000
AXPZ20 KNHC 161525
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN AUG 16 2009

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 
1500 UTC.

...SPECIAL FEATURE...

HURRICANE GUILLERMO CENTERED AT 20.1N 138.7W AT 1500 UTC MOVING 
WNW OR 285 DEGREES AT 13 KT. MAXIMUM SUSTAINED WINDS ARE 85 KT 
WITH GUSTS TO 105 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 973 
MB. GUILLERMO IS SURROUNDED BY NUMEROUS STRONG CONVECTION WITHIN 
75 NM RADIUS OF THE CENTER AND SCATTERED MODERATE ISOLATED 
STRONG CONVECTION ELSEWHERE WITHIN 120 NM OVER THE N SEMICIRCLE 
AND 90 NM OVER THE S SEMICIRCLE. GUILLERMO IS EXPECTED TO WEAKEN 
OVER THE NEXT SEVERAL DAYS AS IT CONTINUES MOVING WNW. SEE THE 
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. 

...TROPICAL WAVES...

A TROPICAL WAVE IS LOCATED ALONG 88W N OF 06N AND INTO THE 
YUCATAN PENINSULA...MOVING W AT ABOUT 15 KT. THE WAVE IS WEAK 
AND BARELY IDENTIFIABLE ON EARLY MORNING VISIBLE SATELLITE 
IMAGERY. A SMALL AREA OF SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS LOCATED AHEAD OF THE WAVE AXIS TO 93W FROM 11N TO 
14N.

A TROPICAL WAVE IS LOCATED ALONG 100W N OF 06N TO THE MEXICAN 
COAST...MOVING W AT ABOUT 15 KT. THIS WAVE IS ALSO WEAK WITH 
ISOLATED MODERATE TO STRONG CONVECTION WITHIN TWO DEGREES EITHER 
SIDE OF THE WAVE AXIS FROM 14N TO 16N. 

A TROPICAL WAVE IS LOCATED ALONG 116W FROM 06N TO 14N...MOVING W 
10 TO 15 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
LOCATED WITHIN TWO TO THREE DEGREES EITHER SIDE OF THE AXIS FROM 
12N TO 16N. 

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED ALONG AXIS FROM 
10N85W TO 10N122W TO 11N130W TO 10N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS LOCATED FROM 02N TO 07N E OF 
80W...WITHIN 60 NM EITHER SIDE OF A LINE FROM 06N90W TO 
08N100W...FROM 08N TO 12N BETWEEN 107W AND 110W...AND WITHIN 90 
NM EITHER SIDE OF A LINE FROM 12N132W TO 11N140W. 

...DISCUSSION...

W OF 110W...
A LARGE AND WELL-DEFINED MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION 
IS CENTERED NEAR 23N117W AND IS MOVING W ABOUT 15 KT. THE 
DIAMETER OF THE CIRCULATION IS ABOUT 10 DEGREES ACROSS. MODERATE 
SOUTHWESTERLY ALOFT COVERS THE AREA N OF GUILLERMO TO 32N W OF 
125W. STRONG SUBSIDENCE AS NOTED BY WATER VAPOR IMAGERY IS 
LOCATED OVER THE NORTHERN GULF OF CALIFORNIA WESTWARD TO 125W N 
OF 27N. FLOW ALOFT OVER THE TROPICS S OF 15N IS EASTERLY TO 
NORTHEASTERLY WITH SATELLITE CLOUD DRIFT WINDS INDICATING SPEEDS 
IN THE 25 TO 40 KT RANGE. AN UPPER LEVEL ANTICYCLONIC 
CIRCULATION IS FORECAST TO FORM OVER THE NW PART OF THE 
DISCUSSION AREA NEAR 31N133W IN 48 HOURS.

E OF 110W...
A MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED OVER SE 
MEXICO IN THE VICINITY OF 18N93W AND IS NEARLY STATIONARY WITH 
RESULTING NORTHWESTERLY FLOW ALOFT LOCATED OVER THE GULF OF 
TEHUANTEPEC. SOUTH OF ABOUT 10N TO THE EQUATOR WINDS ALOFT ARE 
MAINLY EASTERLY WITH LIGHT TO MODERATE WINDS SPEEDS. AN UPPER 
LEVEL RIDGE IS FORECAST TO DEVELOP ALONG 102W N OF 12N INTO 
CENTRAL MEXICO IN 48 HOURS. AT THE SURFACE FROM 10N TO 12N E OF 
89W INCLUDING THE GULF OF PAPAGAYO WINDS ARE NE TO E 20 KT AND 
SEAS LESS THAN 8 FT.

$$
CAB