marine weather discussion

NWS ocean prediction center Washington DC

800 PM EST Fri 20 Nov 2009

.Forecast discussion: major features/winds/seas/significant

.Weather for North Atlantic ocean W of 50w from 30n to 50n.

Cold front has pressed E over Georges Bank and appears as pre

frontal winds likely maxed out at 25 kt over ern nt1 waters this

afternoon. Will continue with W winds up to 25 kt glf of ME

overngt into Sat per guidance/latest obs. At 23z 20 kt buoy obs

were relegated to coastal ME/MA. Obs off Cape Hatteras

indicating that getting the N 25 kt surge behind front. Models

continued in decent agreement thru the weekend...but large

differences still exist with any mid Atlc cstl

dvlpmnt/track/winds sun ngt into next week. 18z GFS was further

offshore and slower with sfc low than its previous run...but

remained faster than 12z Canadian. Forecast remains one of low

confidence early next week... especially with 12z ECMWF/UKMET

now both shearing out upper support offering little sfc reflctn.

Will maintain forecast continuity with this evenings

updates...but if any weaker trend in 00z GFS/Canadian appear may

have to make some adjustments to forecast with early morning

issuances.

Wavewatch iii appears reasonable when compared to 00z ship/buoy

obs over cstl/offshore areas.

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...Previous discussion...

A cold fnt will move E across the ofshr wtrs this aftn...then

pass E of the nt1 and nrn nt2 tonite into Sat mrng while

stalling across the srn and cntrl nt2 areas. The stnry fnt will

persist over the srn and cntrl nt2 areas later Sat into sun. Rdg

will move E over the wtrs N of Cape Hatteras late Sat into

sun...then move NE of the nt1 wtrs Mon into Tue. A Gulf CST low

will move E NE to the GA/SC CST late sun...turn N NE and track

across the nt2 wtrs Mon...drift NE over the nt1 wtrs Tue into

early Wed...then move NE across Nova Scotia later Wed. Another

rdg will move E into the ofshr wtrs Wed.

The Med rng mdls are in gud agreement thru sun...but diffs

emerge during the Mon and Tue timeframe. The 12z GFS is faster

with the low...and keeps its trajectory closer to the

CST...while the 12z ECMWF/Gem are slower and go with a more

ofshr trajectory. The 12z GFS and 12z Gem are stgr...suggesting

gale to near gale conds on Mon and Tue over the nrn nt2 and nt1

wtrs...while the 12z ECMWF is still signif wkr with the winds.

The UKMET has been inconsistent over the past three runs...and

is not preferred attm. Since the 12z GFS looks too slow and W

with the track...and the 12z ECMWF looks too weak with the winds

ascd with low...am planning to favor the 12z Gem for Mon and Tue

but tone down its intensity a bit over the nt1 wtrs on Tue...in

deference to the weaker GFS/ecwmf solns.

Seas...12z wavewatch iii mdl sea hts look reasonable over the

cstl and ofshr wtrs thru the fcst prd...except the mdl guidance

aprs to be a bit underdone over the glf of Maine and Georges

Bank wtrs during the Mon and Tue timeframe.

.Warnings/forecast confidence...Warnings are preliminary and are

subject to change. Any changes will be coordinated through AWIPS

12 planet chat or by telephone.

.Nt1 New England waters...

.Gulf of Maine...gale Mon and Tue...low confdc.

.Georges Bank...Gale Mon into Tue...low confdc.

.S of New England...Gale Mon...low confdc.

.Nt2 mid Atlc waters...

.Hudson to balt cnyn...none.

.Balt cnyn to Hague line...Gale Mon into Tue...low confdc.

.Balt cnyn to Hatteras cnyn...None.

.Hatteras cnyn to Cape Fear...None.

.Cape Fear to 31n...None.

.Forecaster Clark/Scovil. Ocean forecast branch.