Friday, July21, 2017 L-36.com


Marine Weather and Tides
Washington, DC

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.

Sunrise 5:59AMSunset 8:29PM Friday July 21, 2017 6:52 PM EDT (22:52 UTC) Moonrise 3:06AMMoonset 5:53PM Illumination 3% Phase: Waning Crescent; Moon at 28 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- 614 Pm Edt Fri Jul 21 2017
Tonight..W winds 5 kt. Waves less than 1 ft. Isolated tstms. Scattered showers, mainly this evening.
Sat..SW winds around 5 kt. Waves 1 ft. A chance of showers and tstms.
Sat night..SW winds around 5 kt. Waves 1 ft. Showers and tstms likely.
Sun..SW winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Sun night..W winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Mon..W winds 5 kt. Waves less than 1 ft.
Mon night..NW winds 5 kt. Waves less than 1 ft.
Tue..NE winds 5 kt. Waves less than 1 ft.
Wed..S winds around 5 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 614 Pm Edt Fri Jul 21 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Light winds are expected with high pressure to the south through the weekend. Scattered Thunderstorms are expected each afternoon and evening. A cold front will move through Sunday night.

7 Day Forecast for Marine Location Near Washington, DC
   Hourly   EDIT   Help
location: 38.89, -77.03     debug


Area Discussion for - Baltimore, MD/Washington
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 klwx 211759
afdlwx
area forecast discussion
national weather service baltimore md washington dc
159 pm edt Fri jul 21 2017

Synopsis Weak upper level disturbances will be possible
tonight through Sunday. An upper level trough of low pressure
will move over the northeastern us early in the new week.

Near term through tonight
Showers and thunderstorms moving across the appalachians will
likely hold together as they move across the southern half of
the fcst area. Thermodynamic profiles are very warm aloft
(-3c @500 mb) and no svr warnings have been issued by offices
to the west. T-storms will likely dissipate during the early
evening. Otherwise, another very warm and muggy night similar to
last night but with more cloud cover.

Short term Saturday through Sunday night Global and hi-res
models continue to show an MCS forming over southern wisconsin
late tonight and moving across chicago and eastern oh and WRN pa
by Sat morning. While this complex is expected to weaken toward
daybreak, redevelopment is expected during the afternoon across
the local area. 0-6km shear increases somewhat supporting
organized convection. CAPE is also on the increase given hotter
temperatures and plenty of moisture (850 mb dewpoints of 15c).

Some severe wx is possible, but ensemble guidance shows a large
spread in CAPE values with some members showing only weak cape.

Sunday appears to be shaping up a potentially more significant
severe convective day. Models progged a stronger upper level
disturbance with significant height falls for summertime
standards. Shear is also on the increase and many ensemble
members show moderate CAPE and some even high CAPE values over
3500 j kg. Expect clusters of storms to move across the area
some with damaging winds.

Long term Monday through Friday
A cold front will approach the region Monday before pushing across
the region Monday night. Showers and thunderstorms will develop
along and ahead of this front. Highs will reach the 90s again.

The front could stall just to our south Tuesday, allowing for a
couple of showers or a thunderstorm to develop.

High pressure will build in from the west and northwest Tuesday
night through Thursday. Temperatures will be nearly 10 degrees
cooler than previous days with a comfortable relative humidity.

The next cold front will arrive and push across the region Thursday
night and Friday. Another active pattern of showers and
thunderstorms during the period and could linger into the weekend if
the front stalls across portions of the region.

Aviation 18z Friday through Wednesday Sct-bkn clouds
tonight. A t-storm is possible at kcho. Sct-nmrs t-storms more
likely Sat and especially sun.

MVFR to ifr conditions possible with showers and thunderstorms
Monday and Monday night.VFR conditions expected Tuesday. A shower
cant be ruled out. Winds northwest becoming southwest 5 to 10 knots
Monday and Monday night. Winds north 10 knots Tuesday, becoming
northeast 5 to 10 knots Tuesday night.

Marine Sct-nmrs t-storms Sat and Sun may require smws.

No marine hazards expected Monday through Tuesday night. Winds
southwest 5 to 10 knots Monday and Monday night. Winds becoming
northwest 10 knots Tuesday, then northeast 5 to 10 knots Tuesday
night.

Climate
Late july is climatologically the warmest time of the year,
just like six months from now is the coldest time. How has the
heat of 2017 compared with heat waves (up to now) in other
years? I chose "consecutive days that reached 90 and above" as
the criteria.

At dca there have been two times this summer with stretches of
six consecutive days - beginning june 29 and again july 10. In
terms of ranking (going back to 1871) these are #49 and 50.

Currently dca has exceeded 90 on four consecutive days.

July 16 was 89, otherwise dca would have exceeded 90 on eleven
days in a row.

For baltimore there were also six consecutive days beginning
june 29, which puts it in 37th place. Currently bwi has
exceeded 90 on four consecutive days.

July 16 was 89, otherwise bwi would have exceeded 90 on eleven
days in a row.

The all-time record for june-aug: for baltimore 25 consecutive
days beginning 7 12 1995. For dc there have been two periods of
21 consecutive days - beginning 7 29 1988 and 7 25 1980.

Lwx watches warnings advisories
Dc... Heat advisory until 8 pm edt this evening for dcz001.

Md... Heat advisory until 8 pm edt this evening for mdz011-013-014-
016>018-504-506-508.

Va... Heat advisory until 8 pm edt this evening for vaz037>039-
050>057-502-506.

Wv... None.

Marine... None.

Synopsis... Lfr
near term... Lfr
short term... Lfr
long term... Klw
aviation... Lfr klw
marine... Lfr klw
climate... Woody!


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 1 mi52 min NW 1.9 G 5.1 93°F 87°F1010.9 hPa (-1.6)
BSLM2 - Chesapeake Bay, MD 19 mi142 min SE 4.1 90°F 1012 hPa73°F
APAM2 - 8575512 - Annapolis, MD 30 mi52 min 92°F 1011.3 hPa (-1.3)
44063 - Annapolis 31 mi42 min SSW 5.8 G 7.8 88°F 1011.8 hPa
TPLM2 - Thomas Point, MD 31 mi52 min S 8 G 8.9 88°F 85°F
CPVM2 35 mi52 min 88°F 76°F
BLTM2 - 8574680 - Baltimore, MD 35 mi52 min SSE 6 G 8.9 88°F 86°F1011.2 hPa (-1.4)
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 35 mi52 min SE 8.9 G 9.9 89°F 1011.5 hPa (-1.3)
44043 - Patapsco, MD 38 mi42 min S 5.8 G 7.8 88°F 1012.5 hPa
NCDV2 39 mi52 min E 5.1 G 7 91°F 89°F1010.7 hPa (-1.8)
44062 - Gooses Reef, MD 40 mi42 min SSE 9.7 G 9.7 89°F 1012.7 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 47 mi52 min SSE 4.1 G 5.1 89°F 87°F1012.1 hPa (-1.4)
COVM2 - 8577018 - Cove Point LNG Pier, MD 48 mi52 min S 7 G 8 87°F 1012.8 hPa (-1.1)

Wind History for Washington, DC
(wind in knots)    EDIT      (on/off)   Help
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
5
PM
6
PM
Last
24hr
SW5
G8
S8
S6
S6
SE4
G7
S5
NW2
NW6
G9
NW2
G5
NW3
NW1
NW1
NW4
NW4
NW6
G11
NW5
G9
W3
SW4
G7
S5
S6
E1
NW4
G7
W5
NW2
G5
1 day
ago
--
SW5
S4
S7
S4
S4
G8
S4
S3
S3
SW2
S3
SW1
NW4
NW5
W5
NW6
NW7
G11
NW4
W5
G9
W2
G6
SW6
SW4
G8
SW5
2 days
ago
SE1
SE1
SE3
SE4
S4
G7
S6
SE4
SE4
S3
NW1
S2
W1
E1
S1
NW4
N2
G5
W4
W4
W1
S2
S5
G8
S6
G9
E1
S7
G10

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Washington/Reagan National Airport, DC, VA2 mi60 minVar 510.00 miMostly Cloudy94°F70°F46%1011.7 hPa
College Park Airport, MD9 mi64 minW 310.00 miPartly Cloudy93°F69°F46%1011.5 hPa
Camp Springs / Andrews Air Force Base, MD9 mi54 minW 610.00 miFair93°F68°F45%1012.2 hPa
Fort Belvoir, VA14 mi54 minESE 410.00 miFair93°F73°F53%1011.8 hPa
Fort Meade / Tipton, MD20 mi64 minS 410.00 miFair88°F69°F55%1012.5 hPa
Gaithersburg - Montgomery County Airport, MD21 mi56 minW 410.00 miFair89°F73°F59%1014.5 hPa
Washington/Dulles International Airport, DC, VA23 mi60 minSSE 310.00 miOvercast89°F71°F55%1011.2 hPa

Wind History from DCA (wind in knots)
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
5
PM
6
PM
Last 24hrSW9S7S7S8S6S5CalmNW7NW6NW5CalmSW3N5N7N10NW8N3E4SE5S8CalmNW7SW65
1 day agoSW9SW10SW7S9S6S6S7S5S4S4SW5SW4CalmCalmN6N6NW756SW76W9W9SW8
2 days agoN3CalmS7S7S7S7S5S6S5SW4SW3SW4SW4CalmE3N5N5N5E5S9S9S944

Tide / Current Tables for Washington, Potomac River, D.C.
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Washington
Click for Map
Fri -- 12:57 AM EDT     0.20 feet Low Tide
Fri -- 04:06 AM EDT     Moonrise
Fri -- 05:59 AM EDT     Sunrise
Fri -- 06:28 AM EDT     3.57 feet High Tide
Fri -- 02:04 PM EDT     0.07 feet Low Tide
Fri -- 06:52 PM EDT     Moonset
Fri -- 07:09 PM EDT     3.02 feet High Tide
Fri -- 08:28 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.30.20.41.22.23.13.53.53.12.51.81.20.70.30.10.31.12.12.732.92.31.71.1

Tide / Current Tables for Bladensburg, Anacostia River, Maryland
   EDIT      (on/off)   Help   One Week of Data
Bladensburg
Click for Map
Fri -- 01:23 AM EDT     0.22 feet Low Tide
Fri -- 04:06 AM EDT     Moonrise
Fri -- 05:59 AM EDT     Sunrise
Fri -- 06:59 AM EDT     3.78 feet High Tide
Fri -- 02:29 PM EDT     0.08 feet Low Tide
Fri -- 06:52 PM EDT     Moonset
Fri -- 07:40 PM EDT     3.20 feet High Tide
Fri -- 08:28 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.50.20.30.81.92.93.63.83.52.92.21.610.50.10.20.81.82.63.13.22.82.11.4

Weather Map and Satellite Images
       (on/off)   Help
Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Mid-Atlantic    EDIT
Geos

Wind Forecast for Baltimore, MD/Washington (18,4,5,8)
      (on/off)   Help

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

Ad by Google

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.