000
AXPZ20 KNHC 190406
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED SEP 19 2007

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 
0345 UTC.

...SPECIAL FEATURE...

TROPICAL STORM IVO CENTERED NEAR 14.5N 109.3W AT 19/0300 UTC 
MOVING WNW AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 
MB. MAXIMUM SUSTAINED WIND SPEED HAS INCREASED TO 40 KT WITH 
GUSTS TO 50 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. THIS SYSTEM HAS 
BECOME BETTER ORGANIZED THROUGHOUT THE NIGHT. THE CLOUD 
STRUCTURE IS INCREASINGLY CIRCULAR AND ASSOCIATED DEEP 
CONVECTION HAS EXPANDED AND GAINED CURVATURE. SCATTERED MODERATE 
TO ISOLATED STRONG IS FROM 12N TO 18N BETWEEN 106W AND 112W.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 82W N OF 4N MOVING W AT 10-15 KT.  
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS INLAND OVER 
COSTA RICA AND NICARAGUA FROM 9N TO 12N BETWEEN 83W AND 86W.  

TROPICAL WAVE IS ALONG 126W FROM 7N TO 20N MOVING W 10-15 KT. A 
1008 MB LOW IS EMBEDDED ON THE WAVE AXIS NEAR 15N126W.  
ASSOCIATED CONVECTION IS EXTENSIVE.  SCATTERED MODERATE TO 
STRONG IS FROM 11N TO 18N BETWEEN 122W AND 130W.  TROPICAL 
CYCLONE FORMATION IS POSSIBLE WITHIN THE NEXT 24 HOURS WITH THIS 
LOW.   

...ITCZ...
ITCZ AXIS CENTERED ALONG 9N84W 13N100W 12N116W 16N125W 11N140W. 
BESIDES THE CONVECTION MENTIONED IN THE SPECIAL FEATURES AND 
TROPICAL WAVE SECTIONS... SCATTERED MODERATE IS FROM 10N TO 13N 
BETWEEN 104W AND 107W. SCATTERED MODERATE IS FROM 9N TO 11N 
BETWEEN 110W AND 117W. SCATTERED MODERATE IS FROM 13N TO 15N 
BETWEEN 116W AND 118W. SCATTERED MODERATE IS FROM 14N TO 17N 
BETWEEN 130W AND 138W.  

...DISCUSSION...
20 KT WINDS ARE FUNNELING THROUGH THE GULF OF TEHUANTEPEC WITH 
SEAS TO 8 FT EXTENDING 90 NM OUT TO SEA.  THESE WINDS ARE 
FORECAST TO REMAIN UNTIL FRIDAY 21 SEP.  FURTHER W...THE 
TROPICAL BELT REMAINS SOMEWHAT ACTIVE W OF 105W ENHANCED BY THE 
TROPICAL STORM AND A TROPICAL LOW/WAVE.  THE LARGER SCALE 
PRESSURE PATTERN ACROSS THE SUBTROPICS IS DOMINATED BY A 1034 MB 
HIGH CENTERED NW OF THE AREA NEAR 40N151W.  THE TIGHTENED 
GRADIENT BETWEEN THIS HIGH AND LOW PRES TROUGHING ALONG THE ITCZ 
IS MAINTAINING STRONG NELY TRADES W OF ABOUT 125W.  

IN THE MID AND UPPER LEVELS...A WEAKENING UPPER LOW IS PULLING 
OFF TO THE NE CENTERED NEAR 32N136W.  AN UPPER LEVEL HIGH LIES 
FURTHER SE NEAR 21N124W. THIS HIGH IS PROVIDING NE/ELY SHEAR 
OVER THE TROPICS W OF 115W.  A SHORT WAVE TROUGH EXTENDS SWD 
INTO THE TROPICS FROM NEW MEXICO TO SOUTHERN BAJA.  WATER VAPOR 
IMAGERY SHOWS A MOISTURE PLUME EXTENDING ACROSS THE AREA S OF 
20N. DRY STABLE AIR DOMINATES THE REMAINDER OF THE REGION N OF 
20N AND W OF 110W.

$$
FORMOSA