000
AXPZ20 KNHC 270332
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU SEP 27 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 IS ALONG 97W/98W N OF 7N MOVING W 10 KT. A WEAK 
AREA OF LOW PRES...LIKELY IN THE MID-LEVELS...HAS FORMED TO THE 
W OF THE WAVE NEAR 15N102W. THIS WAS THE FOCUS FOR CONVECTION 
DURING THE AFTERNOON HOURS BUT SINCE THEN CONVECTION HAS GREATLY 
DIMINISHED WITH ONLY POCKETS OF SCATTERED SHOWERS AND TSTMS FROM 
12N-15N BETWEEN 102W-105W. THE WAVE ITSELF IS NOT WELL DEFINED 
AND IT MIGHT BE RELOCATED ON FUTURE MAPS TO MATCH UP WITH THE 
MID-LEVEL TURNING...IF THAT PERSISTS.

TROPICAL WAVE IS ALONG 110W/111W FROM 6N TO 15N MOVING W 10 KT. 
A WEAK AREA OF LOW PRES...1010 MB...IS ALONG THE WAVE NEAR 11N. 
THIS WEAK LOW IS BASICALLY JUST AN ELONGATED SWIRL OF LOW 
CLOUDS. CONVECTION HAS INCREASED SLIGHTLY MAINLY IN A RATHER 
LINEAR NE-SW LINE WITHIN 30 NM OF 14N119W 12N112W

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 9N84W 12N107W 11N120W 12N130W 
10N140W. SCATTERED MODERATE IS WITHIN 90 NM S OF AXIS BETWEEN 
95W AND 109W. SCATTERED MODERATE IS WITHIN 150 NM N OF AXIS 
BETWEEN 120W AND 130W. 

...DISCUSSION...

THE UPPER FLOW IS FAIRLY SWIFT AND MOSTLY OUT OF THE W TO SW 
ACROSS THE SUBTROPICAL EPAC THIS EVENING. THIS IS DUE TO A 
SERIES OF UPPER FEATURES. THE PRIMARY SYSTEMS CONSIST OF A PAIR 
OF UPPER LOWS LOCATED OFF THE CENTRAL CALIFORNIA COAST AND N OF 
THE HAWAIIAN ISLANDS. UPPER RIDGING LOCATED TO THE S AND E OF 
THE AREA IS ALSO ENHANCING THIS FLOW. WATER VAPOR IMAGES SHOW A 
PLUME OF HIGH LEVEL CIRRUS N OF 25N W OF 120W...BUT NOT MUCH 
ELSE IN THE REGION. IN THE TROPICS...STRETCHED OUT UPPER RIDGING 
IS THE GENERAL THEME. THE MAIN ANTICYCLONES ARE CENTERED OVER 
CENTRAL MEXICO AND NEAR 16N136W. A WEAK UPPER LOW IS SPINNING 
NEAR 20N113W INTERRUPTING THE RIDGING A BIT...BUT NOT PRODUCING 
ANY SENSIBLE WEATHER. CONVECTION IS MOSTLY CONFINED TO THE ITCZ. 

IN THE LOWER LEVELS...THERE ARE NO SYSTEMS SHOWING ANY SIGNS OF 
DEVELOPMENT. A WELL ESTABLISHED SUBTROPICAL RIDGE IS PARKED WELL 
NW OF THE AREA WITH SEVERAL EMBEDDED HIGH CENTERS. THE TIGHTENED 
GRADIENT BETWEEN THE RIDGE AND A WEAK SFC TROUGH ALONG 140W IS 
PRODUCING MODERATE TO FRESH NE TRADES GENERALLY W OF 120W. THESE 
WINDS ARE EXPECTED TO CHANGE LITTLE OVER THE NEXT COUPLE OF DAYS 
AS THE PATTERN HOLDS. THERE IS A SMALL AREA OF ACCELERATED NLY 
WINDS NEAR THE CENTRAL AND SOUTH BAJA COAST...AS INDICATED BY A 
FEW SHIP REPORTS AND SUGGESTED BY THE QUICK MOVING THIN 
STRATOCUMULUS CLOUDS ON SATELLITE IMAGES. THESE WINDS ARE 
ANTICIPATED TO SUBSIDE SHORTLY.

$$
CANGIALOSI