Area forecast discussion
National Weather Service New York New York
434 PM EDT Wednesday Jun 19 2013
Synopsis...
high pressure control through the end of the week. As high
pressure remains anchored across the western Atlantic Ocean...a
series of weak low pressure troughs will pass across the region
through Wednesday.
&&
Near term /until 6 am Thursday morning/...
high pressure continues to build into the region through this
evening with the pressure gradient will continue to weaken through this
evening. Aloft...middle and upper level ridging will be building
overhead.
Excellent radiational cooling conditions are expected tonight with
clear sky conditions...dry airmass...and light to nearly calm winds.
With this in mind...below normal temperatures are forecast tonight.
Weighted low temperatures heavily on the mav guidance and this
yields readings in the middle and upper 40s across the interior and
low to middle 50s closer to the coast. New York City should see
readings near 60 degrees.
There is a moderate risk of rip currents at Atlantic Ocean beaches
today.
&&
Short term /6 am Thursday morning through Friday/...
the center of high pressure shifts offshore on Thursday setting up a
return S-SW flow. Sea breezes should have no problem developing
during the early afternoon hours. Even with a SW-S flow...surface
dewpoints will remain in the middle and upper 40s with drier air
from aloft mixing down to the surface. High temperatures in the
upper 70s to lower 80s are forecast.
Dry weather continues into Thursday night. Temperatures in the 50s
t0 lower 60s in the city are forecast which are still below normal
for this time of year...but are several degrees warmer than
Wednesday night...especially across the interior.
There is a low risk for rip currents at Atlantic Ocean beaches on
Thursday.
&&
Long term /Friday night through Wednesday/...
temperatures gradually rising to slightly above normal with slight
chances of mainly afternoon and evening showers and thunderstorms Sat through
Monday.
Global forecast models are in good general agreement through this
period showing the local area along the southern periphery of the
upper level westerlies as high pressure aloft remains south of the local
area.
A series of weak short waves will move east with the mean flow.
These weak waves will be difficult to time.
The first short wave is forecast to advect southeast toward the area Friday
aftn/eve. Because of limited moisture..decided to maintain the
existing dry forecast although a shower is possible northwest of NYC.
The second slightly stronger short wave is also forecast to advect southeast
toward the area Sat afternoon - night. With increasing low level moisture
ahead of this system...low chance probability of precipitation were continued for the region from
northwest to southeast through the day Sunday.
Additional weak waves are forecast Monday - Wednesday...bringing a chance of
mainly afternoon/evening scattered showers and thunderstorms.
Heat index values are forecast to remain below 95 degrees through
the period. Temperatures are forecast to slowly rise into the middle and upper 80s
Sunday through Wednesday. With moderate humidity...it will feel
uncomfortable.
&&
Aviation /21z Wednesday through Monday/...
hipres builds over the region tonight and offshore on Thursday.
VFR through the taf period.
North winds into this evening except where sea breeze flow develops. Gust
potential will continue to diminish as winds aloft lighten.
Nearly calm overnight with southerly flow developing after 12z Thursday. Enhanced
flow along the S coasts after 17-19z...with sustained winds likely to
be at or above 15kt at kjfk.
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: variability in prevailing wind direction
possible through 22z as gust frequency decreases.
Kewr fcster comments: variability in prevailing wind direction
possible through 00z as gust frequency decreases. Amendments possible
based on evolution of sea breeze.
Kteb fcster comments: no unscheduled amendments expected.
Khpn fcster comments: no unscheduled amendments expected.
Kisp fcster comments: no unscheduled amendments expected.
Outlook for 18z Thursday through Monday...
Thu-Fri...VFR. Prevailing SW winds.
Sat-Mon...mainly VFR. Areas of MVFR or lower in the morning. Isolated-scattered
afternoon/evening thunderstorms possible...especially north and west of the city. SW
winds.
&&
Marine...
high pressure will be centered over the waters tonight with winds no
greater than 5 knots. The high pressure shifts offshore on Thursday
setting up a S-SW flow. Could see a few gusts around 15 knots in the
afternoon but otherwise tranquil conditions will therefore prevail
through Friday morning.
Friday through Monday...winds and seas are forecast to remain below
Small Craft Advisory levels of 25 knots and 5 feet.
S-SW winds of 10 to 15 knots will prevail through this period with
significant wave heights ranging from 2 to 4 feet across the Atlantic
Ocean and coastal waters and 1 foot or lower elsewhere.
&&
Hydrology...
no widespread significant rainfall is forecast.
A series of weak troughs of low pressure will produce scattered showers
and thunderstorms...mainly during the afternoon and evening daily starting
Saturday. Less than 1/4 inch rain is likely with each round of
showers.
&&
Okx watches/warnings/advisories...
CT...none.
New York...none.
New Jersey...none.
Marine...none.
&&
$$
Synopsis...gc/ds
near term...ds
short term...ds
long term...gc
aviation...jmc
marine...gc/ds
hydrology...gc/ds
