000
AXPZ20 KNHC 090345
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON JUL 9 2007

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...TROPICAL WAVES...
TROPICAL WAVE N OF 5N ALONG 84W MOVING W 10-15 KT. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION...ASSOCIATED WITH ITCZ... 
FROM 7N TO 10 BETWEEN 86W AND 90W.

TROPICAL WAVE FROM 8N122W TO 19N115W WITH WEAK 1008 MB LOW PRES 
NEAR 16N117W MOVING NW 10-15 KT. THIS WAVE IS PART OF A BROAD 
AREA OF LOW PRES THAT EXTENDS ROUGHLY 150 NM EITHER SIDE OF THE 
WAVE AXIS. SCATTERED MODERATE ISOLATED STRONG CONVECTION... 
ASSOCIATED WITH ITCZ...FROM 11N TO 19N BETWEEN 115W AND 121W.

TROPICAL WAVE ALONG 138W/139W MOVING W 15 KT. CONVECTION IS 
DECREASING AND THE WAVE IS MOVING OUT OF DISCUSSION AREA.

...ITCZ...
AXIS IS CENTERED ALONG 10N85W 9N95W 15N116W 11N126W 11N134W 
9N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 
NM S OF AXIS E OF 107W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION FROM 11N TO 18N BETWEEN 114W AND 121W. SCATTERED 
MODERATE CONVECTION FROM 6N TO 10N W OF 138W.

...DISCUSSION...
THE WEAK SURFACE LOW NEAR 16N117W REMAINS THE PRIMARY FEATURE. 
OVER THE PAST 24 HRS ITS BROAD CIRCULATION HAS FAILED TO ORGANIZE
AND CONSOLIDATE...LEAVING ONLY AN ELONGATED TROUGH WITH MULTIPLE 
LOW LEVEL CENTERS. THE PRIMARY CENTER APPEARS TO BE IN NRN PART 
OF TROUGH. BROAD UPPER RIDGE OVER THE LOW PRES TROUGH IS ALLOWING
GOOD OUTFLOW OVER THE SURFACE TROUGH. THIS SHOULD KEEP CONVECTION
FIRING AS THE TROUGH MOVES WEST. FURTHER WEST...WHAT APPEARED TO 
BE ANOTHER WEAK SURFACE LOW NEAR 8N137W IS MERELY A TROPICAL WAVE
AS ANIMATED VISUAL SATELLITE IMAGERY SHOWS NO LOW LEVEL ROTATION
AND ONLY PRONOUNCED DIRECTION SHEAR ON EITHER SIDE OF WAVE AXIS.
THE ITCZ IS FAIRLY ACTIVE EAST OF 110W. QUIKSCAT EARLIER THIS 
EVENING SHOWED ENHANCED SOUTHERLY CROSS-EQUATORIAL FLOW INTO THE 
TROUGH...RESULTING IN INCREASED SHOWER ACTIVITY IN THE EASTERN 
PART OF THE ITCZ. THE MOST STRIKING FEATURE INDICATED BY GLOBAL 
MODEL FORECAST OVER THE NEXT 36-60 HOURS IS A SURFACE LOW OFF 
THE CENTRAL CALIFORNIA COAST WHICH RETROGRADES TO A POSITION 
NEAR 36N128W TUESDAY EVENING. THE NET EFFECT S OF 30N WILL BE A 
MAJOR DISRUPTION IN THE NORMAL TRADE WIND PATTERN IN THE NW PART 
OF THE DISCUSSION AREA...WHICH WILL REDUCE NE TRADES TO AROUND 
5-10 KT BETWEEN 125W-135W.

$$
MUNDELL