000
AXPZ20 KNHC 112205
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON AUG 11 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2130 UTC.

...SPECIAL FEATURE...

TROPICAL STORM HERNAN IS CENTERED NEAR 19.0N 131.2W AT 2100 UTC 
MOVING W OR 270 DEG AT 08 KT. MAXIMUM SUSTAINED WINDS ARE 60 KT 
WITH GUSTS TO 70 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 988 
MB. MODERATE CONVECTION NEAR THE CENTER OF HERNAN IS LIMITED TO 
WITHIN 60 NM AND CONTINUES TO WEAKEN THIS AFTERNOON. SEE LATEST 
NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADER MIATCMEP4/WTPZ24 
KNHC FOR MORE DETAILS.

...TROPICAL LOWS...

.LOW PRES IS ANALYZED NEAR 14N113W WITH CENTRAL PRESSURE 
ESTIMATED AT 1011 MB. SCATTERED MODERATE TO STRONG CONVECTION IS 
OBSERVED WITHIN 300 NM NW SEMICIRCLE. THE LOW IS FORECAST TO 
MOVE W OVER THE NEXT 48 HOURS.

.LOW PRES IS ANALYZED NEAR 15N100W WITH CENTRAL PRESSURE 
ESTIMATED AT 1010 MB. SCATTERED MODERATE TO STRONG CONVECTION 
CAN BE FOUND WITHIN 180 NM SE SEMICIRLCE.  THERE IS ALSO 
NUMEROUS MODERATE TO STRONG CONVECTION DISPLACED FROM THE 
SURFACE LOW OBSERVED WITHIN 60 NM EITHER SIDE OF 104W BETWEEN 
17N AND 20N. THIS LOW PRES SYSTEM IS EXPECTED TO MOVE W OVER THE 
NEXT 48 HOURS.

...TROPICAL WAVES... 

A TROPICAL WAVE IS ALONG 81W AT THE MOMENT AND HAS BEEN MOVING W 
AT ABOUT 15 KT. CONVECTION ASSOCIATED WITH THIS TROPICAL WAVE 
CAN BE FOUND WITHIN 270 NM E OF THE WAVE FROM OFF THE COAST OF 
PANAMA NORTHWARD INTO NICARAGUA AND HONDURAS.  

...ITCZ...

ITCZ AXIS IS ALONG 10N83W TO 11N100W TO 07N115W TO 10N130W TO 
12N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION WITHIN 
90 NM OF 07N86W...WITHIN 120 NM EITHER SIDE OF A LINE FROM 
03N95W TO 08N98W...AND WITHIN 60 NM EITHER SIDE OF A LINE FROM 
08N109W TO 10N113W.

...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 EDGE OF THE 
ANTICYCLONE CURRENTLY NEAR 19N102W AND E FLOW S OF 15N SHOULD 
CONTINUE TO SUPPORT THE AREA OF CONVECTION AS IT PUSHES W OVER 
THE NEXT TWO DAYS.  EXPECT THE CONVECTION TO MOVE W IN TANDEM 
WITH THE SFC LOW PRESSURE SYSTEM CURRENTLY FOUND AT 15N100W

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