000
AXPZ20 KNHC 111557
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON AUG 11 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 
1530 UTC.

...SPECIAL FEATURE...

HURRICANE HERNAN IS CENTERED NEAR 19.0N 130.2W AT 1500 UTC 
MOVING WEST-NORTHWEST OR 285 DEG AT 09 KT. MAXIMUM SUSTAINED 
WINDS ARE 70 KT WITH GUSTS TO 85 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 983 MB. MODERATE CONVECTION NEAR THE CENTER OF 
HERNAN IS LIMITED TO WITHIN 60 NM. THE EYE NOTED EARLIER ON 
SATELLITE IMAGERY HAS FILLED AND HERNAN IS FORECAST TO GRADUALLY 
WEAKEN AS IT MOVES SW OVER THE NEXT 48 HOURS. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMEP4/WTPZ24 KNHC 
FOR MORE DETAILS.

.LOW PRES IS ANALYZED NEAR 15N114W WITH CENTRAL PRESSURE 
ESTIMATED AT 1008 MB. SCATTERED MODERATE TO STRONG CONVECTION IS 
OBSERVED WITHIN 210 NM OVER ITS N SEMICIRCLE. THE LOW IS 
FORECAST TO MOVE W OVER THE NEXT 48 HOURS WITH THE POSSIBILITY 
OF TROPICAL CYCLONE DEVELOPMENT.

...TROPICAL LOW...

.LOW PRES IS ANALYZED NEAR 15N98W WITH CENTRAL PRESSURE 
ESTIMATED AT 1008 MB. NUMEROUS MODERATE TO STRONG CONVECTION IS 
OBSERVED WITHIN 60 NM EITHER SIDE OF 104W BETWEEN 16N AND 19N. 
SCATTERED CONVECTION CAN BE FOUND ELSEWHERE WITHIN 120 NM OF 103 
AS WELL AS WITHIN 180 NM S SEMICIRCLE OF THE LOW PRES CENTER.  
THIS LOW PRES SYSTEM IS EXPECTED TO MOVE W OVER THE NEXT 48 
HOURS.

...TROPICAL WAVES... 

A TROPICAL WAVE IS ALONG 80W AT THE MOMENT AND HAS BEEN MOVING W 
AT ABOUT 15 KT. CONVECTION ASSOCIATED WITH THIS TROPICAL WAVE 
CAN BE FOUND IN THE PACIFIC BASIN WITHIN 60 NM OF THE COAST OF 
PANAMA.  

...ITCZ...

THE ITCZ AXIS IS ALONG 09N84W TO 10N96W TO 08N105W TO 14N115W TO 
13N122W TO 11N130W TO 15N140W. SCATTERED MODERATE CONVECTION CAN 
BE FOUND S OF THE ITCZ AXIS FROM 05N TO 08N BETWEEN 93W AND 98W. 
SCATTERED MODERATE CONVECTION CAN BE FOUND WITHIN 120 NM S OF 
AXIS BETWEEN 108W AND 112W.

...DISCUSSION...

A SURFACE HIGH PRESSURE CENTER WILL REMAIN NW OF THE FORECAST 
AREA THROUGH THE NEXT TWO DAYS. CURRENTLY...A RIDGE AXIS EXTENDS 
FROM THE HIGH THROUGH A LINE FROM 30N130W TO NEAR 20N120W.  LOOK 
FOR THE RIDGE AXIS TO SHIFT W IN THE WAKE OF HURRICANE HERNAN.  
HERNAN IS FORECAST TO TAKE A MORE S OF W TURN OVER THE NEXT TWO 
DAYS AS IT PASSES S OF THE HIGH PRESSURE CENTER.  THIS TURN WILL 
CARRY THE SYSTEM OVER SLIGHTLY WARMER WATER WHICH MAY HELP 
ENHANCE CONVECTION BRIEFLY BEFORE THE SYSTEM ULTIMATELY 
WEAKENS.

TO THE E...UPPER LEVEL DIFFLUENCE BETWEEN THE SW EDGES OF 
THE ANTICYCLONES CURRENTLY NEAR 20N115W AND 20N104W AND E FLOW S 
OF 15N SHOULD CONTINUE TO SUPPORT AREAS OF CONVECTION AS THEY 
PUSH W OVER THE NEXT TWO DAYS.  EXPECT THE CONVECTION TO MOVE W 
IN TANDEM WITH THE SFC LOW PRESSURE SYSTEMS CURRENTLY FOUND AT 
15N114W AND 15N98W...RESPECTIVELY.

THE TROPICAL WAVE CURRENTLY MOVING THROUGH PANAMA WILL FEED INTO 
DEEP MOISTURE FROM THE ITCZ IN THE EASTERN PACIFIC OVER THE NEXT 
TWO DAYS. A REGION OF UPPER LEVEL DIFFLUENCE ON THE LEADING EDGE 
OF THE WAVE IS EXPECTED TO SHIFT N INTO CENTRAL AMERICA AS THE 
TROPICAL WAVE PROGRESSES W...ENHANCING THE CHANCE OF CONVECTION 
N THROUGH CENTRAL AMERICA AND THE IMMEDIATE COAST OVER THE NEXT 
FEW DAYS.

$$
SCHAUER CLARK