000
AXPZ20 KNHC 172156
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN SEP 17 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...SPECIAL FEATURES...

TROPICAL STORM MIRIAM IS CENTERED NEAR 19.3N 114.0W...OR 300 NM 
SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA...AT 17/2100 UTC 
MOVING N 4 KT. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH 
GUSTS TO 45 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB.  
MIRIAM IS EMBEDDED IN NE MID TO UPPER LEVEL FLOW SE OF AN UPPER 
RIDGE WITH THE RESULTANT NLY SHEAR EXPOSING THE LOW LEVEL 
CENTER...CURRENTLY SCATTERED MODERATE CONVECTION IS NOTED WITHIN 
240 NM SW OF THE CENTER. MIRIAM IS EXPECTED TO MOVE INTO AN AREA 
OF INCREASED WIND SHEAR AND COOLER WATERS OVER THE NEXT COUPLE 
OF DAYS THUS A GRADUAL WEAKENING TREND IS FORECAST. SEE LATEST 
NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 
KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 86W N OF 4N MOVING W 12 KT. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS ENHANCED FROM 4N TO 13N 
BETWEEN 78W AND 85W WITH THE STRONGEST CONVECTION MOVING ACROSS 
NICARAGUA AT THE MOMENT. 

TROPICAL WAVE ALONG 95W N OF 4N HAS BEEN RELOCATED BUT IS 
ESTIMATED TO BE MOVING W AT 12 KT. BROAD CYCLONIC TURNING IS 
NOTED N OF 10N ALONG THE WAVE WITH SCATTERED MODERATE CONVECTION 
NOTED WITHIN 180 NM OF 14N94W. 

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N82W 7N106W 16N116W 10N133W 
10N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 120 NM EITHER 
SIDE OF LINE 5N80W 7N115W. 

...DISCUSSION...

AN UPPER CYCLONE IS NEAR 32N132W WITH ITS ENVELOPE OF UPPER 
CYCLONIC FLOW SHRINKING WITH TIME AND CURRENTLY ABOUT 480 
NM DIAMETER. A TROUGH EXTENDS SW FROM THE CYCLONE TO NEAR 
23N135W. 

AN UPPER ANTICYCLONE IS QUASI-STATIONARY AT 23N123W WITH A RIDGE 
EXTENDING SW TO A SHARP CREST NEAR 17N143W. A RIDGE ALSO EXTENDS 
E TO CREST NEAR 24N109W. TO THE N OF THIS RIDGE...A SHORTWAVE 
TROUGH OVER WRN N AMERICA EXTENDS S INTO THE DISCUSSION AREA 
FROM 32N109W TO A BASE AT 24N103W. A BAND OF VERY DRY UPPER AIR 
IS INDICATED WITHIN 90 NM EITHER SIDE OF LINE 32N104W 17N137W 
AND IS SURROUNDED BY RELATIVELY DRY AIR OVER THE DISCUSSION AREA 
NW OF LINE 12N140W 21N118W 27N103W.

SOME OF THE UPPER DEBRIS MOISTURE FROM MIRIAM AND THE REMNANTS 
OF TROPICAL CYCLONE LANE IS ADVECTED SW WITHIN 120 NM EITHER 
SIDE OF LINE 27N100W 17N110W 6N132W.

A TUTT EXTENDS FROM A DEEP LAYERED CYCLONE OVER THE SW ATLC NEAR 
35N70W THROUGH ANOTHER WEAK CYCLONE NEAR 20N95W THEN ACROSS 
CENTRAL AMERICA TO A WEAK CYCLONE...OR WEAK INVERTED UPPER 
TROUGH...NEAR 4N107W. DRY UPPER AIR IS ACCOMPANIES THIS UPPER 
TROUGH...ROUGHLY WITH 150 NM EITHER SIDE OF LINE 26N85W 20N97W 
11N105W.
   
ELSEWHERE AT THE SURFACE A RIDGE EXTENDS ALONG 32N134W 23N117W. 

$$
NELSON