Area Forecast Discussion


827 
FXUS61 KAKQ 180028
AFDAKQ
AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
828 PM EDT Tue Sep 17 2019
.SYNOPSIS...
Surface high pressure builds down into the region from the 
north tonight through Thursday. Meanwhile, Hurricane Humberto 
is forecast to track well east of the Southeast coast through 
midweek.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 830 PM EDT Tuesday...
Latest MSAS has the cold front across the Carolinas with weak high
pressure over the lwr MD ern shore. Most if not all the shwrs have
moved ssw of the fa, although some light echoes noted across swrn
Mecklenburg county. Will keep slght chc PoPs there for anthr hr or
so. Meanwhile, clouds have scattered out from the bay on east toward
the coast. Models continue to slowly erode the clouds westward thru
the overnight hrs with skies becoming mstly clr to pt cldy aftr 
midnite. Data also suggests some SC dvlp[ng late along the coast due
to the persistant onshore wind flow. Cooler with lows 55-60 except
lwr 60s se coastal areas. 
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
As of 220 PM EDT Tuesday...
High pressure continues to build swd from the eastern Great 
Lakes/New England Wednesday. Forecast soundings show some 
lingering low level moisture with the onshore flow, which should
result in partly cloudy conditions along the coast, with mostly
sunny conditions west of I-95 to the piedmont. However, dry 
conditions should prevail with limited deep layer moisture. 
Comfortable conditions are expected, with highs topping out in
the 70s to near 80F...and dewpoints falling into the 50s for 
most areas. Remaining rather breezy along the coast, due to the
cooler airmass over the warm water and a strong pressure 
gradient between the high to the N and Humberto well offshore. 
Pleasant Wednesday night with lows in the low/mid 50s inland, 
and upper 50s/low 60s closer to and along the coast.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 220 PM EDT Tuesday...
Cooler, drier conditions look to persist for the mid to latter
portion of the week. Ridge of sfc high pressure will prevail
over the Mid-Atlantic into the southeastern US for the late week
period. Aloft, the region will remain on the periphery of an 
upper level ridge of high pressure, which will rebuild over the 
region from the southwest during the upcoming weekend, bringing 
a gradual warm- up late in the weekend into early next week.
Warm days and cool nights persist into the weekend, with high 
temperatures Thursday through Saturday near to slightly below 
seasonal averages with highs in the upper 70s to lower 80s. 
Overnight lows falling back into the low to mid 50s inland 
(though a smattering of upper 40s possible in typical cool spots
Thu/Fri mornings)...with low to mid 60s at the coast. The 
warming trend begins Saturday into early next week, with high 
pressure at the surface and building heights aloft. Above 
average temperatures likely prevail through this period with 
highs in the mid/upper 80s to around 90 degrees with early
morning lows generally in the 60s area wide.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
As of 720 PM EDT Tuesday...
Low clouds have slowly been eroding along the coast and expect
that trend to continue westward over the next few hours. VFR
conditions at all TAF locations through the evening. NE winds
have been gusting 15-20kts at ORF/PHF/ECG...while maintaining
10kts or below at RIC/SBY. SCT to BKN CU is expected to develop
Wednesday morning across eastern VA/NC and periods of MVFR
ceilings are possible especially at eastern TAF sites. 
Beyond Wednesday...VFR conditions through the weekend as high
pressure settles in resulting in dry and mainly clear weather.
&&
.MARINE...
As of 355 PM EDT Tuesday...
Afternoon surface analysis shows high pressure migrating eastward 
from the Great Lakes region with Hurricane Humberto continuing to 
organize off the Southeast coast. The gradient between these two 
features is leading to northeasterly winds of 15-20 knots with a few 
gusts at elevated sensors nearing 25 knots this afternoon. Waves are 
1-2 ft across the northern Bay and 2-3 ft across the south. Seas 
offshore are continuing to increase with 5-6 ft S and 4-5 ft N.
By late this aftn, NE winds increase to 17-20 kt (sustained) on the 
bay and Lower James River/20-25 kt on the ocean and Currituck Sound. 
Additionally, seas increase to 5-6 ft (w/ 2-4 ft waves on the Ches 
Bay) by this evening. The high becomes centered over nrn New England 
by Wed AM as Humberto continues to track to the ENE. Winds increase 
slightly (by a few knots) tonight and a few gusts to 30 kt are 
likely over the Mouth of the Ches Bay/srn coastal waters by late 
tonight/Wed AM. The potential for ~30 kt gusts in these areas 
continues through the day on Wed. Sustained winds of ~20 kt on the 
bay/25 kt on the ocean are expected on Wed (lasting through the 
first part of Wed night). There is a chc that SCAs may be needed for 
the upper rivers for a time on Wed, with at least a few gusts of ~20 
kt likely. Seas build from 5-7 ft early Wed AM to 7-10 ft by 00z Thu 
(highest S of the VA/NC border). A High Surf Advisory has been 
hoisted for VA Beach and points south from Wednesday morning through 
Thursday evening and will potentially need to be extended northward 
and later in time in subsequent forecasts. SCAs remain in effect 
through 7 PM Wed for the Ches Bay, Lower James River and Currituck 
Sound (and may need to be extended further in subsequent forecast 
packages). The SCA for the ocean extends through 7 PM Thu (due to 
very high confidence in seas remaining aoa 5 ft).
On Thursday, the high is expected to build SSW toward the area as 
Humberto continues to slowly pull away to the ENE. This will finally 
allow for winds to turn to the N slowly diminish from Thu AM-Thu 
night. The current forecast has wind gusts dropping below SCA 
thresholds by late Thu afternoon. The high is expected to settle 
into the region from Fri-Sat before moving to the SE of the area on 
Sun. Winds are expected to become light (aob 10 kt) by late Fri and 
remain that way through much of the weekend. However, seas (and 
waves near the mouth of the Bay) will be slow to diminish. SCAs may 
need to be extended for the mouth of the Ches Bay through Fri/ocean 
through Sat (due to waves/seas).
&&
.TIDES/COASTAL FLOODING...
As of 420 PM EDT Tuesday...
A strong NE wind will push tidal anomalies to 1.0-1.5ft above 
normal by Wednesday and Thursday. This has the potential to 
produce minor tidal flooding, particularly on the south and west
sides of the Ches Bay, James River, and associated tributaries.
In addition...with the persistent NE wind/swell...water likely 
gets trapped in the upper Ches Bay by Thu. This will lead to 
steadily increasing anomalies on the Bayside of the Lower MD Ern
Shore. Borderline minor/moderate tidal flooding is possible in 
vulnerable areas of southern Dorchester County by the high tide 
Thursday evening, with a chc of minor flooding at 
Cambridge/Crisfield. Water levels are forecast to crest just 
above minor flood thresholds at Bishop's Head by late Wed aftn. 
The current forecast keeps water levels just below minor flood
thresholds along the Atlantic coast of MD, VA, and NC. However,
there is a slight chc that water levels exceed minor flood
thresholds on the oceanside of the VA Ern Shore/NC during the
higher astronomical tides on Wed/Thu.
A high rip current risk is forecast for today and Wednesday, 
and will likely continue into Thursday, as swell from Humberto 
propagates toward the coast.
&&
.EQUIPMENT...
KDOX radar has returned to service as of Tuesday evening.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...High Surf Advisory from 7 AM Wednesday to 7 PM EDT Thursday 
     for NCZ102.
VA...High Surf Advisory from 7 AM Wednesday to 7 PM EDT Thursday 
     for VAZ098.
MARINE...Small Craft Advisory until 7 PM EDT Wednesday for ANZ630>634-
     638.
     Small Craft Advisory until 7 PM EDT Thursday for ANZ650-652-
     654-656-658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MPR
SHORT TERM...AJZ/MAM
LONG TERM...MAM
AVIATION...CMF
MARINE...ERI/RHR
TIDES/COASTAL FLOODING...AKQ
EQUIPMENT...AKQ