000
AXPZ20 KNHC 250325
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI AUG 25 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 
0300 UTC.

...SPECIAL FEATURE...

HURRICANE ILEANA IS CENTERED NEAR 21.2N 116.0W...OR 350 NM WSW 
OF THE SOUTHERN TIP OF BAJA CALIFORNIA...AT 25/0300 UTC MOVING 
NW 7 KT. MAXIMUM SUSTAINED WIND SPEED IS 80 KT WITH GUSTS TO 100 
KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 975 MB. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC 
FOR MORE DETAILS. ILEANA HAS MAINTAINED A WELL-DEFINED EYE EVEN 
AS THE SURROUNDING CONVECTION BEGINS TO WEAKEN. THE COLDEST 
CLOUD TOPS ARE NOW LOCATED WITH A SPIRAL BAND EXTENDING 80 NM S 
OF THE CENTER AND NOT IN THE ACTUAL EYEWALL. THE STRONGEST 
OUTFLOW IS STILL NOTED OVER THE SRN SEMICIRCLE AND IS ENTIRELY 
RESTRICTED TO THE N AND W OF THE SYSTEM. ILEANA IS EXPECTED TO 
GRADUALLY DECREASE IN INTENSITY AS IT MOVES OVER COOLER WATERS 
AND INTO A MORE STABLE ENVIRONMENT. SCATTERED MODERATE/STRONG 
CONVECTION IS IN SPIRAL BANDS WITHIN 90 NM N AND 120 NM S 
SEMICIRCLES.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 88W N OF 3N MOVING W 10-15 KT. A WELL- 
DEFINED MID-LEVEL CIRCULATION IS STILL APPARENT IN SATELLITE 
IMAGERY JUST SW OF GUANACASTE COSTA RICA NEAR 9N...WITH A BAND 
OF CONVECTION CURLING AROUND THE S SIDE. A 0005Z SSMI MICROWAVE 
PASS PARTIALLY SUGGESTED THAT A LOW-LEVEL CENTER COULD BE 
LOCATED A BIT FARTHER N NEAR 10N...PROBABLY ALONG THE ITCZ AXIS. 
SCATTERED MODERATE/STRONG CONVECTION FROM 5N-10N BETWEEN 
84W-93W. SCATTERED MODERATE/STRONG N OF 12N BETWEEN 87W-91W NEAR 
THE COAST FROM NW NICARAGUA TO GUATEMALA.

TROPICAL WAVE ALONG 102W S OF 15N MOVING W 10-15 KT. A 1007 MB 
LOW HAS BEEN ANALYZED ALONG THE WAVE AXIS NEAR 10N BASED ON A 
CIRCULATION NOTED IN THE LAST FEW VISIBLE IMAGES AND EARLIER 
QUIKSCAT DATA. STRONG NE/ELY SHEAR HAS PUSHED MUCH OF THE 
CONVECTION W OF THIS LOW...WITH A BAND OF SCATTERED MODERATE 
CONVECTION NOTED ALONG AND S OF THE ITCZ AXIS FROM 8N-11N 
BETWEEN 103W-110W. ISOLATED SHOWERS/TSTMS ARE ALSO N/NE OF THE 
LOW FROM 10N-13N BETWEEN 96W-104W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 11N84W 10N88W 11N102W 15N111W 
8N140W. SCATTERED MODERATE CONVECTION WITHIN 60 NM OF THE AXIS 
BETWEEN 112W-120W. OTHER CONVECTION ASSOCIATED WITH TROPICAL 
WAVES.

...DISCUSSION...

LARGE AREA OF DRY MID/UPPER LEVEL AIR COVERS THE NW AND FAR W 
PACIFIC AREA...WITH A STABLE LAYER PRODUCING WIDESPREAD 
STRATOCUMULUS N OF 14N W OF 120W. A MID/UPPER LOW IS CENTERED 
NEAR 20N130W WITH A TROUGH EXTENDING THROUGH IT FROM 24N130W TO 
7N135W. UPPER LEVEL MOISTURE IS LIMITED TO E OF 125W S OF 
20N...AND E OF HURRICANE ILEANA N OF 20N. THIS MOISTURE IS BEING 
ADVECTED WWD BY A LARGE AREA OF UPPER LEVEL EASTERLIES 
ORIGINATING FROM CENTRAL AMERICA AND CIRCULATING AROUND AN UPPER 
HIGH CENTERED NEAR GUADALAJARA MEXICO. VERTICAL SHEAR OVER THE 
PACIFIC E OF 110W IS CURRENTLY IN THE 20-30 KT RANGE AND WOULD 
SEEM TO INHIBIT DEVELOP OF THE TROPICAL WAVES IN THE REGION. 
HOWEVER...THE CONVECTIVE SIGNATURES OF EACH WAVE ARE NOT TOO 
SHABBY SO THEY WILL HAVE TO BE MONITORED IN THE COMING DAYS.

$$
BERG