000
AXPZ20 KNHC 161606
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN SEP 16 2007

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.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 98W N OF 10N MOVING W 5-10 KT. COMPARISONS 
OF SATELLITE IMAGERY AND EARLY MORNING SCATTEROMETER DATA SHOW A 
MID LEVEL ROTATION PERSISTING ALONG THE WAVE AXIS NEAR 11N98W. 
SCATTERED CONVECTION IS NOTED UNDER THE CONVECTION AT THE BASE 
OF WAVE...ROUGHLY WHERE IT MEETS THE ITCZ.

TROPICAL WAVE ALONG 111W S OF 18N MOVING W 5 KT. A 1009 MB LOW 
IS ALONG THE AXIS NEAR 14N112W MOVING NW NEAR 5 KT. BANDING IS 
DEVELOPING IN A WIDE ARC APPROXIMATELY 180 NM N OF THE CENTER. 
THE SCATTERED LIGHT TO ISOLATED MODERATE CONVECTION IS LIMITED 
HOWEVER IN STRONG ELY SHEAR. EARLIER SCATTEROMETER DATA AND THE 
FIRST VISIBLE SATELLITE IMAGERY OF HT DAY SHOW THE LOW LEVEL 
CENTER EMBEDDED IN THE ITCZ AND ALONG THE WAVE.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N85W 10N96W 14N112W 16N121W 
12N132W 11N140W. SCATTERED MODERATE CONVECTION WITHIN 120 NM OF 
AXIS BETWEEN 96W AND 98W...NEAR TROPICAL WAVE AT 97W. SCATTERED 
MODERATE ISOLATED STRONG WITHIN 120 NM S OF AXIS BETWEEN 118W 
AND 121W. SCATTERED MODERATE WITHIN 90 NM N OF AXIS BETWEEN 125W 
AND 130W.

...DISCUSSION...

E OF 110W...
WEAK ANTICYCLONIC OUTFLOW ALOFT OVER THE SW CARIBBEAN IS 
PROVIDING MODERATE NE SHEARING OVER THE WATERS S OF CENTRAL 
AMERICA. A WELL DEFINED UPPER LOW IS CENTERED OVER THE BAY OF 
CAMPECHE. DIVERGENCE ALOFT ON THE SRN EDGE OF THE UPPER LOW IS 
ENHANCING THE CONVECTION NEAR THE WAVE ALONG 98W AS DISCUSSED 
ABOVE. MODERATE TO STRONG SHEARING IS EVIDENT BETWEEN THE UPPER 
LOW OVER THE BAY OF CAMPECHE AND AN UPPER RIDGE OVER CENTRAL 
MEXICO...HAMPERING DEVELOPMENT OF THE CLUSTERS OF CONVECTION 
ALONG THE ITCZ.

W OF 110W...
BROAD UPPER ANTICYCLONE CENTERED NEAR 23N118W IS CONTINUING THE 
MODERATE TO STRONG ELY SHEAR ACROSS THE ITCZ. THE UPPER RIDGE 
AXIS EXTENDS FROM CENTRAL MEXICO TO THE CENTER OF THE UPPER 
ANTICYCLONE TO 16N140W. UPPER DIVERGENCE ON THE SW PERIPHERY OF 
THE UPPER ANTICYCLONE IS AIDING CONVECTION IN A BROAD SWATH 
ALONG THE ITCZ BETWEEN 125W AND 130W. THE UPPER DIVERGENCE IS 
ALSO SUPPORTING A SURFACE LOW 1009 MB NEAR 14N126W WITH A TROUGH 
EXTENDING TO THE NE TO 19N122W. FRESH NELY WINDS ARE EVIDENT N 
OF THE ITCZ BETWEEN THE LOW PRES AND STRONG HIGH WELL TO THE N.


$$
CHRISTENSEN