000
AXPZ20 KNHC 140907
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON SEP 14 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.

...TROPICAL WAVES...

A TROPICAL WAVE IS ANALYZED ALONG 98W N OF 7N TO INLAND SE 
MEXICO MOVING W AT 15 KT. WEAK ISOLATED TSTMS ARE WITHIN 30 NM 
OF 15N98W.

A TROPICAL WAVE IS ANALYZED ALONG 111W/112W FROM 5N-17N MOVING W 
10 KT. LATEST SATELLITE IMAGERY SHOWS THAT THE WAVE IS PART OF
A LARGE AREA OF DISORGANIZED MULTILAYERED CLOUDS WITH CONVECTION
AS DESCRIBED BELOW UNDER ITCZ. ISOLATED SHOWERS AND TSTMS ARE 
ALONG AND WITHIN 30 NM OF THE AXIS FROM 14N-17N. BEING THAT THE
WAVE IS NOW UNDER A DIFFLUENT UPPER PATTERN...AND THIS WHOLE AREA
OF CLOUDS AND CONVECTION IS BASICALLY TIED INTO A LARGE MONSOONAL
CIRCULATION GENERALLY BETWEEN 98W-112W EXPECT CONVECTION TO
CONTINUE IN INTERMITTENT BURSTS THROUGH THE NEXT 48 HOURS.

...THE ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE 06N77W TO 
08N100W TO 09N120W TO 08N140W. SCATTERED MODERATE TO STRONG 
CONVECTION IS WITHIN 100 NM OF THE POINT 14.5N106W. SCATTERED 
MODERATE TO STRONG CONVECTION IS WITHIN 60 NM OF THE POINT 
15.5N109W AND THE POINT 12.5N113W. SCATTERED MODERATE TO STRONG 
CONVECTION IS WITHIN THE AREA FROM 08N TO 10.5N FROM 120W TO 
125W.

...DISCUSSION...

DEEP LAYER TROUGH IS NORTH OF A LINE FROM THE NORTHERN GULF OF 
CALIFORNIA TO 25N120W TO BEYOND 21N140W. THE AREA ID DRY AND 
CLOUD FREE IN THE MIDDLE AND UPPER LEVELS WITH OVERCAST 
STRATOCUMULUS SOUTH OF 30N AND SCATTERED STRATOCUMULUS NORTH OF 
30N. THE TROUGH IS FORECAST TO WEAKEN AS THE RIDGE TO THE 
SOUTHEAST BUILDS NORTHWARD IN ADVANCE OF A STRONG MIDDLE 
LATITUDE TROUGH THAT WILL APPROACH THE NORTHWEST PART TUESDAY.

ANOTHER DEEP LAYER TROUGH IS OVER NORTHEASTERN MEXICO EAST OF 
105W AND NORTH OF 21N. THE TROUGH IS A SOUTHERN EXTENSION OF A 
WELL DEFINED CYCLONIC CIRCULATION CENTERED OVER TEXAS. THERE IS 
SOME CONVECTION ALONG THE SOUTHEAST FLANK OF THE TROUGH OVER 
MAINLAND MEXICO OTHERWISE THE AREA IS CLEAR.

A THIRD DEEP LAYER TROUGH IS EAST OF A LINE FROM NORTHEAST 
YUCATAN PENINSULA TO THE ITCZ NEAR 94W. THIS AREA IS MOSTLY DRY 
AND CLOUD FREE AT ALL LEVELS THE EXCEPTION IS AN AREA OF 
CONVECTION NEAR THE CAST OF NORTHERN COSTA RICA AND SOUTHERN 
NICARAGUA WITH SCATTERED MODERATE TO STRONG CONVECTION WITHIN 60 
NM OF THE POINT 11N87W.

A LARGE ANTICYCLONE COVERS THE REMAINDER OF THE AREA. THE FLOW 
IS DIFFLUENT IN THE UPPER LEVELS SOUTHEAST OF A LINE FROM 
22N105W TO THE ITCZ NEAR 135W. NORTHWEST OF THIS LINE THE 
ATMOSPHERE IS DRY AND CLOUD FREE AT ALL LEVELS EXCEPT FOR A 
PATCH OF OVERCAST STRATOCUMULUS NORTH OF 18N FROM 115W TO 130W. 
THE DIFFLUENT AREA IS MOIST ALOFT WITH MULTI LEVEL CLOUDS AND 
EMBEDDED AREAS OF CONVECTION. THE DIFFLUENCE ALOFT IS CAUSING 
CONVERGENCE IN THE LOWER LEVELS WITH A LOW CENTER NEAR 11N110W 
1009 MB. LOW TO MIDDLE LEVEL CYCLONIC TURNING IS BEGINNING TO 
FORM IN THE AREA NEAR THE LOW. THE COMPUTER MODELS DEVELOP THIS 
LOW AND MOVE IT SLOWLY NORTHWEST.

A WEAKENING SURFACE FRONTAL SYSTEM IS OVER THE NORTHWEST PART OF 
THE AREA AND IS FORECAST TO DISSIPATE TODAY. THE REMNANT 
CIRCULATION OF LINDA EXTENDS OUT SEVERAL HUNDRED MILES FROM THE 
CENTER NEAR 20N134W. THE LOW IS FORECAST TO DRIFT WEST AND 
WEAKEN. A NEW LOW IS ANALYZED NEAR 11N110W. OTHERWISE A BROAD 
TROUGH COVERS THE AREA.

$$
LL