000
AXPZ20 KNHC 210923
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN JUN 21 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 
0900 UTC.

...SPECIAL FEATURES...
A 1004 MB SURFACE LOW IS CENTERED NEAR 15N100W DRIFTING WNW. 
BROAD CYCLONIC TURNING CAN BE SEEN IN A LARGE AREA SURROUNDING 
THE SYSTEM. WITH THIS LARGE BROAD SYSTEM RAINBANDS ARE EXTENDING 
FROM GUATEMALA INTO SOUTHERN MEXICO. THE CONVECTION OVER THE 
CIRCULATION CENTER HAS INCREASED OVER THE PAST SEVERAL HOURS.
AN UPPER LEVEL OUTFLOW OVER THIS REGION...AND IS PROVIDING AN 
ENVIRONMENT FAVORABLE FOR CONTINUED DEEP CONVECTION.

...ITCZ...
AXIS IS ALONG 7N78W 13N95W 13N102W 7N120W 9N130W 5N140W. 
NUMEROUS STRONG N OF 04N E OF 82W. SCATTERED MODERATE TO STRONG 
CONVECTION N OF 07N FROM 90W-105W. SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 90NM S AND 60 NM N OF AXIS FROM 123W-132W.

...DISCUSSION...
MIDDLE AND UPPER RIDGE IS N OF 25N W OF 135W. RIDGE IS FORECAST 
TO WEAKEN THROUGH THE NEXT COUPLE OF DAYS AND BY MON THIS 
AREA WILL BE PART OF A BROAD TROUGH THAT DEVELOPS OVER THE 
NORTHERN PORTION OF THE AREA. THE AREA IS DRY AND CLOUD FREE IN 
THE MIDDLE AND UPPER LEVELS DUE TO MODERATE TO STRONG SUBSIDENCE 
WITH OVERCAST TO BROKEN STRATOCUMULUS IN THE LOWER LEVELS.

MID/UPPER LEVEL TROUGH IS N OF 17N FROM 110W-125W...WITH AXIS 
FROM NORTHERN BAJA CALIFORNIA NEAR 32N115W TO 17N115W. THE AREA 
IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS. IN THE 
LOWER LEVELS MOSTLY OVERCAST STRATOCUMULUS IS OBSERVED OVER THE 
PACIFIC. DIFFLUENT UPPER FLOW E THE TROUGH IS PRODUCING A LARGE
AREA OF DEEP LAYER MOISTURE WITH BROKEN/OVERCAST MULTI-LAYERED 
CLOUDS ALONG WITH SCATTERED CONVECTION N OF 5N E OF 105W. IN THE 
DEEP TROPICS AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED 
NEAR 10N128W. UPPER LEVEL DIFFLUENT FLOW WITH WITH ANTICYCLONE 
IS ENHANCING CONVECTIVE ACTIVITY WITH A SURFACE LOW NEAR 9N129W.

MODERATE SURFACE RIDGE IS N OF 15N W OF 115W WITH RIDGE AXIS 
FROM 30N140W TO 15N116W. SURFACE TROUGH EXTENDS FROM 12N128W TO
A 1009 MB LOW PRES ANALYZED ALONG THE ITCZ NEAR 9N129W...THE
TROUGH CONTINUES TO 7N130W. A LARGE AREA OF CONVECTION 
ASSOCIATED WITH THE ITCZ AND THE LOW IS DESCRIBED ABOVE.
 
$$
DGS