Tuesday, September22, 2020
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Marine Weather and Tides
Potomac Heights, MD

Version 3.4
NOTICE
8/26/2020 The 7 day forecast is taking about 5 seconds to load but it will eventually load. NOAA is still working on it.
8/18/2020 NOAA continues to have trouble. Wind guest will occasionally be left off graphs. I am working with NOAA to resolve the issue.
12/16/2019 NOAA is having trouble with requests that include wind gusts. I am posting graphs without wind gusts until it gets fixed.
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.

Sunrise 6:55AMSunset 7:06PM Tuesday September 22, 2020 12:08 AM EDT (04:08 UTC) Moonrise 11:59AMMoonset 9:51PM Illumination 24% Phase: Waxing Crescent; Moon at 5 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
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ANZ535 Tidal Potomac From Key Bridge To Indian Head- 1037 Pm Edt Mon Sep 21 2020
Rest of tonight..N winds 5 kt. Waves less than 1 ft.
Tue..NW winds 5 to 10 kt. Waves 1 ft.
Tue night..NW winds 5 kt. Waves less than 1 ft.
Wed..NW winds 5 to 10 kt. Waves 1 ft.
Wed night..NW winds around 5 kt. Waves 1 ft.
Thu..SW winds around 5 kt. Waves 1 ft.
Thu night..SW winds around 5 kt. Waves 1 ft or less.
Fri..SE winds around 5 kt. Waves 1 ft or less.
Sat..S winds around 5 kt. Waves 1 ft. A chance of showers through the night.
ANZ500 1037 Pm Edt Mon Sep 21 2020
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will gradually build over and then south of the waters through the week while teddy departs through the canadian maritimes.


7 Day Forecast for Marine Location Near Potomac Heights, MD
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location: 38.62, -77.13     debug


Area Discussion for - Baltimore, MD/Washington
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FXUS61 KLWX 220114 AAA AFDLWX

Area Forecast Discussion . UPDATED National Weather Service Baltimore MD/Washington DC 914 PM EDT Mon Sep 21 2020

SYNOPSIS. High pressure will gradually build over and then south of the area through the week while Teddy departs through the Canadian Maritimes. A cold front will approach this weekend.

NEAR TERM /THROUGH TUESDAY/. Another chilly night with lows in the mid 30s where Frost Advisories are in effect. Could still see a few spots drop below freezing like we had this morning, but not expecting a widespread freeze although it sill should turn out cooler than this morning.

SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/. While notable weakening in the surface ridge is expected, the region will be coming off another chilly night. Areas of frost are likely to start off Tuesday morning, mainly west of the Blue Ridge and into colder sections of northern Maryland. Gradually all locations will warm up as nocturnal radiational inversions are mixed out by mid-morning. On the synoptic scale, a powerful upper trough is forecast to be located well off the Atlantic coast as Hurricane Teddy is steered toward the Canadian Maritimes. Farther upstream along the Eastern Seaboard, a transient shortwave ridge moves through which bumps temperatures up a bit. With 1000-500 mb thicknesses rising by around 3 to 5 dm from the previous day, expect afternoon highs to reach the low 70s accompanied by low dew points.

Heading into Tuesday evening and night, additional western U.S. wildfire smoke will again enter the picture. Recent HRRR smoke loops and cross-sections show mid to upper-level smoke filling the skies. While this will not influence surface visibilities, it should create a hazy appearance in the sky. These conditions are likely to be in place at least through Wednesday which may keep temperatures down during the afternoon. Most ensembles bring highs to around 80 which may be difficult to muster depending on how much smoke limits incoming solar radiation. Unlike previous nights, Wednesday night will be much milder given an increase in cloud cover and the surface high shifting its position into the Tennessee Valley.

LONG TERM /THURSDAY THROUGH MONDAY/. Overall good agreement amongst guidance in regards to the extended period. High pressure will remain offshore Thursday into Friday, resulting in continued dry conditions. Meanwhile, the leftover moisture from Beta will be picked up by the southern jet stream as it slowly moves eastward. Strong high pressure over the Gulf of Maine may suppress most of the moisture south of our CWA, keeping the bulk over southern VA/NC. However, cannot rule out some shower activity both Saturday and Sunday as a decent amount of uncertainty remains.

AVIATION /01Z TUESDAY THROUGH SATURDAY/. VFR expected thru Wed night.

HRRRX cross sections and upstream satellite suggest smoke from western wildfires is again likely to move over the area by around nightfall Tuesday and persist through Wednesday as low as 8-12 kft AGL.

VFR conditions are expected Thursday and Friday with high pressure offshore, coupled with a light southerly flow. Patchy fog may briefly reduce vsbys during the early morning hours both days.

MARINE. Winds have diminished and model trends indicate winds continue to weaken tonight as high splits and settles over the area. Have canceled advisories. As the high center weakens and shifts south, winds will become westerly Tuesday into Wednesday.

High pressure will build offshore Thursday and Friday, and a southerly flow is expected. However, the gradient should be light enough for winds to remain below SCA criteria most of the time.

TIDES/COASTAL FLOODING. Onshore flow will maintain elevated water levels through tonight. Minor flooding is likely for sensitive areas with the high tide cycle through high tide Tue morning.

The flow will turn more westerly for Tuesday and may cause anomalies to decrease. However, there will be water piled up near the mouth of the Bay, and some of that water may still make it into our area since the flow will be relatively light. Therefore, minor flooding is still possible. Confidence is low at this time.

EQUIPMENT. The KLWX (Sterling, VA) WSR-88D is out of service until further notice. The outage is due to a failure within the Radar Data Acquisition Functional Area that occurred early in the morning on September 20, 2020.

KLWX will be out of service for at least several days, as subject-matter experts from the National Weather Service Radar Operations Center will diagnose the failure, and then perform maintenance action in order to return-to-service.

Users of KLWX can utilize adjacent weather radars located in Dover DE (KDOX), Mt. holly NJ (KDIX), Pittsburgh PA (KPBZ), Charleston WV (KRLX), Blacksburg VA (KFCX), and Wakefield VA (KAKQ).

Further updates to keep users informed about the situation will be issued as information becomes available. Thank you for your understanding during this extended outage.

LWX WATCHES/WARNINGS/ADVISORIES. DC . Coastal Flood Advisory until 2 AM EDT Tuesday for DCZ001. MD . Frost Advisory until 9 AM EDT Tuesday for MDZ003>006-501>503- 505-507. Coastal Flood Advisory until midnight EDT tonight for MDZ014. Coastal Flood Advisory until 8 AM EDT Tuesday for MDZ017. VA . Frost Advisory until 9 AM EDT Tuesday for VAZ025>031-040-051- 501>505. WV . Frost Advisory until 9 AM EDT Tuesday for WVZ050>053-055- 501>506. MARINE . None.

SYNOPSIS . LFR/DHOF NEAR TERM . LFR SHORT TERM . BRO LONG TERM . MSS AVIATION . MSS/LFR MARINE . MSS/LFR TIDES/COASTAL FLOODING . EQUIPMENT . LWX


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 18 mi51 min Calm G 1 55°F 70°F1028.9 hPa
NCDV2 21 mi51 min Calm G 1.9
BSLM2 - Chesapeake Bay, MD 25 mi99 min WNW 1.9 1028 hPa
44062 - Gooses Reef, MD 38 mi33 min ESE 5.8 G 7.8 61°F 71°F
SLIM2 - 8577330 - Solomons Island, MD 41 mi51 min ENE 7 G 8.9
COVM2 - 8577018 - Cove Point LNG Pier, MD 42 mi51 min ENE 9.9 G 13 1028.9 hPa
TPLM2 - Thomas Point, MD 42 mi69 min E 9.9 G 11 62°F 71°F1029.4 hPa (-1.5)45°F
APAM2 - 8575512 - Annapolis, MD 43 mi51 min W 4.1 G 5.1 55°F 1028 hPa
PPTM2 - 8578240 - Piney Point, MD 46 mi51 min NNE 2.9 G 4.1
CPVM2 47 mi51 min 61°F 48°F

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Belvoir, VA8 mi73 minN 010.00 miFair46°F43°F91%1029.4 hPa
Quantico Marine Corps Airfield - Turner Field, VA12 mi73 minWNW 910.00 miFair50°F46°F89%1029.5 hPa
Washington/Reagan National Airport, DC, VA17 mi77 minN 010.00 miFair56°F43°F62%1029.3 hPa
Camp Springs / Andrews Air Force Base, MD20 mi73 minN 010.00 miFair47°F42°F83%1029.5 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA22 mi73 minN 010.00 miFair43°F41°F93%1030.1 hPa
Stafford, Stafford Regional Airport, VA23 mi74 minN 010.00 miFair45°F44°F100%1030.5 hPa

Link to 5 minute data for KDAA

Wind History from DAA (wind in knots)
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Last 24hrCalmCalmCalmNW3CalmNW3CalmNW3N3CalmE4CalmNE3N3CalmN4CalmCalmCalmCalmCalmCalmCalmCalm
1 day agoCalmCalmCalmCalmCalmCalmW4NW4CalmN3CalmN5NE3N4NW3CalmE3E3CalmCalmCalmCalmCalmCalm
2 days agoN4N4N5N3N5N5N3N4N3N3NE3N4NE3NW5N3N3N3CalmCalmCalmCalmCalmCalmCalm

Tide / Current Tables for Glymont, Maryland
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Glymont
Click for Map
Tue -- 06:20 AM EDT     0.13 feet Low Tide
Tue -- 06:56 AM EDT     Sunrise
Tue -- 11:51 AM EDT     2.00 feet High Tide
Tue -- 12:59 PM EDT     Moonrise
Tue -- 06:15 PM EDT     0.14 feet Low Tide
Tue -- 07:04 PM EDT     Sunset
Tue -- 10:50 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.31.91.510.70.30.10.20.61.11.61.921.81.410.60.30.10.20.51.11.72.1

Tide / Current Tables for Mount Vernon, Virginia
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Mount Vernon
Click for Map
Tue -- 06:51 AM EDT     0.16 feet Low Tide
Tue -- 06:56 AM EDT     Sunrise
Tue -- 12:21 PM EDT     2.43 feet High Tide
Tue -- 12:59 PM EDT     Moonrise
Tue -- 06:46 PM EDT     0.17 feet Low Tide
Tue -- 07:04 PM EDT     Sunset
Tue -- 10:50 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.92.62.11.510.60.30.20.411.72.22.42.421.50.90.50.20.20.411.82.4

Weather Map
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wmap_A
GEOS Local Image of    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Ground Weather Radar Station Sterling, VA
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