747 FXUS61 KAKQ 110140 AFDAKQ Area Forecast Discussion National Weather Service Wakefield VA 940 PM EDT Wed Oct 10 2018 .SYNOPSIS... A cold front approaches the from the west tonight and Thursday, as tropical cyclone Michael moves northeast across the southeastern states and into the Carolinas. The storm will then track off the Mid Atlantic coast and out to sea Friday morning. Please refer to forecasts from the National Hurricane Center regarding Michael. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of 940 PM EDT Wednesday... Bermuda high pressure remains well offshore, with Hurricane Michael tracking to the northeast through southwestern Georgia. Low-level moisture is streaming northward into the region from central/srn NC, where PWs are ~2-2.2 inches. Scattered showers have developed on the leading edge of increased low-level moisture from central to southeastern NC. Hi-res guidance (notably the HRRR) is forecasting these showers to move into the region from 04-07z. Went ahead and raised PoPs to between 50-60% throughout the region from 06-12z. Otherwise, no significant changes to the forecast. Not much in the way of significant pcpn is expected thru 12Z Thurs, but a few isolated downpours cannot be ruled out. BKN-OVC low stratus increases across the area late tonight, but not as strong of a signal for fog tonight when compared to the past three nights. Another warm and humid night with lows between 70-75. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... As of 400 PM EDT Wednesday... The forecast governed by Michael's track as the wind field conts to weaken as it tracks NNE as it tracks across the sern states tonight then the Carolinas Thursday. Models in decent agreement but subtle differences in the track poses different challenges for the local area. Both the NAM/GFS track the remnant low across srn VA versus ne NC in the ECMWF. This northward adjustment may allow for the threat of svr storms further north Thurs night than the current forecast shows. Something to keep an eye on as the event unfolds. Otw, the main concerns will be heavy rainfall and winds east of the I95 corridor. The axis of heavy rain has shifted north with QPF amts btwn 2-4 inches across the interior north with 3-6 inches south and east. Thus, after coord with other offices along, have elected to expand the flash flood watch north to include all AKQ zones except Louisa and Fluvanna. Deep layered SSW flow, PW's aoa 2 inches along with the best lift / f-gen forcing suggests the heaviest rainfall occurs between 15Z Thurs to 08Z Fri west of I95 and 18Z Thurs to 12Z Fri east of I95. This jibes well with WPC's Day 2 excessive rainfall outlook. Thus Pops will be at 100% along with slight chcs for thunder starting Thurs aftrn and contg Thurs night. Still feeling tropical Thurs with highs upr 70s- lwr 80s. The cold front now progged a bit faster across the region late Thurs night, pushing the deepest moisture offshore by 12Z Fri. Thus, CAA sets in behind the systm allowing temps to drop into the mid 50s nw to mid 60s se. Expect a period of gusty pressure gradient NNW (non-tropical) winds Thurs night with inland gusts 30-40+ mph and 40-60 mph along the coast. This is why we have non-tropical headlines for this event. Given the amount of dry air punching into the region behind the systm, expect Fri to see decreasing cloudiness along with breezy to windy conditions early. Dew points dropping into the 40s as well. Highs Fri mid 60s nw to lwr 70s se. Mstly clr Fri night except for some clouds across the north after midnight. Lows mid 40s nw to mid 50s sern coastal areas. S/W trof passes by north of the local area Sat. Will keep the forecast dry for now with more cloudiness across the north. A stray afternoon shower will be possible north of the local area. Highs 65-70. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As of 400 PM EDT Wednesday... The extended period will start with tranquil weather as sfc high pressure will be centered over the Mid-Atlantic region Saturday night. The area of high pressure will move offshore by the end of the day on Sunday. Sunday will be mainly dry with highs ranging from the mid 60s to mid 70s. The weather will become more active early next week, as a trough of low pressure (along w/ a sfc cold front) are forecast to approach the region. As a result, shower/tstm chances increase from NW to SE late Monday through Tuesday as the cold front crosses the region. There are still some timing differences between the latest 10/12z GFS/ECMWF/GEM regarding the timing of the trough/FROPA. The GFS remains the faster model, as it moves all of the rain south/east of the area by late Tue AM. The ECMWF/GEM move the front through the area by Tue PM. However, they are forecasting some post-frontal rain to develop across the southern half of the CWA late Tue through Tue night (the GFS keeps the area dry behind the front). Leaned slightly toward the GFS with the forecast, but went with an overall blend of the models for the timing of the precipitation Mon night-Wed AM. For now, have PoPs of 30-50% across the entire area (progressing from NW to SE) Mon PM-Tue AM tapering to slight chc PoPs over the southeast by the end of the day on Tue. Mainly dry for Wed with a slight chance of showers over the southeastern CWA. Highs will mainly range from the mid 60s NW to the mid 70s over SE VA/NE NC on Sun, warming into the low 70s to around 80 on Mon. Cooler on Tue/Wed with highs ranging from the low-mid 60s NW to the mid 70s SE. Morning lows on Sun range from the 40s inland to near 60 over the southeast. Expect lows to range from near 50 to the low-mid 60s on Mon/Tue, cooling to the mid 40s NW/upper 50s SE on Wed/Thu. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... As of 800 PM EDT Wednesday... IR satellite is showing BKN mid-high clouds with some obs showing FEW-SCT clouds between 4-5k feet. Mainly dry across the terminals this evening, with a few areas of light rain well south/west of RIC. Expect the terminals to remain dry through 06z tonight, with isolated-scattered showers developing during the second half of the night. CIGS lower to MVFR/IFR levels (due to BKN stratus) late tonight, but no prolonged visibility restrictions are expected through 12z. Scattered to perhaps numerous showers will likely persist well ahead of Michael during the morning hours on Thursday with widespread RA/+RA overspreading the area from SW to NE during the mid afternoon through early evening hours. The area of steady RA/+RA will not arrive SBY until ~8 PM Thursday. The steady RA/+RA will end from W to E across the region between 06-10z Friday. Visibilities will fluctuate between MVFR and (briefly) LIFR levels in the rain, with IFR or low-end MVFR CIGS through the duration of the steady RA/+RA. S/SE winds will likely gust to 15-30 kts after noon on Thursday at the coastal TAF sites. Winds turn to the NNW early Friday morning and are expected to briefly gust to 30-50 kt at the coastal sites, with 20-30 kt gusts expected at RIC. Winds slowly subside during the day on Friday as Michael rapidly moves offshore away from the Mid-Atlantic coast. OUTLOOK... Dry weather/VFR conditions are expected Fri afternoon through Sunday. && .MARINE... As of 400 PM EDT Wednesday... SSE winds around 10 to 15 knots are anticipated through tonight. Seas will average around 4 feet and waves around 1 to 2 feet. Michael made landfall earlier this afternoon on the Panhandle of Florida as a powerful category 4 hurricane. Michael is forecast to get absorbed by an approaching upper level trough, sending the remnant low up the southeast coast through early Friday. The flow will remain S-SE late today into early Thursday, and will increase slightly due to the tightening pressure gradient. Winds quickly increase late Thursday into Friday morning due to a combination of Michael and the approaching strong cold front from the northwest. Models remain in relatively good agreement on the mesoscale details, though some timing differences remain. have edged toward the quicker solution which is also preferred by the NHC official track. On this track, winds are expected to pick up out of the S/SE Thursday night across the southern waters with gusts as high as 50 knots possible. Winds then turn to the NNW Friday morning, behind the frontal passage and as the remnant low moves offshore. Winds may gust to 40 knots over a majority of the waters Friday morning with even higher gusts of 50 to 60 knots across the southern coastal waters/Bay. The current forecast has the strongest winds roughly between 06 and 12Z Friday morning. The strongest winds diminish through Friday morning, but breezy NW winds will linger through the day Friday as high pressure builds over the Ohio Valley. With respect to headlines, the result of all of the above means Storm Warnings are now in effect for the ocean S of Parramore Is. and the entire Ches Bay, along with the Lower James River. The remaining zones have Gale Warnings. For land areas, a High Wind Warning is now in effect for portions of Eastern Virginia and Northeast North Carolina. Wind Advisories extend further inland, surrounding the High Wind Warning. Additional Wind Advisories may be needed further inland as we get closer in time. && .HYDROLOGY... Current river forecasts are based on expected QPF's. So despite most gages progged to go above flood stage, we still have some time to evaluate the forecasts once the heavier rain approaches. && .TIDES/COASTAL FLOODING... As of 430 PM EDT Wednesday... Have issued a broad-brushed coastal flood advisory from thu aftn through Fri morning for NC locations adjacent to the Currituck and Albemarle sound (including nearby rivers). This area has little tidal influence, but expect some water to be driven into the sounds on strong E/SE winds later Thu. Elsewhere, tidal departures currently avg around +1.0 ft in the mid/upper Bay and +0.5 to +0.75 ft in the lower Bay and less than +0.5 ft along the Ocean. Only minor/nuisance flooding is expected through the next high tide cycle overnight/early Thu morning so have extended the coastal flood statement through that timeframe over the bayside of the MD eastern shore and across the northern Neck. Due to the fast motion of Michael, coastal flooding is generally expected to peak only in the minor flood category and the latest 12Z/10 guidance continues to depict the peak surge occurring late Thu evening into early Fri morning. This does not really occur during high tide and even in locations across the lower Bay and Ocean where it is closer to high tide, this will be the lower high tide of the diurnal cycle. Did not issue any coastal flood watches, but expect that the next shift(s) will need some coastal flood advisories. One additional concern is for the eastern side of the Bay where there could be a quick increase in the departures early Fri as the winds shift to the NW and intensify to storm force, forcing water into these locations. Some residual elevated departures may persist along the southern VA/NC ocean locations Fri. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...Flash Flood Watch from Thursday afternoon through Friday morning for MDZ021>025. Wind Advisory from 6 PM Thursday to noon EDT Friday for MDZ021>025. NC...Flash Flood Watch from Thursday afternoon through Friday morning for NCZ014>017-031-032-102. Wind Advisory from 6 PM Thursday to noon EDT Friday for NCZ013- 014-030>032. Flash Flood Watch from 8 AM EDT Thursday through Friday morning for NCZ012-013-030. High Wind Warning from 6 PM Thursday to noon EDT Friday for NCZ015>017-102. Coastal Flood Advisory from 4 PM Thursday to 8 AM EDT Friday for NCZ015>017-031-032-102. VA...Flash Flood Watch from Thursday afternoon through Friday morning for VAZ075>078-082>086-089-090-093-095>100- 518>525. Wind Advisory from 6 PM Thursday to noon EDT Friday for VAZ077- 078-084-085-093-096-523-524. Flash Flood Watch from 8 AM EDT Thursday through Friday morning for VAZ060>062-064>069-079>081-087-088-092- 510>517. High Wind Warning from 6 PM Thursday to noon EDT Friday for VAZ086-095-097>100-525. MARINE...Storm Warning from 6 PM Thursday to noon EDT Friday for ANZ630>634-638-654-656-658. Gale Warning from 9 PM Thursday to noon EDT Friday for ANZ650- 652. Gale Warning from 6 PM Thursday to noon EDT Friday for ANZ635>637. && $$ SYNOPSIS...MPR NEAR TERM...ERI/MPR SHORT TERM...MPR LONG TERM...ERI AVIATION...ERI MARINE...AJB HYDROLOGY...MPR TIDES/COASTAL FLOODING...LKB