Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
706 am EDT Wednesday Aug 5 2015
weak high pressure builds over the area into Thursday. Low
pressure over North Carolina Thursday night slowly tracks east
northeast though the weekend reaching the Gulf of Maine on Sunday.
This system should remain over the open Atlantic and not directly
affect our region. A warm front approaches the region for early
Near term /until 6 PM this evening/...
increased cloud cover this morning as a fairly thick cirrus shield
is moving overhead. This is in association with a 100 knots 300 mb
jet moving across New England. Thinking the cirrus moves east late
this morning into the early afternoon leaving behind mostly sunny
Weak high pressure at the surface will remain over the region
today. Aloft...a shortwave moving out of the Great Lakes region
will move across the region this afternoon. Despite the limited
instability...latest hi res guidance including the hrrr and 4-km NAM
continue to support the potential for isolated showers and
thunderstorms this afternoon. Will continue with low probability of precipitation to
account for this.
Highs today climb into the 80s and lower 90s. Mav/met guidance in
good agreement and was used for temperatures.
There is a moderate risk for rip currents at the ocean beaches
Short term /6 PM this evening through 6 PM Thursday/...
an upper level shortwave will move east of the region tonight. As
it does...the upper flow becomes more zonal. At the surface...weak
high pressure will build back into the region for the short term.
Expect dry conditions. Little cloud cover is expected. Used a
blend of mav/met MOS for temperatures. Lows tonight fall into the
50s and 60s...with highs on Thursday in the 80s.
Long term /Thursday night through Tuesday/...
major change to the forecast for Friday. Based on all available
nwp guidance...it appears likely that the low pressure system will
remain south and east of the local area. Have lowered probability of precipitation to 20
percent (from likely). Have only kept the 20 percent to account
for uncertainty for possibility of flip flop nwp...though that
would seem very unlikely. Called it light rain as at worse we'd be
on the extreme northwest portion of the system.
21z sref...NCEP and Canadian deterministic runs along with 00z gefs
all support a dry forecast. Have also raise temperatures for Friday as a
Flow around the off shore low is northeast for the weekend. Thus
temperatures run about 5 degrees below normal.
A warm front approaches for early next week. More humid...but with
temperatures remaining below normal. Showers and thunderstorms possible.
Low pressure appears possible for middle week...but with lots of
Aviation /11z Wednesday through Sunday/...
VFR as high builds over the terminals today.
Light and variable winds at the start of the taf period give way
to northwest winds 5-10 knots late this morning. Winds back to the west-west-northwest this
afternoon with speeds 10-15 knots and gusts up to 20 knots. SW sea
breeze only only forecast at kgon.
A brief rain showers/thunderstorms and rain is possible this afternoon.
West-northwest-northwest winds diminish this evening and overnight.
..NY 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: timing of gusts may be off by +/- an hour. Low
chance of a sea breeze this afternoon.
Klga fcster comments: timing of gusts may be off by +/- an hour.
Kewr fcster comments: timing of gusts may be off by +/- an hour.
The afternoon kewr haze potential forecast is green...which implies
slant range visibility 7sm or greater outside of cloud.
Kteb fcster comments: timing of gusts may be off by +/- an hour.
Khpn fcster comments: timing of gusts may be off by +/- an hour.
Kisp fcster comments: timing of gusts may be off by +/- an hour. Low
chance of a sea breeze this afternoon.
Outlook for 12z Thursday through Sunday...
Thu-Fri...VFR. Slight chance of a shower on Friday.
Sat...VFR. NE wind gusts 15-20 knots.
a weak pressure gradient over the area waters will allow seas to
continue to subside today. These sub-Small Craft Advisory conditions are expected
to continue into Thursday.
Long term...low pressure passes south and east of the region Friday
through the weekend. NE flow is expect for the period. Winds increase
to perhaps minimal small craft levels (gusts to 25 kt)...though this
may be too high. Seas though on the ocean will build to 4 to 7 feet.
organized significant rainfall is not expected through the
tewr terminal Doppler radar remains unavailable.
short term...British Columbia