258 
 WTNT43 KNHC 070232
 TCDAT3
 TROPICAL STORM MARCO DISCUSSION NUMBER   3
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL132008
 1100 PM EDT MON OCT 06 2008
  
 MINIATURE MARCO HAS MAINTAINED ONE SMALL COLD-TOPPED THUNDERSTORM
 CLUSTER...ABOUT THE SIZE OF THE STATE OF DELAWARE...OVER THE
 LOW-LEVEL CENTER. THEREFORE...THE INITIAL INTENSITY IS BEING KEPT
 AT 55 KT IN LINE WITH THE LAST AIR FORCE RECON DATA...EVEN THOUGH
 DVORAK SATELLITE CLASSIFICATIONS ARE T2.0/30 KT FROM BOTH TAFB AND
 SAB. I HAVE WORKED SOME TINY TYPHOONS IN THE WESTERN PACIFIC
 BEFORE...BUT HORIZONTALLY-CHALLENGED MARCO COULD BE THE SMALLEST
 TROPICAL CYCLONE ON RECORD.
  
 INITIAL MOTION ESTIMATE 295/06. MARCO HAS REMAINED ON THE PREVIOUS
 FORECAST TRACK...SO THERE IS NO CHANGE SIGNIFICANT CHANGE TO THE
 PREVIOUS FORECAST TRACK OR REASONING. MARCO IS EXPECTED TO MAINTAIN
 A GENERAL WEST-NORTHWESTWARD MOTION TO THE SOUTH OF A STRONG
 MID-LEVEL RIDGE PARKED OVER MOST OF THE GULF OF MEXICO...AND MAKE
 LANDFALL IN 18 HOURS OR SO. THE OFFICIAL FORECAST TRACK IS ROUGHLY
 IN THE MIDDLE OF THE NHC MODEL GUIDANCE SUITE.
  
 ALTHOUGH MARCO MAY BE SMALL IN STATURE...IT HAS BEEN ABLE TO
 MAINTAIN DEEP CONVECTION NEAR THE SMALL CIRCULATION CENTER THAT
 ONLY HAS A RADIUS OF MAXIMUM WINDS OF ABOUT 4 NMI. SMALL SYSTEMS
 LIKE MARCO CAN SPIN UP QUICKLY...BUT THEY CAN ALSO SPIN DOWN JUST
 AS FAST. VERTICAL SHEAR IS FORECAST TO REMAIN RELATIVELY LOW AND
 SSTS ARE EXPECTED TO BE ABOVE 28C UNTIL LANDFALL IN ABOUT 18 HOURS.
 THEREFORE...SOME SLIGHT STRENGTHENING IS POSSIBLE. THE SHIPS MODEL
 BRINGS MARCO UP TO HURRICANE INTENSITY IN 12 HOURS...AND UP TO 71
 KT IN 18 HOURS...WHICH SEEMS A LITTLE TO AGGRESSIVE AT THIS STAGE.
 THE OFFICIAL INTENSITY FORECAST IS A BLEND OF THE STRONGER HWRF AND
 THE WEAKER GFDL...WHICH KEEPS MARCO JUST BELOW HURRICANE STRENGTH.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      07/0300Z 19.8N  95.4W    55 KT
  12HR VT     07/1200Z 20.2N  96.4W    60 KT
  24HR VT     08/0000Z 20.7N  97.8W    25 KT...DISSIPATING INLAND
  36HR VT     08/1200Z...DISSIPATED INLAND OVER EASTERN MEXICO
  
 $$
 FORECASTER STEWART