000
AXPZ20 KNHC 190345
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT AUG 19 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...SPECIAL FEATURES...

HURRICANE HECTOR IS AT 17.0N 128.0W AT 19/0300 UTC MOVING WNW OR 
290 DEG AT 11 KT. MAXIMUM SUSTAINED WIND SPEED IS 85 KT WITH 
GUSTS TO 105 KT. HECTOR IS EXHIBITING A VERY WELL DEFINED OVERALL
CLOUD PATTERN WITH STRONG CONVECTION TIGHTLY WRAPPED AROUND THE 
E SEMICIRCLE AND NW QUADRANT. AND EYE FEATURE ABOUT 16 NM WIDE 
IS VISIBLE...ALTHOUGH SOMEWHAT OBSCURED BY HIGH AND MID CLOUDS. 
THE CONVECTION CONSISTS OF SCATTERED STRONG CONVECTION WITHIN
75 NM SE QUADRANT...60 NM N QUADRANT AND 45 NM NW QUADRANT. 
SCATTERED MODERATE CONVECTION IS ELSEWHERE WITHIN 90 NM OF THE 
CENTER. HECTOR IS FORECAST TO ENCOUNTER COOLER WATERS SHORTLY
AND A MORE STABLE ENVIRONMENT...THEREFORE THE LATEST NHC 
ADVISORY HAS IT WEAKENING BEGINNING IN ABOUT 18 HOURS AND IS 
FORECAST TO REACH TROPICAL STORM STRENGTH IN ABOUT 36 HOURS. FOR 
MORE DETAILS SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. 

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS ALONG 91W N OF 4N TO ACROSS GUATEMALA AND 
THE YUCATAN PENINSULA. IT IS MOVING W ABOUT 10-15 KT. NO
DEEP CONVECTION IS NOTED WITH THIS WAVE...HOWEVER SOME BROAD 
TURNING IN MID LEVEL CLOUDS IS SEEN W OF THE WAVE FROM 9N-13N 
BETWEEN 92W-100W. UPPER LEVEL WINDS APPEAR FAVORABLE FOR 
DEVELOPMENT OVER THE NEXT FEW DAYS...AND MODEL GUIDANCE SUGGEST
THAT MORE DEFINED LOW PRESSURE MAY EVOLVE FROM NEAR THIS WAVE
OVER THE NEXT FEW DAYS.

TROPICAL WAVE ALONG 116W FROM 6N-14N MOVING W ABOUT 13 KT.
MODERATE N-NE SHEAR IS PREVENTING THIS WAVE FROM ORGANIZING.
ASSOCIATED CONVECTION IS DESCRIBED BELOW UNDER ITCZ.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N83W 9N95W 9N100W 9N110W 10N120W
13N125W 10N140W. BESIDES FOR THE CONVECTION ASSOCIATED WITH THE 
TROPICAL WAVES...SCATTERED MODERATE/ISOLATED STRONG CONVECTION
IS WITHIN 120 NM S OF THE ITCZ BETWEEN 97W-104W...BETWEEN 
109W-113W...AND FROM 9N-12N W OF 137W.  SCATTERED MODERATE 
CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN 130W-132.5W.

...DISCUSSION...

STRONG MID-UPPER LEVEL RIDGE EXTENDS FROM NRN MEXICO SW TO AN 
ANTICYCLONE NEAR 17N120W. THIS FLOW IS INTERRUPTED BY A WEAKNESS 
FROM A MID-UPPER TROUGH BETWEEN 120W-128W. THIS WEAKNESS IS WHAT 
IS STEERING HECTOR N OVER COOL WATERS AND INTO A DRY 
ENVIRONMENT. FARTHER WEST...A BROAD UPPER LEVEL HIGH IS CENTERED 
NEAR 18N140. DRY STABLE AIR AND FAIR WEATHER COVERS THE 
MAJORITY OF THE AREA NW OF A LINE ALONG 13N140W 15N130W 21N126W 
28N115W. WIDESPREAD MOISTURE LIES TO THE SE OF THIS LINE BUT 
BESIDES FOR HECTOR...THE TROPICAL WAVES AND THE ITCZ...VERY 
LITTLE OF IT IS DEEP IN NATURE 

AT THE SURFACE...TYPICAL PACIFIC RIDGE STRETCHES ACROSS THE AREA 
ALONG 32N130W 25N115W 18N107W. HECTOR IS PUSHING AGAINST THE 
RIDGE...TIGHTENING THE PRES GRAD...ENHANCING NE TRADES BETWEEN 
12N AND 27N W OF 135W WITH WINDS 20 KT AND SEAS 8 FT. CROSS 
EQUATORIAL WINDS ARE 15 TO 20 KT WITH S SWELLS PRODUCING 8 FT 
SEAS S OF 6N BETWEEN 90W-115W. WINDS ALONG THE BAJA COAST ARE NW 
10 TO 15 KT BASED UPON SHIPS AND QUIKSCAT DATA BUT ARE EXPECTED
TO INCREASE FROM THE NW AT 20 KT WITHIN ABOUT 24 HOURS.

$$
AGUIRRE