Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 140817 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 417 AM EDT Sat Oct 14 2017 .SYNOPSIS... Strong high pressure will remain offshore of New England today as a trough of low pressure slowly weakens along the coast. This area of high pressure settles off the Mid Atlantic coast late tonight into Sunday. A cold front passes through the region late Sunday night into Monday. Cool high pressure builds into the region Monday night and Tuesday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... The current surface analysis shows high pressure (~1030mb) centered over Nova Scotia and ridging back to the SW across Srn New England and into the Blue Ridge region of VA/NC. Meanwhile, weak low pressure is situated immediately off the coast of the Outer Banks. Cloudy and cool early this morning, with occasional bands of light rain and areas of drizzle, mainly along and E of the I-95 corridor. Temperatures range from the low 60s over the Piedmont, to the upper 60s over coastal SE VA/NE NC, with northerly wind of 10-15 mph along the coast. The weak low off the coast is expected to lift nwd today and gradually weaken. Model time-height cross-sections indicate that moisture remains stubborn to erode below 900mb E of I-95. Therefore, mostly cloudy to overcast conditions will likely prevail across the ern half of the area, with some areas of light rain and drizzle persisting through midday, and a 20-30% chc of light showers during the aftn. Farther W, moisture is expected to scour out over the Piedmont with the sky becoming partly to mostly sunny by aftn. More clouds to the E will hold high temperatures in the mid 70s, with high nearing 80F over the Piedmont with some clearing. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... A drying trend is expected later tonight into Sunday, as the weak low dissipates, and the strong high off the New England coast settles swd off the Mid-Atlantic coast resulting in SSW low- level flow. This will produce unseasonably warm conditions by Sunday (although not as humid) with the sky becoming mostly sunny. High temperatures Sunday will be in the low/mid 80s, after morning lows in the low/mid 60s. The cold front crosses the mountains Sunday night, and then continues to press ESE through the local area late Sunday night into Monday morning, passing through far SE VA/NE NC late Monday morning per 14/00z model consensus. Becoming mostly cloudy over the NW half of the area after Midnight Monday, while remaining partly cloudy SE. Models depict a narrow band of lift with the front, with the highest PoPs 40-60% across the NW portion of the area late Sunday night, and then shifting to the SE portion of the area Monday morning through midday. Lows Sunday night range from the mid 50s NW, to the low/mid 60s SE. Highs Monday will generally be in the mid/upper 60s, and temperatures may remain steady across SE VA/NE NC, or slowly fall a few degrees Monday morning through midday with clouds/pcpn. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... The cold front is expected to clear the area Monday night into early Tuesday. A few showers may linger in the far southeast into early Tuesday morning. High pressure builds into the area Tuesday into Wednesday with much cooler and drier air being ushered into the region. Highs on Tuesday will be much cooler than what we have become accustomed too with temperatures only in the mid 60s. By Tuesday night, temperatures will fall into the low to mid 40s for many locations away from the coast. Drier and cooler weather is expected to last through the extended period with highs in the 60s and 70s and lows in the 40s and 50s. Temperatures begin to moderate by the end of the period with highs reaching the mid 70s by Friday. It should be noted that while these values will feel much cooler, temperatures will be close to normal for mid October. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... Widespread stratus and areas of light rain and drizzle, associated with onshore flow and weak low pressure off the Outer Banks, continue to impact the region early this morning. Cigs range between 400-600ft, with vsby generally varying between 2-6sm. This area of low pressure gradually lifts nwd off the coast today, and then dissipates this evening. Conditions will be slow to improve today as moisture remains abundant below 5kft, with SBY/PHF/ORF/ECG likely retaining IFR cigs into the aftn, and RIC improving to MVFR. A N/NE wind will generally range from 6-12kt. Cigs begin to improve this evening as the low dissipates and N/NE low-level flow becomes SSW. The wind will remain light Saturday night, so areas of fog and stratus potentially redevelop as low-level moisture remains abundant. High pressure returns Sunday into Sunday evening with conditions improving to VFR. A cold front then pushes across the area Sunday night into Monday morning, bringing the potential for showers. The wind will become NNW behind the front with gusts up to 25kt possible in the wake of the front Monday morning and continuing into the aftn. High pressure and a drier airmass spread into the region Monday night through Wednesday. && .MARINE...
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The models are struggling to handle the winds associated with the weak low off the NC coast. Guidance suggest that winds should be diminishing over the waters already, but obs show that winds are still in the 15 to 20 kt range over the lower Ches Bay. So have amended the forecast to keep winds up for another 6 hours at low end sca levels on the Lower Bay. Seas are slowly beginning to drop over the coastal waters, but expect to keep the seas above 5 FT through the sca period, 6z Sunday. The surface low will slowly elongate today and fill as the surface high pressure system slides off the NE coast and gradually reforms into more of a Bermuda High with Southerly flow developing on Sunday. The S/SW flow will increase Sunday afternoon into Sunday night ahead of a strong cold front that will sweep across the waters. Behind this cold front, expect a strong surge of cool canadian air to arrive. Expect small craft conditions to develop Monday afternoon into Monday night. High pressure slides over the area by Tuesday morning with winds relax below sca levels.
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&& .TIDES/COASTAL FLOODING... Tidal departures still averaging 1.5 to 2.0 feet above normal across much of the region this evening, but currents data at the mouth of the Bay shows outgoing tide dominance so should see falling departures in the Bay overnight/Sat. Seas/winds off the coast are also diminishing so would also expect slowly falling departures for locations adjacent to the Ocean. Coastal flood advisories remain in effect for areas along the middle/upper Bay and upper James river to cover the current high tide cycle. Farther south and for Ocean locations, high tide has passed so the advisories were allowed to expire. Given the trends, and with the next high tide Sat morning being the lower of the two astronomically, additional tidal flooding appears unlikely though next shift will need to monitor this closely. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 11 AM EDT this morning for ANZ632- 634. Small Craft Advisory until 6 AM EDT Sunday for ANZ650-652-654- 656-658. && $$ SYNOPSIS...AJZ/ALB NEAR TERM...AJZ SHORT TERM...AJZ/ALB LONG TERM...AJB AVIATION...AJZ MARINE...ESS TIDES/COASTAL FLOODING... is the U.S. government's official web portal to all federal, state and local government web resources and services.