Sunday, July25, 2021
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Marine Weather and Tides
Arlington, VA

Version 3.4
NOTICE
3/30/2021 -- ANZ330 has been split into ANZ331 and ANZ332. Click EDIT in Marine Forecast and select your new zone.
1/26/2021 -- The West Coast Satellite images havd been updated. They now use GEOS-17.
1/1/2021 -- The 7 day forecast are now working well. Thank you NOAA for your support.

Sunrise 6:02AMSunset 8:27PM Sunday July 25, 2021 11:17 AM EDT (15:17 UTC) Moonrise 9:01PMMoonset 6:28AM Illumination 98% Phase: Waning Gibbous; Moon at 16 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 Am Edt Sun Jul 25 2021
Rest of today..SW winds 10 kt. Waves 1 ft. Isolated showers and tstms this afternoon.
Tonight..SW winds around 5 kt. Waves 1 ft. A chance of showers and tstms.
Mon..NW winds around 5 kt. Waves 1 ft. A chance of showers and tstms.
Mon night..S winds around 5 kt. Waves 1 ft.
Tue..E winds around 5 kt. Waves 1 ft.
Tue night..SW winds around 5 kt. Waves 1 ft.
Wed..SW winds around 5 kt. Waves 1 ft.
Thu..W winds 5 to 10 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 1037 Am Edt Sun Jul 25 2021
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A warm front will lift north of the waters today, as a cold front approaches later tonight before passing through Monday into Monday night. The boundary will stall to the south through midweek as weak high pressure builds toward the region. Another front may approach from the north late in the workweek.


7 Day Forecast for Marine Location Near Arlington, VA
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location: 38.87, -77.06     debug


Area Discussion for - Baltimore, MD/Washington
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FXUS61 KLWX 251411 AFDLWX

Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 1011 AM EDT Sun Jul 25 2021

SYNOPSIS. High pressure will reside offshore as low pressure tracks across southern Canada today while its associated warm front lifts into New England. A cold front will then push southeastward from the Great Lakes and upper Ohio Valley through this evening, dropping into the area overnight and early Monday. The front will settle to our south through midweek as weak high pressure builds back into the region. Another cold front will approach the from the north late in the workweek.

NEAR TERM /THROUGH TONIGHT/.

Mid to high level clouds remain place over our region but the low level cloud cover is steadily eroding. As clouds become more high level in nature, temps will steady rise. I have adjusted temps down slightly to account for the high clouds.

.Previous Discussion High pressure is situated off the Mid-Atlantic coast this morning as an area of low pressure tracks across southern Canada. Extending from said low is a frontal boundary across the Great Lakes and reaching westward into the central U.S. An associated warm front is lifting to our north early this morning, heading for New England today. Plentiful mid to high clouds are streaming south and east over our area this morning from ongoing showers and thunderstorms over the Ohio Valley.

The front will continue its march south and east today as a decent southerly flow over our region will pump in a hot and moist airmass. Despite the cloud debris this morning, we should still manage to rise into the upper 80s to lower 90s for most, with 70s holding on over the higher elevations of the Alleghenies. Surface dewpoints in the 60s to low 70s coupled with the heat will promote modest instability as the front lingers to our northwest through this evening. This setup will allow for isolated to scattered showers and thunderstorms to spark this afternoon over the mountains, tracking eastward toward the metros. Hi-res guidance has been reserved in coverage and strength of thunderstorm activity, likely owing to the weak forcing ahead of the front and aloft. That being said, within the broad northwest flow and the warm/moist airmass in place over the CWA, a few strong to severe storms remains possible. The primary threat would be damaging wind gusts with the strongest activity.

Showers and storms will wane this evening with the loss of daytime heating, with the front to our northwest slowly encroaching on our northern zones during the overnight hours. Can't rule a few showers tonight with the front nearby but most areas will remain dry with lows in the 60s to middle 70s.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/. The front will continue its migration southward Monday, with the focus of afternoon showers and thunderstorms relegated south of I-66 and across central Virginia. Depending on how progressive the front is or is not, will determine where those high rain chances exist. For now, the forecast paints central Virginia and the I-64 corridor southward with those higher POPs. A few strong to severe storms will be possible near and south of the front where the more moist and unstable airmass resides. North of the front, a drier northwest flow and lower dewpoints will really hamper rain and thunder chances. Diminishing rain chances Monday evening and overnight as the front pushes to the south and a more stable airmass wins out. Near normal temperatures expected Monday, with a touch cooler than normal Monday night behind the front.

Weak surface high pressure builds back toward the region Tuesday through Tuesday night as the front stalls out across the Carolinas. Not a huge airmass change behind the front, dewpoints a touch lower, so we should be able to warm decently Tuesday afternoon. Many areas will rise into the low to middle 90s, 80s in the mountains. As we remain within the broad upper trough and energy tracking aloft, as well as sufficient surface heating, can't rule out a few showers or storms over our extreme southern zones in central Virginia. Lows Tuesday night back off into the 60s to low 70s under partly cloudy skies and dry conditions.

LONG TERM /WEDNESDAY THROUGH SATURDAY/. Little to no change is expected in the synoptic pattern with a sprawling upper ridge staying in charge across the middle of the country. This omega block configuration will maintain longwave troughs to either side. Global ensemble solutions maintain lower heights across far north-central Canada down into New England. By next weekend, this negative height anomaly becomes more compact and elongated into the northeastern U.S. while the ridge across the nation's mid-section flattens out. The net result of this pattern shift will drive a more defined cold front across the Eastern Seaboard by Friday with high pressure building in for next weekend.

Persistent cyclonic flow will prevail through the period with a series of impulses sliding through within the northwesterly flow aloft. At the surface, a residual stationary boundary sits to the south over the Carolinas which maintains less humidity over the Mid- Atlantic region. Wednesday is looking dry at this point, although a few isolated showers are not out of the question along and east of I- 95. Convective chances do increase by Thursday with better dynamics in place. The 00Z GFS/ECMWF/CMC all show more substantial vorticity centers racing through the region the first half of Thursday. Some timing issues exist with regard to whether these features will overlap the diurnal peak in buoyancy. Showers and thunderstorms remain in the forecast throughout Thursday as a cold front approaches from the west. This boundary is forecast to clear the area by early Friday with high pressure building in the wake. A return of drier weather ensues for Saturday with a noticeable drop in humidity as well.

High temperatures are likely to reach the low 90s on Wednesday and Thursday. Dew points do come up a bit ahead of the cold front so expect an uptick in humidity levels for Thursday. As usual, the cool spot will be across the Alleghenies with daily highs in the 70s. Temperatures cool off behind the cold front on Friday into next weekend with increasing sunshine accompanying the ridge of high pressure.

AVIATION /14Z SUNDAY THROUGH THURSDAY/.

Some lower ceilings at both CHO and MTN have started to erode this morning and VFR conditions are expected through the remainder of the day.

.Previous Discussion.

Isolated to scattered showers and thunderstorms are expected this afternoon as a cold front approaches to our northwest. Widespread coverage is not expected, but any encounter with a strong storm would yield a brief period of sub VFR conditions, as well as gusty winds. Have inserted VCTS in the TAFs to account for this, but confidence in a terminal impact is low. Southerly winds at around 10 knots will turn more west southwest by days end.

The front will slide southward into the area Monday, with additional shower and thunderstorms chances during the afternoon and early evening hours. Highest chances of impact will be at CHO where the more unstable airmass is expected to reside south of the front. Further north, an episode of sub VFR conditions is plausible at IAD/DCA, but chances are on the low side. The front pushes south of our area Monday night as weak high pressure builds back toward the region Tuesday through Tuesday night. Winds will remain light at less than 10 knots during this time, favor a west northwest trajectory.

VFR conditions are anticipated for middle to latter portions of the work week. Wind directions will shift at times, but should predominantly come out of the west to southwesterly direction. Increasing shower and thunderstorms chances on Thursday may lead to flight restrictions.

MARINE. SCA gusts expected across much of our waterways today as moderate southerly breezes persist. A cold front will approach to our northwest this afternoon and evening, as isolated to scattered showers and thunderstorms develop. The stronger activity could bring a gusty wind threat and the need for Special Marine Warnings during this time. SCA gusts likely linger over our southern Bay waters tonight, thus an SCA remains in effect.

The front slides southward through the waters Monday, with a chance for additional showers and gusty thunderstorms across our southern Bay and tidal Potomac waters. Winds will turn out of the west northwest as the front pushes to the south. The front will settle south of our area Monday night through Tuesday night as weak high pressure builds back toward the region. As a result, a weak gradient will win out and sub SCA conditions are expected in a west northwest flow.

Winds over the marine waters stay below Small Craft Advisory levels on both Wednesday and Thursday. Given a chance for convection each day, particularly on Thursday, Marine Weather Statements and/or Special Marine Warnings may be required for locally stronger storms.

TIDES/COASTAL FLOODING. Southerly flow will continue through the weekend which raises tidal anomalies across the waters. Such winds strengthen through the morning leading to many locations nearing or reaching the Minor Stage during high tide. Given the close proximity to the full moon, the astronomical tides will run higher than usual. Many of the numerical pieces of guidance depict Minor being reached across Annapolis, Baltimore, and Havre de Grace in the mid to upper Chesapeake Bay.

LWX WATCHES/WARNINGS/ADVISORIES. DC . Coastal Flood Advisory until noon EDT today for DCZ001. MD . Coastal Flood Advisory until 2 PM EDT this afternoon for MDZ508. Coastal Flood Advisory until 11 AM EDT this morning for MDZ011. VA . None. WV . None. MARINE . Small Craft Advisory until 10 PM EDT this evening for ANZ530>532-539-540. Small Craft Advisory from 10 PM this evening to 6 AM EDT Monday for ANZ542. Small Craft Advisory until 6 AM EDT Monday for ANZ533-534-537- 541-543.

SYNOPSIS . BKF NEAR TERM . BKF/JMG SHORT TERM . BKF LONG TERM . BRO AVIATION . BKF/BRO/JMG MARINE . BKF/BRO TIDES/COASTAL FLOODING .


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 2 mi47 min SSW 7 G 11 78°F 83°F1013.9 hPa
BSLM2 - Chesapeake Bay, MD 20 mi47 min W 4.1 76°F 1014 hPa69°F
APAM2 - 8575512 - Annapolis, MD 32 mi47 min S 5.1 G 8.9 82°F 82°F1013.5 hPa
44063 - Annapolis 33 mi35 min SSW 9.7 G 12 75°F 79°F1 ft1014.6 hPa
TPLM2 - Thomas Point, MD 33 mi17 min S 13 G 14 76°F 79°F1014.8 hPa (-0.8)70°F
BLTM2 - 8574680 - Baltimore, MD 37 mi47 min SW 4.1 G 6 80°F 82°F1012.9 hPa
CPVM2 37 mi47 min 76°F 70°F
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 37 mi47 min SW 5.1 G 8.9 78°F 1013.2 hPa
FSNM2 37 mi47 min SSW 4.1 G 6 78°F 1013.3 hPa
NCDV2 38 mi47 min SW 6 G 13 79°F 81°F1013.9 hPa
44062 - Gooses Reef, MD 40 mi35 min SSW 14 G 16 76°F 81°F1 ft1015.1 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 48 mi47 min S 12 G 15 76°F 1014.6 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 49 mi47 min SSW 13 G 16 77°F 80°F1013.9 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Washington/Reagan National Airport, DC, VA2 mi25 minSSW 1010.00 miOvercast81°F70°F69%1013.9 hPa
Camp Springs / Andrews Air Force Base, MD10 mi21 minSW 810.00 miA Few Clouds80°F67°F66%1014 hPa
College Park Airport, MD11 mi42 minS 610.00 miFair79°F67°F68%1013.5 hPa
Fort Belvoir, VA12 mi21 minSSE 710.00 miFair80°F70°F72%1014.1 hPa
Gaithersburg - Montgomery County Airport, MD21 mi21 minVar 510.00 miFair82°F71°F69%1015.2 hPa
Fort Meade / Tipton, MD22 mi22 minSSW 310.00 miFair79°F70°F74%1014.2 hPa
Washington/Dulles International Airport, DC, VA22 mi25 minS 710.00 miMostly Cloudy80°F70°F71%1013.5 hPa

Link to 5 minute data for KDCA

Wind History from DCA (wind in knots)
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Last 24hrS8S8S8S10S12SE12
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1 day agoCalmCalmCalmN6CalmN8N6N9SE7SE6S4SE4SW3SW5SW4SW3S3CalmSW3CalmCalmS5S8S6
2 days agoN8
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6NW8NE4N7N7NE4N5CalmSW3CalmCalmCalmCalmN3N6NW7NW6NE4NE6NE9

Tide / Current Tables for Washington, D.C.
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Washington
Click for Map
Sun -- 04:13 AM EDT     0.13 feet Low Tide
Sun -- 06:03 AM EDT     Sunrise
Sun -- 07:27 AM EDT     Moonset
Sun -- 09:36 AM EDT     3.49 feet High Tide
Sun -- 04:58 PM EDT     -0.01 feet Low Tide
Sun -- 08:25 PM EDT     Sunset
Sun -- 10:00 PM EDT     Moonrise
Sun -- 10:10 PM EDT     3.12 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.91.30.80.40.10.312.12.93.43.53.12.51.91.30.70.2-00.31.22.12.83.13

Tide / Current Tables for Fort Washington, Maryland
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Fort Washington
Click for Map
Sun -- 03:41 AM EDT     0.11 feet Low Tide
Sun -- 06:03 AM EDT     Sunrise
Sun -- 07:28 AM EDT     Moonset
Sun -- 09:29 AM EDT     3.07 feet High Tide
Sun -- 04:26 PM EDT     -0.01 feet Low Tide
Sun -- 08:25 PM EDT     Sunset
Sun -- 10:00 PM EDT     Moonrise
Sun -- 10:03 PM EDT     2.74 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.510.60.20.10.51.22.12.7332.62.11.50.90.400.10.61.32.12.62.72.5

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