Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service New York New York
148 am EDT Thursday Oct 23 2014

low pressure south of Montauk will deepen and meander in the
general vicinity today before tracking northeast tonight
and reaching the Canadian Maritimes by late Friday. The low will
remain in the Maritimes through the weekend. A cold front moves
across Saturday night. High pressure returns early to middle next


Near term /until 6 am this morning/...
05z observation still indicating several locations gusting at or close to
wind advsy criteria...therefore have extended the advsy for
Suffolk and coastal CT from New Haven east until 6am and have
reflected this in the wind grids. Otherwise...made some
adjustments to pop grids to better reflect current radar imagery
and trends. Rest of forecast is on track.

Closed upper low continues to slowly deepen and meander S of Long
Island tonight. Bands of light/moderate rain will pivot around
the closed low tonight as it deepens. Temperatures will not
fluctuate much with the rain and cloud cover...and no change in
the air mass...remaining mostly in the lower and middle 50s.


Short term /6 am this morning through 6 PM Friday/...
the upper low remains closed off and by late in the day Thursday
into Thursday night begins to get picked up by the westerlies and
moves a little quicker Thursday night into Friday. Meanwhile the
surface low continues to slowly deepen into Friday. Bands of rain
will continue across the region Thursday into Thursday night with
categorical probability of precipitation early slowly lowering into the afternoon. As the
low pulls to the northeast late Thursday night into Friday
precipitation will be ending from west southwest to the northeast.
Models were in good agreement with the track and low intensity and
a blend was used.


Long term /Friday night through Wednesday/...
vertically stacked low with equivalent barotropic characteristics
near Nova Scotia Friday night eventually becomes diffuse and merges
with another low pressure system in southeast Canada during the

So essentially...low pressure remains in the Canadian Maritimes
Friday night through the weekend. Northwest flow aloft in the region
with more southwest to west flow at the surface Saturday will allow
for a warmer than normal air mass but a cold front moving across
Saturday night will deliver another cool air mass on Sunday. It even
appears there could be a secondary cold front moving through on
Sunday...helping to reinforce the cooler air.

Early next week ridging high pressure will be the dominant feature.
The air mass moderates to warmer than normal on average. Another cold
front approaches for late next Wednesday.

Quite a dry stretch of weather forecast. The cold front Saturday
night into Sunday will be moisture starved with a more northwesterly
flow through the atmosphere. Therefore it could very well move
through dry with perhaps a shower or two but just slight chances.
There is some instability shown and despite the lack of
moisture...the shortwave and vorticity advection is large Saturday
night so this could result in possible convection but with
instability of generally less than 100 j/kg over much of the
area...left any mention of thunder out.


Aviation /06z Thursday through Monday/...
low pressure south of Montauk Point will move slowly northeast
today...passing east of Long Island.

MVFR ceilings should prevail most of the time...although brief VFR
ceilings are possible from time to time this morning. Periods of
rain are also possible...and will be tough to time as they move
from east to west. Still cannot rule out thunder as this storm has
been rather impressive. Timing any storms though is tough...and
cannot be included in tafs. Please refer to terminal forecast
amendments for specifics.

MVFR ceilings are expected to lift to low end VFR...3 to 5
kft...this afternoon. Eastern terminals though will hang onto
lower ceilings a little longer. Then generally expect VFR ceilings
this evening.

Winds remains quite strong from the north this morning. Speeds 15
to 25 knots...with gusts 25 to 35 knots. Winds back slightly to the
north/northwest and remains gusty through the day today. Speeds 15
to 25 kts...with gusts up to 30 kts. Winds diminish somewhat this
evening...except NYC and coastal terminals.

Outlook for 06z Friday through Monday...
tonight...mainly VFR with gusty winds...especially coastal and NYC
Friday...most likely VFR...with low chance spotty MVFR. Northwest winds
g20-25kt possible.
Friday night-Saturday. VFR. Northwest winds g15-20kt possible.
Saturday night...most likely VFR...low chance MVFR in showers.
West winds g20-25kt possible.
Sunday-Sunday night...VFR. Northwest winds g25-30kt possible.


low pressure S of Montauk will meander in this general vicinity
today...then track NE reaching Nova Scotia Friday night. Gale
warnings remain in effect through tonight for all waters...and for
the ocean waters into Thursday afternoon.

Small Craft Advisory level gusts expected on the sound/Harbor/bays today. As the
low pulls northeast Thursday night into Friday the wind will
gradually diminish with Small Craft Advisory level gusts possible into Friday.
Ocean seas will remain above 5 feet through at least Thursday night.

Starting Friday night...probably some residual Small Craft Advisory conditions on the
waters. These will lower to below Small Craft Advisory late Friday night into early
Saturday but will trend back up during the day Saturday. Small Craft Advisory
conditions are forecast to continue Saturday with potential for
gales Sunday into Sunday evening. These lower by later Sunday night
into Monday but Small Craft Advisory conditions will gradually taper down from west
to east Monday afternoon.


generally light rain with periods of moderate rain will continue
into early Friday. Basin average rainfall through Friday morning
will total from around around 1/2 inch across northeastern New
Jersey to 1 1/4 inches across southeastern Connecticut.

No significant widespread precipitation expected Friday night through
the first half of next week.


Okx watches/warnings/advisories...
CT...Wind Advisory until 6 am EDT early this morning for ctz010>012.
New York...Wind Advisory until 6 am EDT early this morning for nyz078>081.
New Jersey...none.
Marine...Gale Warning until 6 am EDT early this morning for anz330-335-
Gale Warning until 6 PM EDT this evening for anz350-353-355.



National Weather Service Glossary of Abbreviations