000
AXPZ20 KNHC 160301
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU AUG 16 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 
0315 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 100W N OF 6N MOVING W 10 KT. THIS APPEARS 
TO BE THE WAVE THAT HELPED SPAWN T.S. ERIN IN THE GULF OF 
MEXICO. CURRENTLY...A WEAK AREA OF LOW PRES IS ANALYZED 1009 MB 
ALONG THE WAVE AXIS NEAR 15N. THE LOW IS NOT WELL DEFINED AT THE 
MOMENT BUT IS LIKELY ASSISTING IN TRIGGERING THUNDERSTORMS.  
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 9N TO 
14N BETWEEN 98W AND 107W. 

TROPICAL WAVE IS ALONG 119W/120W FROM 5N-16N MOVING W 10 KT. A 
1007 MB LOW IS WELL E OF THE WAVE AXIS NEAR 15N107W AS IT HAS 
BEEN NEARLY STATIONARY OVER THE PAST DAY OR TWO.  ADDITIONAL 
DEVELOPMENT IS NOT EXPECTED AS UPPER LEVEL WINDS REMAIN STRONG. 
SCATTERED MODERATE CONVECTION IS FROM 11N TO 14N BETWEEN 114W 
AND 121W.
 
...ITCZ...
ITCZ AXIS IS ALONG 8N79W 10N87W 13N95W 13N110W 
13N130W 11N140W.  SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION IS FROM 9N TO 13N BETWEEN 85W AND 88W.  SCATTERED 
MODERATE TO ISOLATED STRONG CONVECTION IS FROM 9N TO 14N BETWEEN 
98W AND 107W.  SCATTERED MODERATE TI ISOLATED STRONG CONVECTION 
IS FROM 14N TO 17N BETWEEN 109W AND 112W.  SCATTERED MODERATE 
CONVECTION IS FROM 11N TO 14N BETWEEN 114W AND 121W.

...DISCUSSION...

A LARGE UPPER LEVEL LOW CENTERED WELL N OF THE REGION IS 
INDUCING SLIGHT TROUGHING ACROSS THE NW PORTION OF THE AREA. A 
MUCH SMALLER UPPER LOW HAS CUT OFF AND IS DRIFTING SWD NEAR THE 
CENTRAL BAJA COAST AT 26N117W. THIS FEATURE IS ADVECTING A 
BROKEN LAYER OF CIRRUS IN IT'S VICINITY OVER THE EPAC WATERS AND 
TRIGGERING ISOLATED SHOWERS AND TSTMS OVER N MEXICO AND S 
ARIZONA. UPPER LEVEL RIDGING DOMINATES ACROSS MUCH OF THE REGION 
W OF 110W ANCHORED BY AN ANTICYCLONE CENTERED NEAR 20N135W. THIS 
OVERALL STABLE AND SOMEWHAT CONFLUENT PATTERN IS SUSTAINING 
WIDESPREAD DRY AIR ALOFT ACROSS THE AREA N OF 18N W OF 110W. 
ELSEWHERE...THE TROPICAL ERN PACIFIC IS CONSIDERABLY MORE MOIST 
WITH DIFFLUENCE AND STRONG NELY UPPER FLOW ADVECTING A 
CONSIDERABLE MOISTURE PLUME ACROSS THE REGION. CLUSTERS OF 
MODERATE TO STRONG CONVECTION ARE ALONG THE ITCZ E OF 110W.   
ONE OF THE MORE ACTIVE AREAS OF WEATHER APPEARS TO BE 
RELATED/CONTRIBUTED BY THE WEAK LOW PRESSURE SYSTEMS ASSOCIATED 
WITH THE TROPICAL WAVES...DISCUSSED ABOVE.

THE SFC PRES PATTERN REMAINS FAIRLY WEAK ACROSS THE AREA DUE TO 
THE PROXIMITY OF A STATIONARY FRONT WHICH CROSSES OUR NW BORDER 
ALONG 32N132W 29N140W.  AN EARLIER QSCAT PASS SHOWED LIGHT TO 
MODERATE WINDS ACROSS MOST OF THE AREA...EXCEPT SOME 20 KT 
TRADES ACROSS THE W/SW PORTION AND MARGINAL WINDS NEAR THE BAJA 
COAST WHERE THE GRADIENT IS TIGHTENED DUE TO INVERTED TROUGHING 
OVER THE SW U.S. THIS MODEST PRES PATTERN IS EXPECTED TO PERSIST 
OVER THE NEXT COUPLE OF DAYS.

$$
FORMOSA