000
AXPZ20 KNHC 101550
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON AUG 10 2009

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 FEATURE...
TROPICAL DEPRESSION NINE-E AT 14.9N 123.1W OR ABOUT 825 NM SW OF 
SOUTHERN TIP OF BAJA CALIFORNIA MOVING W AT 8 KT AT 1500 UTC AUG 
10.  MAXIMUM SUSTAINED WIND 30 WITH GUSTS TO 40 KT.  ESTIMATED 
MINIMUM CENTRAL PRES 1007 MB.  NUMEROUS MODERATE SCATTERED 
STRONG CONVECTION IN SQUALLS WITHIN 120 NM SE AND 60 NM NW 
SEMICIRCLES OF CENTER.  LOW LEVEL CIRCULATION IS RELATIVELY 
SMALL AND MODELS VARY IN THEIR TIMING...BUT CONSENSUS INDICATE A 
SLOW INTENSIFICATION DESPITE ITS HOSTILE UPPER LEVEL ENVIRONMENT 
WHERE LARGE AMPLITUDE TROUGH BRING STRONG NW SHEAR JUST OVER 
CYCLONE.  SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. 

...TROPICAL WAVES...
TROPICAL WAVE ALONG 92W N OF 02N MOVING W 10-15 KT CARRIES 
LITTLE CONVECTION ASSOCIATED WITH IT DUE TO ADVERSE UPPER 
ENVIRONMENT WITH STRONG AND DRY NE SHEAR ALOFT.  WAVE EXPECTED 
TO APPROACH LESS HOSTILE CONDITIONS LATE IN FORECAST PERIOD WITH 
BETTER CHANCES OF CONVECTION MAINLY N OF ITCZ.

TROPICAL WAVE ALONG 104W N OF 04N MOVING W 10-15 KT.  LARGE AREA 
OF SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 180 NM  
W OF WAVE AXIS N OF ITCZ.  CYCLONIC TURNING AT LOWER LEVELS IS 
NOTED AND MODEL GUIDANCE INCREASE IT AS WAVE MOVES W UNDER VERY 
FAVORABLE UPPER ENVIRONMENT. 

TROPICAL WAVE FROM 07N137W TO 15N133W MOVING W 10 KT.  WAVE AXIS 
ASSOCIATED WITH MODERATE TO STRONG TRADES AND SCATTERED MODERATE 
ISOLATED STRONG CONVECTION AS ANTICYCLONE WITH GOOD DIFFLUENT 
FLOW ALOFT ENHANCES DEVELOPMENT.  MODEL GUIDANCE BUILDS THEN 
MAINTAINS LOW PRES CENTER 1010 MB ON W-SW DRIFT FOR NEXT 48 HR.

...ITCZ...
AXIS ALONG...08N84W TO 08N95W TO 11N103W TO 07N120W TO 12N125W 
TO 06N140W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION 
WITHIN 100 NM S OF AXIS FROM 113W-116W.  SCATTERED MODERATE TO 
STRONG CONVECTION WITHIN 150 NM S AND 60 NM N OF AXIS FROM 
134W-140W.

...DISCUSSION...
BROAD ANTICYCLONE CENTERED AT 20N138W MAINTAINS A DRY STABLE 
ATMOSPHERE OVER AREA N OF 15N W OF 125W.  SECOND...AND WEAKER... 
ANTICYCLONE AT CENTERED AT 11N136W PRODUCES GOOD OUTFLOW FOR 
CONVECTION ASSOCIATED WITH TROPICAL WAVE ALONG 135W.

DEEP LAYER CYCLONE CENTERED AT 25N125W EXTEND DRY SLOT N OF 20N 
W OF 115W.  IT IS THIS DRY STRONG NW FLOW WHICH IS IMPINGING ON 
T.D. NINE-E AND CURTAILING ITS MORE AGGRESSIVE DEVELOPMENT.

THIRD UPPER LEVEL ANTICYCLONE OVER MAINLAND MEXICO ADVECTS 
ABUNDANT TROPICAL MOISTURE FROM CONTINENT INTO E PAC FEEDING IT 
TO TROPICAL WAVE ALONG 104W WHILE ITS DRIER STRONGER NE WINDS 
SHEAR N PORTIONS OF WAVE ALONG 92W.

ELSEWHERE AT THE SURFACE...
FRESH TO STRONG TRADE WINDS CROSS FROM CARIBBEAN SEA THROUGH 
GULF OF PAPAGAYO INTO E PAC WITH FRESH TO STRONG NE-E WINDS E OF 
92W BUT DIMINISHING THROUGH NEXT 48 HR. 

$$
WALLY BARNES