000
AXPZ20 KNHC 061553
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI AUG 06 2010

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 
1530 UTC.

...SPECIAL FEATURE...

AT 06/1500 UTC...TROPICAL DEPRESSION SEVEN-E IS CENTERED NEAR 
16.6N 104.0W MOVING WEST-NORTHWEST OR 290 DEGREES AT 9 KT. 
ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED 
WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC 
FOR MORE DETAILS. CONVECTION HAS INCREASED NEAR THE CENTER 
DURING THE PAST FEW HOURS WITH BANDING FEATURES NOW NOTED IN THE 
SOUTHEAST SEMICIRCLE OF THE DEPRESSION. THE SYSTEM MAY VERY WELL 
BE NEAR TROPICAL STORM STATUS AT THIS TIME. ENVIRONMENTAL 
CONDITIONS ARE FAVORABLE FOR INTENSIFICATION DURING THE NEXT 36 
TO 48 HOURS. THE NHC OFFICIAL INTENSITY FORECAST CALLS FOR THE 
DEPRESSION TO REACH TROPICAL STORM STATUS IN ABOUT 12 HOURS. 

...ITCZ...

THE ITCZ AXIS IS ALONG 10N85W TO 09N100W TO 12N115W TO 10N125W 
TO 10N140W. SCATTERED MODERATE TO ISOLATED STRONG  WITHIN 120 NM 
S OF AXIS FROM 91W TO 97W AND WITHIN 90 NM N OF AXIS FROM 107W 
TO 111W. SCATTERED MODERATE FROM 07N TO 12N BETWEEN 123W AND 
134W.  
 
...DISCUSSION...

ALOFT...AN UPPER LEVEL ANTICYCLONE DOMINATED THE PATTERN OVER 
THE NW WATERS AND WAS CENTERED NEAR 26N141W WITH A RIDGE 
EXTENDING BEYOND 30N130W. A SECOND UPPER LEVEL ANTICYCLONIC 
CIRCULATION WAS LOCATED OVER TEXAS WITH AN ASSOCIATED RIDGE 
EXTENDING ACROSS EXTREME NORTHERN MEXICO THEN SW ACROSS BAJA 
CALIFORNIA INTO THE EPAC TO NEAR 20N130W. TROPICAL DEPRESSION 
SEVEN-E IS MOVING AROUND THE SOUTHERN PERIPHERY OF THIS RIDGE 
AND WAS EMBEDDED WITHIN AN AREA OF UPPER LEVEL EASTERLY FLOW. AN 
UPPER LEVEL TROUGH ENTERS THE FORECAST AREA NEAR 30N120W AND 
CONTINUES SW TO NEAR 22N131. AT THIS POINT...AN INVERTED TROUGH 
IS NOTED EXTENDING SW TO NEAR 14N136W. VERY DRY AIR ALOFT UNDER 
MODERATE TO STRONG SUBSIDENCE IS PRESENT ACROSS THE AREA N OF 
20N AND W OF 115W. ANOTHER INVERTED TROUGH EXTENDS FROM 24N114W 
TO A SMALL CYCLONIC CIRCULATION NEAR 18N117W. EASTERLY/ZONAL 
FLOW PREVAILS ACROSS THE REMAINDER OF THE DISCUSSION AREA IN THE 
DEEP TROPICS S OF 10N. UPPER LEVEL MOISTURE RESULTING FROM ITCZ 
CONVECTION IS BEING ADVECTED TO THE WEST AS A RESULT OF THE 
PERSISTENT EASTERLY WINDS.

AT THE SURFACE...A RIDGE DOMINATES THE N WATERS MAINLY N OF 18N. 
PRES GRADIENT BETWEEN THIS RIDGE A LOWER PRES OVER NW MEXICO IS 
PRODUCING DIURNALLY FORCED NW WINDS OF 20 KT N OF 25N E OF 118W 
TO THE W COAST OF BAJA CALIFORNIA. 

A TROUGH EXTENDS FROM 14N130W TO 7N138W. NE WINDS OF 20 KT AND 
SEAS OF 8 FT ARE OCCURRING WITHIN 90-120 NM EITHER SIDE OF THE 
TROUGH AXIS FROM 08N TO 12N. THESE MARINE CONDITIONS WILL 
PERSIST AHEAD OF THE TROUGH AXIS DURING THE NEXT COUPLE OF DAYS 
AS THE TROUGH MOVES WWD.  

ITCZ DISTURBANCES ARE GENERATING AN AREA OF S-SW WINDS OF 20 KT 
MAINLY FROM 03N TO 08N BETWEEN 90W AND 105W. THIS WEATHER 
PATTERN IS FORECAST TO PERSIST BY THE COMPUTER MODELS OVER THE 
NEXT COUPLE OF DAYS EXTENDING WESTWARD TO 125W IN ABOUT 24 
HOURS.  

REGIONAL SEAS ARE DOMINATED BY LONG PERIOD SW SWELLS OF 15 TO 17 
SECONDS RAISING SEAS TO 9 FT MAINLY S OF 12N BETWEEN 100W AND 
120W. THE SWELLS WILL CONTINUE TO PROPAGATE ACROSS THE BASIN 
WITH OPEN OCEAN SEAS OF 8 TO 10 FT THROUGH 48 HOURS.

$$
COBB