000
AXPZ20 KNHC 282145
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI SEP 28 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 
2100 UTC.
  
...SPECIAL FEATURE...

1007 MB LOW LOCATED ALONG A TROPICAL WAVE AXIS NEAR 15N108W MOVING 
W AT 10 KT. THE LOW IS BEING AFFECTED BY DEEP EASTERLY SHEAR WHICH 
HAS CAUSED MOST OF THE DEEP CONVECTION TO BE DISPLACED WEST OF THE 
LOW-LEVEL CENTER. NUMEROUS MODERATE TO STRONG CONVECTION FROM 13N-17N
BETWEEN 107W-110W. SHEARING EFFECTS MAY RELAX A BIT... ALLOWING THIS 
SYSTEM TO BECOME A LITTLE BETTER ORGANIZED AND DEVELOP INTO A 
TROPICAL DEPRESSION WITHIN THE NEXT 24-48 HOURS.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 118W S OF 16N MOVING W 10 KT. CONVECTION LIES 
ALONG THE ITCZ IN THE VICINITY OF THE WAVE AXIS.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N85W 12N100W 13N117W 11N130W 12N140W. 
SCATTERED MODERATE ISOLATED STRONG WITHIN 150 NM OF AXIS BETWEEN 
100W AND 121W.

...DISCUSSION...

AN UPPER LEVEL RIDGE EXTENDS FROM S/CENTRAL MEXICO WSW TO 18N110W 
THEN W TO 18N140W. DEEP EASTERLY FLOW IS PRODUCING MODERATE TO STRONG
EASTERLY SHEAR S OF 15N. ABUNDANT DEEP MOISTURE IS BETWEEN 90W-110W 
DUE TO THE PRESENCE OF T.D. LORENZO AND THE AREA OF LOW PRESSURE 
NEAR 18N108W. AN AXIS OF LOW-LEVEL CONVERGENCE EXTENDS FROM NEAR 
PUERTO VALLARTA SW TO 17N110W WITH SCATTERED MODERATE CONVECTION 
ALONG THE AXIS. A VIGOROUS UPPER TROUGH IS MOVING INLAND OVER THE W 
COAST OF THE UNITED STATES WITH A TRAILING TROUGH AXIS JUST N OF THE 
DISCUSSION AREA W OF 125W. WESTERLY FLOW HAS STRENGTHENED S OF THE 
TROUGH AXIS WITH A 70-95 KT JET FROM 28N140W TO 30N123W TO N MEXICO. 
A LARGE AREA OF MODERATE SUBSIDENCE IS EVIDENT N OF 17N...DOMINATED 
BY STABLE LOW-LEVEL STRATOCUMULUS. THE ITCZ IS VERY ACTIVE PROBABLY 
DUE TO UPPER LEVEL DIVERGENCE WHERE UPPER LEVEL WINDS ACCELERATE S 
OF 10N TO THE EQUATOR.

$$
MUNDELL