000 
TTAA00 KNHC 222048
HURRICANE NORA DISCUSSION NUMBER  25
NATIONAL WEATHER SERVICE MIAMI FL
2 PM PDT MON SEP 22 1997

SATELLITE IMAGERY SHOWS THE DEEP CONVECTION SURROUNDING THE LARGE
EYE OF HURRICANE NORA TO BE WARMING.  THE INITIAL INTENSITY IS
LOWERED TO 105 KNOTS...AND SOME GRADUAL WEAKENING APPEARS TO BE
UNDERWAY.  THE RATE OF WEAKENING SHOULD INCREASE LATER IN THE PERIOD
AS THE CYCLONE BECOMES INVOLVED WITH LAND AND THE SHEAR INCREASES.

INITIAL MOTION IS 310/7...IN RESPONSE TO A CURRENT WEAKNESS IN THE
RIDGE TO THE NORTH OF THE HURRICANE.  THE MODELS HAVE BEEN
FORECASTING A SHORTWAVE TROUGH OFF THE COAST OF CALIFORNIA WHICH IS
NOW BECOMING VISIBLE ON WATER VAPOR IMAGERY AND IS DEPICTED WELL BY
THE SATELLITE WINDS FROM THE UNIVERSITY OF WISCONSIN SPACE SCIENCE
AND ENGINEERING CENTER.  ALL GUIDANCE CONTINUES TO INDICATE A TURN
TOWARD THE NORTH IN RESPONSE TO THIS TROUGH...BUT THERE IS
CONSIDERABLE SCATTER IN THE TRACKS.  OUR CURRENT TRACK IS A
REASONABLE BLEND OF THE GUIDANCE.  THE MID AND DEEP LAYER BAMS ARE
SLOWER AND TO THE LEFT.  THE UKMET AND GFDL ARE FASTER AND TO THE
RIGHT.

THIS CYCLONE HAS THE POTENTIAL FOR PRODUCING LOCALLY HEAVY RAINFALL
OVER PORTIONS OF THE SOUTHWEST UNITED STATES NEAR THE END OF THIS
FORECAST PERIOD.

MAYFIELD
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     22/2100Z 19.0N 112.0W   105 KTS
12HR VT     23/0600Z 19.8N 112.7W   100 KTS
24HR VT     23/1800Z 21.1N 113.1W   100 KTS
36HR VT     24/0600Z 22.8N 113.3W    95 KTS
48HR VT     24/1800Z 25.0N 113.4W    90 KTS
72HR VT     25/1800Z 31.0N 114.0W    75 KTS