FXUS61 KLWX 131430 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 1030 AM EDT Tue Sep 13 2016 .SYNOPSIS... High pressure will drift east from the northern Mid-Atlantic coast rest of today. A mainly dry cold front will cross the area Wednesday night. High pressure returns to the area through Friday before a cold front crosses the area Sunday night. && .NEAR TERM /THROUGH TONIGHT/... Low level SWly flow will bring mid to upper teen 850mb temps today with temperatures a few degrees higher than yesterday...maxima 85 to 90F. Less cloud cover expected tonight with valley/ground fog possible. Warmer with lows 65 to 70 due to a strengthening Sly flow. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... H85 temps rise to 18-20C and sfc winds become westerly ahead of cdfnt moving through the eastern Great Lks and New England states. MOS guidance looks too cool and have used a model trend for MaxT Wed. Expecting temps to reach the mid 90s with record highs likely at DCA and IAD. Cdfnt will be moving through the area during the evening and have kept a slight chance (20% POP) for MD counties along the Mason- Dixon line. High pressure builds Thu through Fri with temperatures at least 10 degs cooler Thu. Low clouds expected to develop behind front Thu and Thu night with some very light precip over the Blue Ridge mountains due to upslope flow. && .LONG TERM /FRIDAY THROUGH MONDAY/... High pressure will be located over New England on Friday, with upper ridging moving overhead. A light onshore wind combined with the low level thermal trough axis passing through may mean Friday is the coolest day of the week (and dry), as highs may stay below 80F for a large portion of the area. The high will move farther east Saturday as a low pressure system moves into the Great Lakes. Am thinking Saturday remains dry, with the best chance for any storms over the western terrain where heights will be lower and there will be a SE upslope component to the low level flow. It's also possible pre-frontal convection from the west approaches during the evening or overnight. Otherwise, increasing temperatures can be expected. For Sunday-Monday, model spread begins to increase significantly in how to handle the approaching cold front, upper level energy, and possible interaction with moisture along the southeast coast. The 00Z ECMWF is flatter with the upper flow and quicker with the front, whereas the 00Z GFS develops a closed low at 500mb, a wave along the front, and a slower passage on Monday. Therefore, the forecast will call for chances of showers and storms through this time period. Temperatures are expected to remain above normal through Monday. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... VFR through Wed night. Southerly flow around 10 kt rest of today. Winds shift west Wednesday gusting around 15 kt ahead of a dry cold front that crosses Wednesday night. NWly flow gusts around 20 knots Thursday. MVFR/IFR cigs possible Thu and especially Thu night due to onshore flow behind fropa. There is potential for MVFR clouds due to onshore flow Friday and Saturday mornings, mainly at IAD/MRB/CHO. && .MARINE... South winds 10 to 15 kt through this evening with high pressure offshore. Winds expected to strengthen Wed night with SCA conditions likely Thu through Fri morning. High pressure will move off the coast Friday into Saturday. Onshore flow Friday will become southerly on Saturday. Winds may approach small craft advisory levels by late in the day. && .FIRE WEATHER... MODIS and VIIRS True color images from yesterday revealed that significant drying has occurred across northern VA and north central MD especially in Washington, Frederick and western Loudoun counties. Record high temperatures likely Wed with Rh's dropping into the low twenties as winds become westerly. Red flags conditions are not expected since winds are expected to remain below criteria, but an elevated fire weather threat will exist due to low humidities and drying fuels. && .TIDES/COASTAL FLOODING... Light south flow has raised water levels about one foot above normal. No coastal flooding is expected with this lesser high tide during the day today (though Straits Pt and Annapolis will be close), but is expected for sensitive locations for the preferred high tide cycle tonight. && .CLIMATE... Unseasonably hot weather will return to the area briefly on Wednesday. Here is a list of record daily high and warm low temperatures for September 14th. Washington DC area (Ronald Reagan National Airport, DCA) Record daily high temperature: 94 (1981, 1980 and 1915) Record daily high minimum temperature: 75 (2008 and 1961) Baltimore MD area (Baltimore-Washington International Thurgood Marshall Airport, BWI) Record daily high temperature: 94 (1931) Record daily high minimum temperature: 74 (1915) Dulles International Airport VA (IAD) Record daily high temperature: 95 (1998) Record daily high minimum temperature: 71 (2008) && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...BAJ/LFR NEAR TERM...BAJ/LFR SHORT TERM...LFR LONG TERM...ADS AVIATION...BAJ/ADS/LFR MARINE...BAJ/ADS/LFR FIRE WEATHER...lfr/baj TIDES/COASTAL FLOODING...baj CLIMATE...lwx  FXUS61 KLWX 210851 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 351 AM EST Mon Nov 21 2016 .SYNOPSIS...Low pressure over southern Quebec will continue to cause blustery conditions through today. High pressure will build over the region tonight through Tuesday night and move offshore Wednesday. A cold front will pass through Thanksgiving day. && .NEAR TERM /THROUGH TONIGHT/...Tight pressure gradient will remain across the local area through today but some weakening of winds aloft will begin to occur later today. Aircraft data shows a low- level jet extending from central PA sewd through the Baltimore area with speeds as high as 50-kt. Have extended wind advzy for the mtns and along the PA border where NSSL-WRF ARW synthetic imagery shows the strongest subsidence and European ensembles show high prob of 40-kt gusts or greater. Temps about a deg or two cooler than yday. Snow showers over the mtns will diminish as subsidence inversion strengthens. Winds will finally diminish tonight as pressure gradient relaxes as high pressure begins to build and nocturnal inversion sets up. Temps tonight only a deg or two colder than today's. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...High pressure builds overhead Tue through Tue night. Cold with lows in the 20s. High pressure begins to move offshore Wed afternoon. A slow warm up occurs Wed as shortwave-ridge builds in ahead of next s/w trough over the upper Midwest. Have rain showers moving into western areas by day's end with likely prob of showers Wed night. Very little or no concern for any wintry precip. && .LONG TERM /THURSDAY THROUGH SUNDAY/...Low pressure will be located over the Great Lakes Thursday morning. There is some model spread about how this system will translate eastward -- i.e. the development of a secondary low along the coast -- as well as how much moisture will be associated with it. At this time, there is support for a chance of light showers through at least the first half of Thanksgiving. The end of the week will be marked by low amplitude flow in the upper atmosphere and a quick succession of troughs and ridges. As such, there could be some minor timing differences, but on the whole, the forecast looks to be mostly dry into the weekend. However, the western upslope areas could see some snow showers with the Friday night trough. High pressure will build overhead by Saturday night and Sunday. With weak baroclinicity in this pattern, temperatures shouldn't stray too far from normal for the end of the week and weekend. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... Gusts 30-35kt through this afternoon diminishing after sunset. No cigs or vsbys restrictions. Rain showers likely Wed night ahead of next front. Sub-VFR conditions will remain possible throughout at least a portion of Thanksgiving Day as low pressure brings lower clouds and possible showers. VFR expected for Friday. && .MARINE...Gale force winds will continue through this afternoon with SCA conditions through Tue. With low pressure in the vicinity Thursday, winds may approach SCA criteria, but confidence about the evolution of this system is low at this time. Lighter winds are expected by daytime Friday with brief high pressure, although another weak low will approach Friday night. && .FIRE WEATHER...Observations from ASOS sites indicated that Rh failed to meet/reach the Rh RFW criteria yesterday, although some of the typical suspicious AWOS did fall below 30%. Also, a look at previous model runs indicate that the 20/00Z ECMWF run nailed the RH forecast almost perfectly and the latest run shows Rh will fail to reach the criteria where winds are expected to be the strongest. Given that the lowest Rh's are not likely to overlap the strongest winds and vice versa, have cancelled the fire weather watch and issue a special weather statement instead for elevated fire danger. Fire activity...A high resolution VIIRS pass at 0730Z showed two distinct hotspots one over Nelson county and a more significant hotter one over Amherst county in RNK's CWA indicative of active fires in those two counties. && .TIDES/COASTAL FLOODING...Blowout tides expected through Tue with water levels 1 to 2 below astronomical levels. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...Wind Advisory until 6 AM EST early this morning for DCZ001. MD...Wind Advisory until 6 AM EST early this morning for MDZ013-014- 503-504. Wind Advisory until 5 PM EST this afternoon for MDZ003>006-011- 501-502-505>508. VA...Wind Advisory until 6 AM EST early this morning for VAZ025>031- 040-052>054-501-505>508. Wind Advisory until 5 PM EST this afternoon for VAZ503-504. WV...Wind Advisory until 6 AM EST early this morning for WVZ053. Wind Advisory until 5 PM EST this afternoon for WVZ050>052-055- 501>506. MARINE...Small Craft Advisory from 6 PM this evening to 6 AM EST Tuesday for ANZ530>532-538>540. Gale Warning until 6 PM EST this evening for ANZ530>532- 538>540. Small Craft Advisory until 6 PM EST this evening for ANZ535- 536. Gale Warning until 6 AM EST early this morning for ANZ535-536. Small Craft Advisory from noon today to 6 AM EST Tuesday for ANZ533-534-537-541>543. Gale Warning until noon EST today for ANZ533-534-537-541>543. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...ADS AVIATION...ADS/LFR MARINE...ADS/LFR FIRE WEATHER...LFR TIDES/COASTAL FLOODING...LFR