Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
046 FXUS61 KLWX 141850 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 250 PM EDT Fri Jun 14 2024 .SYNOPSIS... A cold front will cross the Mid-Atlantic tonight. High pressure builds in this weekend. A warm front lifts across the region Monday as high pressure shifts off the East Coast through next week. A prolonged period of hot temperatures take hold of the region next week. && .NEAR TERM /THROUGH TONIGHT/... As of 2 PM prefrontal showers over the Alleghenies are pushing east into the Shenandoah Valley. Large dew point depressions to start off likely means most of this is virga, though stronger updrafts are being noted on radar, with some moderate rain in the Waynesboro to Harrisonburg area. This light precip/cloud cover moves east of the Blue Ridge through late afternoon. Temperatures have reached the upper 80s to low 90s east of the Blue Ridge, and low to mid 80s west. The bay breeze has pushed onshore along the Western Shore, with 70F dew points observed behind it. Deeper mixing just to the west of the bay breeze toward the Piedmont has dropped dew points to the upper 50s to low 60s. The broad cloud cover and westerly/downslope flow across most of the area west of the Blue Ridge is likely to prevent severe storms from developing. The main area to watch is northern to northeast MD where the bay breeze boundary, and higher moisture/instability are currently present. The frontal boundary across western PA to central OH will slide south this evening, generating isolated to scattered showers and storms along the way. SPC has extended the Slight Risk across the I-70/I-68 corridor, with Marginal Risk for most of the rest of the CWA. However, as previously mentioned the best chance for severe storms looks limited to north/northeast MD, maybe down to the far northern DC suburbs. Trailing showers and a few storms linger through around midnight, then conditions dry out as the front pushes south of the area. Skies clear out late as temperatures settle in the upper 50s out west to mid 60s along I-95. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... Large surface high over southern ON/central Great Lakes on Saturday quickly shifts east over the Northeast, then off the southern New England coast Sunday night. Dry and seasonal conditions expected. Afternoon highs reach the low to mid 80s each day, with mid to upper 70s in the mountains. Seasonal overnight lows in the mid 50s to low 60s Saturday night. A warm front lifts north through the area Sunday night, bringing in milder temperatures. && .LONG TERM /MONDAY THROUGH FRIDAY/... Strong upper level ridging will dominate the weather pattern throughout the long term period, with dry conditions and well above normal temperatures expected. At the surface, high pressure builds over the Mid-Atlantic and lingers through the week. There remains uncertainty amongst global guidance with regards to the exact placement of the upper level ridge, with the ECMWF having the driest solution. On the contrary, the GFS and Canadian show increased moisture aloft as the ridge pivots overhead leading to a chance of showers and thunderstorms in the afternoon. For the forecast, PoPs are trending low with primarily dry conditions expected for our area but a stray shower or sprinkle cannot be ruled out in the western portions of the area. The main weather hazard for next week will be above normal temperatures. High temperatures east of the Alleghenies will rise well into the 90s each day with increased humidity leading to warming heat indices and record high temperatures are possible. Heat indices in the upper 90s are expected with lower to mid 100`s possible. As the ridge axis pivots over the area, southerly winds will shift to southeasterly, providing a slight cool down with high temperatures in the mid 90s expected. That being said, relative humidities will increase with southeasterly flow which will possibly lead to continued heat index concerns. Heat advisories or heat watches may be needed at some point during the long term. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... A cold front will cross the area this evening, bringing scattered showers and thunderstorms to most terminals between 21Z to 01Z. As of now, activity looks to remain scattered, so no TEMPO groups have been added to the 18Z TAFs. Still, any storm that does move over a terminal could produce brief restrictions, in addition to gusty winds. A few showers could linger into the evening. Behind the front, VFR conditions are expected tonight through the weekend. Northerly winds Saturday weaken Saturday night into Sunday, eventually becoming east to southeast. VFR conditions are expected both Monday and Tuesday with hot and dry conditions expected at all terminals. Winds remain light, blowing 5- 10 knots, out of the south. && .MARINE... A Small Craft Advisory is in effect for the main channel of the Chesapeake Bay between Sandy Point MD and Smith Point VA. Southerly channeling combined with the afternoon bay breeze should be sufficient for a period of gusts around 20 knots. A brief period of NW 15-20 knot gusts is possible in the wake of a cold front this evening, with gustier winds possible in shower or thunderstorm activity (may require Special Marine Warnings). Northerly channeling behind the cold front will produce SCA conditions over most of the waters of the Chesapeake Bay and Lower Tidal Potomac. Another Small Craft Advisory is in effect from early Saturday morning through Saturday afternoon. After that, winds diminish below SCA conditions through Sunday night as high pressure shifts offshore of the New England coast. Local winds go from north to east, then southeast Sunday afternoon. Southerly channeling will lead to possible SCA conditions both Monday and Tuesday. Outside of gusty winds, hot and dry conditions are expected to start out the week. && .CLIMATE... High temperatures for next week. Below is a list of record high temperatures for June 17th, 18th, 19th, and the 20th and the year the record was set, and the current forecast high temperatures for those days. Daily temperature records are currently only maintained at DCA, IAD, BWI, and MRB. Others are shown for reference. Monday Jun 17th Climate Site Record High Forecast High Washington-National (DCA) 99F (2022) 95F Washington-Dulles (IAD) 96F (2022) 95F Baltimore (BWI) 96F (2022+) 93F Martinsburg (MRB) 98F (1939+) 93F Charlottesville (CHO) 97F (2022) 94F Annapolis (NAK) 96F (1939) 88F Hagerstown (HGR) 96F (1952) 94F Tuesday Jun 18th Climate Site Record High Forecast High Washington-National (DCA) 97F (1944) 97F Washington-Dulles (IAD) 94F (2018+) 97F Baltimore (BWI) 97F (1957+) 95F Martinsburg (MRB) 99F (1943) 95F Charlottesville (CHO) 96F (2014+) 96F Annapolis (NAK) 96F (1957) 90F Hagerstown (HGR) 95F (1957) 97F Wednesday Jun 19th Climate Site Record High Forecast High Washington-National (DCA) 99F (1994) 94F Washington-Dulles (IAD) 98F (1994) 95F Baltimore (BWI) 99F (1994) 92F Martinsburg (MRB) 96F (1994+) 93F Charlottesville (CHO) 97F (2018) 94F Annapolis (NAK) 96F (1993) 87F Hagerstown (HGR) 97F (1994) 95F Thursday Jun 20th Climate Site Record High Forecast High Washington-National (DCA) 99F (1931) 94F Washington-Dulles (IAD) 97F (1964) 95F Baltimore (BWI) 100F (1931) 92F Martinsburg (MRB) 98F (1931) 93F Charlottesville (CHO) 98F (1933) 93F Annapolis (NAK) 98F (1988) 88F Hagerstown (HGR) 98F (1931) 94F + indicates that value has been reached on multiple years, with the year displayed being the most recent. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from 4 AM to 11 AM EDT Saturday for ANZ530>532-539>541. Small Craft Advisory until 9 PM EDT this evening for ANZ532>534-537-542. Small Craft Advisory from 4 AM to 3 PM EDT Saturday for ANZ533- 534-537-542-543. && $$ SYNOPSIS...DHOF/KRR NEAR TERM...KRR SHORT TERM...KRR LONG TERM...AVS AVIATION...KRR/AVS MARINE...KRR/AVS CLIMATE...LWX