Sunday, July22, 2018 L-36.com


Marine Weather and Tides
Halfway, MD

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Sunrise 6:00AMSunset 8:34PM Sunday July 22, 2018 2:51 AM EDT (06:51 UTC) Moonrise 3:24PMMoonset 1:07AM Illumination 69% Phase: Waxing Gibbous; Moon at 9 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
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ANZ538 Patapsco River Including Baltimore Harbor- 132 Am Edt Sun Jul 22 2018
.small craft advisory in effect until 2 am edt early this morning...
Overnight..W winds 10 kt with gusts to 20 kt. Waves 1 ft. Rain. Patchy fog. Vsby 1 nm or less.
Sun..SE winds 5 to 10 kt. Waves 1 ft. Showers likely with a chance of tstms.
Sun night..SE winds 5 to 10 kt with gusts to 20 kt. Waves 1 ft. Showers likely with a chance of tstms. Patchy fog. Vsby 1 to 3 nm.
Mon..SE winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft. Showers with a chance of tstms.
Mon night..SE winds 10 kt with gusts to 20 kt. Waves 1 ft. Showers likely.
Tue..SE winds 10 kt. Waves 1 ft. Showers and tstms likely.
Tue night..SE winds 5 to 10 kt. Waves 1 ft. Showers and tstms likely.
Wed..S winds 5 to 10 kt. Waves 1 ft. A chance of showers in the morning, then showers and tstms likely.
Thu..SW winds 5 to 10 kt. Waves 1 ft. Showers and tstms likely, then a chance of showers after midnight. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 132 Am Edt Sun Jul 22 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. An area of low pressure will move near the delmarva coastline overnight before another low approaches from the west on Sunday and stalls into early next week. Small craft advisory conditions are possible Monday through Wednesday.

7 Day Forecast for Marine Location Near Halfway, MD
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location: 39.62, -77.79     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 220141
afdlwx
area forecast discussion
national weather service baltimore md washington dc
941 pm edt Sat jul 21 2018

Synopsis
An area of low pressure will move north across the delmarva
peninsula. Meanwhile, a broad and slow moving low pressure
system will drop from the upper midwest into the southern
appalachians by the end of the weekend. This low will continue
to influence the mid atlantic during the early part of the
coming week.

Near term until 6 am Sunday morning
Low pressure will continue moving northward through the
delmarva this evening and tonight, reaching northeastern pa by
Sunday morning. Widespread heavy rain has occurred and will
continue to occur over the next several hours, before rain moves
northward and out of the region after midnight. Widespread
amounts of 2-5" have already fallen along and east of a line
from spotsylvania-fauquier-jefferson counties eastward, with
localized amounts of 5-7" in fairfax, prince william, stafford,
spotsylvania, and charles counties. This has led to numerous
reports of flooding and flash flooding. Please refer to warning
products for additional information. As the low moves northward,
the axis of additional heavy rain will shift northward into
central and northern maryland and will need to monitor for
additional flooding concerns. Flash flood watch will remain in
effect until 2 am.

After main area of rain exits, off and on light rain or drizzle
could continue in convergent surface flow. Light fog and low
clouds will also be likely much of the night.

Short term 6 am Sunday morning through Monday night
For Sunday and Monday, upper low will be drifting south to our
west. This mean copious moisture will continue to be drawn into
the region with nearly constant chances of showers and
thunderstorms. While there will be some diurnal component,
especially to convective elements, forcing and moisture will
support chances of rain through the nights as well. Details
regarding timing and locations of heaviest rain will be ironed
out as finer scale features are identified. Unidirectional flow
and or southeast low level flow into the terrain could enhance
the threat for locally heavy rain at times. High temperatures
will be below normal in the 80s, while lows remain in the 60s
to lower 70s due to the high dew points.

Long term Tuesday through Saturday
The upper low will remain anchored to our southwest through
Thursday, thanks to a blocking upper-level ridge over the northern
atlantic. Multiple fluxes of moisture from the southeast and south,
along with the meandering trough of low pressure will induce several
rounds of showers and thunderstorms through Thursday night.

Expecting the shower and thunderstorm activity to peak during the
warmest part of the afternoon each day. Although we are currently
not anticipating widespread flooding, pwat values approaching and
exceeding 2 inches will provide plenty of moisture for heavy
rainfall with any showers or storms. This could potentially
lead to some flooding concerns over localized areas through this
period, if heavy rain sits over one area long enough. With
constant cloud cover throughout this period, expect high
temperatures in the mid 80s, with lows only in the low to mid
70s.

The upper level ridge over the northern atlantic should begin to
break down and move east late Thursday into Friday. This will allow
for that stubborn upper-level trough to move out of the area.

However, the chance of showers and a few thunderstorms still linger
Friday and Friday night because of the added lift of a front. High
temperatures will be closer to normal as we could see a southwest
wind develop along a weak boundary as it moves east.

Aviation 01z Sunday through Thursday
Low pressure is moving up the coast with widespread rainfall
(except cho, which may largely miss out). Conditions have
largely deteriorated into ifr and will persist at least into the
early morning hours. Some improvement is likely after the rain
exits. Some llws is possible as a low level jet moves overhead
through this evening, but surface winds 10-15 kt may limit the
threat.

Conditions improving somewhat Sunday into Tuesday, but risk of
showers t-storms will remain into tue. Otherwise, expect bkn
cigs that areVFR during the day but could drop at night. Patchy
fog also can't be ruled out due to the moist atmosphere.

Showers and thunderstorms each day Tuesday through Thursday. The
warmest time in the afternoon into the early evening hours would be
the more prominent time to encounter these showers and
thunderstorms. Occasionally MVFR or perhaps ifr could develop with
the showers and thunderstorms through the period. Winds generally
southeast to south at 5 to 10 knots with higher gusts in
thunderstorms Tuesday through Wednesday night. Winds could become
southwesterly at 5 to 10 knots Thursday ahead of the trough.

Marine
Low pressure is advancing toward the waters from the south, with
sca conditions common and gusts 25-30 kt. Gale warning remains
in place for the bay and lower tidal potomac into early Sunday
morning.

Sca remains in effect for Sunday afternoon in the mid bay and
Sunday night north through pooles island due to increasing
southerly flow. This regime will continue through Monday.

Small craft advisories likely Tuesday. Small craft advisories
possible Tuesday night and Wednesday. Winds southeast to south at 10
to 15 knots gusts 20 to 25 knots Tuesday. Winds southerly around 10
knots gusts to 15 to perhaps 20 knots Tuesday night and Wednesday.

Hydrology
Widespread rain amounts of 2-5" with localized 5-7" amounts are
expected into this evening. This magnitude of rain coupled with
rates of up to 2" in one hour have resulted in and will continue
to result in numerous flooding incidents with localized flash
flooding. The main areas of concern have been from fairfax
county southward to spotsylvania county, but as rain shield
shifts northward, this will spread into central maryland.

Additional flooding concerns are possible into this week, but
uncertainty remains high.

Tides coastal flooding
Minor coastal flooding forecast at most sites into early Sunday
morning, with the exception of have de grace. Moderate coastal
flooding is ongoing at straits point this evening.

There may be a momentary decrease in water levels early Sunday,
but they will rise again later Sunday into Monday with southerly
flow in place.

Lwx watches warnings advisories
Dc... Flash flood watch until 2 am edt Sunday for dcz001.

Coastal flood advisory until 8 am edt Sunday for dcz001.

Md... Flash flood watch until 2 am edt Sunday for mdz003>006-011-013-
014-016>018-503>508.

Coastal flood advisory until 2 am edt Sunday for mdz016-018.

Coastal flood warning until 2 am edt Sunday for mdz017.

Coastal flood advisory until 5 am edt Sunday for mdz014.

Coastal flood advisory until 6 am edt Sunday for mdz011.

Va... Flash flood watch until 2 am edt Sunday for vaz052>055-057-505-
506.

Coastal flood advisory until 2 am edt Sunday for vaz057.

Coastal flood advisory from 1 am to 6 am edt Sunday for vaz054.

Wv... Flash flood watch until 2 am edt Sunday for wvz053.

Marine... Small craft advisory from 6 pm Sunday to 6 am edt Monday for
anz531-532-539>542.

Gale warning until 4 am edt Sunday for anz530>534-537-539>543.

Small craft advisory until 2 am edt Sunday for anz535-536-538.

Small craft advisory from 2 pm Sunday to 6 am edt Monday for
anz533-534-537-543.

Synopsis... Ads
near term... Ads mm
short term... Ads
long term... Cjl
aviation... Ads mm cjl
marine... Ads mm cjl
hydrology... Mm
tides coastal flooding... Mm


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 66 mi34 min WNW 7 G 11 1004.7 hPa
BLTM2 - 8574680 - Baltimore, MD 69 mi40 min NW 7 G 12 68°F 81°F1002.3 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 72 mi34 min W 14 G 18 68°F 1002.4 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hagerstown, Washington County Regional Airport, MD7 mi59 minNW 97.00 miLight Rain63°F62°F97%1006.4 hPa
Eastern WV Regional Airport/Shepherd Field, WV18 mi59 minNW 410.00 miOvercast63°F61°F93%1006.1 hPa

Wind History from HGR (wind in knots)
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Last 24hrS9SE7E6E5E7E6E4E10E10E10E9E9NE11NE10NE9N10N12N8N12N12N9N10N10NW9
1 day agoSE3SE3E6E5CalmNW3CalmSE6SE9S12SE11
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2 days agoCalmCalmNE5N8N4N33N3Calm4NW4W75Calm3W5SE5S5SE4E5E6E5SE5Calm

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
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Sun -- 02:05 AM EDT     Moonset
Sun -- 05:11 AM EDT     3.34 feet High Tide
Sun -- 06:00 AM EDT     Sunrise
Sun -- 12:04 PM EDT     0.33 feet Low Tide
Sun -- 04:19 PM EDT     Moonrise
Sun -- 05:42 PM EDT     2.88 feet High Tide
Sun -- 08:28 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.51.11.92.63.13.33.22.72.21.61.10.60.30.51.11.82.42.82.92.521.40.90.5

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
Click for Map
Sun -- 02:05 AM EDT     Moonset
Sun -- 05:15 AM EDT     3.33 feet High Tide
Sun -- 06:00 AM EDT     Sunrise
Sun -- 12:06 PM EDT     0.30 feet Low Tide
Sun -- 04:19 PM EDT     Moonrise
Sun -- 05:46 PM EDT     2.88 feet High Tide
Sun -- 08:28 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.411.82.53.13.33.22.82.21.61.10.60.30.51.11.82.42.82.92.621.40.90.5

Weather Map and Satellite Images
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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.
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Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Baltimore, MD/Washington (2,6,7,8)
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Ground Weather Radar Station Sterling, VA
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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.