Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
649 PM EST Thursday Nov 20 2014
a cold front moves out to sea tonight as low pressure moves into
the Canadian Maritimes. High pressure will begin building into the
area late Friday into Friday night...then south of the area into
the weekend. A warm front is expected to lift across the area
Sunday night into Monday morning...with a cold frontal passage
Near term /through Friday/...
a dry cold front will swing east of the region through this
evening. Mostly clear conditions overnight...with only some scattered
strato-cumulus across southern and eastern portions of tri-state this
evening with frontal passage...and from extended streamers off the
Great Lakes late tonight as shortwave energy pivots through. An
isolated flurry possible across areas well n&w of NYC late tonight
with this energy.
Winds will remain gusty through the night...subsiding a bit across
outlying areas late tonight. A colder night than last night with
cold air advection...with low generally in the lower to middle 20s.
Short term /Friday night through 6 PM Friday/...
dry weather continues to be expected into Friday as drier air
continues to filter in across the area with precipitable water values remain well
below one-quarter of an inch. A weaken surface trough should cross
the area during the day...which should mainly lead to a decrease in
afternoon dewpoints. It should be another breezy day...with wind
gusts of at least 20-25 miles per hour expected...with isolated gusts near 30
miles per hour possible.
Long term /Friday night through Thursday/...
tried to maintain continuity through the long term forecast...
using a combination of previous forecast...mosguide...and wpc
High pressure builds across the area Friday night...then pushes
south of the area into the weekend. Dry weather is expected Friday
night into Saturday as the absence of any short wave/vorticity
impulses should keep the weather precipitation free.
Overnight Saturday into Sunday morning...model guidance is
indicating an increase in low-middle level moisture...along with a
weak short wave/vorticity impulse. This may lead to some light
precipitation developing across the area. If this does pan
out...temperatures at the surface are expected to be cold enough
for areas of freezing rain to develop as there is a warm layer
aloft which will melt any precipitation as it falls before
refreezing. For now...we kept this as slight chance probability of precipitation due to
After a drying out period during the day Sunday...more confidence
is building for a rain event Sunday night into Monday. A warm
front is forecast to lift across the area overnight into Monday
morning as an area of low pressure lifts through the Great Lakes
region and into southern Canada. Temperatures are forecast to be
above freezing which should keep all precipitation liquid.
Once the warm front lifts north of the area Monday morning...there
will remain a chance of showers for the remainder of the day into
Monday night when the cold front is expected to move across the
area. Precipitation should come to an end from west to east overnight
Monday into Tuesday behind the cold front. Temperatures are
expected to remain above freezing...so any precipitation through
Tuesday should remain liquid in form.
Then question return for the Wednesday period as the GFS and European model (ecmwf)
both showing an area of low pressure moving northward along the
boundary once it's offshore. However...there is differences in
how close the low tracks to the coast. The GFS keeps it far enough
offshore to keep the weather dry...the European model (ecmwf) brings it close
enough to bring precipitation into the area. For now we will keep a
slight chance for the eastern half of the area through Wednesday.
Aviation /00z Friday through Tuesday/...
hi pressure builds in from the west through Friday night.
VFR through the taf period.
Satellite and observation indicate mainly sky clear across the region. A few residual
lake clouds may clip northern terminals tonight as the flow aloft veers
slightly to the west-northwest...otherwise sky clear expected at this time. Winds will
remain strong overnight...especially at the coasts.
Friday...VFR with just some high based cumulus clouds. Northwest
winds will increase with sustained speeds 15 to 20 kts and peak
gusts to around 30 knots. Expect most peak winds to occur by middle
afternoon with a decrease of winds and speeds toward evening.
New York metropolitan enhanced aviation weather support...
Detailed information...including hourly taf wind component forecasts
can be found at: http:/www.Erh.NOAA.Gov/zny/n90 (lower case)
Kjfk fcster comments: no unscheduled amendments expected.
Klga fcster comments: no unscheduled amendments expected.
Kewr fcster comments: gusts may be occasional at times overnight.
Kteb fcster comments: gusts may only be occasional tonight.
Khpn fcster comments: gusts may only be occasional tonight.
Kisp fcster comments: gusts may be occasional at times overnight.
Outlook for 00z Sat through Tuesday...
Friday night-Sat night...VFR.
Sun night-Mon...MVFR/IFR. Possibly sub-IFR. Rain and fog with low level wind shear
the Gale Warning was extended through the night as there remains the
potential for gale force gusts...especially overnight as a secondary
cold surge pushes through.
Then a return to Small Craft Advisory conditions is expected for
Friday. Conditions should drop below advisory levels Friday night as
high pressure builds across the area and continue into early
Saturday. A return to advisory level winds is likely by late
Saturday and should continue into early next week with gale force
winds possible late Sunday into early Monday.
dry weather through Sunday. Rain is expected Sunday night into
Monday. However...no hydrologic impacts are anticipated with this
event at this time.
Marine...Small Craft Advisory until 6 PM EST Friday for anz335-338-345.
Gale Warning until 7 am EST Friday for anz330-340-350-353-355.