000
AXPZ20 KNHC 281549
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON JUN 28 2010

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 FEATURES....

AT 28/1500...TROPICAL STORM CELIA IS CENTERED NEAR 15.2N 124.2W 
PRESENT MOVEMENT IS NEAR STATIONARY. THE MAXIMUM SUSTAINED WIND 
SPEED IS 35 KT WITH GUSTS TO 45 KT...AND THE ESTIMATED MINIMUM 
CENTRAL PRESSURE IS 1005 MB. THE REMAINING DEEP CONVECTION OVER 
CELIA HAS CONTINUED TO DIMINISH WITH ONLY SCATTERED MODERATE 
WITHIN 60 NM SW SEMICIRCLE OF CENTER. CELIA IS EXPECTED TO 
CONTINUE TO WEAKEN TO A TROPICAL DEPRESSION LATER TODAY AND 
FURTHER WEAKEN TO A POST TROPICAL REMNANT LOW PRESSURE ON TUE 
AND OPENING INTO A WEAKENING TROUGH BY THU. REFER TO THE LATEST 
NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP4/WTPZ24 
KNHC FOR MORE DETAILS. 

AT 28/1500...DARBY IS DOWNGRADED TO A TROPICAL DEPRESSION. AT 
THIS TIME...IT IS CENTERED NEAR 14.1N 99.6W MOVING E OR 090 DEG 
AT 8 KT. THE MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS 
TO 40 KT...AND THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 
MB. EASTERLY SHEAR HAS COMPLETELY EXPOSED THE CENTER OF DARBY 
WELL TO THE EAST OF THE DEEP CONVECTION THAT HAS ALSO CONTINUED 
TO DIMINISH DURING THE MORNING HOURS. DARBY IS EXPECTED TO 
WEAKEN TO A REMNANT LOW PRESSURE LATER TODAY. REFER TO THE 
LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCPEP5/WTPZ25 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

SEE SPECIAL FEATURES.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG AXIS 09N79W TO 10N96W TO 08N110W 
TO 11N120W TO 08N140W. SCATTERED MODERATE ISOLATED STRONG N OF 
ITCZ TO THE COAST OF CENTRAL AMERICA BETWEEN 87W AND 95W. 
SCATTERED MODERATE FROM 08N TO 12N BETWEEN 95W AND 100W. SIMILAR 
CONVECTION IS WITHIN 90 NM N OF AXIS BETWEEN 108W AND 114W...AND 
FROM 1ON TO 12N BETWEEN 120W AND 123W.

...DISCUSSION...

A CUT-OFF LOW IS OVER THE SW CONUS WITH A TROUGH EXTENDING 
MAINLY S TO NEAR 25N109W. THE UPPER ANTICYCLONE ASSOCIATED WITH 
TROPICAL STORM CELIA IS CENTERED NEAR 21N109W WITH A RIDGE 
EXTENDING W TO NEAR 19N122W. ANOTHER UPPER ANTICYCLONE IS 
LOCATED NEAR 22N132W WITH A RIDGE STRETCHING NW BEYOND 30N140W. 
NE UPPER-LEVEL WINDS DOMINATE THE E PORTION OF THE AREA MAINLY E 
OF 105W.  

AT THE SURFACE...HIGH PRESSURE NW OF AREA EXTENDS A RIDGE SE 
COVERING THE WATERS N OF 20N. THE GRADIENT E OF THE RIDGE 
CONTINUES TO PRODUCE NW 20 KT WINDS WITHIN 300 NM OF THE 
SOUTHERN BAJA PENINSULA. THE TROPICAL CYCLONES HAVE GENERATED 
MULTIPLE SWELL FIELDS RESULTING IN CONFUSED SWELL OVER MOST OF 
THE AREA SURROUNDING THE CYCLONES...ROUGHLY S OF 20N W OF 
105W...AND IS ALSO MIXING WITH CROSS EQUATORIAL SOUTHERLY SWELL. 

A WEAKENING FRONTAL BOUNDARY WILL CLIP THE N WATERS LATER TODAY 
FOLLOWED BY N TO NE WINDS OF 20 KT AND NEW SET OF N SWELL. THIS 
SWELL EVENT WILL SPREAD ACROSS THE AREA LATER TONIGHT MIXING 
WITH THE SOUTHERLY SWELLS OVER THE WATERS N OF 27N BETWEEN 110W 
AND 115W IN ABOUT 24 HOURS. THE GRADIENT IS ALSO TIGHT SE OF THE 
TROPICAL STORM DARBY WITH THE SW MONSOON FLOW ENHANCED BY THE 
DEEPENING LOW PRESSURE OF ATLANTIC TROPICAL STORM ALEX IN THE E 
BAY OF CAMPECHE. ANOTHER PULSE OF REINFORCING SOUTHERLY SWELL IS 
JUST BEGINNING TO CROSS THE EQUATOR E OF 120W. 

$$
GR/MN