000
AXPZ20 KNHC 211548
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON JUN 21 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 21/1500 UTC...HURRICANE CELIA IS CENTERED NEAR 11.8N 102.4W 
MOVING W OR 270 DEG AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE 
IS 986 MB. MAXIMUM SUSTAINED WIND SPEED IS 70 KT WITH GUSTS TO 
85 KT. SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCPEP4/WTPZ24 KNHC FOR MORE DETAILS. CONVECTION HAS INCREASED 
DURING THE MORNING HOURS NEAR THE CENTER...AND CONSISTS OF 
NUMEROUS MODERATE SCATTERED STRONG CONVECTION WITHIN 60 NM OF 
CENTER. NUMEROUS MODERATE ISOLATED STRONG CONVECTION IS NOTED IN 
BANDS PARTICULARLY WITHIN 200 NM SW AND NW QUADRANTS. EASTERLY 
UPPER LEVEL WINDS ARE CURRENTLY IMPACTING THE EASTERN SEMICIRCLE 
OF CELIA PREVENTING OUTFLOW OVER THAT PORTION OF THE CYCLONE. 
THE LATEST NHC ADVISORY CALLS FOR CELIA TO STRENGTHEN TO 85 KT 
IN 36 HOURS...AND TO 95 KT IN 72 HOURS.

AT 21/1500 UTC...TROPICAL DEPRESSION BLAS IS CENTERED NEAR 18.0N 
118.4W MOVING W OR 270 DEG AT 11 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 1007 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH 
GUSTS TO 40 KT. SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCPEP3/WTPZ23 KNHC FOR MORE DETAILS. SOME CONVECTION 
CONTINUES TO DEVELOP IN THE SOUTHWESTERN QUADRANT OF BLAS DURING 
THE PAST SEVERAL HOURS...ENOUGH TO KEEP THE SYSTEM AS A TROPICAL 
CYCLONE. BY THE END OF THE DAY... BLAS IS EXPECTED TO WEAKEN 
INTO A REMNANT LOW DUE TO COLD SEA SURFACE TEMPERATURES AND A 
STABLE ATMOSPHERIC ENVIRONMENT. THE SYSTEM WILL DISSIPATE IN 
ABOUT 72 HOURS.     

...TROPICAL WAVE...

A TROPICAL WAVE IS ALONG 91W N OF 06N WITH A 1008 MB LOW PRES 
NEAR 09N91W WHICH NOW COINCIDES WITH THE GYRE THAT WAS W OF OF 
THE TROPICAL WAVE DURING THE PAST FEW DAYS. A BAND OF SCATTERED 
MODERATE TO ISOLATED STRONG CONVECTION IS NOTED WITHIN 30 NM OF 
LINE FROM 13N93W TO 12N94W TO 11N93W. ISOLATED MODERATE 
CONVECTION IS NEAR THE LOW CENTER. 

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 08N78W TO 
10N89W TO 11N97W...THEN RESUMES AT 11N110W TO 08N120W TO 09N129W 
TO 07N140W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM S OF 
AXIS BETWEEN 91W AND 96W...AND FROM 08N TO 10N BETWEEN 108W AND 
114W. 

...DISCUSSION...

A DEEP LAYER TROUGH ENTERS THE AREA NEAR 30N130W THEN CONTINUES 
SW TO JUST N OF THE HAWAIIAN ISLANDS. TO THE E OF THE TROUGH... 
THERE IS A BROAD RIDGE ANCHORED ON AN UPPER LEVEL ANTICYCLONE 
CENTERED OVER SOUTH-CENTRAL TEXAS. ANOTHER ANTICYCLONIC 
CIRCULATION IS OVER SOUTH-CENTRAL MEXICO. SATELLITE WATER VAPOR 
IMAGERY DEPICTS MODERATE TO STRONG SUBSIDENCE LEADING TO STABLE 
ENVIRONMENTAL CONDITIONS OVER MUCH OF THE REGION W OF A LINE 
FROM 26N112W TO 10N130W AND ABUNDANCE OF TROPICAL MOISTURE E OF 
THE SAME LINE WHICH INCLUDES CONVECTION ASSOCIATED WITH THE 
TROPICAL CYCLONES...THE TROPICAL WAVE...AND THE ITCZ. UPPER 
LEVEL EASTERLY FLOW TO THE S OF THE RIDGE CONTINUES TO IMPACT 
T.D. BLAS AND HURRICANE CELIA BUT IS EXPECTED TO DIMINISH OVER 
CELIA DURING THE NEXT COUPLE OF DAYS. 

AT THE SURFACE...A 1031 MB HIGH LOCATED NW OF AREA EXTENDS A 
RIDGE SE OVER THE FORECAST WATERS COVERING THE ROUGHLY THE AREA 
N OF 15N W OF 120W. THE PRES GRADIENT BETWEEN THIS RIDGE AND 
LOWER PRES OVER THE SW CONUS CONTINUES TO RESULT IN NW TO N 
WINDS OF 20 KT OVER THE NE PORTION OF THE AREA. THE PRES 
GRADIENT IS BEGINNING TO TIGHTEN BETWEEN BLAS AND THE SURFACE 
RIDGE ALLOWING FOR WINDS TO INCREASE TO 20 KT AND SEAS TO BUILD 
TO 8 FT OVER A LARGE AREA PARTICULARLY NW OF BLAS TO A LINE FROM 
30N130W TO 24N140W. THIS WINDS WILL DIMINISH SOME IN ABOUT 48 
HRS AS THE HIGH TO THE N WEAKENS...AND BLAS BECOMING A WEAKENING 
REMNANT LOW.

CROSS EQUATORIAL SOUTHERLY SWELLS ARE RESULTING IN SEAS TO 9 FT 
MAINLY S OF CELIA WITH S TO SW WINDS OF 20 KT OVER AN AREA FROM 
2N TO 9N BETWEEN 95W AND 105W. S TO SW WINDS TO 20 KT ARE NOTED 
FROM 2N TO 6N BETWEEN 85W AND 95W. THE AREA OF S TO SW WINDS OF 
20 KT SHOULD EXPAND CLOSE TO 48 HRS THANKS TO A BROAD AREA OF 
LOW PRES E OF CELIA THAT NOW COINCIDES WITH THE 1008 LOW PRES  
ALONG THE TROPICAL WAVE AS PREVIOUSLY MENTIONED. 
 
$$
GR