000
AXPZ20 KNHC 251605
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI SEP 25 2009

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 
1500 UTC.

...SPECIAL FEATURE...
TROPICAL DEPRESSION NORA HAS BECOME DEVOID OF ANY SIGNIFICANT 
DEEP CONVECTION OVERNIGHT...WITH THE MID LEVEL CIRCULATION 
SHEARED COMPLETELY AWAY AND OFF TO THE NE OF THE LOW LEVEL 
CENTER...AND HAS BEEN DOWNGRADED FROM A TROPICAL DEPRESSION TO A 
REMNANT LOW. THIS LOW LEVEL CENTER WAS LOCATED NEAR 16.8N 122.8W 
AT 1500 UTC MOVING WSW AT 10 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE WAS 1007 MB. MAXIMUM SUSTAINED WINDS WERE 30 KT WITH 
GUSTS TO 40 KT. SEE THE LAST NHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. THE 
REMNANT LOW OF NORA IS EXPECTED TO CONTINUE TO MOVE IN GENERALLY 
A WESTERLY MOTION OVER THE NEXT FEW DAYS UNDER THE INFLUENCE OF 
HIGH PRESSURE ACROSS THE NE PACIFIC. 

...THE ITCZ...
AXIS WAS ALONG 08N77W TO 11N95W TO 11N110W TO 15N120W TO 
10N140W. SCATTERED MODERATE TO ISOLATED STRONG WITHIN 180 NM 
AXIS FROM 90W TO 104W AND WITHIN 240 NM OF AXIS FROM 113W TO 
118W AND WITHIN 120 NM OF AXIS FROM 132W TO 137W.

...DISCUSSION...
A LARGE UPPER LOW WAS NEARLY STATIONARY OVER THE CENTRAL PLAINS 
OF THE U.S. THIS MORNING WITH A TROUGH EXTENDING FROM THE BASE 
SW ACROSS NRN BAJA CALIFORNIA TO A BROAD MID TO UPPER LEVEL 
CYCLONIC CIRCULATION CENTERED NEAR 25N132W WITH A TROUGH 
CONTINUING W TO A LOW ACROSS THE HAWAIIAN ISLANDS. MODERATE TO 
STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MID TO UPPER LEVELS 
OF THE ATMOSPHERE COVERS THE AREA N OF 20N W OF 120W. AN UPPER 
LEVEL RIDGE IS S OF THIS L/W TROUGH...EXTENDING FROM A HIGH NEAR 
14N132W NE TO ANOTHER UPPER HIGH ACROSS THE FLORIDA PANHANDLE. 
THIS HAS CREATING A LONG JET OF SWLY WINDS FROM NEAR 22N120W 
INTO THE GREAT PLAINS LOW. DIFFLUENT FLOW ALOFT UNDERNEATH THESE 
HIGHS AND ALONG THE S SIDE OF THE RIDGE CONTINUES TO VENTILATE 
AND SUSTAIN CONVECTION ALONG THE ITCZ. 

A DEEP LAYERED TROUGH ALONG 95/96W EXTENDED FROM THE EPAC ITCZ N 
ACROSS CENTRAL AMERICA AND HAD ENTRAINED A LARGE AREA OF 
TROPICAL MOISTURE BETWEEN 80W AND 015W...AND WAS ENHANCING LOW 
TO MID LEVEL CONVERGENCE WITHIN THE EPAC MONSOON 
CIRCULATION...WHERE SCATTERED TO NUMEROUS CONVECTION WAS SPREAD 
OUT ACROSS AN AREA FROM 07N TO THE PACIFIC COASTLINES BETWEEN 
90W AND 104W. 

SURFACE HIGH PRES RIDGE IS N OF 20N W OF 115W. BROKEN TO OVERCAST
STRATOCUMULUS CLOUDS WITHIN THE RIDGE N OF 15N W OF 120W...WITH 
MODERATE TO FRESH NELY WINDS ACROSS THE REGION. 

$$
STRIPLING