Sunrise 5:49 AM   Sunset 8:21 PM Moonrise 5:46 PM   Moonset 3:30 AM

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ANZ535 Tidal Potomac From Key Bridge To Indian Head- 734 Pm Edt Tue May 21 2024
Tonight - S winds 5 kt. Waves less than 1 ft. Wed - S winds around 5 kt. Waves 1 ft. Wed night - S winds around 5 kt. Waves 1 ft. A chance of showers and tstms. Thu - SW winds around 5 kt. Waves 1 ft. Showers likely with a chance of tstms. Thu night - W winds around 5 kt. Waves 1 ft or less. A chance of showers and tstms. Fri - W winds around 5 kt. Waves 1 ft. A chance of showers. Fri night - S winds around 5 kt. Waves 1 ft. A chance of showers and tstms. Sat - W winds around 5 kt. Waves 1 ft. A chance of showers and tstms. Sun - S winds around 5 kt. Waves 1 ft. A chance of showers and tstms.
winds and waves higher and visibilities lower in and near tstms.

ANZ500 734 Pm Edt Tue May 21 2024
Synopsis for the tidal potomac and md portion of the chesapeake bay -
high pressure will build over the waters tonight. A strong cold front will approach the waters Wednesday into Thursday. This frontal system will settle south of the area Friday before retreating back toward the waters this weekend. Small craft advisories may be needed for portions of the waters Wednesday.

FXUS61 KLWX 220109 AFDLWX

Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 909 PM EDT Tue May 21 2024

SYNOPSIS
High pressure will move offshore through Wednesday. A cold front will approach from the Midwest late Wednesday, then cross the northern Mid-Atlantic Thursday. The front will stall to the north across Pennsylvania keeping the local area in a warm and humid air mass through early next week.

NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/
Storms that formed in response to terrain circulations over the higher terrain in Pendleton, Grant, Hardy, and Highland Counties earlier are slowly drifting eastward into Rockingham and Augusta Counties this evening. SPC Mesoanalysis still shows around 1000 J/kg of MLCAPE present in those locations, so these storms may continue over the next 1-2 hours before eventually dissipating prior to midnight. Elsewhere, dry conditions are expected through the night. Remnant cloud debris associated with these storms may linger through a good portion of the night, but clearing is expected again prior to daybreak. Some patchy fog can't be ruled out in locations that saw storms this afternoon and evening, especially if skies clear out. Winds will remain light out of the south, and overnight low temperatures are expected to be in the low to mid 60s for most.

SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/
High pressure will continue to slide further east on Wednesday, with approaching low pressure system centered just west of the Great Lakes. This low and its associated cold front will continue to slide further east Wednesday into Thursday. Unsettled weather will be possible both Wednesday and Thursday.

For Wednesday, isolated to widely scattered showers and thunderstorms will be possible during the afternoon and evening hours. Cannot rule out a strong to severe thunderstorm, especially along and west of the Blue Ridge where areas will be most separated from the lingering subsidence as a result of the departing ridge.
Highs on Wednesday will rise into the mid to upper 80s. Cannot completely rule out a few localized sites hitting 90 degrees.

A more potent setup on Thursday will be possible across the Mid- Atlantic as a result of the approaching cold front. Timing continues to be favorable for peak heating with moving through the area.
Increased instability parameters will allow for increasing showers and thunderstorms. Some of these storms may be strong to severe in nature. The main hazards for these storms will be damaging winds and large hail. The best chances for any severe storms will be along and south of I-66. Highs will be in the upper 70s to mid 80s for most areas. The storms should begin dissipate by Thursday night with lows tracking into the upper 50s in the mountains to the low to mid 60s further east across the lower elevations.

LONG TERM /FRIDAY THROUGH TUESDAY/
On Friday, shortwave energy aloft will be approaching the area before traversing to our north Saturday afternoon. At the surface, a frontal boundary will be draped south of the Great Lakes will be pushed southward towards our area. This will leave the region in the warm sector, leading to a prolonged period of unsettled weather. The frontal boundary is set to sink over the area on Saturday before stalling over the region throughout the long term. Daily thunderstorms driven by diurnal heating and the nearby frontal boundary are expected with warm and humid conditions leading to the possibility of some storms being severe. Daily CAPE values greater than 1000 J/kg and lapse rates greater than 6 C/Km are expected each afternoon. While conditions are the most favorable on Sunday with the highest levels of CAPE and steepest lapse rates,

Low pressure to our south will provide the area with plenty of moisture on Friday. WPC has the southwestern portions of the forecast area in a marginal risk for excessive rainfall on Friday with locally heavy rain possible during storms.

High temperatures will be in the upper 70s to low 80s each day with overnight low temperatures dipping into the mid 50s to mid 60s each night. Temperatures cool slightly in the wake of the cold front early next week.

AVIATION /01Z WEDNESDAY THROUGH SUNDAY/
Prevailing VFR conditions will continue through the night. Some patches of fog or low clouds are possible to the west of the Blue Ridge late tonight, but not at any of the TAF sites.
Scattered showers and thunderstorms may develop Wednesday afternoon and early evening, especially west of the metros. VCTS has been introduced tomorrow afternoon at MRB, and may need to be considered further south and east with future TAF issuances.
Otherwise, VFR is expected through Thursday morning. Sub- VFR conditions are possible with potentially more widespread shower and thunderstorm activity Thursday into Thursday night as a cold front crosses. Winds will shift to northwest.

VFR conditions are expected at all terminals Friday and Saturday with the exception of during precipitation and thunderstorms which are expected each afternoon. Winds will be out of the south on Friday before shifting to westerly Saturday afternoon.

MARINE
Light SSE flow will continue through Thursday ahead of a cold front passage during the day on Thursday. SCAs will be possible Wednesday afternoon and evening with increasing pressure gradient in place.
There is a potential for a few showers or thunderstorms over the waters late Wednesday. The threat increases Thursday as a cold front approaches the waters later in the day. SMWs may be needed Thursday.

Southerly winds on Friday shift to westerly Saturday afternoon and are expected to remain below SCA criteria.

TIDES/COASTAL FLOODING
Anamolies will continue to be elevated this afternoon through the overnight hours. Sensitive locations like Annapolis may reach minor flood stage for the high tide cycle overnight tonight.

LWX WATCHES/WARNINGS/ADVISORIES
DC...None.
MD...Coastal Flood Advisory from 2 AM to 9 AM EDT Wednesday for MDZ014.
VA...None.
WV...None.
MARINE...None.

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Chain Bridge
Click for Map
Tue -- 01:45 AM EDT     0.53 feet Low Tide
Tue -- 04:29 AM EDT     Moonset
Tue -- 05:50 AM EDT     Sunrise
Tue -- 07:55 AM EDT     3.34 feet High Tide
Tue -- 02:48 PM EDT     0.47 feet Low Tide
Tue -- 06:45 PM EDT     Moonrise
Tue -- 08:20 PM EDT     Sunset
Tue -- 08:27 PM EDT     2.80 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Chain Bridge, D.C., Tide feet

Chain Bridge
Click for Map
Tue -- 01:40 AM EDT     0.53 feet Low Tide
Tue -- 04:29 AM EDT     Moonset
Tue -- 05:50 AM EDT     Sunrise
Tue -- 07:50 AM EDT     3.34 feet High Tide
Tue -- 02:43 PM EDT     0.47 feet Low Tide
Tue -- 06:45 PM EDT     Moonrise
Tue -- 08:19 PM EDT     Sunset
Tue -- 08:22 PM EDT     2.80 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Chain Bridge, one mile below, D.C., Tide feet

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