Tuesday, December10, 2019
Privacy Policy
L-36.com


Marine Weather and Tides
Potomac Heights, MD

Version 3.4
NOTICE
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.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen

Sunrise 7:14AMSunset 4:48PM Tuesday December 10, 2019 4:15 PM EST (21:15 UTC) Moonrise 3:57PMMoonset 5:26AM Illumination 99% Phase: Waxing Gibbous; Moon at 14 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
    EDIT      (on/off)   Help
ANZ535 Tidal Potomac From Key Bridge To Indian Head- 338 Pm Est Tue Dec 10 2019
Rest of this afternoon..NW winds 10 kt. Waves 1 ft. Showers.
Tonight..NW winds 5 to 10 kt. Gusts up to 20 kt until early morning. Waves 1 ft. Rain or snow showers. Vsby 1 to 3 nm.
Wed..NW winds 5 kt. Waves less than 1 ft. A chance of snow showers. Vsby 1 to 3 nm.
Wed night..NW winds 5 kt. Waves less than 1 ft.
Thu..E winds around 5 kt. Waves 1 ft.
Thu night..NE winds around 5 kt. Waves 1 ft or less.
Fri..N winds around 5 kt. Waves 1 ft. A chance of rain through the day, then rain through the night.
Sat..W winds 5 kt. Waves less than 1 ft. A chance of showers.
ANZ500 338 Pm Est Tue Dec 10 2019
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure will drag its trailing cold front across the region through Wednesday. High pressure will follow Wednesday night through Thursday. Another low pressure system developing over the northern gulf of mexico will move northeastward toward the region Friday into Saturday. Small craft advisories may be needed Wednesday night and again Friday night.


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


Area Discussion for - Baltimore, MD/Washington
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
FXUS61 KLWX 102002 AFDLWX

Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 302 PM EST Tue Dec 10 2019

SYNOPSIS. A cold front will cross the area this afternoon. A weak wave of low pressure will pass by to the southeast as it rides northeastward along the front tonight. Canadian high pressure will then build across the region Wednesday afternoon through Thursday. Another, stronger low pressure system will then develop in the Gulf of Mexico and push northward across the eastern United States Friday and Saturday.

NEAR TERM /THROUGH WEDNESDAY/. A strong area of low pressure is still located over central Quebec, with a cold front draped south across the Appalachains down through the western Carolinas and northern Georgia. Additionally, a stationary/warm front is situated over central Maryland and central Virginia. At the intersection of these two frontal features is a weak wave of low pressure over northwestern North Carolina, moving gradually to the northeast.

The cold front will continue to progress eastward through this evening, clearing the area late this evening. As the front clears, cooler air will push into the region tonight. Meanwhile, in the upper levels, much of the major forcing mechanisms will be pushing in behind the front, so precipitation will continue and intensify behind the front itself. Additionally, the aforementioned weak low will be sliding northeast along the frontal boundary, adding more surface forcing as well. As the cold air pushes in, expecting a changeover from rain to snow across much of the area as we head into late tonight and early Wednesday morning. Snow will start earliest at the higher elevations including the Blue Ridge, so snow will start there around 9-10 PM or so, with much of the rest of the area changing between midnight and 5 AM from west to east.

Still some indication of dry air intrusion at the low-mid levels behind the cold front, but thinking the abundant forcing should be plenty to overcome this. Generally between I-81 and I-95, expecting 1-2 inches of accumulation, primarily on grassy surfaces. Along the I-95 corridor itself, expecting less than an inch. Along the Blue Ridge, could see areas of 3-5+ inches though, where the longest period of snow is, and the best combination of forcing mechanisms. Wet roads and warm road temperatures will likely keep accumulations off of roads. However, more intense banding is possible where the best forcing lines up, so could see a quick inch on roads for those that end up directly under any heavier band. Some of the hi-res guidance hints at strong banding over southern Maryland as well, so will need to monitor guidance trends, though surface temps exceeding 60 over southern Maryland Tuesday afternoon cast uncertainty in accumulation and impacts.

Precip moves out quickly Wednesday morning, and sunshine will return. Combined with warm ground and temps in the 30s to low 40s, much of the snow should end up melting quickly by the afternoon.

SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/. Arctic high pressure will build in from the Great Lakes and Canada, then dominate Wednesday night through Thursday. Dry and cold conditions are expected during this time. Lows may reach the teens Wednesday night in spots, and highs Thursday likely stay in the 30s across much of the region.

The next system organizing near the Gulf Coast will start to bring warm advection northward Thursday night. Models are gradually coming to a better consensus with precipitation approaching the I-64 corridor by around daybreak Friday, at which time a warm nose aloft coupled with cold surface temperatures could result in freezing rain.

LONG TERM /FRIDAY THROUGH MONDAY/. A shortwave moving through the broad trough over the Midwest will kick off a low pressure system over the Gulf of Mexico Friday. This low is forecast to track up through the southeast. There is some slight disagreements on the exact track of the surface low between the 12Z ECMWF and GFS. The GFS keeps the low slightly further east, tracking just along the East Coast, while the ECMWF keeps the low further inland. What both models do agree on is a cold air damming signature resulting in at or near freezing temperatures for locations near and west of the Blue Ridge.

The exact track will determine for how long cold air lingers. Overall, models have been trending towards a warmer solution as southerly flow ahead of the precip shield scours out some of the cold air prior to precip onset. However, do think there will be some light freezing rain for locations west of the Blue Ridge for late Friday, continuing overnight, before changing to all rain by Saturday morning. Elsewhere, temperatures at the surface will be above freezing thus expecting a plain rain event throughout Saturday late afternoon. As the surface low shifts further northeastward and starts to occlude, additional precip due to upsloping is possible Sunday for locations mainly along and west of the Allegheny Front.

High pressure will build briefly back over our region Sunday into early Monday before a warm front lifts northward through our area Monday afternoon into Tuesday, resulting in our next chance at precipitation.

AVIATION /20Z TUESDAY THROUGH SUNDAY/. Some showers across the region this afternoon/evening will result in periods of MVFR CIGs and VSBYs, with even a few instance of IFR VSBYs possible at times in heavier showers.

Temperatures will fall tonight as the cold front pushes through the region. Rain will change to snow at all terminals by Wednesday morning. MRB will be the first to change over, at roughly 03z, with IAD/CHO changing over between 04z-06z, and DCA/BWI/MTN changing over by 09z or so. These are rough time periods, but most guidance is in good agreement on timing at this point. Not expecting a lot of snow (<1 inch for all except MRB, who may get 1-2 inches).

VFR returns by midday Wednesday and persists through Thursday night, though a risk of FZRA exists down at CHO late Thursday night as the next system approaches.

Areas of rain and/or freezing rain will bring MVFR or IFR conditions to the terminals on Friday. Primary threat for freezing rain will be at MRB, with areas east most likely to stay all rain. Rain again on Saturday could lead to sub-VFR conditions at times.

MARINE. Southerly flow likely to gradually diminish today as cold front approaches, but northwest flow picks back up behind it, so SCA's continue into Wednesday for some portions of the waters. By late Wednesday, building high pressure may help the gradient relax and allow winds to drop below SCA levels. However, a reinforcing shot of cold air Wednesday night could reinvigorate the winds briefly.

As a surface low tracks through our region, gusty winds are expected over the waters Friday night into Saturday. Small Craft Advisories will be possible during this period.

LWX WATCHES/WARNINGS/ADVISORIES. DC . None. MD . Winter Weather Advisory from midnight tonight to 7 AM EST Wednesday for MDZ003. Winter Weather Advisory from 2 AM to 8 AM EST Wednesday for MDZ004>006-503-505-507. VA . Winter Weather Advisory from 10 PM this evening to 7 AM EST Wednesday for VAZ507-508. Winter Weather Advisory from midnight tonight to 7 AM EST Wednesday for VAZ025>031-040-501. Winter Weather Advisory from 2 AM to 8 AM EST Wednesday for VAZ505-506. WV . Winter Weather Advisory from midnight tonight to 7 AM EST Wednesday for WVZ050>053-055. MARINE . Small Craft Advisory from 6 PM this evening to midnight EST tonight for ANZ532-539-540. Small Craft Advisory from 6 PM this evening to 6 AM EST Wednesday for ANZ533-537-541-542. Small Craft Advisory until noon EST Wednesday for ANZ534-543.

SYNOPSIS . CJL NEAR TERM . CJL SHORT TERM . RCM LONG TERM . MSS/JMG AVIATION . CJL MARINE . CJL


Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 18 mi46 min NW 5.1 G 8.9 56°F 44°F1013.3 hPa
NCDV2 21 mi52 min W 4.1 G 6 59°F 49°F1011.3 hPa
BSLM2 - Chesapeake Bay, MD 25 mi106 min SSW 4.1 60°F 1010 hPa58°F
44062 - Gooses Reef, MD 38 mi46 min WSW 3.9 G 5.8 53°F 1012.8 hPa
SLIM2 - 8577330 - Solomons Island, MD 41 mi46 min WSW 6 G 8 57°F 48°F1011.6 hPa
TPLM2 - Thomas Point, MD 42 mi76 min WSW 4.1 G 5.1 55°F 46°F1012.5 hPa (+0.9)55°F
44063 - Annapolis 43 mi34 min NW 9.7 G 9.7 53°F 46°F1013.3 hPa
APAM2 - 8575512 - Annapolis, MD 43 mi46 min 58°F 1012 hPa
PPTM2 - 8578240 - Piney Point, MD 46 mi46 min WSW 4.1 G 5.1
CPVM2 47 mi46 min 57°F

Wind History for Washington, DC
(wind in knots)    EDIT      (on/off)   Help
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
Last
24hr
S8
S7
S9
G12
S10
S8
G11
S8
G12
SW10
G14
S10
S11
G15
S9
G12
S10
G15
S11
S10
G15
S7
G11
S8
S5
S7
S8
G12
S7
SW5
G10
S3
--
--
NW7
G10
1 day
ago
S5
S1
SE1
SE4
W1
S1
SE5
G10
S6
S4
SE2
SE3
W1
G7
NW3
--
S2
S3
S4
G7
S6
S6
S7
S6
S6
G9
S6
S8
G11
2 days
ago
NW7
NW4
G7
NW3
W3
N2
SW1
SE1
--
--
NE1
W1
SW1
SE1
--
--
--
--
SW1
S3
S3
SW7
S6
S7
S8

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Belvoir, VA8 mi80 minWNW 410.00 miOvercast59°F55°F88%1012.5 hPa
Quantico Marine Corps Airfield - Turner Field, VA12 mi80 minN 06.00 miFog/Mist56°F54°F93%1012.5 hPa
Washington/Reagan National Airport, DC, VA17 mi24 minNW 710.00 miLight Rain57°F53°F87%1013.5 hPa
Camp Springs / Andrews Air Force Base, MD20 mi80 minWNW 510.00 miOvercast58°F57°F96%1012.1 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA22 mi20 minVar 47.00 miOvercast55°F54°F96%1014.2 hPa
Stafford, Stafford Regional Airport, VA23 mi21 minNW 510.00 miOvercast60°F60°F100%1014.2 hPa

Link to 5 minute data for KDAA

Wind History from DAA (wind in knots)
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
Last 24hrCalmS3S5--S7S7S6S5S5S5S5CalmS6S3S5CalmS3S3CalmS3W3S3NW4NW4
1 day agoCalmCalmCalmW4CalmSE5SE4CalmCalmSE3NW4CalmCalmCalmSE3CalmCalmS3S4--CalmS3--S4
2 days agoNW5CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmSE7SE3S7SE9S4S3

Tide / Current Tables for Glymont, Maryland
   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Glymont
Click for Map
Tue -- 05:25 AM EST     Moonset
Tue -- 05:43 AM EST     1.58 feet High Tide
Tue -- 07:15 AM EST     Sunrise
Tue -- 11:45 AM EST     -0.03 feet Low Tide
Tue -- 03:56 PM EST     Moonrise
Tue -- 04:47 PM EST     Sunset
Tue -- 05:50 PM EST     1.84 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

12
am
1
am
2
am
3
am
4
am
5
am
6
am
7
am
8
am
9
am
10
am
11
am
12
pm
1
pm
2
pm
3
pm
4
pm
5
pm
6
pm
7
pm
8
pm
9
pm
10
pm
11
pm
00.10.511.31.51.61.410.60.20-00.10.51.11.51.81.81.71.30.90.50.2

Tide / Current Tables for Mount Vernon, Virginia
   EDIT      (on/off)   Help   One Week of Data
Mount Vernon
Click for Map
Tue -- 12:29 AM EST     0.01 feet Low Tide
Tue -- 05:25 AM EST     Moonset
Tue -- 06:13 AM EST     1.92 feet High Tide
Tue -- 07:15 AM EST     Sunrise
Tue -- 12:16 PM EST     -0.04 feet Low Tide
Tue -- 03:56 PM EST     Moonrise
Tue -- 04:46 PM EST     Sunset
Tue -- 06:20 PM EST     2.24 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

12
am
1
am
2
am
3
am
4
am
5
am
6
am
7
am
8
am
9
am
10
am
11
am
12
pm
1
pm
2
pm
3
pm
4
pm
5
pm
6
pm
7
pm
8
pm
9
pm
10
pm
11
pm
00.10.40.91.41.81.91.81.40.90.50.1-000.411.622.22.21.81.40.90.5

Weather Map
       (on/off)   Help Weather Map
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 (16,3,4,5)
      (on/off)   Help

Ground Weather Radar Station Sterling, VA
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

Cookie Policy:
This webiste uses cookies to save your settings. No personal information is saved. You can disable cookies in your browser if you like but it is not recommended for this site. I do not sell cookies. Go to a bakery for that. In fact I do not sell anything. To disable cookies from L-36.com, please refer to the Help button in your browser.
Privacy Policy:
I do not sell or share any user data or anything else for that matter. I do not keep site logs longer than I need to to keep bad actors off the site. Basically, I delete them after looking at them. If you are subject to CCPA, Google ads on this site will not be based on your past behavior so you will likely not see an ad for a lawn mower just because you looked for one at a big box website. I do not believe this site is subject to CCPA but I am doing what I can to follow the guidelines anyway.
Disclaimer:
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 numerious 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.