Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 070246 AFDAKQ AREA FORECAST DISCUSSION National Weather Service Wakefield VA 946 PM EST Fri Dec 6 2019 .SYNOPSIS... A cold front crosses the area tonight with high pressure returning for the weekend. Low pressure tracks across the Great Lakes region early next week, dragging a strong cold front across the area Tuesday night. Canadian high pressure builds in on Thursday before moving offshore by late Friday. && .NEAR TERM /THROUGH SATURDAY/... As of 945 PM EST Friday... Late this evening, a cold front was pushing through nrn VA/MD/DE. Also, sfc high pressure was building into the upper Midwest. Latest radar showed very light showers moving across NE NC. Otherwise, the sky ranged from partly cloudy to cloudy over the CWA with temps ranging from the mid 40s to lower 50s. The cold front will drop across the region overnight. Isolated light showers will push SE of the area and off the coast in the next few hours. Decreasing clouds from NW to SE overnight into Sat morning. Winds become north allowing for some CAA to set in. Lows by 12Z Sat mainly in the 30s except for lower 40s in SE VA/NE NC. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... As of 345 PM EST Friday... Sunny but cool Sat as high pressure builds into the Northeast CONUS and the sfc flow turns to the NNE. Not particularly cold for early December (850 mb temps of -1 to -3C) with highs ranging from the mid 40s N to the upper 40s S. Clear w/ light winds Sat night as the high becomes centered over srn New England, with sfc ridging extending SSW into our area. Given the clear skies/light winds, went a bit cooler than model consensus Sat night. Forecast lows are mainly in the mid 20s inland, with low 30s across coastal SE VA/NE NC. The high pushes offshore of the New England coast on Sun. This allows the sfc flow to become SSE, veering to the WSW in the mid-levels. This will allow WAA to commence on Sun. Deep-layer moisture starts to increase during the latter half of the day on Sun as a series of disturbances in WSW-SW flow aloft approach the local area (as a trough aloft starts to amplify in the Rockies/High Plains). In addition, a trough of low pressure develops at the sfc along the Carolina coast by Sun evening. Milder Sun with highs ranging from the upper 40s NW to the upper 50s SE. Rain quickly develops/moves into the area Sun night from S to N as a warm mid-level airmass overruns relatively cooler air near the surface. This happens as the weak trough of low pressure approaches from the S. PoPs of 30-50% during the evening increase to 60-70% in most areas after 06z Mon. QPFs through 12z Mon are mainly in the 0.1-0.25" range. Lows Monday morning range from around 40F N to around 50F SE. Periods of showers continue throughout the day on Mon as the first upper level disturbance/area of sfc low pressure crosses the region. Models are hinting at a (relative) lull in the pcpn across sern zones during the latter half of the day on Mon, while numerous showers move across northern/western portions of the CWA (w/ somewhat of an in-situ wedge lingering across the Piedmont). Adjusted PoPs to reflect this thinking (chc PoPs across SE VA/NE NC with likely PoPs north/west from 18z Mon-00z Tue). Highs Mon range from the low-mid 50s NW to the mid-upper 60s SE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 345 PM EST Friday... The aforementioned trough aloft quickly amplifies across the Midwest Mon night-Tue as strong sfc low pressure deepens as it tracks from the Upper Midwest to SE Canada. A series of upper disturbances (in SW flow aloft) will continue to track toward/across the region through Tue as the associated cold front slowly approaches from the W/NW. Strong WAA will continue through Tue (850 mb temps rising to 8-11C by 12z Tue) under deep-layered SW flow. With the area likely remaining in the warm sector from Mon night-Tue, expect at least a chc of (occasional) showers to continue from Mon night through the first part of the day on Tue. Have PoPs in the 30-60% range for the most part from 00-18z Tue, as most of the rain will remain to our west through midday Tue (latest 12z/06 models are slowing the eastward progression of the upper trough axis). Mild Monday night with lows mainly in the 50s. It is still looking like the frontal passage holds off until sometime during the latter half of the day on Tue. As a result, look for highs well into the 60s on Tuesday...with the potential for some low 70s in Hampton Roads/NE NC. PoPs increase to 60-70% by Tue aftn in all areas except for far SE VA/NE NC as the upper trough axis continues to slowly move toward the region. The cold front is progged to move S of the CWA by late Tue night, but a long-duration light to moderate rain is expected to continue before ending from NW to SE Wed AM (as the upper trough axis finally approaches/crosses the region). As cooler air filters into the region behind the front Tue night, the rain is expected to change over to snow in areas to our NW (while a cold rain continues across our CWA). Cannot rule out a brief changeover to snow (or a rain/snow mix) closer to 12z Wed across our far NW zones, but not expecting any impacts from snow that does fall (temps remain above freezing). Additionally, 12z/06 EPS probabilities of at least 1" of snow are only 10-20% across Louisa/Fluvanna counties from Tue night-Wed AM. Lows Tue night range from the mid 30s north/west to the low-mid 40s in SE VA/NE NC. It will be dry but colder from Wed aftn-Thu as strong high pressure builds into the Great Lakes by midweek before quickly migrating eastward. The high becomes centered near/over the local area by Thursday evening. This will result in a short- lived period of below average temperatures from Wed night-Thu night, due to cold Canadian air sweeping across the region behind the departing front. Forecast highs are mainly in the mid-upper 40s on Wed (some readings around 50 across the SE), Colder on Thu with highs ranging from the upper 30s-low 40s. Lows Wed night/Thu night mainly in the 20s (although some teens are possible across NW zones). Model consensus is forecasting the high to move offshore of the New England Coast on Fri as low pressure develops near the Gulf Coast. This low will likely track across our region next weekend. However, it is looking like any threat for impacts due to wintry precipitation will likely remain N of the region (12z EPS probs for 1" of snow are ~0% across our CWA next weekend). && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... As of 705 PM EST Friday... VFR conditions will prevail through the 00z TAF period. Mid/high level clouds (CIGS 7-12k feet) will affect the TAF sites this evening into early Sat morning, as a cold front drops across the area. There is a slight (15-20%) chc of SHRAs at SBY/ECG from 00-06z Sat, but did not include any mention of pcpn in the TAFs (even if SHRAs do occur, conditions will remain VFR). The other terminals should remain dry through the TAF period. The sky will clear out from N to S Sat morning. SKC conditions then prevail through the day on Sat. SW winds 5-15 kt this evening will turn to the W tonight before eventually becoming N-NNE Sat morning. NNE winds could gust to 20 kt at ORF/ECG on Sat, with a few gusts to 15 kt possible elsewhere. OUTLOOK...High pressure builds into the area Sat into Sat night before moving offshore on Sun. VFR conditions are expected to continue through the weekend. Periods of showers are then expected from late Sun night through Tue night, as low pressure tracks well to our NW (which will drag a strong cold front through the region). Degraded flight conditions are likely during this time period (due to both CIGs/VSBYs). && .MARINE... As of 300 PM EST Friday... SW winds are currently running 10-15 kt, except 15-25 kt with gusts up to 30 kt off the lower Eastern Shore. These winds will continue through the evening hours ahead of a cold front. Waves 1-2 ft; seas 2-4 ft (highest north). SCAs remain in effect north of Parramore Island. Winds become N/NW late tonight into early Saturday after the front crosses the area waters. Winds increase to 15-20 kts in the bay with gusts to 25 kts, and 20-25 kts with gusts to around 30 kts in the coastal waters. Waves in the bay build to 2-4 ft and seas build to 3- 5 ft in the middle and northern coastal waters and 4-6 ft in the southern coastal waters. SCA will be in effect for the bay, rivers, coastal waters, and Currituck sound from early Saturday morning through early Saturday afternoon, lingering into Saturday evening for the southern coastal waters and Currituck sound. Winds along with waves/seas will subside by late Saturday night as the pressure gradient relaxes and high pressure builds into the area for the remainder of the weekend. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory from 1 AM to 1 PM EST Saturday for ANZ635>638-654. Small Craft Advisory until 1 PM EST Saturday for ANZ630>632- 634. Small Craft Advisory from 1 AM to 7 PM EST Saturday for ANZ633- 656-658. Small Craft Advisory until 1 PM EST Saturday for ANZ650-652. && $$ SYNOPSIS...ERI/TMG NEAR TERM...ERI/TMG SHORT TERM...ERI/MPR LONG TERM...ERI AVIATION...ERI/TMG MARINE...JDM is the U.S. government's official web portal to all federal, state and local government web resources and services.