Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
1101 PM EDT Friday Oct 24 2014
low pressure near the Canadian Maritimes will continue to depart
tonight. A cold front approaches the region Saturday and moves
across the region Saturday night. High pressure builds across the
area Sunday through Monday...then offshore by Tuesday. Another
cold front will move across the region Wednesday. High pressure
builds back across the area Thursday.
Near term /until 7 am Saturday morning/...
brief tightening of the pressure gradient through 09z as high
pressure builds in...with occasional gustiness. Winds should relax
towards daybreak as high pressure noses in.
Clearing skies and weakening winds late should allow for a late
decent radiational cooling window...allowing lows to drop into the
middle and upper 30s across the interior...in the low to middle 40s most
elsewhere...and in the upper 40s to lower 50s in NYC late tonight.
If winds decouple earlier than predicted temperatures across outlying
areas could drop a few more degrees...leading to patchy frost
formation in interior valleys and Pine barrens. This is a low
probability at this time.
Short term /7 am Saturday morning through Saturday night/...
weak high pressure remains over the region on Saturday...providing
mostly sunny skies and dry conditions. A cold front will approach
from the west late in the day Saturday...and move across the region
Saturday night. Will continue to go with a dry forecast Saturday
night...however there could be some cloud cover with the front.
Expect high temperatures on Saturday to climb into the 60s...while
Saturday night lows fall into the 40s. Followed a mav/met blend of
guidance for temperatures.
Long term /Sunday through Friday/...
high pressure builds in the wake of the cold front during Sunday.
Its ridge axis passes through during Monday...and will be offshore
on Tuesday. Dry weather all three days...but breezy on Sunday. High
temperatures near normal for Sunday...but a little cooler on Monday
due to more limited mixing. A return flow with SW winds will help
push high temperatures above normals on Tuesday.
A cold front approaches Tuesday night and passes through on
Wednesday. Passage appears to be slow due to the front becoming
aligned with the flow aloft. Will go with low chances of showers
from late Tuesday night through Wednesday evening. Right now it
looks like the daytime hours of Wednesday have the overall best chance of
showers. Weak high pressure returns dry weather on Thursday.
Models differ for Friday. GFS has trended towards European model (ecmwf) with a
potential low pressure system affecting the region. Support from
ensemble means are not great so far...but Worth at least slight chance
probability of precipitation.
Aviation /03z Saturday through Wednesday/...
high pressure will slowly build from the west tonight...and pass
to the south on Sat. A cold front will approach Sat night.
High confidence in VFR conds. Broken VFR ceilings over most of Long
Island and southern CT will slowly move east tonight.
A weak low pressure trough in vicinity of NYC is dissipating..with winds
becoming northwest around 10 knots with gusts 15-18 knots late this evening.
Otherwise...northwest flow under 10 knots overnight into Sat morning should
increase to around or just over 10 knots by late morning or midday...
and then back west-southwest during middle afternoon. Winds could briefly gust
up to 20 knots as the winds back west-southwest.
Outlook for 00z Sunday through Wednesday...VFR. Northwest winds g25-30kt on
Sunday...highest NYC metropolitan.
pressure gradient briefly tightens through 09z with gusts into
the lower 20s on ocean and around 20 on nearshore
waters...diminishing towards daybreak.
Sub Small Craft Advisory conditions on Saturday.
A cold front will move across the area Saturday evening...with seas and
winds increasing to small craft. Will adjust Small Craft Advisory
start a bit earlier for all waters starting Sat evening at
midnight with a strong northwest flow.
Small Craft Advisory conditions for all waters Sunday with a gusty northwest flow. Winds
then subside Sunday night and Monday as the center of high pressure
approaches the eastern Seaboard...so sub-Small Craft Advisory conditions for all
waters by Monday afternoon. A SW return flow will be relatively
light on Tuesday...but gusts and seas on the ocean could be
marginally at Small Craft Advisory levels on Wednesday with the passage of a cold
no significant widespread precipitation expected through the first
half of next week.
Marine...Small Craft Advisory from 8 PM Saturday to 6 PM EDT Sunday for
short term...British Columbia