000
AXPZ20 KNHC 151519
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED AUG 15 2007

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 
1515 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 98W N OF 6N MOVING W 10 KT. THIS APPEARS TO 
BE THE WAVE THAT HELPED SPAWN T.D. FIVE IN THE GULF OF MEXICO. 
CURRENTLY...A WEAK AREA OF LOW PRES IS ANALYZED 1008 MB ALONG 
THE WAVE AXIS NEAR 14N. THE LOW IS NOT WELL DEFINED AT THE 
MOMENT BUT IS LIKELY ASSISTING IN TRIGGERING SCATTERED MODERATE 
TO STRONG CONVECTION FROM 11N-16N BETWEEN 93W-103W.

TROPICAL WAVE ALONG 117W FROM 6N-17N MOVING W 10 KT. THE 
ASSOCIATED 1010 MB LOW IS ANALYZED DETACHED TO THE E OF THE WAVE 
ITSELF NEAR 14N113W...AS IT HAS BEEN ON A SLOW DRIFT OVER THE 
PAST DAY OR TWO. THIS SYSTEM HAS BECOME A LITTLE BETTER 
ORGANIZED SINCE YESTERDAY WITH AN INCREASE OF SHOWERS AND TSTMS 
TO THE W OF THE LOW-LEVEL CENTER. HOWEVER...ADDITIONAL 
DEVELOPMENT WOULD BE SLOW TO OCCUR AS UPPER NELY WINDS REMAIN 
SOMEWHAT UNFAVORABLE. 

TROPICAL WAVE ALONG 138W FROM 6N-17N MOVING W 10-15 KT. THIS 
WAVE HAS CHANGED LITTLE OVER THE PAST COUPLE OF DAYS RETAINING A 
FAIR AMOUNT OF LOW-LEVEL TURNING BUT WITH MINIMAL SIGNIFICANT 
CONVECTION.

...ITCZ...
ITCZ AXIS IS ALONG 8N79W 12N97W 14N111W 12N140W. SCATTERED 
MODERATE TO ISOLATED STRONG CONVECTION FROM 10N TO 17N BETWEEN 
92W AND 104W. ISOLATED MODERATE CONVECTION FROM 11N TO 16N 
BETWEEN 110W AND 135W..

...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. THIS FEATURE IS ADVECTING A BROKEN LAYER OF 
CIRRUS IN IT'S VICINITY OVER THE EPAC WATERS AND TRIGGERING 
SCATTERED 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 ALONG THE 
TROPICAL WAVES...DISCUSSED ABOVE.

THE SFC PRES PATTERN REMAINS FAIRLY WEAK ACROSS THE AREA DUE TO 
THE PROXIMITY OF A COLD FRONT WHICH CROSSES OUR NW BORDER. A 
1318Z QSCAT PASS SHOWED LIGHT TO MODERATE WINDS ACROSS MOST OF 
THE AREA...EXCEPT SOME 20 KT TRADES ACROSS THE W 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.

$$
CANGIALOSI