000
AXPZ20 KNHC 281608
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN SEP 28 2008

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 1600 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 83W N OF 4N MOVING W 10-12 KT. SCATTERED 
MODERATE CONVECTION INDICATED IN THE GULF OF PANAMA N OF 4N 
AND E OF 82W. 

TROPICAL WAVE N OF 5N ALONG 96W MOVING W 10 KT. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION ASSOCIATED WITH THIS WAVE 
COVERS THE AREA FROM 6N TO 15N BETWEEN 90W AND 104W. VISIBLE 
SATELLITE IMAGERY INDICATED LOW TO MID LEVEL TURNING E OF THE 
WAVE AXIS NEAR 12N93W. IN ADDITION STRONG WINDS OF 35-30 KT IN 
THE GULF OF TEHUANTEPEC ARE FUNNELING SWD W OF THIS AREA OF 
CYCLONIC TURNING. 

TROPICAL WAVE FROM 08N TO 18N ALONG 107W MOVING W 10-12 KT. 
SCATTERED WEAK CONVECTION IS NOTED WITHIN 120 NM E OF WAVE AXIS
FROM 16N TO 18N.

TROPICAL WAVE FROM 07N TO 15N ALONG 118W MOVING W 10 KT. A 1010 
MB LOW PRES IS NOTED ALONG THE WAVE NEAR 16N. CONVECTION IS 
MINIMAL WITH THIS TROPICAL WAVE AND CONFINED TO WITHIN 90 NM
OF THE LOW IN THE E SEMICIRCLE. 

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 10N85W TO 12N107W TO 11N120W TO 
10N140W. NUMEROUS MODERATE SCATTERED STRONG CONVECTION WITHIN 
300 NM N OF AXIS BETWEEN 86W AND 99W AND S OF AXIS BETWEEN 92W 
AND 106W. SCATTERED MODERATE CONVECTION WITHIN 150 NM EITHER 
SIDE OF AXIS BETWEEN 131W AND 135W.

...DISCUSSION...
EXPECT WINDS AND SEAS TO INCREASE OVER FAR NW WATERS BY TONIGHT 
AS A DEEP LAYERED TROUGH MOVES INTO THE REGION. SURFACE WINDS 
NEAR THE COLD FRONT PASSING INTO NW WATERS WILL BE IN THE 20 TO 
30 KT RANGE...WITH SEAS FCST TO BUILD TO 12-14 FT IN THE REGION 
BY LATE MON. IN THE MEANTIME...THE MID TO UPPER LEVEL TROUGH 
WITH NO SIGNIFICANT SENSIBLE WEATHER IMPACTS AT THE SURFACE 
CURRENTLY ALONG 30N130W TO NEAR 23N140W IS BEING BUMPED 
NORTHEAST OF THE STATIONARY  UPPER LEVEL ANTICYCLONE CENTERED 
NEAR 22N112W BY THIS APPROACHING DEEP LAYERED TROUGH. 

LOW TO MID LEVEL TROUGHING FROM 18N106W TO 10N130W IS PROVIDING 
A FOCUS FOR THE AVAILABLE TROPICAL MOISTURE.  WITHIN THIS 
REGION...A TROPICAL WAVE LIES ALONG 117W WITH AN EMBEDDED 1010 
MB LOW PRES CENTER AT 16N.  WHILE CONVECTION IS CURRENTLY WEAK 
WITH THIS SYSTEM...UPPER LEVEL DIFFLUENCE IS EXPECTED TO LIFT 
THE AVAILABLE MOISTURE ALLOWING FOR CONVECTION TO ENHANCE.  ESE 
OF THIS REGION FROM 00N TO 11N E OF 120W...EASTERLY FLOW ALOFT 
IN THE 20 TO 45 KT RANGE...IS EXPECTED TO CONTINUE TO LIMIT DEEP 
CONVECTION DESPITE PLENTIFUL AVAILABLE MOISTURE E OF 105W.  

AN ENHANCED PRESSURE GRADIENT BETWEEN SURFACE TROUGHING IN THE 
VICINITY OF THE WESTERN YUCATAN PENINSULA AND RIDGING ALONG THE 
WESTERN BAY OF CAMPECHE AND THROUGH THE CHIVELAS PASS IS 
FUNNELING MODERATE TO STRONG N TO NE SURFACE WINDS INTO THE GULF 
OF TEHUANTEPEC WITH A 1232 UTC HIGH RESOLUTION QUIKSCAT PASS 
INDICATING WINDS OF 25-30 KT IN THE AREA. THESE WINDS ARE ALSO
SPILLING SWD W OF LOW TO MID LEVEL CIRCULATION NEAR 12N93W. 
THESE WINDS ARE EXPECTED TO CONTINUE FOR THE NEXT 48 HOURS.  

$$
COBB