000
AXPZ20 KNHC 060945
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON AUG 06 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.

...SPECIAL FEATURE...

LOW PRES 1009 MB NEAR 13N117W MOVING WNW 10 KT. SOLID AREA OF 
STRONG CONVECTION WITHIN 30 NM OF THE CENTER. OTHER SCATTERED 
MODERATE WITHIN 120 NM OF THE CENTER. THE DISTURBANCE CONTINUES 
TO SLOWLY STRENGTHEN. THE OUTFLOW HAS IMPROVED WITH LESS SHEAR 
THAN THE PAST TWO NIGHTS.  

...TROPICAL WAVES...

TROPICAL WAVE ALONG 93W N OF 4N AND IS MOVING W 15 KT. THIS WAVE 
CONTINUES TO PACK A PUNCH EVEN THOUGH IT HAS BEEN OVER LAND THE 
PAST 24 HR. STRONG CONVECTION IN THE BAY OF CAMPECHE AND GULF OF 
TEHUANTEPEC ARE TESTAMENT TO THIS WAVES' VIRILITY. 

TROPICAL WAVE ALONG 105W MOVING W 12 KT. NO EVIDENCE OF THIS 
WAVE.

TROPICAL WAVE ALONG 129W FROM 8N TO 22N MOVING W 12 KT. NO 
CONVECTION NOTED AT THIS TIME. ONLY OVERCAST LOW AND MID CLOUDS.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG...9N78W 10N93W 12N105W 13N117W 
8N140W. SCATTERED MODERATE TO STRONG CONVECTION FROM 4N TO 8N 
BETWEEN 78W AND 84W AND WITHIN 30 NM OF A LINE FROM 7N91W TO 
11N103W TO 10N110W AND FROM 11N123W TO 8N137W.

SCATTERED MODERATE TO STRONG CONVECTION WITHIN 90 NM OF THE 
COAST FROM 12N90W TO 15N95W TO 15N100W. CONVECTION ASSOCIATED 
WITH A TROPICAL WAVE.

...DISCUSSION...

UPPER TROUGH ALONG 125W TAKING ADVANTAGE OF WEAKENING PRES 
PATTERN TONIGHT. HIGH PRES RIDGES HAVE DOMINATED THE MID LEVEL 
SCENE THAT PAST FEW WEEKS..NOW ONE RIDGE IS SLIDING EWD ALONG 
30N AND THE OTHER RIDGE OVER THE EXTREME NW CORNER HAS RECEDED 
NW. WATER VAPOR IMAGERY TONIGHT SHOWS A NEW SURGE HEADING SWD IN 
THE TROUGH WHICH SHOULD LOWER MID LEVEL HEIGHTS S OF 30N. ON THE 
SURFACE TONIGHT A TRPL DISTURBANCE ON THE ITCZ NEAR 13N116W 
CONTINUES TO SLOWLY INTENSIFY AND A DEPRESSION COULD FORM IN THE 
NEXT 24 HR. OTHERWISE THE PACIFIC RIDGE EXTENDS WEAKLY OVER THE 
REGION TO 16N108W AND IS PRODUCING NE TRADES TO 20 KT W OF 130W. 
WINDS ALONG THE BAJA COAST ARE NWLY 15 KT. GAP WINDS MOSTLY 
LIGHT. CROSS EQUATORIAL SLY WINDS 15 TO 20 KT WITH INCREASING 
SLY SWELL TO 8 FT.

LATER DAY 1 THE GFS MODEL SHOWS MID LEVEL HEIGHTS NOT FALLING AS 
EXPECTED. IN FACT MID LEVEL RIDGING IS FORECAST TO WORK IT'S WAY 
WWD ALONG 23N BACK TO 130W. AN EMBEDDED SHORTWAVE TROUGH OVER NW 
MEXICO CONTINUES TO WORK IT'S WAY NW. ON THE SURFACE LATER DAY 1 
THE DISTURBANCE ON THE ITCZ WILL BE MONITORED FOR FURTHER 
DEVELOPMENT. OTHERWISE LITTLE CHANGE TO THE OVERALL PATTERN. 

FOR DAY 2 MID LEVEL RIDGING CONTINUES TO EXTENDS WSW TO 20N135W 
WHICH WILL KEEP ANY DISTURBANCES S OF 20N MOVING IN A WLY 
DIRECTION. THE MID LEVEL TROUGH ALONG 130W LIFTS NE AND INLAND 
OVER THE WRN CONUS BUT A WEAK TROUGH HANGS BACK TO 30N140W. ON 
THE SURFACE DAY 2 WHILE THE PACIFIC RIDGE REMAINS WEAK..PRES 
GRADIENT ALONG THE BAJA COAST TIGHTENS DUE TO LOWER PRES INLAND 
..THUS NW WINDS INCREASE TO 15 TO 20 KT AND SEAS 6 TO 7 FT. 
OTHERWISE THE ITCZ DISTURBANCE WILL BE MONITORED FOR FURTHER 
DEVELOPMENT. LITTLE CHANGE TO CROSS EQUATORIAL WINDS BUT SEA 
SWELL FROM THE S WILL INCREASE TO 8 TO 10 FT IN LONG PERIOD 
SWELL. GAP WINDS WILL REMAIN LIGHT.

$$
RRG