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marine weather discussion
NWS ocean prediction center Washington DC
145 am EST Wed 3 Dec 2008
.Forecast discussion: major features/winds/seas/significant
.Weather for North Atlantic ocean W of 50w from 30n to 50n.
Quikscat pass from 2328z confirmed presence of N to NW gales ovr
outer central and srn nt2 wtrs but with conds shftg NE with
secondary fntl wave wrngs S of Cape Fear have been dropped. The
00z GFS rmns very consistent with prev runs in fcstg this sfc
low to race NE overnight into Wed with gale force ascd bl winds
contg to affect outermost nt2 wtrs...well beyond the adjacent
cstl zones. Hence no sgfnt chngs are planned to the prev ofshr
fcsts rgrdg this system. GFS at 09-12z has the gales with bl
wnds to 35 kt only in far se balt cnyn to Hague line S of 1000
FM so will retain current gale wrng for start of new fcst only
in that zone.
Otrw for the period thru Sat 00z mdls are in good agrmt in rgrds
to timing of a cold front sliding ofshr late Thu/Thu nite. Opnl
NAM still looks a bit weak with this fropa in comparison with
its new parallel run. Hwvr overall mdls are weaker with its ascd
h5 shrtwv which shows less digging versus previous runs and
hence are showing a weaker push of caa bhnd fnt. Will maintain
fcst of 25 or 30 kt SW wnds ahd of fnt but lower wnds slgtly to
25 kt bhnd fnt FM hat cnyn area nwd. 00z ECMWF is simuilar
topping out at 25 kt 10 M wnds ahd of fnt and 20 kt bhnd fnt.
Fnt stalls acrs srn wtrs Fri and by Sat mdls dvlp flat fntl wave
or waves ESE of hat cnyn.
By sun with apch of stg shrtwv dropping se out of Canada 00z GFS
has come more in ln with dvlpg the fntl wave just E of nt2
wtrs...almost on top of 00z ECMWF/UKMET with a gale nr Georges
Bank sun mrng. With less emphasis on frmg low on incoming cdfnt
coming FM W apprs outer wtrs Georges Bank S may see gales first
then sprdg W during sun as caa is ingested. Will go with 00z
gfsfor early sun and blend with 00z ECMWF late sun which gives
soln close to existing HPC Med rng giidance. By late sun with
00z ECMWF showing wdsprd 30 and 35 kt 10m wnd barbs and GFS with
30-35 kt bl wnds mainly N of Cape Fear will cont with previosly
fcstd gales to 40 kt N of hat and 35 kt S to Cape Fear dvlpg
sun. Hence will tweak confdc lvls up to mod espcly in nt2 wtrs.
The 00z wna wavewatch iii fcst seas look representative. Will
lkly follow its guidance rather closely excp will lkly boost
guidance by svrl ft most zones by late sun based on blend with
stronger wnds suggested by ECMWF bl wnds and mdl biases in stg
caa.
.Warnings/forecast confidence...Reliminary. Any changes will be
coordinated through AWIPS 12 planet chat or by telephone:
.Nt1 New England waters...
.Gulf of Maine...gale sun...low to mod confdc.
.Georges Bank...Gale sun...low to mod confdc.
.S of New England...Gale sun...mod confdc.
.Nt2 mid Atlc waters...
.Hudson to balt cnyn...gale sun...mod confdc.
.Balt cnyn to Hague line...Gale overnight E...low to mod confdc.
Gale sun...mod confdc.
.Balt cnyn to Hatteras cnyn...Gale sun...mod confdc.
.Hatteras cnyn to Cape Fear...Gale sun...low to mod confdc.
.Cape Fear to 31n...None.
.Forecaster Bancroft. Ocean forecast branch.
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