000
WTNT41 KNHC 200254
TCDAT1
 
TROPICAL STORM ALBERTO DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL012012
1100 PM EDT SAT MAY 19 2012
 
THE INTENSITY OF ALBERTO HAS BEEN DIFFICULT TO DECIPHER THIS
EVENING. WHILE AN EARLIER SHIP REPORT SUGGESTED THE STORM WAS
STRONGER...THE SATELLITE AND RADAR PRESENTATION HAS BEEN ON THE
DECLINE SINCE THEN...WITH A NOTABLE DECREASE IN WINDS FROM THE
COASTAL DOPPLER RADARS. THE INITIAL INTENSITY OF 45 KT IS A
COMPROMISE BETWEEN THE SHIP REPORT AND THE LOWER SATELLITE/RADAR
ESTIMATES. ALTHOUGH THE CYCLONE IS EXPECTED TO MOVE NEAR THE WARM
GULF STREAM WATERS FOR THE NEXT DAY OR TWO...MODERATE SHEAR ALONG
WITH PROBABLE ENTRAINMENT OF A DRY AIRMASS TO THE NORTH OF THE
SYSTEM COULD PREVENT SIGNIFICANT STRENGTHENING. THE INTENSITY
GUIDANCE REMAINS SPLIT WITH THE DYNAMICAL GUIDANCE SUGGESTING SOME
WEAKENING...AND THE STATISTICAL TOOLS SHOWING STRENGTHENING. THE
OFFICIAL FORECAST IS UNCHANGED FROM THE PREVIOUS ONE AND LIES NEAR
THE CONSENSUS.
 
ALBERTO APPEARS TO BE MOVING SOUTHWESTWARD AT ABOUT 5 KT...AS IT IS
BEING STEERED PRIMARILY BY A LOW- TO MID-LEVEL RIDGE OVER THE
EASTERN UNITED STATES.  THIS RIDGE IS EXPECTED TO BREAK DOWN IN A
DAY OR SO...WITH A COMPLEX STEERING FLOW PROBABLY CAUSING THE
CYCLONE TO TURN TOWARD THE NORTHEAST IN A COUPLE OF DAYS.  THE
GUIDANCE ENVELOPE HAS SHIFTED SOMEWHAT TO THE SOUTHWEST IN THIS
MODEL CYCLE...THOUGH MOST OF THE RELIABLE MODELS STILL KEEP THE
STORM OFFSHORE.  THE NHC FORECAST IS SHIFTED SOUTHWEST OF THE
PREVIOUS ONE THROUGH THE FIRST 36 HOURS...AND IS NEAR THE TVCA
MULTI-MODEL CONSENSUS.
 
ALTHOUGH THE OFFICIAL FORECAST CALLS FOR THE TROPICAL-STORM-FORCE
WINDS TO REMAIN JUST OFFSHORE...THERE IS TOO LITTLE MARGIN FOR
ERROR TO NOT ISSUE A TROPICAL STORM WATCH AT THIS TIME.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/0300Z 31.8N  78.5W   45 KT  50 MPH
 12H  20/1200Z 31.6N  79.0W   45 KT  50 MPH
 24H  21/0000Z 31.4N  79.5W   45 KT  50 MPH
 36H  21/1200Z 31.8N  79.4W   45 KT  50 MPH
 48H  22/0000Z 32.7N  78.2W   45 KT  50 MPH
 72H  23/0000Z 35.0N  75.0W   45 KT  50 MPH
 96H  24/0000Z 38.0N  70.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
120H  25/0000Z...DISSIPATED
 
$$
FORECASTER BLAKE/FRANKLIN