000
AXPZ20 KNHC 161821 AAA
TWDEP 

TROPICAL WEATHER DISCUSSION...UPDATED      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1820 UTC THU AUG 16 2007

...UPDATED TO ADD TROPICAL WAVE ALONG 122W...

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 
1800 UTC.

...TROPICAL WAVES...UPDATED

TROPICAL WAVE ALONG 102W N OF 5N IS MOVING W 10-15 KT. THIS WAVE 
IS ASSOCIATED WITH A LARGE AREA OF DISORGANIZED SCATTERED 
MODERATE TO STRONG CONVECTION THAT EXTENDS FROM 12N-18N E OF 
110W TO THE MEXICAN COAST. 1008 MB LOW PRES IS CENTERED TO THE W 
OF THE WAVE NEAR 15N107W MOVING W ABOUT 5-10 KT. BOTH THE LOW 
AND WAVE ARE EMBEDDED IN A BROAD TYPE MONSOON FLOW PATTERN THAT 
COVERS THE AREA FROM 7N17N E OF 115W.

TROPICAL WAVE ALONG 122W FROM 6.5N-17N IS MOVING W 10 KT. 
CONVECTION WITH THIS WAVE REMAINS MINIMAL DUE TO UPPER LEVEL 
SUBSIDENCE. ONLY RELATED CONVECTION IS ALONG ITCZ AS DESCRIBED 
BELOW.

WEAK TROPICAL WAVE ALONG 140W FROM 7N-15N IS MOVING W ABOUT 12 
KT. ONLY WEAK ISOLATED CONVECTION IS ALONG THE WAVE AXIS WITHIN
90 NM N OF THE ITCZ W OF 139W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N85W 12N90W 14N102W 14N110W 13N120W
12.5N130W 11N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION 
IS WITHIN 90 NM OF THE AXIS BETWEEN 111W-114W...AND WITHIN 45 NM 
EITHER SIDE OF THE AXIS BETWEEN 124W128W. SCATTERED MODERATE 
CONVECTION IS WITHIN 90 NM S OF THE AXIS BETWEEN 120W-122W.

...DISCUSSION...

A LARGE UPPER LEVEL LOW CENTERED WELL N OF THE REGION CONTINUES
EXTENDS A TROUGH SW TO WELL WEST OF THE DISCUSSION AREA. A 
SMALLER UPPER LOW HAS CUT OFF AND IS DRIFTING WSW TO THE W OF 
THE CENTRAL BAJA COAST NEAR 25N120W. MID UPPER LEVEL MOISTURE IN 
THE FORM OF MIDDLE LEVEL CLOUDS IS ADVECTED SWD IN THE REGION N 
OF 26N E OF 120W. A MID/UPPER LEVEL ANTICYCLONIC CIRCULATION 
MOVING W 10-15 KT IS NEAR 21N137W. THE COMBINATION BETWEEN THIS 
ANTICYCLONE AND THE UPPER LEVEL LOW NEAR 25N120W IS RESULTING IN 
UPPER LEVEL NLY FLOW FROM 19N-29N BETWEEN 122W-134W. THIS IS 
BRINGING MODERATE TO STRONG SUBSIDENCE AND A DRY STABLE 
ENVIRONMENT FROM 16N-32N W OF ABOUT 122W. N OF THESE FEATURES
...THE FLOW IS BROAD SWLY. MID LEVEL MOISTURE IS APPROACHING THE 
FAR WESTERN SIDE OF THE AREA N OF 25N.

OVER THE EASTERN PORTION OF THE E PACIFIC...MID/UPPER LEVEL 
RIDGING EXTENDS FROM ACROSS MEXICO ALONG 24N BETWEEN 100W-105W 
WNW ACROSS NORTHERN AND CENTRAL BAJA CALIFORNIA. THE UPPER LEVEL 
FLOW PATTERN S OF THE RIDGE REMAINS CONSIDERABLY MOIST WITH 
DIFFLUENCE AND STRONG NELY UPPER FLOW ADVECTING A CONSIDERABLE 
AMOUNT OF HIGH LEVEL CLOUDINESS WESTWARD TO NEAR 114W. THIS 
DIFFLUENCE IS AIDING CONVECTION ASSOCIATED WITH THE DISORGANIZED 
AREA OF CLOUDS AND CONVECTION DUE TO THE WAVE ALONG 102W.

THE SFC PRES PATTERN REMAINS FAIRLY WEAK ACROSS THE AREA DUE TO 
A WEAKNESS IN THE TYPICAL RIDGE PATTERN AS A STATIONARY FRONT
PUSHES SE INTO THE NW PART OF THE AREA. RIDGE EXTENDS SE INTO
THE AREA THROUGH 27.5N140W 26N127W 23N120W. HIGH PRES COVERS
THE AREA N OF 18N W OF 125W. THE TRADE WIND REGIME IS RATHER 
LIGHT IN THE 15-20 KT RANGE ACROSS THE HIGH SEAS FORECAST AREA. 
NW WINDS TO 20 KT CAN BE SEEN ALONG AND NEAR THE BAJA COAST DUE 
TO THE COMBINATION OF THE PACIFIC HIGH AND AN INVERTED TROUGH 
OVER THE SW U.S. THIS MODEST PRES PATTERN IS EXPECTED TO PERSIST 
OVER THE NEXT COUPLE OF DAYS.

$$
AGUIRRE