FXUS61 KLWX 180830 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 330 AM EST Wed Feb 18 2026 .WHAT HAS CHANGED... Continue to monitor the dense fog and low stratus in Maryland that is slowly trying to work its way south/west into the DC Metro. Additional expansion of the Dense Fog Advisory is possible. && .KEY MESSAGES... - 1) A meandering frontal boundary brings periods of showers, changing temperatures, and morning fog through end of week. - 2) Colder this weekend with potential for coastal storm, with colder temperatures persisting into early next week. && .DISCUSSION... KEY MESSAGE 1...A meandering frontal boundary brings periods of showers, changing temperatures, and morning fog through end of week. A weak cold front is forecast to sag south into the area this afternoon, then stall over southern VA tonight. The front remains just to our south through Thursday afternoon, then meanders north over the area Thursday night into Friday. A stronger cold front crosses the area Friday afternoon that brings an end to precipitation. The initial frontal passage today will bring scattered showers to the area, though the highest chances for rain are going to be in the Alleghenies and along the MD/PA border. Once fog burns off this morning temperatures warm to well above average - in the low to mid 60s south of the Potomac River. There'll be a sharp temp gradient of mid 40s to upper 50s across central to northeast MD where clouds linger into the afternoon. Cooler and cloudy conditions are likely on Thursday as the front will be south of the area. This looks to be the rainiest day of the entire week. Temperatures were lowered from what NBM had as it is struggling to deal with the CAD setup. On and off rain continues into Friday before a stronger cold front crosses the area in the afternoon. The Dense Fog Advisory for northeast Maryland continues through 10 AM this morning, with the possibility that fog expands further south/west. The fog gets scoured out from southwest to northeast as southwesterly winds increase late morning into the afternoon. Northeast MD is likely to hold on to fog/low clouds the longest. Fog is likely to be a possibility during each night to early morning through Friday given the abundance of low level moisture and light to calm winds. KEY MESSAGE 2... Colder this weekend with potential for coastal storm, with colder temperatures persisting into early next week. Pattern supportive of leader-follow system this weekend with leader coming Friday and follower Sunday. Upper-level trends over the past few synoptic runs in deterministic and ensemble guidance have trended slightly more favorable for a Sunday system to materialize. More blocking in the Atlantic with a ridge going up offshore has trended to more amplification and models hinting at a storm (potentially bigger). However, just as many ensembles show a weaker system with ridging and suppressed storm out to sea. Moisture does appear to be plentiful; the main uncertainty is how much cold air there will be to work with. Would need a stronger system to get impactful snow outside terrain in order to get more cold air brought into system. Even if a storm does develop, may not be all snow outside mountains with rain mixing in. Overall H5 pattern does support upslope snow behind the departing trough. To show the uncertainty, the EPS 50th percentile is currently a coating to an inch for most (several inches in the Alleghenies), while the 90th percentile is a solid 10-15". If the storm does come to fruition, it could be rather impactful as seen in WPC PWSSI probs. Could also be a swing and a miss; time will tell. Regardless of this precipitation uncertainty, model guidance is in general agreement for a period of colder temperatures following this system, and the start of next week could trend significantly colder with highs in the 20s for most of the region. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... LIFR to VLIFR conditions are ongoing at BWI/MTN this morning due to widespread low stratus and fog. The clouds/fog could reach DCA by around sunrise, though it is uncertain if this will produce IFR or LIFR conditions at DCA. It is possible that IAD experiences some impacts from low clouds, but confidence is much lower there. The low clouds/fog start to erode mid morning from southwest to northeast, starting at IAD/DCA. The clouds will hang around BWI/MTN until the afternoon. VFR conditions return to most, if not all, terminals by late afternoon. Scattered showers cross the area this afternoon, but coverage and intensity are expected to be low enough to not present an issue for the terminals. Another round of low clouds is likely tonight as a frontal boundary stalls south of the area. These Sub-VFR conditions are likely to persist Thursday into Friday with much higher rain chances. Towards Sunday, periods of sub-VFR conditions could occur dependent on a significant low causing lower ceilings and VSBYs at times across terminals. Winds will likely shift northwesterly aligning with this low. && .MARINE... High pressure shifting offshore will result in stronger southwest winds over the waters today. Small Craft Advisories have been issued for the Potomac south of Indian Head and the Chesapeake Bay south of North Beach where gusts of 20-25 kt are expected. Sub-SCA winds expected tonight through Friday, though rain chances increase due to a nearby stalled frontal boundary. Sub-SCA conditions are currently expected Thursday-Saturday; winds will start to pick up on Sunday, and increase throughout the day Monday once Sunday's low becomes coastal and starts to track northeast. Currently still showing below gale force conditions, but SCAs are likely for Sunday and Monday. Winds should slowly start to decrease again starting Tuesday, or after this weekend's low moves out of the area. && .TIDES/COASTAL FLOODING... Tide levels are likely to remain steady through the end of this week in meandering southwest to east winds as a frontal boundary stalls near the area. Sensitive locations are likely to reach Action Stage during high tide each day. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Dense Fog Advisory until 10 AM EST this morning for MDZ005-006- 008-011-014-505>508. Dense Fog Advisory until 10 AM EST this morning for MDZ008. VA...None. WV...None. MARINE...Dense Fog Advisory until 10 AM EST this morning for ANZ530. Dense Fog Advisory until 10 AM EST this morning for ANZ530>532- 538>540. Small Craft Advisory from 8 AM this morning to 5 PM EST this afternoon for ANZ533-534-536-537-541>543. && $$ DISCUSSION...KRR/SRT AVIATION...KRR/SRT MARINE...KRR/SRT