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Marine Weather and Tides
Version 3.4 |
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 6:48AM | Sunset 5:45PM | Tuesday February 19, 2019 11:54 PM EST (04:54 UTC) | Moonrise 5:56PM | Moonset 7:02AM | Illumination 100% | ![]() |
ANZ530 Chesapeake Bay North Of Pooles Island- 943 Pm Est Tue Feb 19 2019
Rest of tonight..NE winds 5 to 10 kt. Waves 1 ft or less. A slight chance of snow with vsby 1 to 3 nm.
Wed..E winds 5 to 10 kt. Waves 1 ft. Snow or sleet. Vsby 1 nm or less.
Wed night..E winds 5 to 10 kt...becoming sw late. Waves 1 ft. Rain.
Thu..W winds 5 to 10 kt with gusts to 20 kt. Waves 1 ft. A chance of rain.
Thu night..NW winds 5 to 10 kt. Waves 1 ft.
Fri..NW winds 5 kt. Waves less than 1 ft.
Fri night..NE winds around 5 kt. Waves flat.
Sat..SE winds 5 kt. Waves less than 1 ft. Rain.
Sun..SW winds 10 to 15 kt...becoming w. Waves 2 ft. Showers likely through the day.
Rest of tonight..NE winds 5 to 10 kt. Waves 1 ft or less. A slight chance of snow with vsby 1 to 3 nm.
Wed..E winds 5 to 10 kt. Waves 1 ft. Snow or sleet. Vsby 1 nm or less.
Wed night..E winds 5 to 10 kt...becoming sw late. Waves 1 ft. Rain.
Thu..W winds 5 to 10 kt with gusts to 20 kt. Waves 1 ft. A chance of rain.
Thu night..NW winds 5 to 10 kt. Waves 1 ft.
Fri..NW winds 5 kt. Waves less than 1 ft.
Fri night..NE winds around 5 kt. Waves flat.
Sat..SE winds 5 kt. Waves less than 1 ft. Rain.
Sun..SW winds 10 to 15 kt...becoming w. Waves 2 ft. Showers likely through the day.
ANZ500 943 Pm Est Tue Feb 19 2019
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A strong low pressure system will impact the region late tonight through Wednesday night. Low pressure will then push off to the north and east on Thursday as a frontal boundary passes through the waters. High pressure will build to the north through week's end. Small craft conditions will be possible on Thursday.
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A strong low pressure system will impact the region late tonight through Wednesday night. Low pressure will then push off to the north and east on Thursday as a frontal boundary passes through the waters. High pressure will build to the north through week's end. Small craft conditions will be possible on Thursday.
7 Day Forecast for Marine Location Near Elkton, MD
Hourly EDIT Helplocation: 39.57, -75.85 debug
Area Discussion for - Philadelphia/Mount Holly, PA
  (on/off)  Help NOTE: mouseover dotted underlined text for definitionFxus61 kphi 192347 afdphi area forecast discussion national weather service mount holly nj 647 pm est Tue feb 19 2019 Synopsis High pressure over the mid-atlantic region tonight will give way on Wednesday to a complex low pressure and frontal system moving into the eastern u.S. This system will bring a mix of wintry precipitation across the area through Wednesday night. High pressure will build into the area for Thursday and Friday. Strong low pressure moving across the great lakes should bring mostly rain to the region for much of Saturday and Sunday. High pressure is forecast to return early next week. Near term until 6 am Wednesday morning One more period with the surface high in place over the region, resulting in mostly dry conditions. As mid level dry air advection begins to develop late tonight, we should see increasing cloudiness and some precipitation could even reach portions of DELMARVA by the pre-dawn hours. The increasing clouds will limit radiational cooling, so we should see temperatures near normal, with lows in the teens and 20s across the region. Short term 6 am Wednesday morning through Wednesday night This is the period of greatest concern with the potential for wintry weather across the region starting very early Wednesday morning and continuing through Wednesday night (though for many locations there will be a changeover to all rain as early as Wednesday afternoon - more on that below). Changes with this forecast: the biggest change involved the headlines: far NE md and chester, berks, and upper montgomery co in pa are now under a winter storm warning. A winter weather advisory has been issued for the remainder of the area. Synoptic mesoscale pattern: as the large surface high that has been sitting over our region for the last few days shifts east, a warm front will propagate north into the region. In the mid and upper levels, a large closed low will cross from the dakotas to the great lakes region. What is interesting about this system is that the main area of synoptic scale lift stays well north and west of the region. Thus, the amount of precipitation is highly dependent on mesoscale (mostly with frontogenesis) lift. Unfortunately, this leads to another source of uncertainty as it is difficult to pick out the areas of greatest mesoscale lift this far out. Timing: timing for the onset and ending of precipitation has changed little with the latest model runs. Precipitation is expected to start very early Wednesday morning in delmarva, but it may not begin until early afternoon for portions of northern nj. Precipitation should come to an end early Thursday morning as the surface low lifts northeast away from our region. Precipitation type:the biggest source of uncertainty with both impacts and snow ice amounts is the precipitation type and the timing of any precipitation type changes. We have relatively high confidence that the precipitation will begin as all snow. Once the warm front arrives, ptype gets very uncertain. As is often the case with warm fronts, we will likely see an elevated warm layer develop from south to north. When this develops, we should see snow begin to change over to sleet. Based on model soundings, it looks like the elevated warm layer will initially be high enough to preclude much freezing rain - it will be mostly snow or sleet. As the elevated warm layer becomes deeper, and the base lowers closer to the surface, the threat for freezing rain increases. Snow and ice amounts: no significant changes in forecast snow and ice amounts. Having said that, there is still considerable uncertainty with the snow and ice amounts as it will be very dependent on the timing of changeovers. Impacts: regardless of the exact snow and ice amounts, I am very concerned that much of the region could be seeing the greatest impacts coincident with the evening commute. The one exception is DELMARVA and SE nj which should see the change over to all rain before this time. Even if the snow and ice amounts are lower, the potential for ice on top of snow, could result in very slippery conditions. Long term Thursday through Tuesday The long term period starts out with a break from stormy weather as the low pressure and frontal system associated with the wed- wed night event will have moved north east of the area by 12z on Thursday. Precip should be over for most areas by then, except possibly southern de or south coastal section of nj. There is some cold advection behind this system, but no big surge of arctic air, and temps are forecast to remain near or somewhat above normal, even as surface high pressure builds in from the west through the end of the week. Meanwhile a mid- upper-level ridge is forecast to build over the eastern u.S., while another shortwave trof begins to eject out of the southwest. Winds aloft become southwest and begin to bring increasing cloud and moisture into the mid-atlantic. Light precip is forecast to develop and spread northeast into the area on Saturday, or possibly late Friday night in delmarva. Confidence in the time of arrival is relatively low, and any rain amounts on Saturday should be light. Temps should be warm enough to avoid any sig snow or ice with this event. Saturday night looks more favorable for significant rain as uvv and warm advctn increase ahead of the upper trof and deepening sfc low, both moving northeast into the great lakes. A warm front is forecast to move north through the area early Sunday resulting in mild temps and more showery precip in the sfc low warm sector during the day. A cold front passage late in the day |
should end the precip. High pressure is expected to build into the area early next week, bringing fair wx an a return to near normal temps for late feb. Aviation 00z Wednesday through Sunday The following discussion is for kphl, kpne, kttn, kabe, krdg, kilg, kmiv, kacy and surrounding areas. Tonight...VFR. Increasing high clouds early then mid-level clouds arrive towards dawn. Light winds from the N mostly. Wednesday...VFR early then lowering CIGS as snow overspreads from the SW during the morning. Phl fcst beginning time is 15z presently. Sharply lowering vsbys then CIGS (ifr or lifr) after snow begins. Precip will mix with or change to sleet across the SRN terminals during the afternoon. Rain snow mix at kphl after 21z (limited confid). Winds mostly E or SE around 10 knots. Outlook... Thursday... MVFR or lower conditions are possible in the morning, improving toVFR by the afternoon. Winds becoming W nw between 10-15 knots with some gustiness. High confidence. Friday...VFR conditions with northwesterly winds under 10 knots. High confidence. Saturday... GenerallyVFR conditions early but possibly lowering to MVFR in the afternoon. Light southeast winds. Saturday night... Widespread MVFR ifr conditions expected in rain and fog. Variable winds mostly less than 10 kt. Moderate confidence. Sunday... Conditions should improve toVFR MVFR but lower at times in showers. South winds becoming gusty and shifting to west late in the day. Low confidence on timing. Marine Winds and seas could reach small craft advisory criteria as early as Wednesday afternoon on the coastal waters, and will likely continue Wednesday night. Outlook... Thursday... Seas building to SCA levels by Thursday am on ocean waters with west winds gusting 20 to 25 kt. Friday Saturday... Seas winds dipping below SCA by early Friday morning with sub-sca conditions prevailing through Saturday. Sunday... SCA conditions possible in gusty SW winds and building seas. Tides coastal flooding Northeast flow develops late tonight, and then east to southeast flow increases on Wednesday as low pressure approaches from the south and west. The higher of the two high tide cycles will occur Wednesday morning, when departures should be around 1 2 foot above normal. Minor coastal flooding thresholds may be touched in some spots Wednesday morning, but not anticipating widespread minor coastal flooding advisory. Although locally minor coastal flooding cannot be ruled out, do not think it will be widespread enough to warrant a coastal flood advisory for the high tide Wednesday morning at this time. Elevated tides may continue into Thursday morning. Phi watches warnings advisories Pa... Winter weather advisory from 10 am Wednesday to 1 am est Thursday for paz105. Winter weather advisory from 7 am to 9 pm est Wednesday for paz070-071-104-106. Winter weather advisory from 10 am Wednesday to 6 am est Thursday for paz054-055-061-062. Winter storm warning from 10 am Wednesday to 1 am est Thursday for paz060-101>103. Nj... Winter weather advisory from 10 am Wednesday to 1 am est Thursday for njz008>010-012>015. Winter weather advisory from 7 am to 9 pm est Wednesday for njz016>027. Winter weather advisory from 10 am Wednesday to 6 am est Thursday for njz001-007. De... Winter weather advisory from 7 am to 9 pm est Wednesday for dez001. Winter weather advisory from 7 am to 4 pm est Wednesday for dez002>004. Md... Winter weather advisory from 7 am to 4 pm est Wednesday for mdz015-019-020. Winter storm warning from 7 am to 4 pm est Wednesday for mdz008-012. Marine... Small craft advisory from 1 pm Wednesday to 6 am est Thursday for anz450>455. Synopsis... Amc near term... Johnson mps short term... Johnson long term... Amc aviation... Amc o'hara marine... Amc johnson tides coastal flooding... |
Weather Reporting Stations
EDIT (on/off)  Help NOTE: Click on distance to see the station location on a mapStations | Dist | Age | Wind | Air Temp | Water Temp | Waves | Pressure | DewPt |
CHCM2 - 8573927 - Chesapeake City, MD | 4 mi | 54 min | Calm G 1 | 30°F | 39°F | 1036.9 hPa (-0.0) | ||
DELD1 - 8551762 - Delaware City, DE | 14 mi | 54 min | N 6 G 7 | 33°F | 34°F | 1036.4 hPa (-0.4) | ||
RDYD1 - 8551910 - Reedy Point, DE | 15 mi | 60 min | 1035.8 hPa | |||||
MRCP1 - 8540433 - Marcus Hook, PA | 28 mi | 60 min | 33°F | 39°F | 1035.9 hPa | |||
SJSN4 - 8537121 - Ship John Shoal, NJ | 31 mi | 54 min | N 7 G 8.9 | 33°F | 38°F | 1036.2 hPa (-0.3) | ||
TCBM2 - 8573364 - Tolchester Beach, MD | 32 mi | 54 min | ENE 1.9 G 2.9 | 33°F | 39°F | 1036.9 hPa (-0.0) | ||
DRSD1 - Delaware Reserve, DE | 40 mi | 144 min | Calm | 31°F | 1036 hPa | 19°F | ||
FSKM2 - 8574728 - Francis Scott Key Bridge, MD | 43 mi | 54 min | E 5.1 G 6 | 34°F | 1036.8 hPa (-0.0) | |||
FSNM2 | 43 mi | 60 min | NE 6 G 6 | 34°F | 1035.9 hPa | |||
BLTM2 - 8574680 - Baltimore, MD | 44 mi | 60 min | ENE 5.1 G 6 | 35°F | 38°F | 1036.5 hPa | ||
PHBP1 - 8545240 - Philadelphia, PA | 45 mi | 60 min | 33°F | 38°F | 1035.7 hPa | |||
CPVM2 | 49 mi | 54 min | 35°F | 13°F |
Wind History for Chesapeake City, MD
(wind in knots) EDIT (on/off)  Help12 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 | |
Last 24hr | NW G13 | NW G11 | N G11 | NW G8 | N | N G10 | NW | NW | NW | NW G12 | NW G11 | NW G12 | N G13 | N G13 | N G18 | N G11 | N G11 | NW G9 | NW | -- | S | N | -- | SW |
1 day ago | SE G12 | SE | SE G9 | NW | -- | N G5 | SW | W | NW | W G7 | W G8 | W G13 | NW G18 | W G22 | NW G24 | NW G22 | NW G20 | NW G21 | NW G15 | NW G15 | NW G11 | NW G13 | NW G14 | NW G13 |
2 days ago | N | N | N | N | NE | N | N | N | NE | E G10 | E G9 | E G9 | S G8 | E | S G7 | SE G9 | S | SE | S | SE G6 | SE | SE | N | NW G5 |
Airport Reports
EDIT (on/off)  Help Click EDIT to display multiple airportsAirport | Dist | Age | Wind kt | Visibility | Sky/Weather | Temp | DewPt | Humidity | Pressure |
Wilmington, New Castle County Airport, DE | 15 mi | 63 min | N 3 | 10.00 mi | Fair | 31°F | 10°F | 43% | 1036.5 hPa |
Phillips Army Air Field / Aberdeen, MD | 18 mi | 4 hrs | NNE 4 | 7.00 mi | Overcast | 30°F | 10°F | 43% | 1037.2 hPa |
Wind History from ILG (wind in knots)
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 | |
Last 24hr | NW | NW | NW | NW | NW | NW | N | NW | NW | NW | NW | NW | NW | NW | NW G20 | NW G18 | NW | NW | NW | NW | NW | NW | N | N |
1 day ago | SE | Calm | SE | Calm | E | NW | Calm | NW | Calm | W | W | W G19 | NW G31 | W G27 | W G33 | NW | NW G27 | NW G31 | NW G22 | NW G22 | NW | NW | NW G24 | N |
2 days ago | N | N | N | N | N | N | N | N | NE | E | E | E | Calm | S | S | S | S | S | SE | SE | SE | Calm | Calm |
Tide / Current Tables for Old Frenchtown Wharf, Maryland
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of DataOld Frenchtown Wharf
Click for Map
Tue -- 03:41 AM EST -0.19 feet Low Tide
Tue -- 06:50 AM EST Sunrise
Tue -- 07:01 AM EST Moonset
Tue -- 08:53 AM EST 1.88 feet High Tide
Tue -- 10:53 AM EST Full Moon
Tue -- 03:09 PM EST -1.00 feet Low Tide
Tue -- 05:44 PM EST Sunset
Tue -- 05:56 PM EST Moonrise
Tue -- 09:46 PM EST 2.84 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Click for Map
Tue -- 03:41 AM EST -0.19 feet Low Tide
Tue -- 06:50 AM EST Sunrise
Tue -- 07:01 AM EST Moonset
Tue -- 08:53 AM EST 1.88 feet High Tide
Tue -- 10:53 AM EST Full Moon
Tue -- 03:09 PM EST -1.00 feet Low Tide
Tue -- 05:44 PM EST Sunset
Tue -- 05:56 PM EST Moonrise
Tue -- 09:46 PM EST 2.84 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
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 |
1.5 | 0.9 | 0.3 | -0.1 | -0.2 | 0.1 | 0.7 | 1.3 | 1.7 | 1.9 | 1.6 | 1.1 | 0.4 | -0.3 | -0.8 | -1 | -0.9 | -0.4 | 0.4 | 1.4 | 2.2 | 2.7 | 2.8 | 2.6 |
Tide / Current Tables for Chesapeake and Delaware Canal, Maryland/Delaware Current
EDIT (on/off)  Help One Week of DataChesapeake and Delaware Canal
Click for Map
Tue -- 12:15 AM EST -1.73 knots Max Ebb
Tue -- 03:13 AM EST 0.05 knots Slack
Tue -- 06:28 AM EST 2.14 knots Max Flood
Tue -- 06:50 AM EST Sunrise
Tue -- 07:00 AM EST Moonset
Tue -- 09:03 AM EST -0.02 knots Slack
Tue -- 10:53 AM EST Full Moon
Tue -- 12:33 PM EST -2.41 knots Max Ebb
Tue -- 04:20 PM EST 0.02 knots Slack
Tue -- 05:44 PM EST Sunset
Tue -- 05:56 PM EST Moonrise
Tue -- 07:14 PM EST 2.36 knots Max Flood
Tue -- 10:33 PM EST -0.04 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Click for Map
Tue -- 12:15 AM EST -1.73 knots Max Ebb
Tue -- 03:13 AM EST 0.05 knots Slack
Tue -- 06:28 AM EST 2.14 knots Max Flood
Tue -- 06:50 AM EST Sunrise
Tue -- 07:00 AM EST Moonset
Tue -- 09:03 AM EST -0.02 knots Slack
Tue -- 10:53 AM EST Full Moon
Tue -- 12:33 PM EST -2.41 knots Max Ebb
Tue -- 04:20 PM EST 0.02 knots Slack
Tue -- 05:44 PM EST Sunset
Tue -- 05:56 PM EST Moonrise
Tue -- 07:14 PM EST 2.36 knots Max Flood
Tue -- 10:33 PM EST -0.04 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
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 |
-1.7 | -1.6 | -1.2 | -0.5 | 1.1 | 1.7 | 2.1 | 2.1 | 1.6 | 0.4 | -1.5 | -2.1 | -2.4 | -2.4 | -2.1 | -1.7 | -0.9 | 1.3 | 2 | 2.3 | 2.2 | 1.8 | 1.1 | -0.9 |
Weather Map and Satellite Images
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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 Philadelphia/Mount Holly, PA (23,6,7,8)
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Ground Weather Radar Station Dover AFB, DE
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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. |