Sunday, August18, 2019 L-36.com


Marine Weather and Tides
Greenbriar, VA

Version 3.4
NOTICE
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 6:24AMSunset 8:02PM Sunday August 18, 2019 5:05 PM EDT (21:05 UTC) Moonrise 8:56PMMoonset 8:07AM Illumination 89% Phase: Waning Gibbous; Moon at 18 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- 436 Pm Edt Sun Aug 18 2019
Rest of this afternoon..S winds 5 kt. Waves less than 1 ft. Isolated showers and tstms.
Tonight..S winds 5 kt. Waves less than 1 ft.
Mon..SW winds around 5 kt. Waves 1 ft.
Mon night..W winds around 5 kt. Waves 1 ft.
Tue..S winds around 5 kt. Waves 1 ft. A chance of showers and tstms.
Tue night..S winds around 5 kt. Waves 1 ft. A chance of showers.
Wed..SW winds around 5 kt. Waves 1 ft. A chance of tstms. A chance of showers.
Thu..NW winds around 5 kt. Waves 1 ft. A chance of tstms. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 436 Pm Edt Sun Aug 18 2019
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure over the atlantic will control the weather pattern through Monday. A trough will approach the waters by midweek. Small craft advisories may be needed for portions of the waters Wednesday.


7 Day Forecast for Marine Location Near Greenbriar, VA
   Hourly   EDIT   Help
location: 38.88, -77.39     debug


Area Discussion for - Baltimore, MD/Washington
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 klwx 181915
afdlwx
area forecast discussion
national weather service baltimore md washington dc
315 pm edt Sun aug 18 2019

Synopsis
A weak surface boundary will remain over the area through the
middle of the week. Southerly flow will bring hot and humid air
into the region during this time. A cold front will sweep
through the area during the second half of the week, with high
pressure following for next weekend.

Near term through Monday
As expected, isolated to scattered thunderstorms have developed
this afternoon. One in particular got caught and backbuilt over
baltimore city, dropping two inches of rain, dime size hail,
and gusty winds of at least 30 mph.

With little in the way of synoptic forcing, the existing outflow
boundaries from ongoing convection, and terrain, will be the
primary drivers of convective initiation through the early
evening hours. Some of these storms will likely be as robust as
the one in baltimore -- perhaps even stronger.

Overnight tonight, model guidance shows more fog than this
morning but not as much as Saturday morning. Have indicated that
in the forecast. Otherwise, the ongoing convection should end
with sunset, and guidance has backed off on the idea of
overnight showers... For now.

We will rinse and repeat this for Monday, most likely with
temperatures a degree or two hotter than today. This will put
heat index values very close to heat advisory criteria in the
eastern half or so of the forecast area. Due to ongoing storms,
will pass the advisory decision on to later shifts.

There should not be as much in the way of showers and storms on
Monday, but isolated activity -- perhaps with strong gusty winds
-- is still on the table.

Short term Monday night through Tuesday night
The only thing likely to hold Tuesday back from the extreme heat
will be increased cloud storm coverage in the afternoon, before
it has a chance to get as hot or hotter than Monday. A heat
advisory could still be required. Things start to change
Tuesday as a stronger, deeper shortwave approaches, not to
mention a cold front from the northwest. CAPE remains plentiful
Tuesday and pw's near 2 inches. Thus, decided it was prudent to
insert a mention for severe weather and flooding into the hwo
for this day, given the higher potential compared to prior days.

The SPC has also placed us in a marginal risk for severe
weather Tuesday.

Long term Wednesday through Saturday
A surface trof will be in place Wednesday while temperatures remain
hot in the middle 90s. A downward trend in convection is indicated
by model guidance. Substantial height falls are indicated on
Thursday as mid-upper level trof crosses the eastern great lks to
northern new england with the GFS being much more amplified with
this trof than the ecmwf. Nevertheless, anticipating Thu we'll see
decent convective cvrg. Some drying will begin to take place thu
night as front crosses the area, but expecting showers to linger
into Fri across the southern areas as front will be slow to clear
area. Dry conditions are likely for the weekend at least for
northern areas, although central va and far southern areas could
still see chances of showers prevail as front stalls across southern
va.

Aviation 19z Sunday through Friday
Vfr expected through the valid TAF period except in pop-up
showers and storms... Which today seem to be popping up right
near the terminals. When those storms occur, lowered visibility
and gusty winds are possible.

This will repeat Monday afternoon but with less storm coverage
expected. Better chance again on Tuesday and Wednesday.

Enhanced risk of t-storms Thursday with passage of cold front.

Marine
Models have backed off on the potential for southerly channeling
this evening that would reach small craft advisory gust
criteria. But it will remain close and we will monitor.

Gusty winds possible in storms over the waters this afternoon
and early evening; same story Monday and Tuesday. Otherwise
light winds though with high pressure in control after today.

Sca conditions possible Wed and Thu as gradient tightens. Smws
may be required thu.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Je
near term... Je
short term... Rcm
long term... Lfr
aviation... Je lfr
marine... Je lfr


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 20 mi53 min SE 6 G 8 91°F 84°F1014.3 hPa
BSLM2 - Chesapeake Bay, MD 37 mi155 min SSE 6 91°F 1015 hPa75°F
NCDV2 43 mi59 min ESE 9.9 G 12 87°F 89°F1014 hPa
APAM2 - 8575512 - Annapolis, MD 49 mi47 min 89°F 1014.2 hPa

Wind History for Washington, DC
(wind in knots)    EDIT      (on/off)   Help
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
24hr
SE8
E1
G6
S8
SW3
G7
NW4
N1
--
S2
S4
S4
G7
S4
SW3
S3
S3
G9
SW3
S4
S2
SE2
S2
S3
S6
S5
G8
SE9
G12
SE7
1 day
ago
S4
G7
S7
SE7
G11
S8
S4
S2
SE1
SE1
SW1
S2
SE1
E1
--
SE1
E1
E1
SW1
--
SE1
S3
G6
S5
S6
S4
G8
S2
2 days
ago
SW4
SE3
G6
E3
G6
SE2
E1
G5
SE12
G19
E1
G5
E3
SE3
G6
SE2
SE2
NE1
NE1
E1
SE1
G4
E2
G5
NE2
G5
SE2
SW3
W1
W1
G4
S2
W1
SE2
G8

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Washington/Dulles International Airport, DC, VA6 mi73 minSE 610.00 miMostly Cloudy90°F70°F52%1014.5 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA13 mi69 minSE 710.00 miPartly Cloudy94°F71°F48%1014.9 hPa
Fort Belvoir, VA15 mi2.2 hrsESE 910.00 miA Few Clouds96°F70°F45%1015.1 hPa
Leesburg / Godfrey, VA17 mi90 minWSW 810.00 miPartly Cloudy97°F71°F44%1015.2 hPa
Washington/Reagan National Airport, DC, VA19 mi73 minESE 810.00 miPartly Cloudy92°F73°F54%1014.7 hPa
Gaithersburg - Montgomery County Airport, MD23 mi69 minSE 1110.00 miMostly Cloudy91°F71°F52%1016.4 hPa

Link to 5 minute data for KIAD

Wind History from IAD (wind in knots)
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
5
PM
Last 24hrS6S7E8SW4CalmS3CalmCalmCalmS3SE3SE3CalmCalmCalmCalmNW3Calm5SE84SE8SE65
1 day agoE4S6S3SE4S3S3CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmSE3CalmCalmSW5SW5W56SW6
2 days agoE5E5E4N3CalmE3E5SE4SE3CalmCalmE3CalmSE5SE6SE4E333Calm4W3S5SE4

Tide / Current Tables for Chain Bridge, D.C.
   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Chain Bridge
Click for Map
Sun -- 05:34 AM EDT     0.50 feet Low Tide
Sun -- 06:24 AM EDT     Sunrise
Sun -- 09:06 AM EDT     Moonset
Sun -- 11:15 AM EDT     3.18 feet High Tide
Sun -- 05:53 PM EDT     0.38 feet Low Tide
Sun -- 07:59 PM EDT     Sunset
Sun -- 09:54 PM EDT     Moonrise
Sun -- 11:37 PM EDT     3.12 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
2.92.41.81.20.80.50.50.91.62.433.23.12.621.30.80.50.40.61.22.12.73.1

Tide / Current Tables for Chain Bridge, one mile below, D.C.
   EDIT      (on/off)   Help   One Week of Data
Chain Bridge
Click for Map
Sun -- 05:29 AM EDT     0.50 feet Low Tide
Sun -- 06:24 AM EDT     Sunrise
Sun -- 09:06 AM EDT     Moonset
Sun -- 11:10 AM EDT     3.18 feet High Tide
Sun -- 05:48 PM EDT     0.38 feet Low Tide
Sun -- 07:59 PM EDT     Sunset
Sun -- 09:54 PM EDT     Moonrise
Sun -- 11:32 PM EDT     3.12 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
2.92.41.81.20.80.50.50.91.72.533.23.12.61.91.30.80.50.40.61.32.12.83.1

Weather Map and Satellite Images
       (on/off)   HelpWeather Map
wmap_A
GOES 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 (17,4,5,8)
      (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.