000
AXPZ20 KNHC 130919
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU AUG 13 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...SPECIAL FEATURES...

TROPICAL STORM GUILLERMO NEAR 16.9 120.5W OR ABOUT 700 NM SW OF 
THE SOUTHERN TIP OF BAJA CALIFORNIA AT 0900 UTC AUG 13. 
GUILLERMO WAS MOVING TOWARD THE WEST-NORTHWEST OR 290 DEGREES AT 
14 KT. MAXIMUM SUSTAINED WINDS WERE NEAR 45 KT WITH GUSTS TO 55 
KT. ESTIMATED MINIMUM CENTRAL PRESSURE WAS 999 MB. SEE THE 
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. OUTFLOW IN THE UPPER 
LEVELS IS GOOD IN THE NW SEMICIRCLE AND SOMEWHAT RESTRICTED IN 
THE SE SEMICIRCLE. THE CONVECTION IS BECOMING MORE ORGANIZED 
WRAPPING AROUND THE CENTER WITH SCATTERED TO NUMEROUS STRONG 
CONVECTION WITHIN 90 NM OF CENTER. THE SYSTEM IS FORECAST TO 
STRENGTHEN SLOWLY THROUGH FRIDAY BUT REMAIN TROPICAL STORM 
STRENGTH.

...TROPICAL WAVES...

TROPICAL WAVE N OF 04N ALONG 88W MOVE W 15 KT. NO SIGNIFICANT 
CONVECTION WAS NOTED WITH THIS FEATURE.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG THE 
LINE...05N77W TO 08N110W TO 12N120W TO 08N130W TO 08N140W.
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 60 NM OF THE 
POINTS 07N79.5W AND 07N82.5W. SCATTERED MODERATE TO STRONG 
CONVECTION IS WITHIN THE AREA FROM 06N TO 12N FROM 98W TO 103W.

...DISCUSSION...

AN UPPER LEVEL LOW IS CENTERED OVER THE MEXICAN COAST NW OF 
ACAPULCO NEAR 18N103W. ASSOCIATED TROUGH COVERS THE AREA FROM 
95W TO 112W NORTH OF THE ITCZ AND EXTENDING OVER MUCH OF CENTRAL 
AND NORTHERN MEXICO. DIVERGENCE ALOFT ON THE SE SIDE OF THE 
TROUGH IS ENHANCING CONVECTION WITHIN AND NORTH OF THE ITCZ FROM 
06N TO 12N BETWEEN 98W AND 103W. 

UPPER TROUGH IS NW OF A LINE THROUGH 32N116W TO THE ITCZ NEAR 
135W. THIS AREA IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER 
LEVELS WITH OVERCAST STRATOCUMULUS IN THE LOWER LEVELS NORTH OF 
20N EAST OF 135W AND SCATTERED TO BROKEN STRATOCUMULUS 
ELSEWHERE. 

BETWEEN THE TWO TROUGHS BROAD ANTICYCLONIC FLOW IS NOTED.
THIS INCLUDES THE DIFFLUENT FLOW OVER GUILLERMO. THIS AREA IS 
MOIST ALOFT WITH BROKEN TO OVERCAST HIGH CLOUDS ASSOCIATED WITH 
GUILLERMO SOUTH OF 25N AND WEST OF 117W.

WEAK SURFACE RIDGE IS NORTH OF 22N WEST OF 115W. ELSEWHERE 
EXCEPT FOR GUILLERMO A BROAD SURFACE TROUGH IS ANALYZED.

GAP NORTHERLY WINDS OF 20 KT IN THE GULF OF TEHUANTEPEC REGION 
WILL END TODAY. 

GAP NE TO E WINDS OF 20 KT IN AND DOWNSTREAM OF THE GULF OF 
PAPAGAYO REGION OUT TO 90W WILL CONTINUE THROUGH THE NEST COUPLE 
OF DAYS.

$$
LL