000
AXPZ20 KNHC 240916
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI AUG 24 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 IS ALONG 122W MOVING W 10 TO 15 KT. SOME SCATTERED 
CONVECTION ALONG THE ITCZ OTHERWISE NO EVIDENCE OF THIS WAVE.

...ITCZ...
ITCZ AXIS IS ALONG 8N76W 6N84W 14N106W 8N122W 9N140W. SCATTERED 
MODERATE CONVECTION WITHIN 45 NM OF 6N78W AND FROM 11N95W TO 
11N110W. ISOLATED MODERATE TO STRONG NEAR 10N117W. SCATTERED 
MODERATE FROM 7N132W TO 9N140W.

SCATTERED MODERATE TO STRONG CONVECTION WITHIN 45 NM OF 15N95W 
AND 24N108W.

...DISCUSSION...

THE MID LEVEL SCENE OVER THE ERN PACIFIC CONTINUES TO BE 
DOMINATED BY A RIDGE OVER THE SRN CONUS AND ANOTHER RIDGE JUST 
NW OF THE AREA. IN BETWEEN IS A WEAKNESS IN THE MID LEVEL PRES 
FIELD BETWEEN 110W AND 130W. THIS WEAKNESS AREA HAS SHIFTED 
SLIGHTLY E ABOUT 10 DEGREES IN THE PAST WEEK. WATER VAPOR 
IMAGERY SHOWS FAIRLY STRONG HIGH LEVEL WINDS FROM THE NE AND E 
OVER THE ERN PACIFIC E OF 115W AND PLENTY OF HIGH LEVEL 
MOISTURE. W OF 120W THE MID ATMOSPHERE DRIES OUT TO JUST W OF 
140W. ON THE SURFACE TONIGHT THE PACIFIC RIDGE EXTENDS WEAKLY 
OVER THE REGION WITH STRONGEST NE WINDS N OF 24N W OF 134W. 
WINDS ALONG THE BAJA COAST TONIGHT ARE 15 TO 20 KT ACCORDING TO 
QUIKSCAT AND IN GOOD AGREEMENT WITH THE GFS MODEL 06Z WINDS. 
TRPL WAVES ARE QUITE WEAK ALONG 82W AND 120W. GAP WINDS ARE 
LIGHT AND CROSS EQUATORIAL SLY WINDS ARE STRONGEST S OF 8N 
BETWEEN 115W AND 120W WITH SPEEDS TO 25 KT. SLY WINDS TO 20 KT 
ARE EVIDENT S OF 10N BETWEEN 90W AND 110W. SLY SWELL TO 9 FT IS 
CROSSING THE EQUATOR TO 8N. 

LATER DAY 1 WHILE BOTH MID LEVEL RIDGES APPEAR TO WEAKEN 
SLIGHTLY..THEY LOOK TO BE TRYING TO CLOSE THE GAP OR WEAKNESS 
BETWEEN THEM. A MID LEVEL TROUGH TO THE N OF THE WEAKNESS IS 
FORECAST TO SHIFT EWD ALLOWING THE TWO RIDGES TO WORK CLOSER 
TOGETHER. ON THE SURFACE LATER DAY 1 LITTLE CHANGE TO THE 
PACIFIC RIDGE AND NE TRADES REMAIN FAIRLY WEAK OVER THE REGION N 
OF 20N W OF 122W. THEY INCREASE SOME N OF 28N W OF 135W TO 20 
KT. BAJA WINDS REMAIN LIGHT AS WELL AS GAP WINDS. CROSS 
EQUATORIAL SLY WINDS TO 20 KT WILL CONTINUE S OF 10N BETWEEN 95W 
AND 130W WITH SLY SWELL TO 9 FT S OF 10N OVER THE REGION. 

FOR DAY 2 THE MID LEVEL PATTERN SHOWS A GENERAL WEAKENING TREND. 
WHILE THE TROUGH TO THE N CONTINUES EWD AND AWAY FROM THE AREA.. 
THE MID LEVEL RIDGE TO THE NW ALSO WEAKENS. THE SRN CONUS MID 
LEVEL RIDGE WHILE ALSO WEAKENING CONTINUES TO SLIDE WWD ALONG 
35N TRYING TO BUILD A WEAK RIDGE AXIS WWD ALONG 35N. ON THE 
SURFACE DAY 2 LITTLE CHANGE TO THE OVERALL PATTERN WITH 
STRONGEST NE TRADES STILL CONFINED TO N OF 28N W OF 135W. WEAK 
HIGH PRES WILL COVER THE AREA N OF 10N WITH BAJA WINDS REMAINING 
LIGHT NWLY. GAP WINDS ALSO REMAIN LIGHT. CROSS EQUATORIAL SLY 
WINDS OF 20 KT WILL PREVAIL S OF 8N E OF 130W WITH CONTINUED SLY 
SWELL TO 9 FT.

$$
RRG