000
WTNT45 KNHC 102042
TCDAT5
 
TROPICAL STORM NATE DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL152011
400 PM CDT SAT SEP 10 2011
 
THE STRUCTURE OF NATE HAS IMPROVED THIS AFTERNOON...WITH AN INCREASE
IN DEEP CONVECTION...PARTICULARLY IN A LARGE CURVED BAND TO THE
EAST OF THE CENTER. THE HURRICANE HUNTER AIRCRAFT MEASURED A PEAK
850-MB FLIGHT LEVEL WIND OF 68 KT IN THE NORTHEAST QUADRANT AND AN
SFMR WIND OF 52 KT AS THE PLANE EXITED THE CENTER TO THE NORTHEAST.
BASED ON THESE DATA THE INITIAL INTENSITY IS INCREASED TO 55 KT.
STEADY INTENSIFICATION SEEMS LIKELY THROUGH LANDFALL AS NATE MOVES
OVER VERY WARM WATERS IN A LOW SHEAR ENVIRONMENT. THE OFFICIAL
FORECAST REFLECTS THIS THINKING AND SHOWS THE SYSTEM REACHING
HURRICANE STRENGTH BEFORE LANDFALL...IN GOOD AGREEMENT WITH THE
SHIPS MODEL.
 
AFTER PAUSING EARLIER THIS AFTERNOON...NATE AGAIN APPEARS TO BE
MOVING TOWARD THE WEST OR 270 DEGREES AT ABOUT 5 KNOTS. THE TRACK
FORECAST REASONING REMAINS UNCHANGED...AS THE CYCLONE SHOULD
CONTINUE MOVING WESTWARD OR JUST SOUTH OF DUE WEST THROUGH LANDFALL
TO THE SOUTH OF A MID-LEVEL RIDGE. THE NEW NHC FORECAST WAS
ADJUSTED NORTHWARD A LITTLE DUE TO THE INITIAL POSITION BEING A BIT
NORTH OF EARLIER ESTIMATES...BUT WAS OTHERWISE UNCHANGED AND LIES
BETWEEN THE GFS AND ECMWF MODELS.
 
A HURRICANE WARNING IS NOW REQUIRED FOR A PORTION OF THE COAST OF
MEXICO FROM TUXPAN TO VERACRUZ.
 

FORECAST POSITIONS AND MAX WINDS
 
INIT  10/2100Z 20.1N  94.6W   55 KT  65 MPH
 12H  11/0600Z 20.0N  95.3W   60 KT  70 MPH
 24H  11/1800Z 19.9N  96.4W   65 KT  75 MPH
 36H  12/0600Z 19.8N  97.5W   40 KT  45 MPH...INLAND
 48H  12/1800Z 19.7N  98.7W   30 KT  35 MPH...INLAND
 72H  13/1800Z...DISSIPATED
 
$$
FORECASTER BRENNAN