Wednesday, April25, 2018 L-36.com


Marine Weather and Tides
Frederick, MD

Version 3.4
What's New / NOTES
3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.
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.

Sunrise 6:15AMSunset 7:59PM Wednesday April 25, 2018 4:31 AM EDT (08:31 UTC) Moonrise 2:26PMMoonset 3:10AM Illumination 75% Phase: Waxing Gibbous; Moon at 10 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
ANZ538 Patapsco River Including Baltimore Harbor- 134 Am Edt Wed Apr 25 2018
.small craft advisory in effect until 4 am edt early this morning...
Overnight..NE winds 10 kt with gusts to 20 kt. Waves 1 ft. Rain. Patchy fog. Vsby 1 to 3 nm.
Wed..NW winds 5 to 10 kt. Waves 1 ft. Numerous showers. Patchy fog. Vsby 1 to 3 nm.
Wed night..NW winds 10 kt. Waves 1 ft.
Thu..NW winds 10 kt. Waves 1 ft.
Thu night..S winds 5 kt. Waves less than 1 ft. A chance of showers.
Fri..SE winds 5 kt. Waves less than 1 ft. Showers likely.
Fri night..SW winds around 5 kt. Waves 1 ft or less. A chance of showers.
Sat..NW winds 5 to 10 kt. Waves 1 ft or less. A chance of showers.
Sun..NW winds 5 to 10 kt. Waves 1 ft.
ANZ500 134 Am Edt Wed Apr 25 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure will move northward from the carolinas tonight before passing overhead Wednesday. High pressure will then move near the area Thursday. Another low pressure system may affect the waters by overnight Thursday into Friday. A cold front will pass through the waters Saturday and high pressure will return for Sunday. Small craft advisories may be needed Thursday.

7 Day Forecast for Marine Location Near Frederick, MD
   Hourly   EDIT   Help
location: 39.43, -77.41     debug


Area Discussion for - Baltimore, MD/Washington
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 klwx 250740
afdlwx
area forecast discussion
national weather service baltimore md washington dc
340 am edt Wed apr 25 2018

Synopsis
Low pressure will pass by just to east today and high pressure
will return for tonight into Thursday. Low pressure will
approach the area Thursday night before passing through the area
Friday. A cold front will pass through Saturday and high
pressure will return for early next week.

Near term through tonight
Cutoff low pressure to our south early this morning will get
absorbed by the jetstream and it will track northeast, passing
by to our just to our east today. The steady rain for most areas
overnight will gradually breakup early this morning as the dry
slot moves in overhead. However, the upper-level trough axis
will remain overhead... And this combined with plenty of moisture
in place suggest that scattered showers will persist through the
morning rush. Also, low-level moisture will be trapped
underneath the nocturnal inversion and this will result in low
clouds along with patchy fog. Fog may be locally dense in higher
elevations through the morning rush.

A northwest flow will gradually develop later this morning
through this afternoon as the low passes by to our east.

However, advection will be weak so drier conditions will be slow
to take place. Having that been said... Low clouds should
gradually dissipate but a mostly cloudy to cloudy sky will
remain in place this afternoon as the upper-level trough axis
continues to swing through the area. Isolated to scattered
showers are expected during this time, but it will not be a
washout. Coverage may be a bit more widespread across southern
maryland and for locations near the bay... Closer to the surface
low and upper-level low that is associated with the surface low.

Max temps should top off in the 60s for most locations.

The low will continue to move away from the area tonight and it
will strengthen just a bit. This will cause the northwest flow
to strengthen a bit and dry advection will be more pronounced.

Therefore, any leftover showers should dissipate this evening
and skies will clear out as well. Cool conditions are expected
overnight with min temps in the 40s for most places north and
west of interstate 95 and lower to middle 50s south and east of
i-95.

Short term Thursday through Friday night
High pressure will build overhead for Thursday and it will
remain dry and seasonable. High clouds may build later in the
day ahead of the next area of low pressure.

That low pressure is expected to approach the area Thursday
night before passing through Friday. Guidance has come into
better agreement with the details of this system, but some
uncertainty does remain. As of now, it looks like this system
will dip into some southern stream moisture and it will be
strong enough to bring the likelihood for a period of rain
overnight Thursday into Friday. The low will move off to the
northeast later Friday, but the upper-level trough axis
associated with the low will be passing through, so a few
showers may persist Friday afternoon as well. Drier conditions
are likely Friday night as any showers dissipate due to the loss
of daytime heating and a westerly flow.

Long term Saturday through Tuesday
An upper level disturbance will move from the eastern great
lakes to the northeast u.S. Saturday. An associated surface
cold front will drag across our region Saturday and then to our
southeast Saturday night. A moisture-starved cold front may only
squeeze out a shower or two in parts of out region.

Temperatures will be seasonable.

High pressure will build in behind the cold front Sunday and linger
through the middle of next week. Sunday's highs could be 10 degrees
cooler than Saturday's high temperatures. Temperatures will modify
on Monday, possibly reaching the upper 60s. Then, much of the region
could encounter lower to middle 70s Tuesday with high pressure
lingering over the mid-atlantic.

Aviation 07z Wednesday through Sunday
Low-level moisture will remain trapped underneath the subsidence
inversion resulting in low clouds and patchy fog early this
morning. Ifr conditions are expected. Low pressure will pass by
to the east today and a northwest flow will develop. However,
the flow will contain little in the way of dry or cold air
advection. Therefore, low clouds are expected to take a while to
burn off. Will continue with ifr conditions for most of the
morning perhaps even into the early and middle afternoon hours.

Dry advection will become a little more pronounced later this
afternoon and evening, and this should allow for a return ofVFR
conditions.

High pressure will build over the terminals tonight through
Thursday. There may be a period of northwest wind gusts around
15 to 20 knots tonight into Thursday ahead of the building high.

Low pressure will approach the terminals Thursday night before
passing through Friday. Rain and subvfr conditions are likely
with the passage of this system. Drier conditions are expected
Friday night, but patchy fog is possible.

Vfr conditions at all terminals Saturday through Sunday night. A
brief period of MVFR cannot be ruled out in any passing showers
on Saturday. Winds Saturday northwest 5 to 10 knots Saturday
and Saturday night. Winds northwest 10 knots Sunday, diminishing
Sunday night.

Marine
Low pressure will pass by to the east today and the gradient
will be relatively weak close to the low. Therefore, winds are
expected to remain below SCA criteria. High pressure will build
toward the waters tonight before settling overhead Thursday. A
pressure surge will cause northwest winds to increase. A small
craft advisory is in effect for the bay and lower tidal potomac
river. The SCA may need to be expanded to include the upper and
middle potomac river as well, but confidence was too low at this
time given the unfavorable timing of the pressure surge. For
now, gusts have been capped around 15 knots across these areas.

Low pressure will approach the waters Thursday night before
passing through Friday. Winds may approach SCA criteria for
portions of the waters, but confidence is low at this time due
to uncertainly as to exactly how strong the low will be. Light
winds are expected Friday night.

No marine hazards expected Saturday through Sunday night. Winds
northwest around 10 knots Saturday and Saturday night. Winds
northwest 10 to 15 knots Sunday and Sunday night.

Tides coastal flooding
Water levels running about a 1 to 1.5 feet above astronomical
normals this morning. The winds over the waters have diminished,
but anomalies should not change too much from where they are
now through the morning tide cycle. Will continue with the
coastal flood advisory for st marys county through the high tide
cycle this morning. A coastal flood advisory is also in effect
for washington dc and alexandria where current anomalies if they
hold will cause water levels to be right around the thresholds
for minor tidal flooding.

A northwest flow will develop later today but it will be light.

This may cause anomalies to drop just a bit this afternoon, but
confidence is low. If anomalies do not drop too much, then minor
flooding for sensitive areas is possible. The northwest flow
will strengthen tonight and this should cause anomalies to drop
more significantly.

Lwx watches warnings advisories
Dc... Coastal flood advisory until 7 am edt this morning for dcz001.

Md... Coastal flood advisory until 2 pm edt this afternoon for
mdz017.

Va... Coastal flood advisory until 7 am edt this morning for vaz054.

Wv... None.

Marine... Small craft advisory from 9 pm this evening to 11 am edt
Thursday for anz530>534-537>543.

Synopsis... Bjl
near term... Bjl
short term... Bjl
long term... Klw
aviation... Bjl klw
marine... Bjl klw
tides coastal flooding... 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
WASD2 - 8594900 - Washington, DC 44 mi44 min NNE 1.9 G 5.1 56°F 56°F1010.3 hPa
BLTM2 - 8574680 - Baltimore, MD 45 mi44 min E 6 G 7 56°F 56°F1010.4 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 49 mi44 min ENE 6 G 7 56°F 1010.7 hPa
FSNM2 49 mi44 min E 8 G 11 55°F 1010.4 hPa

Wind History for Washington, DC
(wind in knots)    EDIT      (on/off)   Help
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
12
AM
1
AM
2
AM
3
AM
4
AM
Last
24hr
E3
G9
N2
G6
E2
G6
NE3
G7
E2
G8
SE3
G12
SE10
SE9
G18
SE7
G11
SE5
G16
SE9
G18
SE4
G7
E2
G12
E3
G7
E5
NE4
G7
NE6
G12
NE2
G7
NE5
E1
G5
NE3
G7
NE1
G4
NE2
G7
N2
1 day
ago
S1
SE2
SW1
--
S3
W1
SW2
S2
G6
S10
G18
SE9
G14
SE8
G11
SE8
G13
S13
G18
SE10
G13
SE7
G15
SE10
G13
SE7
SE5
G8
SE3
E2
G5
E3
E3
G7
E4
SE4
G7
2 days
ago
S3
SE2
SE1
E2
SE2
SE4
E3
G9
E5
G8
E5
G10
E5
G11
S5
G10
E5
G9
SE4
G9
SE7
G11
SE4
G12
SE5
G8
SE2
SE4
SE4
G7
SE4
S5
S3
--
SE3

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Frederick Municipal Airport, MD2 mi57 minN 75.00 miRain52°F51°F100%1012.5 hPa
Gaithersburg - Montgomery County Airport, MD22 mi36 minVar 310.00 miLight Rain53°F52°F96%1013.9 hPa

Wind History from FDK (wind in knots)
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
-12
PM
1
AM
2
AM
3
AM
4
AM
Last 24hrE4CalmE3--SE5SE5SE10
G20
--SE10
G20
SE10
G15
SE10
G16
E7E4NE5NE3NE6NE5NE6N7N7N9N8N8N7
1 day agoCalmCalmCalmCalmCalmCalmCalm5SE12S12S12SE9SE8
G16
SE8SE8SE8SE5SE6SE5SE3CalmCalmSE3E4
2 days agoCalmCalmCalmNE5CalmE5E8E65CalmCalmCalm5CalmSE6SE3SE4SE3CalmCalmCalmCalmCalmCalm

Tide / Current Tables for Chain Bridge, D.C.
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Chain Bridge
Click for Map
Wed -- 04:07 AM EDT     Moonset
Wed -- 05:27 AM EDT     3.20 feet High Tide
Wed -- 06:18 AM EDT     Sunrise
Wed -- 12:11 PM EDT     0.32 feet Low Tide
Wed -- 03:26 PM EDT     Moonrise
Wed -- 05:51 PM EDT     3.20 feet High Tide
Wed -- 07:55 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.30.71.42.22.83.23.12.72.21.610.60.30.51.122.63.13.22.92.41.81.30.8

Tide / Current Tables for Chain Bridge, Washington, D.C.
   EDIT      (on/off)   Help   One Week of Data
Chain Bridge
Click for Map
Wed -- 04:07 AM EDT     Moonset
Wed -- 05:28 AM EDT     3.23 feet High Tide
Wed -- 06:18 AM EDT     Sunrise
Wed -- 12:10 PM EDT     0.27 feet Low Tide
Wed -- 03:26 PM EDT     Moonrise
Wed -- 05:51 PM EDT     3.23 feet High Tide
Wed -- 07:55 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.20.61.42.22.93.23.22.82.21.510.50.30.41.11.92.73.13.232.41.81.20.7

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.
target = "new">Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Baltimore, MD/Washington (4,6,7,8)
      (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.