On Sep 30, 3:24*pm, "Martin Rowley"
wrote:
... not labelled as such, but the Low on the bottom/left of the ASXX
12Z he-
http://www.weather.org.uk/charts/UKCpf000.gif
is Tropical Storm 'Laura' see various guidance below ex-NHC
http://www.nhc.noaa.gov/refresh/grap...46.shtml?tswin...
000
WTNT42 KNHC 301433
TCDAT2
TROPICAL STORM LAURA DISCUSSION NUMBER * 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL * AL122008
1100 AM EDT TUE SEP 30 2008
WHILE SOMEWHAT OF A PARADOX...LAURA CAN NOW BE DESIGNATED AS A
TROPICAL CYCLONE DESPITE THE FACT THAT IT CONTINUES TO MOVE
NORTHWARD OVER PROGRESSIVELY COLDER WATERS. *THE ONE ASPECT WHICH
WAS HOLDING US BACK FROM DECLARING IT TROPICAL WAS THE UPPER LOW
COLLOCATED WITH THE SYSTEM. *WATER VAPOR IMAGERY INDICATES THAT
THIS FEATURE HAS BECOME OFFSET AND STRETCHED TO THE SOUTHWEST OF
LAURA...AND UPPER LEVEL OUTFLOW IS NOW EXPANDING TO THE NORTH OF
THE CYCLONE. *IN ADDITION...SCATTEROMETER DATA INDICATE THAT THE
RADIUS OF MAXIMUM WINDS HAS CONTINUED TO CONTRACT TO ABOUT 60 NM.
CLOUD TOP TEMPERATURES ARE NOT ALL THAT COLD...BUT THAT IS QUITE
NORMAL FOR HIGH-LATITUDE TROPICAL CYCLONES DUE TO THE LOWER
TROPOPAUSE. *FRANKLY...LAURA NOW LOOKS LIKE A TROPICAL STORM.
THEREAFTER...SOME RE-STRENGTHENING AND AN EXPANSION OF
THE WIND FIELD COULD OCCUR AS THE EXTRATROPICAL LOW RACES EAST
WITHIN THE MID-LATITUDE WESTERLIES TOWARDS THE NORTHERN BRITISH
ISLES. *EXCEPT FOR A SLIGHT WESTWARD SHIFT IN THE TRACK GUIDANCE AT
36-48 HOURS...THERE HAS BEEN NO SIGNIFICANT CHANGE IN THE GLOBAL
MODELS FOR THIS CYCLE AND THE OFFICIAL FORECAST LIES VERY CLOSE TO
THE MODEL CONSENSUS.
FORECAST POSITIONS AND MAX WINDS
INITIAL * * *30/1500Z 41.2N *48.8W * *50 KT
*12HR VT * * 01/0000Z 42.8N *48.4W * *50 KT
*24HR VT * * 01/1200Z 45.5N *47.4W * *45 KT...EXTRATROPICAL
*36HR VT * * 02/0000Z 48.7N *45.6W * *40 KT...EXTRATROPICAL
*48HR VT * * 02/1200Z 51.7N *43.6W * *40 KT...EXTRATROPICAL
*72HR VT * * 03/1200Z 56.0N *35.0W * *45 KT...EXTRATROPICAL
*96HR VT * * 04/1200Z 57.0N *19.0W * *50 KT...EXTRATROPICAL
120HR VT * * 05/1200Z 58.0N * 3.5W * *50 KT...EXTRATROPICAL
--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N * Long: 01.88W
NGR: SU 082 023
Here's the end of the five day cone!
http://www.nhc.noaa.gov/graphics_at2...?5day#contents
Cheers, Alastair.