Area Forecast Discussion
Issued by NWS Wakefield, VA
FXUS61 KAKQ 282007
Area Forecast Discussion
National Weather Service Wakefield VA
407 PM EDT SAT MAY 28 2016
High pressure will push farther off the Mid Atlantic coast tonight.
Low pressure northwest of the Bahamas will approach the South
Carolina coast overnight, and will linger along the coastal Carolinas
through the holiday weekend.
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Latest analysis depicts 1025+ mb surface high pressure well off
the VA/NC Coast, ridging back toward the Mid- Atlantic/Carolina
piedmont. To our south, sfc low pressure (still TD #2) is located
SSE of Charleston SC. Aloft, strong upper level ridge centered
offshore is still ridging back west into VA.
Another warm/dry dry prevails across the local area, the upper
ridge holding strong and leading to mostly sunny conditions over
the CWA. Models seem to be verifying well with the large-scale zone
of subsidence this aftn and suggest little to no chance for any
precip this evening. A band of scattered showers off the NC coast
may brush our ne NC zones this evening so will have POPS slowly
ramping up later this evening though even here the best chances
for rain should hold off until after midnight.
Models remain in good agreement with showing upper ridge buckling
e-ne tonight, with TD#2 (or possibly Tropical Storm Bonnie by
that point), approaching the SC coast. PW values AOA 2" expected
to push into ne NC after midnight, and expand N into southern VA by
daybreak. GFS remains most aggressive with northward expansion of
POP, with the remainder of CAMs and probabilistic guidance in
decent agreement in trending pops upward from south to north late
tonight into Sunday morning. Warm and becoming more humid tonight
with increasing moisture and clouds...lows range from the low-mid
60s north/central zones to upper 60s/near 70 F south.
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Tropical Storm Bonnie forecast to slow down and linger along the
SC coast on Sunday, before lifting ne and lingering along the
Carolina coast through Mon. More uncertainty in track develops
thereafter. Refer to discussions issued by the National Hurricane
Center for the official track and forecast.
An unsettled period will dominate the short term, with a warm and
quite humid airmass in place. Expect a chance of showers in the
morning, expanding NNW and becoming more widespread by late
morning/aftn. Models still suggest greatest lift and instability
to be inland from the coast along an inverted trough by aftn and
will continue forecast with highest POPS/80% to be along/west of
i-95 by aftn. Accordingly expect to see numerous periods of rain,
falling moderate to heavy at times. Highs on Sun generally in the
upper 70s wrn 2/3 to to lwr 80s acrs the eastern 1/3.
The low is slow to weaken acrs the Carolinas and get slowly
transported NE Sun night/Mon as upper level trough from the W
tries to push through. The increasing support from the upper
levels may lead to the most widespread precip for the entire event
Sun night. Potentially very wet conds, with occasional moderate
to heavy showers are expected in the modified tropical airmass.
Will have likely to categorical POPS Sun night into Mon morning,
with likely POPS lingering into Monday aftn/evening along the
coast. Warm and humid with early morning lows 65-70 F Monday
morning and highs in the upper 70s/lower 80s on Memorial Day.
Disagreement amongst deterministic models by Tuesday, with the
12z/Operational GFS wanting to dry western portions of the area out
under developing weak sfc ridging, The ECMWF is slower to clear
out the sfc low altogether, ejecting it quicker to the NE.
Will continue to follow a WPC blended solution, weighted towards
the more consistent respective ensemble means. This translates to
a decreasing rain chance for Tuesday, but still mostly cloudy with
POPS to around 50% SE to 20-30% NW. Highs Tuesday in the low 80s
inland, upper 70s to low 80s along the coast.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TD2 is progged to linger in the vicinity of the NC coast Wednesday
and Thursday. There was some agreement in the earlier model runs,
but the 28/12z ECWMF lifts the low center farther north off the VA
coast Wednesday and Thursday. Main impacts from that solution would
be better chance for showers/thunderstorms east of Interstate 95,
cooler temperatures, and north to northeast winds of 10 to 15 mph.
Have stuck with overall model consensus with keeping the low in the
vicinity of the NC coast, but have bumped POPS Weds and Thurs up
slightly east of Interstate 95. For Wednesday and Thursday, a warm
and humid air mass will be in place over the local area with
vorticity maxima associated with the mid level features of TD2
providing modest forcing for ascent. Expect generally scattered
showers and diurnal thunderstorms. Subsidence between TD2 and an
upstream cold front expected to limit showers/thunderstorms over the
Piedmont Weds, with better chances Thursday as a warm front lifts
northward over the central Appalachians. Highs in the low to mid
80`s and lows in the 60`s. Sky averages Partly Cloudy.
Upstream trough and associated cold front reach the Central
Appalachians Thursday night, either kicking the low off the coast or
weakening the system over the region. Best chance for dry conditions
appears to be Thursday night, before POPs ramp back up Friday as the
front reaches the local area. Trough progged to deepen over the Ohio
Valley Friday and Friday night, with the front slowing as it reaches
the coast. Will keep 30-40% POPs into the weekend as unsettled
conditions linger. Highs in the low to mid 80s Friday before cooling
into the upper 70s to around 80. Lows in the 60`s. Sky averages
partly cloudy to mostly cloudy.
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
VFR conditions should continue through this afternoon into this
evening as high pressure remains in control with a dry airmass
across the area. As Tropical Depression Two moves toward the South
Carolina Coast, tropical low level moisture will move northward
and surge off the Atlantic and into the region later tonight into
Sunday. This will allow for IFR cigs to spread across the area
late tonight. Higher low level dewpoints may allow for some ifr
vsbys overnight as well. On Sunday, rain will spread from south to
north during the day. In turn...cigs/vsbys will likely raise to
mvfr Sunday morning.
Outlook...Despite the depression forecast to dissipate to a
remnant low, the guidance suggests that the tropical moisture will
persist across the area for much of the week. As such...expect
plenty of shower activity through the week esepcially across far
south VA and NE NC. Expect many periods of VFR through the week,
however with the moist airmass in place, there will be periods of
MVFR or IFR conditions through much of the week, especially in the
overnight and early morning hours.
Latest surface analysis centers TD2 roughly 150 miles southeast of
Charleston SC. High pressure remains over the western Atlantic,
extending over the local waters. Obs indicate south to southeast
winds of 10-15 kt over the waters. Waves 1-2 ft and seas 2 to 3 ft.
TD2 is expected to strengthen slightly over the Gulf Stream as it
lifts northwest toward the SC coast. Impacts for the local waters
remain limited to showers and thunderstorms Sunday and Monday.
Otherwise, flow will generally be out of the southeast at or below
15 kt. GFS/ECMWF lifts a wave of low pressure along a weak coastal
boundary off the Mid-Atlantic coast Monday with light (possibly
offshore) flow behind the wave. Seas may reach 5 ft in the northern
coastal zones late Monday into Monday evening. The main surface low
remains in the vicinity of the North Carolina coast, with the ECMWF
now lifting the center of the low off the Virginia coast by
Wednesday. Flow expected to be onshore at or below 15 kt, but if the
ECMWF verifies SCA conditions will be possible Wednesday and
Thursday. Gusts to 25 kt and high seas. Forecast reflects
persistence and general model consensus. A cold front is forecast to
reach the waters late in the week into next weekend. Sub-SCA
For more information on TD2, please refer to NHC.
The monthly rainfall total to date for May at Richmond is 8.41".
May 2016 is currently the 6th wettest month of May on record at
Richmond. There is a good chance for additional rain Sun/Mon with
the potential to end as the wettest May on record.
Top 6 wettest months of May at Richmond
1. 9.13" 1889
2. 8.98" 1873
3. 8.87" 1972
4. 8.67" 1886
5. 8.59" 2003
6. 8.41" 2016 (to date)