000
AXPZ20 KNHC 270914
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU AUG 27 2009

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...

IGNACIO HAS BEEN DOWNGRADED TO A TROPICAL DEPRESSION. IGNACIO 
WAS CENTERED NEAR 24.6N 126.6W OR ABOUT 920 NM W OF THE SOUTHERN 
TIP OF BAJA CALIFORNIA AT 27/0900 UTC... MOVING NW OR 325 
DEGREES AT 12 KT. MAXIMUM SUSTAINED WINDS ARE 30 KT WITH GUSTS 
TO 40 KT AND THE ESTIMATED MINIMUM PRESSURE WAS 1005 MB. IGNACIO 
IS EXPECTED TO BECOME A REMNANT LOW LATER TODAY. ADDITIONAL 
INFORMATION CAN BE FOUND UNDER AWIPS/WMO HEADERS MIATCMEP3/ 
WTPZ23 KNHC.

A BROAD AREA OF LOW PRESSURE IS CENTERED NEAR 10N111W MOVING W 
NEAR 10 KT. SATELLITE IMAGES SHOW AN ASSOCIATED LARGE CLOUD 
FIELD WITH CONVECTION LOOSELY ORGANIZED IN BANDS WELL AWAY FROM 
THE CIRCULATION CENTER FROM 06N TO 13N BETWEEN 106W AND 120W.    
MANY OF THE NUMERICAL MODELS SHOW SOME DEVELOPMENT OF THIS 
SYSTEM OVER THE NEXT FEW DAYS AS IT TRACKS WEST-NORTHWESTWARD.

...TROPICAL WAVES...
A TROPICAL WAVE IS ALONG 96W/97W N OF 06N MOVING W NEAR 15 KT 
OVER THE PAST 24 HOURS. CONVECTION HAS INCREASED IN COVERAGE AND 
INTENSITY NEAR THE NORTH PORTION OF THE WAVE N OF 11N BETWEEN 
94W-100W....ENHANCED BY DIFFLUENT FLOW ALOFT ON THE SW PERIPHERY 
OF AN UPPER RIDGE. WHILE CONVECTION HAS INCREASED...IT REMAINS 
DISORGANIZED WITH LITTLE INDICATION OF A CIRCULATION CENTER. 

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG 09N84W 11N100W 
09N111W 12N140W. SCATTERED MODERATE CONVECTION IS FROM 09N TO 
12N W OF 132W.

...DISCUSSION...

A STRONG COLD FRONT LIES A COUPLE HUNDRED NM NW OF THE 
DISCUSSION ZONE...SUPPORTED BY A LARGE UPPER TROUGH OVER THE N 
PACIFIC. THIS UPPER TROUGH IS PIVOTING NE WHICH WILL CAUSE THE 
FRONT TO WEAKEN AS IT CROSSES 30N140W LATE TONIGHT. WHILE WINDS 
SHOULD BE FAIRLY LIGHT ALONG THE FRONT AT THAT TIME...NW SWELL 
COMBINED WITH THE EFFECTS OF WEAKENING IGNACIO WILL PRODUCE 8-12 
FT CONFUSED SEAS OVER THE NW PORTION OF THE SUBTROPICS.

ELSEWHERE AT THE MID AND UPPER LEVELS...A LARGE ANTICYLONE IS 
LOCATED NEAR 20N120W AND A NARROW TROUGH EXTENDS FROM 30N135W 
THROUGH 23N140W. SOME MOISTURE IS BEING DRIVEN NORTHWARD 
ASSOCIATED WITH IGNACIO E OF 127W...BUT MUCH OF THIS IS ONLY 
IN THE FORM OF MID-HIGH LEVEL CLOUDINESS.  

GULF OF TEHUANTEPEC...A HIGH RESOLUTION 0038 UTC QUIKSCAT PASS 
INDICATED THAT WINDS HAVE SHIFTED NE TO E ACROSS THE GULF OF 
TEHUANTEPEC DUE TO THE TROPICAL WAVE MOVING THROUGH THE AREA. 
WHILE THIS FLOW WILL LIMIT FUNNELING THROUGH THE GAP...A BROAD 
AREA OF E 20 KT WINDS IS EXPECTED TO CONTINUE FOR ANOTHER DAY OR 
SO DUE TO THE PRESSURE GRADIENT BETWEEN THE WAVE AND RIDGING 
OVER THE GULF OF MEXICO/MEXICO.

$$
CANGIALOSI