Area forecast discussion
National Weather Service Mount Holly New Jersey
228 am EDT Sat may 25 2013
Synopsis...
low pressure along an offshore cold front will continue to slowly
progress northeast tonight and over the weekend, reaching the
Canadian Maritimes by Sunday night. Meanwhile, an area of high
pressure will gradually build east through the weekend from around
the Great Lakes region. By middle week, a warm front is expected to
lift northward through our region, followed by a Bermuda type high
pressure system building to our east for the end of next week.
&&
Near term /until 6 am this morning/...
an area of low pressure developing to our NE will continue to move
northeastward through today. At the same time, high pressure will build in
from the west.
As a result, we will keep very strong northwesterly flow over the area. We
have issued a Special Weather Statement for wind gusts around 45 miles per hour for the higher
elevations of Carbon and Monroe counties. Mpo came in with a gust
to 43 miles per hour late in the afternoon, and winds have been diminishing
very slowly since. With the slow moving low to the NE it will keep an
abundance of clouds over the region. Precipitation chances should gradually
decrease from SW to NE.
Overnight low temperatures will be quite crisp with most locations
into the 40s and some even into the 30s.
&&
Short term /6 am this morning through 6 PM Sunday/...
on Sat, the aforementioned low will continue its slow progression
away from the region. Clouds will be plentiful in the mrng, and
decrease through the day. Precipitation chances will be highest in the NE to
almost non-existent across the SW. Temperatures will only make it into the
low to middle 60s which is generally 10 to 15 degrees below normal.
&&
Long term /Sunday night through Friday/...
to start the long term, a middle level low/trough will be moving away
to the northeast, and we expect any lingering light showers over our
northeast zones to be quickly diminishing by Saturday evening. Of
note, a pronounced cyclonic flow will still be in place across our
region through Saturday night, and the northwest winds will remain
elevated through the night in the 10 to 20 miles per hour range. With this in
mind, we generally took a blend of higher mav guidance with
continuity across the forecast area for minimum temperatures, with
lows ranging from the upper 30s and lower 40s for our northwest
zones to the middle and upper 40s in the lower Delaware valley and
Delaware-Maryland-Virginia region.
Going into Sunday, the overall pressure gradient will begin to relax
across the region, but another breezy day is in store with northwest
winds in the 15 to 25 miles per hour range. Dry conditions are anticipated, but
with a few shortwaves/vorticity maxes passing overhead in the still
cyclonic flow aloft, some clouds will mix with the sunshine,
especially north. Going into Sunday night, both the GFS and European model (ecmwf)
show an area of high pressure from around the Great Lakes building
east and over our area, with the gradient relaxing. With lighter
winds and fairly clear skies, we anticipate another cool night for
our northwest zones, with minimum temperatures again dropping into
the upper 30s and lower 40s.
High pressure will remain over the region through Monday, as the
airmass begins to moderate, with light westerly winds and
temperatures returning to late may normals. From there going into
the middle and end of the week, maximum temperatures will be steadily
climbing. Overall, Tuesday should feature mainly dry conditions for
the forecast area; although, a warm front will be approaching our
region from the south and west. We maintain the possibility for
showers and isolated T-storms going into Tuesday night as the front
begins to lift northward through the region, and we also kept some
probability of precipitation in place for Wednesday. For the end of the work week then, a
Bermuda high building over the Atlantic will spread its influence
westward over the middle Atlantic and southeast states, with increasing
humidity and above average temperatures expected.
&&
Aviation /07z Saturday through Wednesday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
Although a few patches of MVFR clouds were moving around the area
late Friday evening, we expect skies to be VFR most or all of the time
through the taf period at all of the taf sites. We will start out
with low VFR ceilings that may erode toward daybreak and then re-
develop during the middle-morning hours. Some shower activity also
was moving around the area late Friday evening, but we expect
visibilities in any showers that hit a taf site to remain VFR.
Regarding the wind, surface low pressure developing south of Cape Cod
late Friday evening established a pressure gradient with high
pressure building in from the west. The resultant northwesterly flow will
keep winds gusting in the 20s and 30s knots through the taf period.
Outlook...
Saturday night through Sunday...mainly VFR conditions expected with
gusty northwest winds.
Monday...VFR conditions with light westerly winds.
Tuesday through Wednesday...mostly VFR conditions. Possible sub-VFR
ceilings/visibilities in showers Tuesday night into Wednesday with a warm front
lifting through the region.
&&
Marine...
gale warnings were raised with the afternoon pkg issuance. They are in
effect over the southern waters and del Bay and will go into effect at
10z for the northern waters. Strong northwesterly flow will continue and
strengthen from S to north as high pressure builds in from the west and
low pressure develops along the cold front that passed through this morning.
Outlook...
a Gale Warning will be in effect for our coastal waters and Delaware
Bay into at least the first part of Saturday night as a strong
northwesterly flow will keep wind gusts around 35 knots over the
waters. Seas will also be elevated in the 5 to 6 foot range for the
Atlantic coastal waters, with seas ranging from 3 to 5 feet in
Delaware Bay. Gale force gusts are expected to diminish heading
through the early morning hours of Sunday, but we will likely need a
Small Craft Advisory headline for a time on our waters from the
early morning on Sunday through Sunday afternoon to early evening.
For the remainder of the period then, from Sunday night through
Wednesday, we anticipate sub-Small Craft Advisory conditions on our waters as high
pressure spreads across the region, followed by a warm front lifting
north during the middle week period.
&&
Tides/coastal flooding...
the strong northwest winds down del Bay have created negative water level
departures of -1.5 to 2.5 feet. With the low tide approaching...we
have decided to issue a low water advisory for early this morning.
An Special Weather Statement will be issued soon...if it appears the the del river will
be affected by the low water also.
&&
Rip currents...
there is a moderate risk of rip currents forecast for Saturday.
&&
Phi watches/warnings/advisories...
PA...none.
New Jersey...none.
Delaware...none.
Maryland...none.
Marine...Gale Warning until 2 am EDT Sunday for anz430-431-452>455.
Gale Warning from 6 am this morning to 2 am EDT Sunday for
anz450-451.
Low water advisory until 8 am EDT this morning for anz430-431.
&&
$$
Synopsis...Kline
near term...nierenberg
short term...nierenberg
long term...Kline
aviation...Kline/nierenberg
marine...Kline/nierenberg
tides/coastal flooding...
rip currents...
