000
AXPZ20 KNHC 240306
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON AUG 24 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...SPECIAL FEATURE...

AN AREA OF LOW PRESSURE IS LOCATED NEAR 16N112W WITH AN 
ESTIMATED MINIMUM PRESSURE OF 1008 MB. SATELLITE IMAGES 
THROUGHOUT THE DAY HAVE INDICATED A POORLY DEFINED LOW LEVEL 
TURNING ASSOCIATED WITH THE LOW PRESSURE WITH SCATTERED TO 
NUMEROUS STRONG CONVECTION NOTED WEST OF THE LOW IN THE AREA 
FROM 15N TO 19N FROM 112W TO 119W. CONVECTION ALONG THE ITCZ IN 
THIS AREA HAS WEAKENED. THERE IS A HIGH POTENTIAL FOR TROPICAL 
CYCLONE FORMATION WITH THIS SYSTEM OVER THE NEXT 48 HOURS. 
SEVERAL OF THE NWP MODELS SHOW DEVELOPMENT OF THE SYSTEM AS 
WELL.   

...TROPICAL WAVES...
  
TROPICAL WAVE IS ALONG 125W FROM 09N TO 18N MOVING W 10 KT. 
SATELLITE IMAGES SHOW SOME LOWER TO MIDDLE LEVEL CYCLONIC 
TURNING NEAR 13N. CONVECTIVE ACTIVITY ASSOCIATED WITH THE WAVE 
AND THE AREA OF TURNING HAS DIMINISHED DURING THE DAY WITH ONLY 
ISOLATED CONVECTION NEAR THE WAVE AXIS. 

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG...06N77W TO 06N100W 
TO 10N110W TO 11N140W. SCATTERED MODERATE TO STRONG CONVECTION 
IS OVER THE GULF OF PANAMA. SCATTERED MODERATE TO STRONG 
CONVECTION IS WITHIN 90 NM OF THE POINT 06.5N81.5W.

...DISCUSSION...

RIDGE IS NORTHWEST OF A LINE THROUGH 32N125W TO 20N130W 10N135W. 
THE AREA IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS 
WITH OVERCAST STRATOCUMULUS NORTH OF 25N AND BROKEN 
STRATOCUMULUS SOUTH OF 25N. 

EAST OF THE RIDGE A TROUGH IS OBSERVED WEST OF A LINE THROUGH 
32N11W TO 26N115W TO 13N131W. THIS AREA IS ALSO DRY AND CLOUD 
FREE IN THE MIDDLE AND UPPER LEVELS WITH CLEAR SKIES NORTH OF 
25N AND BROKEN STRATOCUMULUS SOUTH OF 25N. 

A STRONG TROUGH OVER MOST OF THE EASTERN UNITED STATES EXTENDS 
ACROSS EASTERN MEXICO AND THE WESTERN GULF OF MEXICO IN AN AREA 
NORTH OF 15N FROM 105W TO A LINE FROM 15N97W TO BEYOND THE 
NORTHWEST PART OF THE YUCATAN PENINSULA. THE TROUGH AREA IS 
FAIRLY DRY WITH MOSTLY CLEAR SKIES WITH A FEW SMALL 
THUNDERSTORMS OVER MEXICO.

BETWEEN THE ABOVE TWO TROUGHS A RIDGE IS OBSERVED. THIS RIDGE IS 
DIFFLUENT ALOFT WITH WIDESPREAD MULTI LEVEL CLOUDINESS AND 
EMBEDDED AREAS OF CONVECTION. IT IS WITHIN THIS AREA THAT THE 
SPECIAL FEATURE LOW PRESSURE IS EMBEDDED. ACTIVE CONVECTION IS 
LOCATED OVER NORTHWEST MEXICO IN THE SIERRA MADRE OCCIDENTAL. 
THIS CONVECTION HAS BEEN PROPAGATING NORTHWARD FOR THE LAST 
SEVERAL HOURS AND IS APPROACHING THE UNITED STATES BORDER.

EAST OF THE SECOND TROUGH ANOTHER RIDGE IS OBSERVED. THIS RIDGE 
IS ALSO DIFFLUENT ALOFT WITH MULTI LEVEL CLOUDINESS AND EMBEDDED 
AREAS OF CONVECTION.

MODERATE SURFACE RIDGE IS NORTH OF 20N WEST OF 115W. LARGE WEAK 
LOW PRESSURE AREA IS NORTH OF THE ITCZ TO 20N FROM 105W TO 130W. 
THIS AREA INCLUDES THE LOW THAT HAS THE POTENTIAL TO DEVELOP 
INTO A TROPICAL CYCLONE.

GAP NORTHERLY WINDS OF UP TO 20 KT ARE IN THE GULF OF 
TEHUANTEPEC. THESE WINDS WILL CONTINUE THROUGH THE NEXT SEVERAL 
DAYS MAINLY DURING THE NIGHTTIME HOURS.

GAP EASTERLY WINDS OF UP TO 20 KT ARE IN THE GULF OF PAPAGAYO 
REGION. THESE WINDS WILL ALSO CONTINUE THROUGH THE NEXT SEVERAL 
DAYS MAINLY DURING THE NIGHTTIME HOURS.

$$
LL