000
AXPZ20 KNHC 210955
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI SEP 21 2007

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURE...
HURRICANE IVO CENTERED NEAR 19.0N 113.5W...OR 300 NM SW OF CABO SAN 
LUCAS MEXICO...AT 21/0900 UTC MOVING NNW AT 7 KT. MAXIMUM SUSTAINED 
WINDS ARE 70 KT GUSTS TO 85 KT. ESTIMATED MINIMUM CENTRAL PRESSURE
IS 980 MB. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. THE CONVECTION ASSOCIATED 
WITH IVO IS SHOWING WIDE SWINGS IN INTENSITY EVERY FEW HOURS. AN EYE 
WAS EVIDENT AT 0600 UTC BUT QUICKLY DISAPPEARED. SCATTERED MODERATE 
TO STRONG CONVECTION FROM 17N TO 21N BETWEEN 112W AND 115W. THERE 
HAVE BEEN NO RECENT MICROWAVE PASSES OVER THE HURRICANE. 
 
...TROPICAL WAVES...
TROPICAL WAVE ALONG 95W N OF 7N MOVING W 10-15 KT. A WEAK 1008 MB 
LOW IS LOCATED ALONG THE WAVE AXIS NEAR 12N. DEEP CONVECTION NEAR 
THE ITCZ HAS INCREASED SIGNIFICANTLY OVER THE PAST 6 HOURS.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N82W 12N93W 10N102W 17N125W 12N140W. 
SCATTERED MODERATE CONVECTION FROM 9N TO 15N BETWEEN 90W AND 98W. 
SCATTERED MODERATE CONVECTION WITHIN 75 NM OF 11N109W. SCATTERED 
MODERATE CONVECTION WITHIN 120 NM OF AXIS BETWEEN 122W AND 134W.

...DISCUSSION...
ITCZ CONVECTION IS INCREASING E OF 105W AS AN UPPER RIDGE BUILDING W 
NEAR 85W INTERACTS WITH THE DEEP UPPER TROUGH OVER THE WESTERN GULF 
PROVIDING AN EFFICIENT OUTFLOW CHANNEL FOR THUNDERSTORM ACTIVITY OVER
CENTRAL AMERICA. FURTHER NORTH ANOTHER DEEP TROUGH W OF S CALIFORNIA
IS FUNNELING TROPICAL MOISTURE ACROSS BAJA CALIFORNIA INTO AZ NM AND
THE SOUTHERN ROCKIES. BETWEEN THE TWO UPPER TROUGHS A HIGH AMPLITUDE 
N-S ORIENTED RIDGE IS PARKED ALONG 105W-108W. THE LARGE CUT-OFF LOW 
OFF THE CALIFORNIA COAST HAS BROAD CYCLONIC FLOW EXTENDING N OF 20N 
BETWEEN BAJA CALIFORNIA AND 140W. A SURFACE LOW IS SW OF LOS ANGELES 
NEAR 32N122W WITH A SFC TROUGH EXTENDING SW TO 30N125W. THE LOW HAS 
DRAGGED A LARGE AREA OF DRY AIR SWD W OF 125W INTO THE REMNANT 
CIRCULATION OF T.D. 13-E. THE REMNANT LOW IS NEARLY STATIONARY NEAR 
18N131W WITH A CENTRAL PRESSURE OF 1008 MB. OCCASIONAL FLAREUPS OF 
MODERATE CONVECTION ARE OCCURRING NEAR THE CIRCULATION CENTER AS THE 
SYSTEM STRUGGLES TO SURVIVE IN AN ENVIRONMENT HOSTILE FOR TROPICAL 
CYCLONES TO REGENERATE.

$$
MUNDELL