000
AXPZ20 KNHC 162215
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN SEP 16 2007

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2200 UTC.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 99W N OF 8N MOVING W 5-10 KT. A 1010 MB LOW
IS ON THE WAVE AXIS NEAR 11N. THE LOW IS EXHIBITING A 
WELL-DEFINED WHAT APPEARS TO BE A MID LEVEL ROTATION ON 
SATELLITE IMAGERY. SCATTERED MODERATE/ISOLATED STRONG IS WITHIN 
30 NM EITHER SIDE OF LINE 13N96.5W 13N99W 12N101W. THIS SYSTEM 
HAS THE POTENTIAL FOR SOME DEVELOPMENT OVER THE NEXT 48 HRS AS 
IT TRACKS IN A WNW DIRECTION.

TROPICAL WAVE ALONG 112W FROM 8N-19N IS MOVING W ABOUT 7 KT. A 
WEAK 1010 MB LOW IS ON THE WAVE AXIS NEAR 15N. THE LOW IS RATHER
SMALL...AND REMOVED FROM THE DEEP CONVECTION. THE DEEP CONVECTION
IS COMPOSED OF THE SCATTERED MODERATE TYPE INTENSITY WITHIN 
120-180 NM N OF THE LOW WITHIN 45 NM OF 18N111W...AND IS MOVING 
RAPIDLY WNW. THIS SYSTEM IS UNDER ELY SHEAR WHICH IS NOT ALLOWING
CONVECTION ASSOCIATED WITH IT TO ORGANIZE.

...ITCZ...

INTERTROPICAL CONVERGENCE ZONE...9N85W 11N100W 14N112W 14N122W
12N130W 10N140W. SCATTERED STRONG CONVECTION IS WITHIN 60 NM OF 
THE AXIS BETWEEN 120W-123W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 102W-105W. 
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS 
BETWEEN 85W-89W.

...DISCUSSION...

E OF 115W...
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. A SMALL ANTICYCLONE IS TO THE S OF THE UPPER LEVEL LOW
NEAR 13N96W. WITH THE CLOSE PROXIMITY OF THESE TWO FEATURES...
DIVERGENCE ALOFT IS BEING NOTED S OF THE GULF OF TEHUANTEPEC TO 
13N AND E OF THE WAVE ALONG 99W. THIS IS ALLOWING FOR CONVECTION
ASSOCIATED WITH THE LOW AND WAVE ALONG 99W MENTIONED ABOVE TO
CONTINUE TO FLARE UP. MODERATE TO STRONG SHEARING IS EVIDENT 
BETWEEN THE UPPER LOW OVER THE BAY OF CAMPECHE AND AN UPPER 
RIDGE OVER CENTRAL MEXICO. MODERATE TO STRONG NE SHEAR IS EVIDENT
S OF 7N E OF 94W. THIS AS STATED ABOVE UNDER TROPICAL WAVE ALONG 
112W IS KEEPING CONVECTION ALONG AND NEAR THE ITCZ TO A MINIMUM. 
A WEAK PRES PATTERN PREVAILS AT THE SURFACE.
 
W OF 115W...
BROAD UPPER ANTICYCLONE CENTERED NEAR 23N117W 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...AND SW TO OUTSIDE THE REGION AT 
15N144W. UPPER DIVERGENCE ON THE SW PERIPHERY OF THE UPPER 
ANTICYCLONE IS AIDING CONVECTION NEAR THE ITCZ BETWEEN 
120W-130W. A WEAK AND ELONGATED 1009 MB LOW IS AT THE SURFACE 
NEAR 13N127W. A TROUGH EXTENDS NE FROM THE LOW THROUGH 15N124W 
TO 11N122W. THE LOW IS FORECAST TO MOVE IN A NW DIRECTION OVER
THE NEXT 24 HRS AND REMAIN RATHER WEAK.

FRESH NELY WINDS ARE EVIDENT N OF THE ITCZ BETWEEN THE LOW PRES 
AND STRONG HIGH WELL TO THE N. AT THE SURFACE...A RIDGE EXTENDS 
INTO THE AREA THROUGH 32N133W...AND REACHES TO 16N117W. HIGH 
PRES COVERS THE AREA N OF 20N W OF 118W. SCATTERED PATCHES OF
STRATOCUMULUS CLOUDS WITH POSSIBLE ISOLATED SHOWERS ARE NW OF
LINE 14N140W 20N128W TO 32N121W.

$$
AGUIRRE