Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
1225 am EDT Friday Aug 1 2014
high pressure moves offshore tonight and continues to drift to the
northeast on Friday. Low pressure approaches from the south Friday
night. A frontal boundary over the Atlantic coast will impact the
area through the beginning of the week. High pressure then builds
into the region on Tuesday and remains through Thursday.
Near term /until 6 am this morning/...
forecast on track overnight with minor updates to temperatures and dew
points. Surface high pressure over the middle-Atlantic continues to move offshore
overnight. Main upper trough remains to the west.
Isolated showers are possible northwest zones per mesoscale models...but will
maintain dry forecast overnight.
With southerly flow and increasing low-level moisture...patchy
fog is possible well after midnight.
Lows will drop into the upper 60s to near 70 in/around NYC...and
generally in the low to middle 60s elsewhere. Far northwest portions of
Orange County could drop into the middle 50s.
Short term /6 am this morning through 6 PM Saturday/...
deep upper trough digs into the Great Lakes/Ohio Valley on
Friday...and several shortwaves will track along the coast and
into the local area during the day. With increased moisture...surface
dew points will climb into the low-middle 60s...and higher
instability levels...can expect more diurnally driven rain showers/thunderstorms
to develop during the day. Best chances for this activity will be
across NYC/NE New Jersey/lower Hudson Valley/SW CT. 0-6km bulk shear will
average 20-30 knots...so not expecting storms to be too long
lived...but upper level flow is weak...so storms that develop will
be slow to depart. This could result in the potential for
localized urban/poor drainage flooding.
Showers/storms taper off Friday evening. Low pressure developing over
the middle-Atlantic will lift north Friday night...bringing showers
to the region towards daybreak Saturday.
Highs on Friday will moderate to near normal levels...topping off
in the low to middle 80s...with temperatures in the middle 80s across NYC/NE
There is a moderate risk of rip currents Friday for eastern Long
Long term /Saturday night through Thursday/...
high pressure is expected to lift to the northern Atlantic while a
coastal front remains along the East Coast. A southerly flow will
continue to draw moisture into the area resulting in the
development of showers and thunderstorms near or over the area
through the weekend.
A weak front will move across the area Sunday night into Monday
and showers should tapper off by Monday afternoon. Dry weather
returns Tuesday and remains through the end of the extended
Temperatures for the weekend will be slightly below normal...
however temperatures bounce back for the beginning of the week...
with highs in the lower 80s and low in the upper 60s...which is
near normal for this time of year.
Aviation /06z Friday through Tuesday/...
high pressure will remain offshore through Friday.
VFR through the taf period.
Scattered showers and isolated thunderstorms will be possible Friday
afternoon into the early evening. The potential for any one location
Light S to SW wind at the NYC area terminals with light and variable
wind at the outlying terminals tonight. Wind increases out of the
S/southeast middle to late Friday morning.
Outlook for 00z Saturday through Tuesday...
Friday night...VFR. Isolated rain showers/thunderstorms possible in the early evening.
Saturday-Sunday night...MVFR or lower possible in scattered rain showers
and isolated thunderstorms.
Monday-Tuesday...VFR. MVFR possible in isolated rain showers/thunderstorms in the
high pressure moves offshore. A frontal boundary tracks toward the
area and remains nearly stationary for several days.
Sub-Small Craft Advisory conditions are expected on the waters
through next Tuesday.
no significant rainfall is expected through tonight.
Locally heavy downpours in scattered thunderstorms on Friday will present
mainly a urban/poor drainage flood threat due to slow movement...
with a low and localized flash flood threat with any training of
An increasingly moist air mass will be conducive to the
development of heavy showers this weekend.