000
AXPZ20 KNHC 280350
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI SEP 28 2007

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.
  
...TROPICAL WAVES...

TROPICAL WAVE ALONG 104W FROM 5N TO 17N MOVING W 10 KT. A 1007 MB 
LOW IS LOCATED ALONG THE WAVE AXIS NEAR 14N. DEEP EASTERLY SHEAR IS 
DISPLACING MOST OF THE CONVECTION W OF THE WAVE. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION FROM 14N-16N BETWEEN 104W-107W.

TROPICAL WAVE ALONG 113W FROM 5N TO 17N MOVING W 10 KT. A WEAK 1010 
MB LOW IS ALONG THE WAVE AXIS NEAR 12N...EMBEDDED WITHIN THE ITCZ. 
DEEP EASTERLY SHEAR IS DISPLACING MOST OF THE CONVECTION W OF THE 
WAVE. SCATTERED MODERATE ISOLATED STRONG CONVECTION FROM 11N-13N 
BETWEEN 113W-118W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N82W 13N101W 10N123W 12N134W 10N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM OF AXIS 
W OF 101W.

...DISCUSSION...

SHIP OBSERVATIONS AT 0000 UTC HELPED PINPOINT THE LOCATION...WINDS 
AND PRESSURE FOR THE LOW NEAR 14N104W. ANIMATED SATELLITE IMAGERY 
SHOWS SOME CYCLONIC ROTATION AT MID LEVELS IN THE CLOUD PATTERN BUT 
VERY LITTLE ORGANIZATION IS OBSERVED IN THE LOW LEVEL CLOUD MOTION. 
FORECAST MODEL GUIDANCE LEANS TOWARD LITTLE CHANGE IN INTENSITY OVER 
THE NEXT COUPLE DAYS. IT MAY BECOME A TROPICAL DEPRESSION...BUT NOT 
MUCH MORE IS EXPECTED. THE MAIN INHIBITING FACTOR WILL BE DEEP ELY 
SHEAR ASSOCIATED WITH A LARGE UPPER LEVEL RIDGE LOCATED OVER SRN 
MEXICO EXTENDING WSW TO 22N98W. UPPER LEVEL MOISTURE ORIGINATING 
FROM HURRICANE LORENZO IN THE BAY OF CAMPECHE IS BEING ADVECTED 
WESTWARD OVER THE PACIFIC WATERS E OF 110W. THE EASTERLY SHEAR IS 
PUSHING MOST OF THE DEEP CONVECTION WEST OF ORIGIN POINT. ANOTHER 
BROAD UPPER LEVEL RIDGE EXTENDS FROM MEXICO SW TO 14N140W WITH 
MODERATE/STRONG SUBSIDENCE FROM 15N-24N. THE ITCZ REMAINS FAIRLY 
ACTIVE WITH ENHANCED AREAS OF CONVECTION W OF 100W. A WEAK SURFACE 
TROUGH IS LOCATED ALONG 136W S OF 18N MOVING W 10 KT...BUT A LACK OF 
MOISTURE IS SUPPRESSING SHOWER ACTIVITY. A CUT-OFF UPPER LOW IS 
MOVING INTO THE NORTHERN CALIFORNIA COAST WITH A TROUGH EXTENDING 
SW...PUTTING THE N PART OF THE DISCUSSION AREA N OF 23N UNDER W/SW 
FLOW ALOFT. A 100 KT JET EXTENDS FROM 28N140W TO 30N126W...THEN 
WEAKENS AS IT CONTINUES NE INTO THE SW UNITED STATES.

$$
MUNDELL