENCE 
OF TROPICAL CYCLONES ISELLE AND JULIO.
 
LONG PERIOD SWLY SWELLS FROM THE SOUTHERN HEMISPHERE WILL 
CONTINUE TO IMPACT MAINLY THE WATERS E OF 110W...BUILDING SEAS 
TO AROUND 9 FT ACROSS THE SOUTH-CENTRAL WATERS BUT PARTICULARLY  
S OF THE EQUATOR. 

$$ 
FORMOSA