000
AXPZ20 KNHC 022122
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN SEP 02 2007

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...SPECIAL FEATURES...

TROPICAL STORM HENRIETTE CENTERED NEAR 18.6N 106.6W AT 02/2100 
UTC. HENRIETTE IS MOVING W NW AT 3 KT. MAXIMUM SUSTAINED WINDS 
ARE NEAR 60 KT WITH GUSTS TO 75 KT. HENRIETTE IS IN A FAVORABLE 
ENVIRONMENT FOR ADDITIONAL STRENGTHENING WITH UNRESTRICTED 
OUTFLOW ALOFT AND WARM SURFACE WATERS. THUS...HENRIETTE IS 
FORECAST TO BECOME A HURRICANE TONIGHT. ESTIMATED CENTRAL 
PRESSURE IS 994 MB. CURRENTLY...NUMEROUS MODERATE AND STRONG 
CONVECTION IS OBSERVED WITHIN 90 NM OVER THE NW SEMICIRCLE AND 
WITHIN 300 NM OVER THE SE SEMICIRCLE. REFER TO THE LATEST 
NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 
KNHC FOR MORE DETAILS.

...TROPICAL WAVES...

A TROPICAL WAVE ALONG 83W IS ESTIMATED TO BE MOVING W AT 12 KT. 
ONLY SCATTERED MODERATE CONVECTION IS ENHANCED AT THE MOMENT...
OVER THE E PAC WATERS N OF 6N E OF 81W.

A TROPICAL WAVE IS RELOCATED ALONG 93W AND IS MOVING W ABOUT 12 
KT DISPLAYING A CLASSIC INVERTED V ON THIS AFTERNOONS SATELLITE 
IMAGERY. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED 
ALONG 12N WITHIN 90 NM EITHER SIDE OF THE AXIS.

...ITCZ...

AXIS CENTERED ALONG 8N83W 12N93W 11N97W 18N116W 11N130W 10N140W. 
EXCEPT AS MENTIONED IN TROPICAL WAVES SECTION...ONLY SCATTERED 
MODERATE IS NOTED WITHIN 60 NM EITHER SIDE OF LINE 10N96W 
7N103W...AND WITHIN 15 NM OF 8N139W.

...DISCUSSION...

AN UPPER ANTICYCLONE AT 34N120W RIDGES SW INTO THE DISCUSSION 
AREA TO A SHARP CREST AT 27N134W. ANOTHER ANTICYCLONE W OF THE 
AREA NOW RIDGES E TO NEAR 28N137W. RESULTANT VERY DRY UPPER AIR 
IS INDICATED TO THE NW OF THESE RIDGES. AN UPPER CYCLONE NEAR 
30N103W HAS AN UPPER TROUGH EXTENDING SW ACROSS OLD MEXICO INTO 
THE DISCUSSION AREA ALONG 26N112W TO ANOTHER SMALL UPPER CYCLONE 
AT 24N120W WITH THE TROUGH CONTINUING W ALONG 22N130W TO A 
DEVELOPING UPPER CYCLONE AT 16N136W. THIS UPPER TROUGH...TUTT...
IS EFFECTIVELY SEPARATING THE ANTICYCLONIC FLOW ASSOCIATED THE 
AFOREMENTIONED RIDGES FROM THE INCREASING ANTICYCLONIC FLOW 
ASSOCIATED WITH THE UPPER RIDGE OVER CYCLONE HENRIETTE. 

THE REMNANT LOW PRES OF TROPICAL DEPRESSION GIL IS NEAR 
20N123.5W AND LIES JUST S OF THE UPPER TROUGH. DEBRIS MOISTURE 
FROM DISSIPATED CONVECTION IS TRAPPED WITHIN 30 NM EITHER SIDE 
OF LINE 21N118W 22N127W. OTHERWISE DRY UPPER AIR IS ALSO NOTED S 
OF 23N W OF 120W AND IS SUPPRESSING CONVECTION ALONG THE ITCZ W 
OF 100W...EXCEPT FOR A SMALL CLUSTER NEAR 8N139W.
    
AS MENTIONED...THE UPPER VENTILATION OVER HENRIETTE IS EXPANDING 
AND COVERS THE DISCUSSION AREA S OF 23N BETWEEN 90W AND 115W 
WITH THE UPPER DEBRIS MOISTURE FROM THE HURRICANE TRAPPED WITHIN 
THE SAME AREA. THE UPPER FLOW IS NE TO E OVER THE DEEP TROPICAL 
PAC E OF 90W.
   
$$
NELSON