000
AXPZ20 KNHC 221520
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON JUN 22 2009

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURE...

TROPICAL STORM ANDRES IS CENTERED NEAR 16.0N 102.0W OR ABOUT 120 
MILES SSW OF ZIHUATANEJO MEXICO AT 1500 UTC MOVING N-NW 4 KT. 
ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED 
WINDS 45 KT GUSTS 55 KT. SEE LATEST NHC PUBLIC ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCPEP2/WTPZ32 KNHC AND THE FULL FORECAST 
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE 
DETAILS. THE CLOUD STRUCTURE AND ASSOCIATED CONVECTION CONTINUES 
TO BECOME BETTER ORGANIZED UNDER FAVORABLE UPPER LEVEL 
CONDITIONS. NUMEROUS MODERATE TO STRONG CONVECTION IS IN A LARGE 
AREA WITHIN 180 NM OF THE POINT 16N103W. SCATTERED MODERATE WITH 
ISOLATED STRONG CONVECTION IS IN THE SOUTHERLY FLOW EAST OF THE 
SYSTEM WITHIN 120 NM OF THE POINT 14N98W.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...05N77W TO 
09N105W TO 09N120W TO 06N140W. SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION IS WITHIN 75 NM OF THE POINT 04.5N78.5W. 
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE POINT 
09N121W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION IS 
WITHIN 180 NM OF THE POINT 10N124W. SCATTERED MODERATE WITH 
ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE POINT 
07.5N128.5W.

...DISCUSSION...

WEAK MIDDLE LEVEL RIDGE OVER THE FAR NORTHWEST PART OF THE AREA 
WILL WEAKEN FURTHER AND BE WEST OF THE AREA THIS AFTERNOON.

LARGE TROUGH IS OVER THE AREA ELSEWHERE NORTH OF THE ITCZ AND 
WEST OF A LINE FROM 32N107W TO 20N110W TO THE ITCZ NEAR 115W.
AN AREA OF UPPER LEVEL DIFFLUENCE OVER THE ITCZ WEST OF 120W IS 
MOIST IN THE DEEP LAYER WITH MULTI LEVEL OVERCAST CLOUDS FROM 
06N TO 13N WEST OF 120W AND ENHANCED CONVECTION FROM 07N TO 13N 
FROM 120W TO 128W. A SURFACE LOW IS CENTERED NEAR 11N126W 1008 
MB AND IS MOVING EAST-NORTHEAST 5 TO 10 KNOTS. SCATTERED 
MODERATE TO STRONG CONVECTION IS WITHIN THE AREA WITHIN 180 NM 
OF THE POINT 10N124W. THE LOW HAS A LOW CHANCE OF BECOMING A 
TROPICAL CYCLONE. ELSEWHERE WITHIN THE BROAD TROUGH THE 
ATMOSPHERE IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS 
WITH MOSTLY OVERCAST STRATOCUMULUS NORTH OF 20N AND SCATTERED TO 
BROKEN STRATOCUMULUS FROM 15N TO 20N IN THE LOWER LEVELS.

DIFFLUENT UPPER FLOW EAST OF THE BROAD TROUGH IS ASSOCIATED WITH 
A LARGE AREA OF MULTI LEVEL CLOUDS AND EMBEDDED AREAS OF 
CONVECTION THAT EXTENDS EAST TO CENTRAL AMERICA MOSTLY NORTH OF 
THE ITCZ. THIS AREA INCLUDES TROPICAL STORM ANDRES MENTIONED IN 
THE SPECIAL FEATURES SECTION. 

A MODERATE SURFACE RIDGE IS NORTH OF 15N WEST OF 118W. ELSEWHERE 
EXCEPT AS MENTIONED ABOVE A BROAD TROUGH IS ANALYZED AT THE 
SURFACE.

$$
LL