000
AXPZ20 KNHC 102117
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN AUG 10 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 
2100 UTC.

...SPECIAL FEATURE...

HURRICANE HERNAN IS CENTERED NEAR 18.2N 127.5W AT 2100 UTC 
MOVING W-NW OR 295 DEG AT 9 KT. MAXIMUM SUSTAINED WINDS ARE 75 
KT WITH GUSTS TO 90 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 
980 MB.  HERNAN HAS AN 20 NM WIDE EYE WITH NUMEROUS STRONG 
CONVECTION WITHIN 120 NM OF THE CENTER OVER THE EAST SEMICIRCLE 
AND 75 NM OVER THE WEST SEMICIRCLE. SCATTERED MODERATE WITH 
ISOLATED STRONG CONVECTION IS OBSERVED ELSEWHERE WITHIN 150 NM 
OF THE CENTER. OUTFLOW IS SOMEWHAT RESTRICTED IN THE NORTHWEST 
QUADRANT BUT IS GOOD ELSEWHERE. HERNAN IS CONTINUING TO SLOWLY 
WEAKEN AND IS FORECAST TO WEAKEN TO A TROPICAL STORM BY 18 
HOURS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADER 
MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS.

...TROPICAL LOWS...

.LOW NEAR 13N112W 1008 MB DRIFT WEST. CONVECTION HAS DIMINISHED. 
SCATTERED MODERATE TO STRONG CONVECTION IS NOTED WELL NORTHEAST 
OF THE CENTER WITHIN 60 NM OF THE POINT 16N111.5W. THE LOW IS 
FORECAST TO CONTINUE TO MOVE SLOWLY WEST AND MAY DEVELOP INTO A 
TROPICAL CYCLONE.

.LOW NEAR 13N96.5W 1010 MB SLOW NORTHWEST MOVEMENT. SCATTERED 
MODERATE CONVECTION IS NORTHEAST OF THE CENTER WITHIN 90 NM OF 
THE POINT 14N96W. THE LOW IS NOT EXPECTED TO DEVELOP INTO A 
TROPICAL CYCLONE.

...TROPICAL WAVES... 

TROPICAL WAVES NEAR THE ABOVE TWO LOWS HAVE BECOME VERY 
DIFFICULT TO LOCATE ESPECIALLY WITH THE DEVELOPMENT OF THE 
TROPICAL LOW PRESSURES. THE WAVES HAVE BEEN DROPPED FROM THE 
SURFACE ANALYSIS.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS LOCATED ALONG THE LINE... 
07N77W TO 09N100W TO 13N115W TO 12N140W. SCATTERED MODERATE TO 
STRONG CONVECTION IS WITHIN 60 NM OF THE POINT 08N80W. SCATTERED 
MODERATE WITH ISOLATED STRONG CONVECTION IS WITHIN 75 NM OF 
06N82W.  

OTHER CONVECTION...SCATTERED MODERATE WITHIN 90 NM OF THE POINT 
15N102W.

...DISCUSSION...

A MIDDLE AND UPPER LEVEL TROUGH IS OVER THE NORTHWEST PART OF 
THE AREA...NORTHWEST OF A LINE FROM SOUTHEASTERN ARIZONA TO 
22N125W TO 20N140W. THE AREA IS DRY AND CLOUD FREE IN THE MIDDLE 
AND UPPER LEVELS WITH OVERCAST STRATOCUMULUS IN THE LOWER LEVELS 
FROM 24N TO 28N FROM 115W TO 135W. ELSEWHERE IN THIS AREA IN 
THE LOWER LEVELS BROKEN STRATOCUMULUS IS OBSERVED. THE TROUGH IS 
FORECAST TO REMAIN IN PLACE WITH REINFORCING TROUGHS COMING FROM 
THE WESTERLY MIDDLE LATITUDE FLOW NORTH OF THE AREA.

OTHERWISE AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER NORTHERN 
MEXICO WITH A BROAD RIDGE OVER THE REMAINDER OF THE AREA.
NORTH OF THE ITCZ AND SOUTH AND EAST OF THE ABOVE MENTIONED 
TROUGH THE AREA IS MOIST IN THE MIDDLE AND UPPER LEVELS WITH 
AREAS OF MULTI LEVEL CLOUDS WITH EMBEDDED CONVECTION. THESE AREA 
ARE NEAR THE TWO LOWS MENTIONED ABOVE AND ALSO A LARGE AREA OF 
CONVECTION NEAR THE COAST OF COLOMBIA.

AT THE SURFACE MODERATE RIDGE IS NORTH OF 20N WEST OF 110W. 
ELSEWHERE OTHER THAN THE TWO LOWS AND HURRICANE HERNAN A BROAD 
TROUGH IS ANALYZED.

$$
LL