Scientific Forecaster Discussion
fxus61 kakq 240801
Area forecast discussion
National Weather Service Wakefield Virginia
401 am EDT Sat Aug 24 2019
a cold front will stall along the Carolina coast over the weekend.
High pressure will build in from the north behind the front
through today. Low pressure is expected to develop along the
front early next week.
Near term /through tonight/...
as of 400 am EDT Saturday...
As of this morning, a cold front is located just south of the
forecast area with north to northeast winds in its wake. High
pressure builds in from the north through today, bringing drier
air to portions of the region (particularly north of I-64). Do
expect at least partly sunny skies across the northern half of
the forecast area by this afternoon, higher cloud cover will
persist further south. Northeast flow along with plentiful low
level moisture will allow for the continued chances of showers,
especially across far southeast Virginia and NE NC closer to the boundary.
Much cooler today compared to the past couple of days, highs
will generally range from the mid to upper 70s, potentially
cooler in areas where rain showers persist.
Short term /Sunday through Monday/...
as of 400 am EDT Saturday...
By Sunday morning, the surface high looks like it will push the
moisture far enough south to limit the chances for any showers
to mainly NE NC and far southeast Virginia with drying of the mid and upper
level expected to continue through the day on Sunday suppressing
the pcpn farther south through the day. However, the low level
moisture should remain in place with strong easterly flow
through about 850 mb. That may be enough to hold clouds in place
and could limit the day time heating. For now have gone close
to 80s most areas, but if those lower clouds do hold together
could see readings more in the mid 70s toward the southern VA
The forecast for Sunday night into Monday could change rapidly
over the next few days depending on the potential development of
a tropical system of the southeast US coast. The models are struggling
with the development and location of the system with the 00z
GFS quicker to develop the system and move it northward off the
Carolinas by Monday afternoon while the 00z European model (ecmwf) continues to
be slower and farther to the southeast off the coast with much less
impact to the region. Very minor changes to pops with this
update, maintained low chance pops with the moisture overrunning
the wedging high. Again will need to monitor the potential
tropical development along the southeast US coast this weekend.
Long term /Monday night through Friday/...
as of 300 PM EDT Friday...
The early part of the extended forecast will depend much upon any
development and potential track of the tropical disturbance
currently off the Florida coast. Latest NHC outlook suggests that
this system will stay well off the local coast. Despite that,
given the proximity to the tropical system and the potential for
some tropical type showers to move across the area, and some
reinforcing moisture/lift from weak upper disturbances moving
across the mid Atlc and NE states in the west-SW flow aloft, will
maintain low chance pops Mon night through Thu. However, if the
tropical system stays further offshore it is conceivable that
much of the middle of next week will be dry other than perhaps
some widely scattered afternoon/evening storms. Otherwise, by
Friday the GFS and European model (ecmwf) both show drying across the area as a
ridge axis builds in from the west. As such, have kept Friday
Temps on Tuesday will trend slightly below normal due to the
extensive cloudiness (although it will be muggy), but then rise to
near normal for Wed-Fri.
Aviation /08z Saturday through Wednesday/...
as of 145 am EDT Saturday...
The majority of the heavier showers and thunderstorms have now
shifted to the south of the region. Scattered light rain showers
will be possible from roughly ric and south through the early
morning hours. Should see a general, slow, improving trend in
ceilings from south to north through the period. Ceilings across
the south will remain sub-VFR through much of the morning
before all sites become VFR after 18z. North to NE winds will range
around 10 to 15 knots along the immediate coast and diminish to
less than 10 knots further inland. Additional showers and
potentially thunderstorms redevelop across southeastern taf
sites late this afternoon into the evening.
Outlook: low pressure developing along a stalled front and
high pressure building in from the north will keep an easterly
flow across the region through early next week. Easterly flow
will allow for ample moisture, chances for additional showers,
and the potential for sub-VFR ceilings (especially at eastern
taf locations) into early next week.
as of 400 am EDT Saturday...
A cold front is pushing swd through NC early this morning
as high pressure builds across the Great Lakes. The wind has shifted
to north-northeast behind the front 10-15kt, and this has resulted in 3-4ft seas
in the ocean and 2-3ft waves in the Bay. The high will build across
upstate New York and into nrn New England today as the front settles off
the Carolina coast. Therefore, the wind will shift to NE and remain
10-15kt. The high strengthens and remains nearly stationary tonight.
Meanwhile, an inverted trough begins to develop along the old
frontal boundary and the pressure gradient will tighten along the
mid-Atlantic coast. A NE wind should increase to 15-25kt tonight
into Sunday, with seas building to 4-5ft north and 5-6ft S later tonight
into Sunday. Small Craft Advisory flags remain in effect for the Bay and lower James,
and have been added for the ocean (primarily for seas) and the
Currituck Sound. The wind will remain NE Sunday night into Monday as
tropical low pressure organizes off the Carolina coast. Small Craft Advisory
conditions for seas (potentially building to 5-8ft) will likely
linger into early next week as the flow remains onshore and with low
pressure over the ocean. By Tuesday night and Wednesday the wind
should become north and then SW as the low pulls well offshore. This
should allow seas to subside.
Marine...Small Craft Advisory from 6 PM this evening to 6 PM EDT Sunday
Small Craft Advisory from 4 am to 10 PM EDT Sunday for anz633.
Small Craft Advisory from midnight tonight to 6 PM EDT Sunday
Small Craft Advisory from 10 PM this evening to 6 am EDT
Monday for anz650-652-654.
Small Craft Advisory from 4 am Sunday to 6 am EDT Monday for