Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
111 am EST Friday Nov 27 2015
high pressure east of Nova Scotia slowly gives way to an
approaching cold front over the Midwest this evening. The front
will pass through the area around daybreak Saturday...then stalls
just south of the region through the weekend. High pressure builds
into the area early next week. Another storm system is expected to
impact the region during the middle of the week.
Near term /until 6 am this morning/...
radiation fog is dense in spots...not only at ASOS sites from NE
New Jersey up into SW CT...but also across parts of Long Island where ASOS
observation are showing no visibility restriction yet. S winds and steady or
slowly rising temperatures across eastern Long Island and coastal southeast CT also
argue against likelihood of dense fog there. Elsewhere...01z
narre-tl guidance suggests the dense fog will expand in coverage
into most of the County Warning Area except Orange and western Passaic counties.
Have issued dense fog advisory until 9 am as a result.
Temperatures have dropped into the middle/upper 30s in some
spots...otherwise lows will be mainly in the 40s to around 50.
This is well above normal.
Short term /6 am this morning through 6 PM Saturday/...
another warm day across the region with highs getting into the
low to middle 60s most locations as SW flow develops ahead of the
approaching cold front over the Great Lakes.
Clouds will increase Friday night with the cold frontal passage
prior to daybreak most locations. Limited moisture and weak lift
should keep this a mainly dry frontal passage. There is some weak
overrunning behind the front that could result in widely scattered
Lows Sat night will remain mild in the 40s.
Long term /Saturday night through Thursday/...
much of the forecast based on blended model/MOS data.
A cold front associated with a middle and upper level trough will move
across the region Saturday...and stall just south of the County Warning Area
Saturday night and Sunday. The 12z forecast guidance has little
precipitation associated with the frontal passage...so will keep
just slight chance or chance probability of precipitation in the forecast. The 12z
European model (ecmwf)...is hinting at a surface wave developing along this
front...and moving across the region Saturday night into Sunday.
So...will keep the chance probability of precipitation in the forecast for this time period
As the upper trough moves east...weak ridging temporarily builds
into the region Monday. Expect mostly sunny skies and dry
Another area of low pressure approaches for Tuesday and Tuesday
night. There are some timing and positional differences...but with
retreating high pressure...will ramp up probability of precipitation through the day
and into Tuesday night.
High pressure returns late in the week.
Temperatures will remain at or slightly below normal through the
long term period. Followed blended models data which was reasonably
close to wpc guidance.
Aviation /06z Friday through Tuesday/...
fog is developing and becoming dense...eventually spreading
across most terminals overnight. There will be the potential for
dense fog for all terminals except for kswf and perhaps kgon. Any
remaining VFR will eventually drop to MVFR/IFR and potentially
lower overnight. Any vlifr/LIFR is expected to stay nearly
constant through daybreak.
Conditions lift to VFR by 15z Friday.
S to SW winds will generally average 5 knots or less through Friday
morning...then will increase to 5-10 knots...and may be a few knots higher
near the coasts.
Winds diminish to 5 knots or less Friday night. MVFR or lower conds in
fog/stratus may return after 06z Saturday.
Outlook for 06z Saturday through Tuesday...
Friday night-Saturday night. MVFR or lower possible in fog/stratus
Friday night...and then in possible showers through Saturday night.
North-NE winds with 15-20kt gusts possible Saturday afternoon/evening.
Sunday-Sunday night...VFR likely. Low chance of MVFR.
Tuesday...VFR possibly becoming IFR in rain and fog by afternoon.
Small Craft Advisory for hazardous seas remains in effect for the ocean for Friday
into Friday night as a long period swell approaches from the southeast. Seas
will top out around 6 feet Friday night. Elsewhere...sub-sca
conditions will persist with a weak S/SW flow.
Seas will remain around 5 feet through Saturday night for the coastal
ocean waters...due to a swell and winds. It appears seas diminish on
Sunday...however a few left over 5 feet seas may remain across the
Sub-Small Craft Advisory conditions are then expected through Tuesday morning. Winds
and seas will increase Tuesday afternoon through Wednesday as a low
pressure system passes near the area waters.
there is the potential for a widespread rainfall event midweek
as a storm system impacts the region.
CT...dense fog advisory until 9 am EST this morning for ctz005>010.
New York...dense fog advisory until 9 am EST this morning for nyz068>075-
New Jersey...dense fog advisory until 9 am EST this morning for njz004-006-
Marine...Small Craft Advisory for hazardous seas from 11 am this
morning to 6 am EST Saturday for anz350-353-355.
long term...British Columbia