10PM Discussion

[dhweather]

000
WTNT41 KNHC 110319
TCDAT1
TROPICAL STORM ARLENE DISCUSSION NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT FRI JUN 10 2005

LAST MINUTE INFORMATION FROM A NOAA HURRICANE HUNTER REQUIRED SOME
ADJUSTMENTS TO THE WORKING FORECAST TRACK. RECON FOUND A PRESSURE
OF 989 MB IN WHAT APPEARS TO BE A NEW BUT STRONGER LOW-LEVEL VORTEX
THAT DEVELOPED BENEATH A DEEP CONVECTIVE BURST THAT HAS BEEN
ROTATING CYCLONICALLY AROUND THE EAST AND NORTH SIDE OF THE LARGER
CYCLONIC GYRE. I AM NOT READY TO KEY IN ON THE WEST-NORTHWESTWARD
MOTION OF THAT CIRCULATION DURING THE PAST 3 HOURS...SO THE INITIAL
POSITION AND MOTION OF 330/14 IS A LONGER TERM BLEND OF RECON AND
SATELLITE POSITIONS AND MOTION. THE INITIAL INTENSITY OF 60 KT IS
BASED ON 850 MB FLIGHT-LEVEL WINDS OF 75 KT IN THE NORTHEAST QUAD.

THE OFFICIAL FORECAST TRACK WAS SHIFTED A LITTLE TO THE LEFT OF THE
PREVIOUS TRACK DUE TO THE MORE WESTWARD INITIAL POSITION... AND
SUBSEQUENT TRACKS MAY HAVE TO BE SHIFTED A LITTLE MORE TO THE WEST
IF THE WEST-NORTHWESTWARD MOTION TREND CONTINUES FOR ANOTHER 6
HOURS. HOWEVER...MY FEELING IS THAT SOME SIGNIFICANT WOBBLING WILL
OCCUR ALONG A GENERAL NORTH-NORTHWEST TO NORTHWESTWARD TRACK UNTIL
LANDFALL OCCURS. THIS IS MAINLY DUE TO VERTICAL SHEAR AND
OCCASIONAL INTRUSIONS OF DRY AIR ERODING THE DEEP CONVECTION AND
CAUSING THE LOW-LEVEL CENTER TO CONSTANTLY REFORM NEAR NEW
CONVECTIVE BURSTS. THIS TRACK IS CONSISTENT WITH THE NHC MODEL
CONSENSUS AND THE LOW- TO MID-LEVEL SOUTHEASTERLY STEERING FLOW.

TIMING THE VARIOUS CONVECTIVE BURSTS IS NEARLY IMPOSSIBLE. HOWEVER
...ARLENE WILL BE GOING INTO THE CONVECTIVE MAXIMUM PERIOD LATER
TONIGHT AND SATURDAY MORNING...SO SOME NEW DEEP CONVECTION SHOULD
REDEVELOP NEAR THE LOW-LEVEL CENTER AND POSSIBLY ALLOW THE CYCLONE
TO BECOME A CATEGORY 1 HURRICANE. HOWEVER...SOUTHWESTERLY VERTICAL
SHEAR IS FORECAST TO GRADUALLY INCREASE AS ARLENE APPROACHES THE
GULF COAST...SO SOME FLUCTUATIONS IN INTENSITY SHOULD BE EXPECTED.

FORECASTER STEWART


FORECAST POSITIONS AND MAX WINDS

INITIAL 11/0300Z 27.1N 86.1W 60 KT
12HR VT 11/1200Z 28.7N 87.0W 65 KT
24HR VT 12/0000Z 31.0N 88.0W 55 KT...INLAND
36HR VT 12/1200Z 33.5N 88.0W 30 KT...DISSIPATING INLAND
48HR VT 13/0000Z 37.0N 87.6W 20 KT...DISSIPATING INLAND
72HR VT 14/0000Z...DISSIPATED INLAND

[HurryKane]

Not to be all fangirl--ok, to be a fangirl--I love it when Stewart writes the discussions.

[dhweather]

Stewart is the bomb.

[cswitwer]

Anybody see Letterman last night?

BOOM GOES THE DYNOMITE (Stewart, that is)