000
AXPZ20 KNHC 250302
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE AUG 25 2009

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 
0300 UTC.

...SPECIAL FEATURE...

TROPICAL DEPRESSION TWELVE-E HAS BEEN UPGRADED TO TROPICAL STORM 
IGNACIO. IGNACIO WAS CENTERED NEAR 17.0N 117.8W OR ABOUT 570 
NM...1055 KM...SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA 
AT 25/0300 UTC...MOVING WEST-NORTHWEST OR 290 DEGREES AT 9 KT. 
MAXIMUM SUSTAINED WINDS WERE 35 KT WITH GUSTS TO 45 KT AND THE 
ESTIMATED MINIMUM CENTRAL PRESSURE WAS 1004 MB. SATELLITE 
IMAGERY CONTINUES TO SHOW INCREASING ORGANIZATION IN THE CLOUD 
PATTERN. THE STRONGEST CONVECTION WAS IN THE SOUTH QUADRANT WITH 
NUMEROUS STRONG CONVECTION WITHIN 150 NM OF THE POINT 16N118W.  
CLOUD TOP TEMPERATURES WERE -85C WITHIN THE CENTRAL DENSE 
OVERCAST. THE SYSTEM IS IN AN AREA OF GOOD UPPER LEVEL OUTFLOW 
WITH THE EASTERLY SHEAR DECREASING OVER THE CENTER. ADDITIONAL 
INFORMATION CAN BE FOUND UNDER AWIPS/WMO HEADERS 
MIATCMEP3/WTPZ23 KNHC.

...TROPICAL WAVES...

A TROPICAL WAVE HAS MOVED OVER THE EASTERN PART OF THE AREA AND 
IS ALONG 80W/81W NORTH OF 05N AND EXTENDS NORTHWARD OVER THE 
WESTERN CARIBBEAN. THE WAVE IS MOVING WEST 15 TO 20 KNOTS. 
ASSOCIATED CONVECTION IS OVER THE SOUTHWEST CARIBBEAN WITH NO 
CONVECTION OVER THE PACIFIC NEAR THE WAVE.
  
...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG...09N83W TO 07N95W 
TO 07N105W THEN CONTINUE FROM 13N120W TO 10N130W TO 09N140W.
SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION IS WITHIN 75 
NM OF THE POINT 06N88.5W. SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION IS WITHIN 60 NM OF THE POINT 10N136W.

...DISCUSSION...

A SMALL CYCLONIC CIRCULATION IS NEAR THE NORTHWEST PART OF THE 
AREA CENTERED NEAR 28N141W AND THE ASSOCIATED CIRCULATION 
EXTENDS OVER THE FAR NORTHWEST PART OF THE AREA. A SMALL AREA OF 
OVERCAST HIGH CLOUDS IS NORTH OF 26N WEST OF 137W. THE SYSTEM IS 
FORECAST TO DRIFT NORTHEAST FOR THE NEXT 36 HOURS THEN GET 
QUICKLY ABSORBED BY A VERY STRONG DEEP LAYER TROUGH THAT WILL 
APPROACH THE AREA FROM THE NORTHWEST LATE WEDNESDAY.

A DEEP LAYER TROUGH IS NORTHWEST OF LINE THROUGH 32N108W TO 
25N115W TO 18N125W AND EAST OF 125W. THE AREA IS DRY AND CLOUD 
FREE IN THE MIDDLE AND UPPER LEVELS WITH OVERCAST STRATOCUMULUS 
IN THIS AREA WEST OF 120W. THE TROUGH IS FORECAST TO MOVE INLAND 
OVER NORTHERN MEXICO AND THE SOUTHWEST UNITED STATES.

BETWEEN THE TWO ABOVE TROUGHS A RIDGE IS OVER THE AREA. THE 
ATMOSPHERE IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS 
WITH OVERCAST STRATOCUMULUS NORTH OF 27N AND BROKEN 
STRATOCUMULUS SOUTH OF 27N IN THE LOWER LEVELS.

A LARGE TROUGH THAT IS OVER THE EASTERN UNITED STATES EXTENDS 
SOUTHWEST ACROSS THE WESTERN GULF OF MEXICO AND MOST OF 
NORTHERN MEXICO. THE TROUGH IS EAST OF 105W AND EXTENDS EAST TO 
A LINE FROM 10N105W TO NEAR 25N95W. THE AREA IS MOSTLY DRY AND 
CLOUD FREE IN THE MIDDLE AND UPPER LEVELS. SOME CONVECTION IS 
OVER COASTAL MEXICO SOUTH OF 20N DUE TO DIURNAL HEATING.

BETWEEN THE SECOND AND THIRD TROUGHS A LARGE ANTICYCLONIC AREA 
IS OBSERVED. THIS THE AREA OVER TROPICAL STORM IGNACIO. THE AREA 
IS DIFFLUENT ALOFT WITH AREAS OF MULTI LEVEL CLOUDS AND EMBEDDED 
AREAS OF CONVECTION.

EAST OF THE THIRD TROUGH BROAD ANTICYCLONIC FLOW IS OBSERVED. 
WIDESPREAD MULTI LEVEL CLOUDS AND EMBEDDED AREAS OF CONVECTION 
ARE OBSERVED.

WEAK SURFACE RIDGE IS NORTHWEST OF A LINE FROM NORTHERN BAJA 
CALIFORNIA TO 15N140W. ELSEWHERE EXCEPT FOR THE TROPICAL STORM A 
BROAD TROUGH IS ANALYZED AT THE SURFACE.

$$
LL