Friday, February22, 2019 L-36.com


Marine Weather and Tides
Dahlgren Center, VA

Version 3.4
What's New / NOTES
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.

Sunrise 6:48AMSunset 5:54PM Friday February 22, 2019 9:16 PM EST (02:16 UTC) Moonrise 9:40PMMoonset 8:57AM Illumination 86% 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
ANZ536 Tidal Potomac From Indian Head To Cobb Island- 727 Pm Est Fri Feb 22 2019
Tonight..E winds 5 kt. Waves less than 1 ft.
Sat..E winds 5 kt. Waves less than 1 ft. Rain.
Sat night..S winds around 5 kt. Waves 1 ft. Rain. Vsby 1 to 3 nm.
Sun..SW winds 10 to 15 kt. Gusts up to 20 kt... Increasing to 35 kt in the afternoon. Waves 1 to 2 ft. Showers.
Sun night..W winds 10 to 15 kt. Gusts up to 30 kt... Diminishing to 20 kt after midnight. Waves 2 ft.
Mon..NW winds 10 to 15 kt with gusts to 35 kt. Waves 3 ft.
Mon night..NW winds 5 to 10 kt. Waves 1 ft.
Tue..N winds 5 kt. Waves less than 1 ft.
Wed..NW winds 5 kt. Waves less than 1 ft. A chance of showers through the day.
ANZ500 727 Pm Est Fri Feb 22 2019
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A stalled frontal boundary will linger across the southeastern u.s. Tonight as high pressure builds over new england. Low pressure developing over the middle mississippi river valley will strengthen as it moves northeastward across the great lakes into canada this weekend. High pressure will build from the northern great plains toward the great lakes and eventually into the northeast through the first half of next week. Gale conditions are likely over the waters Sunday into Monday.


7 Day Forecast for Marine Location Near Dahlgren Center, VA
   Hourly   EDIT   Help
location: 38.32, -77.03     debug


Area Discussion for - Baltimore, MD/Washington
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 klwx 230156 aaa
afdlwx
area forecast discussion... Updated
national weather service baltimore md washington dc
856 pm est Fri feb 22 2019

Synopsis
High pressure will remain to our north through tonight while a
boundary stalls over the southeastern conus. Low pressure
developing over the middle mississippi river valley will
strengthen as it moves northeastward across the great lakes into
canada this weekend. High pressure will build from the northern
great plains toward the great lakes and eventually into the
northeast through the first half of next week. Low pressure
developing over the tennessee valley could approach the region
during the middle of next week.

Near term until 6 am Saturday morning
Low pressure will begin to strengthen over the rockies
overnight and high pressure will remain to our north. The low-
level flow will begin to turn to the southwest and this will
allow for overrunning to increase. Still feel that most areas
across the central and northern CWA will be dry... Closer to the
high. However, light rain will likely spread north into the
potomac highlands and central virginia toward morning. There
will be enough evaporative cooling for a cold layer to develop
between about 2kft and 4kft. This will cause freezing rain along
the ridges. A winter weather advisory is in effect for the
potomac allegheny highlands and central northern virginia blue
ridge mountains, where confidence is highest for precipitation
to occur in that cold layer. Ice accumulations will be around
one- tenth of an inch or less. Lows generally 28-38f.

Short term 6 am Saturday morning through Sunday night
Low pressure will intensify as it moves through the midwest
Saturday. The low and mid-level flow will strengthen and turn
more south to southwesterly, causing more overrunning. This will
cause rain to overspread the rest of the area from southwest to
northeast Saturday morning into Saturday afternoon. A moderate
to perhaps even locally heavy rain is expected across portions
of the potomac highlands and central virginia south of
interstate 64. A flood watch is in effect for these areas.

Elsewhere, rain should be light enough to prevent flooding
Saturday into Saturday evening, but it could be close during the
evening hours near the charlottesville area. The reason why the
steadier rain will be to the southwest is that overrunning will
be deeper farther away from the high.

Will also have to watch for freezing rain along the ridges as
well. The winter weather advisory continues through Saturday
morning for the central northern blue ridge into the
potomac allegheny highlands. Further expansion may be needed
into western allegany county in maryland, but confidence was
not high enough at this time due to uncertainties with the
timing and arrival of the steadier precipitation.

Low pressure will move into the great lakes Saturday night and
into canada Sunday. The warm front associated with the low will
approach Saturday night before passing through midday Sunday
and the cold front associated with the low will pass through
Sunday afternoon.

For Saturday night into early Sunday, a soaking rain is expected
across most areas due to increased overrunning and forcing from
a strengthening low-level jet. Copious amounts of moisture
remain in place. Rainfall amounts around 0.75 to 1.50" are most
likely, with locally 2-3" possible. The highest amounts for the
entire event (tonight through Sunday morning) are most likely
across the central shenandoah valley into the potomac highlands.

Having that been said, recent snow melt has caused saturated
soils and flood guidance is low due to that. Therefore, flooding
of small streams and creeks as well as low lying urban areas if
possible across the entire area Saturday night into Sunday.

Confidence was not high enough for a watch at this time due to
the later start time of the steadier precipitation and the fact
that it may be separated further from when most of the snow
melting has occurred (Thursday into Friday of this week). Will
have to reassess on later shifts.

Drier conditions will overspread the area from west to east
Sunday morning and low pressure will intensify as it moves into
southern canada. A strong gradient between the low and high
pressure over the central CONUS will cause windy conditions
behind the cold front later Sunday morning into the potomac
highlands and Sunday afternoon elsewhere. The windy conditions
will persist through Sunday night. A high wind watch is in
effect, mainly for the ridges of allegheny and potomac highlands
as well as the blue ridge mountains. Wind gusts around 60 mph
are possible. Elsewhere, wind gusts of 35 to 55 mph are most
likely, especially across northern and central areas (including
the washington and baltimore metro areas). Will continue to
monitor for the potential of wind advisories and or high wind
warnings.

Long term Monday through Friday
Strong canadian high pressure will be building southward into the
central u.S. On Monday, as low pressure lifts away from new
england to the northeast. This will maintain a tight pressure
gradient across the mid atlantic states, so continued windy
conditions can be expected. Dry conditions, near normal
temperatures and mostly clear skies are likely into mid week as
high pressure builds over the region. GFS hinting at the
potential for a weak area of low pressure passing to our north
on Wednesday, although mostly dry conditions look to persist,
outside of some upslope showers. High pressure looks to build
back over the region through Thursday, with continued dry
conditions. We will keep temperatures running near normal for
late february given differing solutions between deterministic
and ensemble guidance at this time.

Aviation 02z Saturday through Wednesday
Vfr conditions are expected through tonight at all terminals.

Chances then begin to increase for MVFR at cho Saturday morning.

Low clouds and rain will then overspread the terminals Saturday
afternoon into Saturday night, and last into Sunday morning with
ifr conditions likely and subifr conditions possible. A cold
front will pass through the terminals Sunday, and strong winds
are possible behind the cold front later Sunday afternoon and
Sunday night.

Vfr conditions expected Monday and Tuesday as high pressure
builds to our west. The gradient will remain tight on Monday
with the exiting low off of new england and the building high,
so strong gusty northwest winds can be expected. The gradient
will weaken Monday night, with light northerly winds forecast
through Tuesday.

Marine
High pressure will build to the north through Saturday and winds
should remain below SCA criteria. Low pressure will pass by to
the west Saturday night into Sunday and the cold front
associated with the low will pass through later Sunday
afternoon. Winds may approach SCA criteria Saturday night, but
confidence is too low for a headline at this time.

Stronger winds are expected Sunday, especially Sunday afternoon
through Sunday night behind the cold front. A gale warning will
likely be needed for the waters during this time.

Gale conditions likely on Monday as the gradient remains quite
strong between an existing low off of new england and high
pressure building into the central u.S. SCA conditions likely
persist into Monday night before dropping below criteria Tuesday
and Tuesday night as high pressure builds toward the region.

Hydrology
Given recent snowmelt and saturated ground, 0.75" to around 1.5"
of rain may be enough to result in minor flooding issues this
weekend, particularly over eastern west virginia. The overall
trend has been for slightly less rain, but not so much less to
completely avoid a flood threat. Despite the slightly lower qpf
totals in the 12z model suite, mmefs still indicates >50%
chance of minor flood at several river forecast points later
this weekend.

Lwx watches warnings advisories
Dc... None.

Md... High wind watch from Sunday morning through Monday morning for
mdz501.

High wind watch from Sunday afternoon through Monday morning
for mdz003-004-502.

Va... Flood watch from Saturday afternoon through late Saturday
night for vaz025-036-037-503-504-508.

Winter weather advisory from 3 am to noon est Saturday for
vaz503-504-508.

High wind watch from Sunday morning through Monday morning for
vaz503-504-507-508.

Winter weather advisory from 7 am to noon est Saturday for
vaz507.

Wv... Winter weather advisory from 3 am to noon est Saturday for
wvz505-506.

High wind watch from Sunday morning through Monday morning for
wvz501>503-505-506.

High wind watch from Sunday afternoon through Monday morning
for wvz050>052-055-504.

Winter weather advisory from 7 am to noon est Saturday for
wvz501-503.

Marine... None.

Synopsis... Bjl
near term... Bjl mm
short term... Bjl
long term... Bkf
aviation... Bjl mm bkf
marine... Bjl mm bkf
hydrology... Bjl


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
NCDV2 0 mi47 min SE 1 G 1.9 42°F 42°F1030.3 hPa
PPTM2 - 8578240 - Piney Point, MD 29 mi47 min NNW 1.9 G 2.9
SLIM2 - 8577330 - Solomons Island, MD 31 mi47 min NNW 1 G 1.9 42°F 40°F1030.5 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 35 mi47 min N 5.1 G 8 43°F
BSLM2 - Chesapeake Bay, MD 36 mi107 min SSE 1.9 42°F 1031 hPa32°F
LWTV2 - 8635750 - Lewisetta, VA 37 mi47 min Calm G 0 44°F 41°F1030.6 hPa
WASD2 - 8594900 - Washington, DC 38 mi47 min Calm G 4.1 45°F 41°F1031.3 hPa
44042 - Potomac, MD 42 mi23 min WNW 1.9 G 1.9 41°F 40°F1031.7 hPa

Wind History for Piney Point, MD
(wind in knots)    EDIT      (on/off)   Help
9
PM
10
PM
11
PM
12
AM
1
AM
-12
PM
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
Last
24hr
--
NW2
NW4
W1
NW4
N5
NE2
N2
SW2
NW5
--
N2
NE4
NE2
SW2
W3
SW1
--
SE4
E2
N3
SW3
W1
1 day
ago
SE6
N9
NW13
NW10
NW13
W6
W6
W4
W5
W3
NW6
NW6
NW10
NW6
N6
N5
N8
NW2
N4
NW5
S4
--
S1
--
2 days
ago
SE3
S4
S4
S4
NE2
E2
E8
E10
S8
E9
G12
E7
SE13
E12
E6
E13
E10
G13
E11
E10
SE11
SE7
N5
E8
NE6
N15

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Quantico Marine Corps Airfield - Turner Field, VA19 mi21 minENE 410.00 miFair44°F36°F73%1031.2 hPa
Stafford, Stafford Regional Airport, VA23 mi42 minNNW 410.00 miFair42°F33°F72%1032.2 hPa
Fredericksburg, Shannon Airport, VA23 mi42 minN 010.00 miPartly Cloudy45°F32°F60%1030.8 hPa

Wind History from NYG (wind in knots)
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
7
PM
8
PM
9
PM
Last 24hrNW4NW7CalmCalmCalmNE4NW3NW6CalmNW6NE6N64E6E8E7E5NE5N4N5NW4NW3N3E4
1 day ago--NW4CalmSW3CalmSW3SW3Calm----Calm--S4S6S3CalmS3CalmCalmS6S5CalmW4NW5
2 days agoNE4E3CalmCalmE5SE6SE8S9E6E9SE6SE10SE5E5E9SE8S4SE6N5CalmE5NW45N4

Tide / Current Tables for Dahlgren, Upper Machodoc Creek, Virginia (2)
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Dahlgren
Click for Map
Fri -- 05:02 AM EST     1.88 feet High Tide
Fri -- 06:50 AM EST     Sunrise
Fri -- 08:56 AM EST     Moonset
Fri -- 11:29 AM EST     -0.27 feet Low Tide
Fri -- 05:30 PM EST     1.82 feet High Tide
Fri -- 05:53 PM EST     Sunset
Fri -- 09:40 PM EST     Moonrise
Fri -- 11:47 PM EST     -0.24 feet Low 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
-0.10.30.91.41.81.91.71.30.90.40-0.2-0.20.10.61.21.61.81.81.510.60.2-0.1

Tide / Current Tables for Mathias Point, Virginia
   EDIT      (on/off)   Help   One Week of Data
Mathias Point
Click for Map
Fri -- 05:45 AM EST     1.43 feet High Tide
Fri -- 06:50 AM EST     Sunrise
Fri -- 08:56 AM EST     Moonset
Fri -- 12:24 PM EST     -0.21 feet Low Tide
Fri -- 05:53 PM EST     Sunset
Fri -- 06:13 PM EST     1.39 feet High Tide
Fri -- 09:40 PM EST     Moonrise
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
-0.2-0.10.30.81.21.41.41.30.90.60.3-0-0.2-0.20.10.511.31.41.310.70.40.1

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 (21,6,7,8)
      (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.