000
AXPZ20 KNHC 210929
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE AUG 21 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 WAVE...

TROPICAL WAVE IS ALONG 102W N OF 4N MOVING W 15 KT. A SMALL AREA 
OF MODERATE CONVECTION WITHIN 30 NM OF 10N100W. SOME ROTATION TO 
MID CLOUDS MAY INDICATE A WEAK LOW ON THE ITCZ. STRONG ELY WINDS 
ALOFT PROBABLY TOO MUCH FOR ANY DEVELOPMENT. 

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N83W 10N100W 13N120W 11N135W 
11N140W. SCATTERED STRONG CONVECTION NEAR 5N78W 8N84W AND 
10N86W. SCATTERED MODERATE AND ISOLATED STRONG WITHIN 30 NM OF A 
LINE FROM 9N91W TO 9N97W TO 10N100W TO 8N102W. SCATTERED 
MODERATE WITHIN 60 NM OF 10N111W. 

ISOLATED STRONG CONVECTION NEAR THE COAST AT 13N88W 13N91W 
15N95W 23N107W 26N110W AND 28N111W.

...DISCUSSION...

A STRONG MID LEVEL RIDGE IS CENTERED NEAR 34N112W TONIGHT AND IS 
MAINTAINING A FAIRLY STRONG ELY FLOW S OF 25N. AN OLD MID LEVEL 
LOW CENTER HAS MOVED IN OVER SRN TX TONIGHT AND WILL BE MOVING 
WWD ACROSS MEXICO THE NEXT 24 TO 36 HRS. THE RIDGE IS STILL 
PRODUCING STRONG NE AND W WINDS ALOFT OVER THE AREA E OF 130W. A 
CUTOFF MID LEVEL LOW IS LOCATED JUST W OF THE REGION NEAR 
32N152W AND NEARLY STATIONARY. AN EMBEDDED CUTOFF AT MID LEVELS 
WAS NEAR 19N137W DRIFTING SLOWLY WWD. ON THE SURFACE TONIGHT A 
WEAKENING LOW WAS NEAR 23N120W WITH NO CONVECTION. ONLY LOW 
CLOUDS SHOW THE CIRCULATION IN SATELLITE PIX. THE PACIFIC RIDGE 
IS WEAK AND NE TRADES ARE 10 TO 15 KT ACCORDING TO QUIKSCAT AND 
SSMI. WINDS ALONG THE BAJA COAST ARE ALSO LIGHT ACCORDING TO 
SSMI AND IN GOOD AGREEMENT WITH THE GFS MODEL 06Z CHART. GAP 
WINDS ARE ALSO LIGHT. CROSS EQUATORIAL SLY WINDS 15 TO 20 KT S 
OF 8N E OF 110W AND S OF 7N W OF 125W WITH SLY SWELL TO 8 FT. 

LATER DAY 1 WHILE THE MID LEVEL RIDGE WEAKENS SLIGHTLY..IT STILL 
MAINTAINS IT'S POSITION ALONG 33N ACROSS THE REGION TO W OF 
140W. THE INVERTED TROUGH OVER SE TX MOVES TO 102W WHILE AN OLD 
INVERTED TROUGH ALONG 138W DRIFTS W. ON THE SURFACE LATER DAY 1 
THE WEAK LOW AT 23N120W DRIFTS W AND GRADUALLY DISSIPATES. WINDS 
AROUND THE LOW REMAIN WEAK ABOUT 15 KT. THE PACIFIC RIDGE 
REMAINS WEAK WITH NE TRADES 10 TO 15 KT. WINDS ALONG THE BAJA 
COAST MOSTLY NWLY 10 TO 15 KT. GAP WINDS REMAIN WEAK. CROSS 
EQUATORIAL SLY WINDS BEGIN TO INCREASE S OF 8N BETWEEN 105W AND 
115W HELPED BY A WEAK LOW ALONG THE ITCZ NEAR 9N109W. 

FOR DAY 2 THE WEAKENING TREND OF THE MID LEVEL RIDGE OVER THE SW 
CONUS CONTINUES WITH A WEAKNESS DEVELOPING BETWEEN 105W AND 
125W. THE RIDGE SEPARATES INTO TWO CELLS..ONE OVER THE SE CONUS 
AND THE OTHER NW OF THE REGION CENTERED NEAR 36N145W. A FAIRLY 
GOOD ELY FLOW WILL CONTINUE S OF 25N WITH ONE INVERTED TROUGH 
MOVING W TO 108W AND THE OLD ONE MOVING W OF THE REGION TO 142W. 
ON THE SURFACE DAY 2 THE PACIFIC RIDGE SHOWS SIGNS OF 
STRENGTHENING SOME WITH NE TRADES INCREASING TO 20 KT N OF 27N W 
OF 125W. WINDS ALONG THE BAJA COAST REMAIN NWLY 10 TO 15 KT 
WHILE GAP WINDS REMAIN LIGHT. CROSS EQUATORIAL SLY WINDS SHOULD 
BE STRONGEST S OF 9N BETWEEN 100W AND 120W AS LONG AS A  LOW 
CONTINUES ALONG THE ITCZ NEAR 10N102W.

$$
RRG