000
AXPZ20 KNHC 260925
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC WED AUG 26 2015

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0815 UTC. 

...SPECIAL FEATURES...

TROPICAL STORM IGNACIO IS CENTERED NEAR 12.3N 134.1W AT 26/0900 
UTC IS MOVING W OR 260 DEG AT 6 KT. ESTIMATED MINIMUM CENTRAL 
PRES IS 1001 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH 
GUSTS TO 55 KT. IGNACIO IS BEING HAMPERED BY ESE VERTICAL WIND 
SHEAR. SCATTERED TO NUMEROUS STRONG CONVECTION IS FROM 11N TO 
15N BETWEEN 133W AND 138W. ELSEWHERE SCATTERED MODERATE 
CONVECTION IS FROM 09N TO 17N BETWEEN 132W AND 138W. IGNACIO IS 
FORECAST TO INTENSIFY TO A MINIMAL HURRICANE IN 24 HOURS OVER 
THE EXTREME WESTERN PART OF THE AREA. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC 
FOR MORE DETAILS.

A LOW PRES SYSTEM NEAR 10N109W WITH PRES OF 1008 MB IS MOVING W 
AT 16 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 
10N TO 15N BETWEEN 108W AND 113W. ENVIRONMENTAL CONDITIONS ARE 
FAVORABLE FOR DEVELOPMENT OF THIS LOW AND THERE IS CURRENTLY 
HIGH CHANCE THAT THIS LOW WILL DEVELOP INTO A TROPICAL CYCLONE 
WITHIN THE NEXT COUPLE OF DAYS. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH AXIS EXTENDS FROM 10N85W TO 08N95W TO 10N115W. 
SCATTERED MODERATE CONVECTION IS FROM 04N TO 12N BETWEEN 83W AND 
98W.

...DISCUSSION... 

UPPER LEVELS...                                                 
AN ANTICYCLONE IS NEAR 19N125W. THIS FEATURE IS PRODUCING 
EASTERLY FLOW ACROSS ITS SOUTHERN PERIPHERY S OF ABOUT 17N. THIS 
FLOW IS INDUCING SHEAR OVER IGNACIO. A BROAD UPPER TROUGH IS 
OVER THE NW PORTION OF THE AREA N OF 20N W OF 130W. OVER THE 
EASTERN PORTION.

SURFACE...HIGH PRESSURE CENTERED N OF THE AREA NEAR 34N130W 
EXTENDS A RIDGE SE TO NEAR 17N110W. OUTSIDE OF TROPICAL STORM 
IGNACIO...GENTLE TO MODERATE TRADE WINDS ARE NOTED ON THE 
SOUTHERN PERIPHERY OF THE RIDGE. A DISSIPATING 1015 MB LOW IS 
OVER THE NW CORNER OF THE FORECAST AREA NEAR 33N138W. THE LOW IS 
FORECAST TO DISSIPATE TO OVER THE NEXT 24 HOURS.

LONG PERIOD CROSS EQUATORIAL SW SWELL WILL CONTINUE TO PROPAGATE 
NORTHEASTWARD ACROSS THE SOUTH CENTRAL WATERS...REACHING THE 
MEXICAN AND CENTRAL AMERICAN COASTS EARLY WED. 
 
GAP WINDS...                                                     
GULF OF TEHUANTEPEC...FRESH TO STRONG NORTHERLY WINDS ARE  
ACROSS THE ISTHMUS OF TEHUANTEPEC. THESE WINDS WILL BEGIN IN THE 
RANGE OF 20-25 KT AND REACH TO 30 KT DURING THE EARLY MORNING 
HOURS WED BEFORE DIMINISHING DURING WED AFTERNOON. THESE WINDS 
THEN MATERIALIZE AGAIN LATE WED NIGHT INTO THU. ASSOCIATED SEAS 
WILL BUILD TO THE 9 FT EACH MORNING. 

$$
FORMOSA