Tropical Depression NORMAN
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TROPICAL DEPRESSION NORMAN DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142012
800 PM PDT FRI SEP 28 2012
IT HAS BEEN DIFFICULT TO LOCATE THE CENTER OF NORMAN IN SATELLITE
IMAGERY...BUT MEXICAN RADAR FROM GUASAVE SUGGEST THAT THE
CENTER OF ROTATION IS ABOUT 20 N MI OFF THE COAST OF SINALOA. THE
CLOUD PATTERN HAS CONTINUED TO BECOME MORE DISORGANIZED...WITH ALL
OF THE DEEP CONVECTION NOW TO THE SOUTH AND EAST OF THE CENTER DUE
TO STRONG WESTERLY SHEAR. BASED ON THIS...IT IS ASSUMED THAT
NORMAN IS NO LONGER PRODUCING SUSTAINED TROPICAL-STORM-FORCE WINDS
AND HAS BECOME A TROPICAL DEPRESSION. A CONTINUED INCREASE IN
VERTICAL SHEAR AND INTERACTION WITH LAND SHOULD CAUSE NORMAN TO
DEGENERATE INTO A REMNANT LOW BY SATURDAY MORNING AND DISSIPATE BY
SUNDAY MORNING...IF NOT SOONER.
NORMAN IS SLOWING DOWN AND HAS TURNED NORTH-NORTHWEST WITH AN
ESTIMATED MOTION OF 345/9 KT. LOW-LEVEL RIDGING WILL BE BUILDING
ACROSS NORTHWESTERN MEXICO DURING THE NEXT 24 HOURS AND SHOULD
CAUSE NORMAN TO SLOW DOWN FURTHER AND TURN NORTHWESTWARD BEFORE IT
DISSIPATES. THE NEW NHC FORECAST HAS BEEN NUDGED A LITTLE WEST OF
THE PREVIOUS ONE SINCE SEVERAL OF THE MODELS...PARTICULARLY THE
GFS...UKMET...AND GFDL...SHOW NORMAN SKIRTING THE COAST AND TURNING
WESTWARD BACK OVER THE GULF OF CALIFORNIA. IF THAT HAPPENS...THE
CHANCES FOR REGENERATION INTO A TROPICAL CYCLONE ARE EXTREMELY LOW.
EVEN IF NORMAN DOES NOT ACTUALLY MAKE LANDFALL...MOST OF THE
INCLEMENT WEATHER IS LOCATED EAST OF THE CENTER AND WILL STILL
LIKELY PRODUCE HEAVY RAINS AND POSSIBLE FLOODING ACROSS SINALOA AND
WESTERN DURANGO THROUGH SATURDAY.
FORECAST POSITIONS AND MAX WINDS
INIT 29/0300Z 25.2N 109.0W 30 KT 35 MPH
12H 29/1200Z 26.0N 109.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 30/0000Z 26.3N 109.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
36H 30/1200Z...DISSIPATED
$$
FORECASTER BERG/AVILA
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