Monday, June1, 2020
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Marine Weather and Tides
Olney, MD

Version 3.4
NOTICE
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 5:42AMSunset 8:30PM Monday June 1, 2020 9:11 PM EDT (01:11 UTC) Moonrise 2:46PMMoonset 2:14AM Illumination 83% Phase: Waxing Gibbous; Moon at 11 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- 736 Pm Edt Mon Jun 1 2020
Tonight..SW winds 5 kt. Waves less than 1 ft.
Tue..SW winds 5 to 10 kt. Waves 1 ft.
Tue night..SW winds 5 kt. Waves less than 1 ft.
Wed..W winds 5 to 10 kt. Waves 1 ft.
Wed night..W winds 5 to 10 kt. Waves 1 ft.
Thu..W winds around 5 kt. Waves 1 ft. A chance of showers and tstms.
Thu night..Light winds. Waves 1 ft. Showers likely.
Fri..SW winds around 5 kt. Waves 1 ft. Showers likely in the morning. A chance of tstms. A chance of showers.
Sat..N winds around 5 kt. Waves 1 ft. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 736 Pm Edt Mon Jun 1 2020
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will move offshore tonight. A warm front will advance across the waters late Tuesday into Tuesday night. A cold front will then approach the waters from the north Wednesday night and Thursday, stalling nearby through Friday. A second cold front will then sweep across the waters over the weekend. Small craft advisories may be need for a portion of the waters Tuesday night and again on Wednesday.


7 Day Forecast for Marine Location Near Olney, MD
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location: 39.15, -77.07     debug


Area Discussion for - Baltimore, MD/Washington
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FXUS61 KLWX 011912 AFDLWX

Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 312 PM EDT Mon Jun 1 2020

SYNOPSIS. High pressure will migrate off the Southeast coast tonight as a warm front advances across the region late Tuesday into Tuesday night. A cold front will then approach from the north Wednesday night and Thursday, stalling nearby through Friday. A second cold front will then sweep across the region over the weekend.

NEAR TERM /THROUGH TONIGHT/. High pressure atop the region this afternoon is delivering sunny skies and temperatures in the upper 60s to lower 70s. Winds are generally light out of the west northwest, with dewpoints very comfortable in the middle 30s to lower 40s. Temperatures will continue to climb upward this afternoon, with low to middle 70s expected CWA wide.

Tonight, the high moves off the Southeast coast as mid to high level clouds start to move into the area from the west northwest. Much the area will remain dry overnight as temperatures settle down into the upper 40s to middle 50s. A weakening shortwave will be dropping southeastward from the Great Lakes the second half of the night, which could result in some light shower activity around daybreak across western Maryland and eastern West Virginia.


Tuesday the warm front will advance across the region. Best forcing for precip will stay north, so best chance of showers will do likewise, but a few could reach DC metro. South of DC odds of a dry day are high. Temps will warm a bit, but the warming will be tempered by plentiful clouds, despite the warm frontal passage. Highs approaching 80, very close to normal overall.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/. Low pressure tracking across the Great Lakes will push a warm front toward the region on Tuesday. This will bring low end chance POPs across the northern third of the CWA, primarily north of the Potomac River. As the flow turns more southerly with the approach and passage of the warm front, an increase in dewpoints/moisture is expected, as well as warmer temperatures. Warmest locations will be across central Virginia and the lower Shenandoah Valley where clouds/showers coverage will be less, with temperatures rising into the lower 80s. Further north and east, said clouds/showers could hamper temperatures a touch, with mid to upper 70s most likely.

The warm front marches to our north Tuesday night as dewpoints surge into the 60s by Wednesday morning. Will keep a mention of showers Tuesday night across northeastern Maryland and the Potomac Highlands, but generally dry conditions are expected for much of the area with lows very mild in the mid to upper 60s.

By Wednesday, south southwesterly flow will continue to pump in ample low level moisture across the area and much warmer temperatures as 850 temps near 20C. High temperatures on Wednesday will soar into the upper 80s to middle 90s, with heat indices reaching the upper 90s near and south of the District.

At the same time a cold front will be dropping southward from the Great Lakes and into Pennsylvania Wednesday afternoon and evening. Instability will increase between 15-20k J/kg across the area, as mid-upper level winds increase and turn westerly, resulting in 40+ knots of shear. As the front inches southward while coinciding with an approaching shortwave from the Ohio, showers and thunderstorms are expected to encroach from the north late Wednesday afternoon and Wednesday night. Question remains how much southward progress the convective activity can make into our CWA during this time before losing the support of daytime heating. That being said, the threat for scattered severe storms will exist across our far northern zones that hug the Mason Dixon Line (SPC Slight Risk), with a more isolated threat extending down to the I-66 corridor. Activity is expected to wane Wednesday night with the loss of insolation, while conditions remain warm and muggy with lows holding in the upper 60s to lower 70s.

LONG TERM /THURSDAY THROUGH MONDAY/. Area will remain in warm humid air mass through Sat morning. So, the risk of t-storms will be present Thu and Fri with potential for severe thunderstorms especially Fri. Only height rises are shown by models through Friday, therefore, forcing will be driven by mesoscale features hard to determine this far out. A cold front is expected to finally push through the area Sat with enough dry air to lower humidity and inhibit t-storm potential.

AVIATION /18Z MONDAY THROUGH SATURDAY/. High pressure over the terminals this afternoon will push off the Southeast coast tonight as light WNW winds turn southerly by Tuesday morning. A warm front will lift through the area late Tuesday into Tuesday night, with scattered shower activity potentially crossing the MRB/BWI/MTN terminals. A low end chance for brief sub VFR conditions will exist but confidence in occurrence is low.

Scattered showers and thunderstorms may impact the area late Wednesday into Wednesday evening as a cold front drops down from Pennsylvania, while our northern terminals will see the highest chance of occurrence and potential sub VFR conditions. Continued chances of showers and storms will exist Thursday and Friday as the frontal boundary lingers nearby and daytime heating helps initiate activity.

MARINE. High pressure in control will drift off the Southeast coast tonight as light westerly breezes turn southerly Tuesday. A warm front will lift through the waters late Tuesday into Tuesday night with the threat for showers crossing the middle and upper Chesapeake Bay waters. As the warm front lifts north Tuesday night, winds could gust near SCA thresholds across the more open waters of the Bay.

South southwesterly flow increases Wednesday as a cold front drops southward across Pennsylvania, which may allow the gradient to tighten enough for gusts to approach SCA levels. Scattered showers and thunderstorms could impact the northern marine district late Wednesday afternoon and evening, with the potential need for Special Marine Warnings.

The aforementioned frontal boundary will reside near the waters Thursday and Friday with continued chances for afternoon showers/storms. The gradient will remain weak enough to hold non-convective winds below SCA thresholds.

LWX WATCHES/WARNINGS/ADVISORIES. DC . None. MD . None. VA . None. WV . None. MARINE . None.

SYNOPSIS . BKF NEAR TERM . BKF SHORT TERM . BKF LONG TERM . LFR AVIATION . BKF MARINE . BKF


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 19 mi54 min SSW 6 G 8.9 72°F 74°F1021.3 hPa
BLTM2 - 8574680 - Baltimore, MD 27 mi54 min WSW 4.1 G 5.1 71°F 65°F1020.3 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 29 mi54 min SSW 5.1 G 7 1020.6 hPa
FSNM2 29 mi72 min SW 2.9 G 7 71°F 1020.6 hPa (-0.5)
BSLM2 - Chesapeake Bay, MD 32 mi162 min SW 2.9 1021 hPa
APAM2 - 8575512 - Annapolis, MD 33 mi60 min 68°F 1020.7 hPa
44063 - Annapolis 35 mi42 min 64°F 68°F1 ft1020.9 hPa
CPVM2 38 mi54 min 68°F 54°F
TPLM2 - Thomas Point, MD 38 mi72 min SSE 15 G 15 67°F 68°F1022 hPa (-0.9)50°F
TCBM2 - 8573364 - Tolchester Beach, MD 44 mi60 min S 5.1 G 8 67°F 71°F1021 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Gaithersburg - Montgomery County Airport, MD5 mi16 minS 410.00 miFair66°F42°F42%1022.8 hPa
College Park Airport, MD14 mi17 minN 010.00 miFair62°F41°F47%1021 hPa
Fort Meade / Tipton, MD16 mi17 minN 010.00 miFair57°F50°F77%1022 hPa
Washington/Reagan National Airport, DC, VA20 mi20 minSSW 810.00 miMostly Cloudy68°F42°F39%1021.4 hPa
Baltimore, Baltimore-Washington International Airport, MD21 mi18 minSSW 410.00 miMostly Cloudy68°F41°F38%1020.5 hPa
Washington/Dulles International Airport, DC, VA24 mi20 minS 510.00 miFair64°F41°F43%1021 hPa

Link to 5 minute data for KGAI

Wind History from GAI (wind in knots)
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Last 24hrNW3CalmCalmCalmCalmCalmCalmCalmCalmCalmNW4333S45CalmW9
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1 day agoCalm34453CalmNW4CalmCalm3436W8634NW11
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2 days agoSW6SW6W7W4W5SW3W4CalmCalmNW4NW7433354W7W8W73NW44NW4

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Mon -- 03:14 AM EDT     Moonset
Mon -- 05:08 AM EDT     3.39 feet High Tide
Mon -- 05:44 AM EDT     Sunrise
Mon -- 12:04 PM EDT     0.38 feet Low Tide
Mon -- 03:46 PM EDT     Moonrise
Mon -- 05:36 PM EDT     3.12 feet High Tide
Mon -- 08:28 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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0.40.91.82.63.23.43.22.72.11.50.90.60.40.61.222.73.13.12.72.11.40.90.5

Tide / Current Tables for Chain Bridge, one mile below, D.C.
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Chain Bridge
Click for Map
Mon -- 03:14 AM EDT     Moonset
Mon -- 05:03 AM EDT     3.39 feet High Tide
Mon -- 05:44 AM EDT     Sunrise
Mon -- 11:59 AM EDT     0.38 feet Low Tide
Mon -- 03:46 PM EDT     Moonrise
Mon -- 05:31 PM EDT     3.12 feet High Tide
Mon -- 08:28 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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0.40.91.82.73.23.43.22.721.40.90.50.40.61.32.12.73.13.12.721.40.80.4

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
Wind Forecast for Baltimore, MD/Washington (21,6,7,8)
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Ground Weather Radar Station Sterling, VA
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The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with L-36.com. I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerous of sources and is presented automatically. It is not checked for accuracy either by anyone at L-36.com or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.