000
AXPZ20 KNHC 090927
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON JUL 9 2007

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...TROPICAL WAVES...
TROPICAL WAVE N OF 5N ALONG 85W MOVING W 10-15 KT. SCATTERED 
CONVECTION ALONG THE ITCZ BUT NOT ORGANIZED.

TROPICAL WAVE FROM 10N119W TO 19N116W WITH WEAK 1008 MB LOW PRES 
NEAR 16N117W MOVING NW 10-15 KT. SCATTERED MODERATE AND STRONG 
CONVECTION MAINLY WITHIN 120 NM NE QUADRANT OF LOW CENTER. 
SYSTEM ASSOCIATED WITH A INVERTED MID LEVEL TROUGH WHICH IS 
TRYING TO WORK IT'S WAY NW THROUGH A DEVELOPING WEAKNESS IN A 
RIDGE.

TROPICAL WAVE ALONG 140W MOVING W 15 KT. ONLY ISOLATED 
CONVECTION WITH NO ORGANIZATION. SYSTEM APPEARS WEAKENING.

...ITCZ...
AXIS IS CENTERED ALONG 8N78W 9N85W 9N102W 8N107W 14N118W 7N140W.
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION WITHIN 3O NM 
OF A LINE FROM 7N78W TO 8N95W TO 11N102W TO 10N107W. SCATTERED 
MODERATE AND ISOLATED STRONG IN AN AREA FROM 10N TO 16N BETWEEN 
113W AND 125W. SCATTERED MODERATE WITHIN 30 NM OF 8N132W. 

.SCATTERED MODERATE AND STRONG WITHIN 120 NM NE QUADRANT OF LOW 
CENTER 16N117W. 

.SCATTERED STRONG CONVECTION NEAR THE COAST FROM 12N90W TO 
16N98W.

...DISCUSSION...

THE MID LEVEL RIDGE OVER THE SW CONUS HAS WEAKENED 
TONIGHT..ALTHOUGH A CENTER REMAINS OVER AZ AND A SECOND CENTER 
IS CENTERED NEAR 25N133W. A MID LEVEL LOW HAS FORMED NEAR 
34N128W WHILE AN INVERTED TROUGH CHUGS ALONG WWD NEAR 120W. ON 
THE SURFACE TONIGHT THE INVERTED TROUGH IS RESPONSIBLE FOR 
STIRRING UP ACTIVITY ON THE ITCZ..IN PARTICULAR A TRPL 
DISTURBANCE NEAR 16N117W. THE SYSTEM IS ELONGATED NE/SW WITH A 
POSSIBLE SECOND CENTER NEAR 14N119W. A MID LEVEL LOW OVER SRN 
MEXICO LAST NIGHT HAS MOVED NW AND WEAKENED. IT WAS NEAR 20N101W 
WITH ISOLATED CONVECTION NEAR IT'S CENTER. THE PACIFIC RIDGE 
REMAINS W OF 115W WITH NE TRADES MOSTLY 20 KT N OF 24N W OF 
130W. WINDS ALONG THE BAJA COAST REMAIN LIGHT NWLY TONIGHT. GAP 
WINDS W OF NICARAGUA ARE ELY TO 20 TO 25 KT ACCORDING TO 
QUIKSCAT AND SSMI IMAGERY. CROSS EQUATORIAL SLY WINDS MOSTLY TO 
20 KT EXCEPT FOR WHERE ACTIVE CONVECTION IS IN PROGRESS ON THE 
ITCZ THEN THE WINDS INCREASE TO 20 TO 25 KT.

LATER DAY 1 LITTLE CHANGE TO THE MID LEVEL HIGH CENTERS OR THE 
MID LEVEL LOW NEAR 33N126W. THE INVERTED TROUGH AT MID LEVELS 
GETS A LITTLE SQUIRRELY..TRYING TO WORK IT'S WAY NWD ALONG THE 
BAJA COAST..POSSIBLY THROUGH THE WEAKNESS BETWEEN THE TWO RIDGE 
CENTERS. ON THE SURFACE LATER DAY 1 THE TRPL DISTURBANCE NEEDS 
TO BE WATCHED FOR POSSIBLE DEVELOPMENT. THE PACIFIC RIDGE 
APPEARS TO BE RECEDING NW WITH WEAKENING GRADIENT OVER THE 
REGION N OF 12N AND W OF 120W..THUS NE TRADES DECREASE TO 20 KT. 
BAJA WINDS REMAIN LIGHT. GAP WINDS THROUGH PAPAGAYO REMAIN ELY 
TO 20 KT WHILE CROSS EQUATORIAL SLY WINDS CHANGE LITTLE. 

FOR DAY 2 AS EXPECTED THE INVERTED MID LEVEL TROUGH ALONG 120W 
SENDS A CHUNCH OF VORTICITY NWD ALONG THE BAJA COAST TOWARD THE 
MID LEVEL LOW NEAR 33N126W WHICH STRENGTHENS THIS SYSTEM. THE 
SECOND RIDGE CENTER MOVES WWD TO 25N140W. THE REMAINDER OF THE 
INVERTED TROUGH CONTINUES WWD TO 130W S OF 15N. ON THE SURFACE 
DAY 2 THE TRPL DISTURBANCE APPEARS INFLUENCED BY THE INVERTED 
TROUGH ALOFT AND ALSO HEADS WWD. THE PACIFIC RIDGE CONTINUES TO 
WEAKEN WITH NE TRADES MAINLY W OF 130W TO 20 KT. WINDS ALONG THE 
BAJA COAST REMAIN LIGHT WITH LITTLE CHANGE TO GAP WINDS OR CROSS 
EQUATORIAL SLY WINDS. 

$$
RRG