Tuesday, May23, 2017 L-36.com


Marine Weather and Tides
Cobb Island, MD

Version 3.4
What's New / NOTES
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.

Sunrise 5:47AMSunset 8:21PM Tuesday May 23, 2017 8:33 PM EDT (00:33 UTC) Moonrise 3:31AMMoonset 4:48PM Illumination 3% Phase: Waning Crescent; Moon at 28 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
ANZ537 Tidal Potomac From Cobb Island To Smith Point- 802 Pm Edt Tue May 23 2017
.small craft advisory in effect through Wednesday morning...
.small craft advisory in effect from Wednesday evening through late Wednesday night...
Tonight..NE winds 10 to 15 kt with gusts to 20 kt. Waves 2 to 3 ft. Rain. Patchy fog.
Wed..E winds 5 to 10 kt with gusts to 20 kt. Waves 1 to 2 ft.
Wed night..SE winds 10 to 15 kt with gusts to 25 kt. Waves 2 to 3 ft. Rain. Patchy fog. Vsby 1 to 3 nm.
Thu..S winds 5 to 10 kt with gusts to 20 kt. Waves 2 ft. Showers likely with a chance of tstms.
Thu night..W winds 10 to 15 kt with gusts to 25 kt. Waves 2 ft. A chance of showers.
Fri..W winds 10 to 15 kt with gusts to 25 kt. Waves 2 ft.
Fri night..NW winds 5 to 10 kt. Gusts up to 20 kt in the evening. Waves 1 to 2 ft.
Sat..S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms through the night. Showers likely with a chance of tstms after midnight.
Sun..SW winds 5 to 10 kt. Waves 1 ft. Showers likely in the morning. A chance of tstms. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 802 Pm Edt Tue May 23 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure will move up the coast near the delmarva tonight. Another area of low pressure will move through the area Wednesday night and Thursday. A cold front will cross the waters late Thursday. High pressure will arrive by Saturday. Small craft advisories may be needed for portions of the waters Thursday and again on Friday.

7 Day Forecast for Marine Location Near Cobb Island, MD
   Hourly   EDIT   Help
location: 38.22, -76.75     debug


Area Discussion for - Wakefield, VA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 kakq 232358
afdakq
area forecast discussion
national weather service wakefield va
758 pm edt Tue may 23 2017

Synopsis
A potent low pressure system will track along a stationary
frontal boundary through midnight, before pushing offshore
overnight. Weak high pressure prevails Wednesday. Unsettled
conditions return Wednesday night and Thursday as an upper level
trough approaches from the west.

Near term until 6 am Wednesday morning
Early evening surface analysis shows ~1005mb sfc low pressure
just SW of edenton at 00z. Quasi-stationary boundary extends w
to E and has lifted up along south of the albemarle sound.

Numerous perturbations on GOES wv imagery moving along the front
early this evening, with kakq radar showing swath of heaviest
showers moving NE from NE nc into the eastern tidewater area.

Have updated pops, with only minor changes per latest trends.

Maintained heavy rainfall wording early this evening across the
se third of the area... And some localized flooding is possible
mainly in urban and poor drainage areas across SE va. Pops then
taper off from w-e late tonight as the primary forcing pushes
offshore. Remaining cloudy with some patchy fog expected once
again across the piedmont. Low temperatures range from the
upper 50s N NW to the low mid 60s se.

Short term 6 am Wednesday morning through Friday
A vigorous upper low gradually drops sewd through the mid-
mississippi valley late tonight through Wednesday. Some
semblance of shortwave ridging develops over the mid-atlantic
late tonight through much of the day Wednesday due to the
combination of a departing shortwave trough and the upper low
digging to the w. Therefore, pops drop below 15% for a roughly
12hr period. Lower clouds will struggle to erode despite some
mid-level drying as the surface pressure gradient will be rather
nebulous resulting in weak low-level flow. The best chc for any
partial clearing will be across the md ERN shore. High
temperatures will average 70-75f (highest se).

The upper low digs into the tennessee valley with yet another
shortwave trough lifting nne across the carolinas and mid-
atlantic Wednesday evening through the early overnight hours. A
secondary wave lifts nne across the blue ridge late Wednesday
evening through the overnight hours. Pops quickly ramp up to
categorical across the SW piedmont early Wednesday evening and
spreading NE into central SE va late evening through the early
overnight hours, before shifting to the ERN shore after
midnight. Mid-level drying and subsidence will result in pops
quickly diminishing from sw-ne late Wednesday night into early
Thursday morning. There is a chc of thunderstorms across mainly
the SRN third of the area. 500mb flow strengthens to 40- 50kt
across SE va NE nc and the presence of a surface warm front will
result in a veering low-level wind field. However, forecast
soundings depict a stable layer below 950mb, so it may be
difficult to get surface based convection and at this time the
severe weather threat is low (spc has the SE counties in a
marginal, 5% risk). Additional QPF Wednesday night averages
0.4-0.6".

The upper low finally begins to lift NE across the mountains
Thursday. A strong shortwave trough will lift across the mid-
atlantic during the afternoon early evening. Once again pops
increase, to ~60% from the piedmont to central va to the md ern
shore, with 40-50% farther se. 500mb flow of 45-55kt is expected
along with modest instability. Therefore, a few stronger to
marginally storms are possible. The main threat would be wind
and hail as low-level shear is minimal. Additional QPF Thursday
aftn evening should average ~0.25" with locally higher amounts.

High temperatures range from the mid 70s to around 80 after
morning lows ranging through the 60s.

The upper low continues to lift NE across pa ny new england
late Thursday night into Friday. Drier conditions finally arrive
as deep layered wnw flow develops over the region. Some
lingering mid-level energy could result in some sct-bkn cu
Friday aftn. Otherwise, drier and breezy with highs in the upper
70s to low 80s, after morning lows in the mid 50s to low 60s.

Long term Friday night through Tuesday
Shortwave ridging builds over the northeast Saturday as an
upper level low tracks into the great lakes region. Weak area of
surface high pressure slides off the mid-atlantic coast
Saturday as a warm front lifts through the region. Weak
perturbations in fast westerly flow aloft will result in low end
chance pops Saturday afternoon for showers and thunderstorms.

Otherwise, warming trend continues with highs in the low to mid
80's. The warm front locates stalls over the northern mid-
atlantic region Saturday night, resulting in continued chances
for showers thunderstorms over the northern local area as
perturbations in the westerly flow track across the region. The
upper low slowly pushes across the great lakes region Sunday
with an associated cold front progged to reach the central
appalachians late Sunday. Pressure falls ahead of the
approaching front will induce a lee side thermal trough over the
region and better chances for diurnally driven showers and
thunderstorms. Highs Sunday generally in the mid 80's. The cold
front reaches the local area Monday, but is expected to stall
over the region as subtropical high pressure strengthens off the
southeast coast. The weak front remains over the eastern local
area through Tuesday, with chances for diurnally driven showers
and thunderstorms. Highs Monday and Tuesday in the low to mid
80's.

Aviation 00z Wednesday through Sunday
Poor aviation conditions will continue through much of the taf
period. A frontal boundary is currently located just south of the
region with waves of showers riding along the boundary. A more
potent low pressure system will track along the boundary this
evening. MVFR to ifr conditions with low clouds and reduced
visibilities due to periods of moderate heavy rain will persist
through tonight. Heavier rain departs the area mainly after 06z, but
low ceilings and the potential for fog will persist through
Wednesday morning.

Outlook: a cold front is expected to impact the region Wednesday
afternoon and into Wednesday night bringing the chance for more
showers and thunderstorms adverse aviation conditions. Scattered
afternoon showers, and potentially a few thunderstorms, are expected
to develop on Thursday allowing for the chance of more sub-vfr
conditions. DryVFR conditions return for Friday and Saturday.

Marine
Latest surface analysis depicts weak area of high pressure
centered just offshore the delmarva, with an area of low
pressure over georgia. A quasi-stationary boundary was located
along the southeast coast. The result is a east to northeast
wind of 10-20 knots over the waters. Few gusts to around 20-25
knots observed in the mouth of the bay and adjacent coastal
waters. Seas generally 3-4 feet and waves 2-3 feet. Low pressure
progged to lift along the boundary into northeast north
carolina and southeast virginia this evening. Pressure falls
ahead of the low in tandem with increasing gradient winds will
result in a period of 15-25 knot onshore winds over the waters.

Nam guidance continues to be on the stronger side, indicating
near gale conditions near the mouth of the bay and in the lower
bay. Believe this is too aggressive as the hi-res guidance
doesn't back the NAM up. Have opted for a GFS cmc solution,
resulting in a period of SCA conditions in the bay, sound,
coastal waters, and lower james river through late tonight into
Wednesday morning. Seas build to 4-7 feet (highest north) with
waves of 2-4 feet. Waves in the lower james build to 2-3 feet.

The low pushes offshore late tonight early Wednesday morning
with flow becoming north to northwest. SCA conditions expected
to linger in the bay through late morning early afternoon, with
seas diminishing through Wednesday afternoon. Another area of
low pressure lifts into the ohio valley Wednesday into Wednesday
night as a meso-low lifts along the appalachians. Sca
conditions are anticipated again Wednesday night over the bay
and coastal waters with speeds of 15-25 knots and seas building
to 3-5 feet.

Southwest flow increases Thursday as the low lifts north of the
region, with speeds of 10-20 knots expected. SCA conditions
could again be possible Thursday night as the low tracks off the
northeast coast.

Tides coastal flooding
A period of onshore flow and higher astro tides (moving toward a
new moon) will result in elevated water levels through Wednesday
night. Many tidal sites will reach action stage during this
evenings overnights high tide cycle. Coastal flood statements
have been issued for the upper james and areas around bishops
head, maryland. Low pressure lifts over the region tonight, with
onshore flow ramping up. However, the low is expected during
periods of low tide. Lower astro tides are expected Wednesday
morning. Higher levels are forecast Wednesday evening night,
with minor flooding possible along the the bay, james river,
and atlantic waters.

Akq watches warnings advisories
Md... None.

Nc... None.

Va... None.

Marine... Small craft advisory until 10 am edt Wednesday for anz630>632-
634.

Small craft advisory until 4 am edt Wednesday for anz633-638-
656-658.

Small craft advisory until 4 pm edt Wednesday for anz650-652-
654.

Synopsis... Ajz jdm
near term... Ajz mam
short term... Ajz
long term... Sam
aviation... Ajb
marine... Sam
tides coastal flooding...



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
PPTM2 - 8578240 - Piney Point, MD 13 mi58 min ENE 6 G 8.9
SLIM2 - 8577330 - Solomons Island, MD 17 mi58 min NE 7 G 8 60°F 67°F
NCDV2 17 mi58 min NNE 1.9 G 2.9 61°F 69°F1008.1 hPa
LWTV2 - 8635750 - Lewisetta, VA 22 mi58 min ENE 8.9 G 11 62°F 68°F1008.6 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 23 mi58 min E 8 G 9.9 60°F 1009.9 hPa
44042 - Potomac, MD 26 mi44 min ENE 12 G 16 62°F 1007.8 hPa
44062 - Gooses Reef, MD 29 mi44 min E 9.7 G 12 63°F 1010.2 hPa
BISM2 - 8571421 - Bishops Head, MD 38 mi58 min NE 8.9 G 9.9 61°F 67°F1009.4 hPa
BSLM2 - Chesapeake Bay, MD 39 mi124 min E 1.9 62°F 1009 hPa56°F
44061 - Upper Potomac, MD 42 mi46 min N 7.8 G 7.8 59°F 69°F1009.6 hPa
CA2 - 8571892 - Cambridge, MD 44 mi58 min 62°F 68°F
WASD2 - 8594900 - Washington, DC 47 mi58 min SE 2.9 G 5.1 63°F 69°F1009 hPa

Wind History for Piney Point, MD
(wind in knots)    EDIT      (on/off)   Help
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
6
PM
7
PM
8
PM
Last
24hr
NE4
NE2
N4
N3
N5
NE6
N4
N4
NE2
NE7
E4
E4
E8
SE12
E9
E8
E11
E12
E10
E8
G11
E8
E4
E5
E7
G10
1 day
ago
SE13
SE12
SE10
SE9
SE8
E7
E5
NE4
NE6
NE6
NE6
E4
E3
NE2
--
E1
--
N4
E3
S3
E3
E3
NW1
NE3
2 days
ago
E13
G17
E11
E8
E6
G9
E12
E8
E8
G11
NE7
E11
E9
SE11
SE3
SE6
E11
SE9
SE9
SE11
S10
SE11
SE10
S12
SE15
SE14
SE14

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
St Marys County Airport, MD12 mi41 minNE 47.00 miOvercast57°F55°F94%1009.8 hPa
St. Inigoes, Webster Field, Naval Electronic Systems Engineering Activity, MD18 mi41 minNE 44.00 miLight Rain Fog/Mist60°F59°F96%1008.5 hPa
Patuxent River, Naval Air Station, MD19 mi42 minENE 65.00 miLight Rain Fog/Mist60°F59°F96%1009 hPa

Wind History from NUI (wind in knots)
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
6
PM
7
PM
8
PM
Last 24hrNW33CalmCalmN3CalmNE3CalmCalmN3NE4NE5NE7E6E7NE5E6E8NE6NE7NE5N3NE5NE4
1 day agoE665E6E3E4CalmCalmN4N4NE4N4NE5NE4CalmE3CalmCalmCalmE5NE4NE5CalmCalm
2 days agoE8NE11
G17
NE8NE8NE4NE5E3NE4NE5NE6E6E8NE5E7E8E7NE8E7E7SE6SE9SE8SE7E7

Tide / Current Tables for Colton's Point, Potomac River, Maryland
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Colton's Point
Click for Map
Tue -- 12:47 AM EDT     2.30 feet High Tide
Tue -- 04:30 AM EDT     Moonrise
Tue -- 05:49 AM EDT     Sunrise
Tue -- 07:06 AM EDT     0.16 feet Low Tide
Tue -- 01:21 PM EDT     2.03 feet High Tide
Tue -- 05:48 PM EDT     Moonset
Tue -- 07:03 PM EDT     0.15 feet Low Tide
Tue -- 08:18 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.22.321.610.60.30.20.20.61.11.51.9221.610.60.30.10.20.51.11.7

Tide / Current Tables for Point Patience, 0.1 mile southwest of, Maryland Current
   EDIT      (on/off)   Help   One Week of Data
Point Patience
Click for MapFlood direction 315 true
Ebb direction 145 true

Tue -- 12:24 AM EDT     -0.00 knots Slack
Tue -- 04:19 AM EDT     -0.94 knots Max Ebb
Tue -- 04:29 AM EDT     Moonrise
Tue -- 05:48 AM EDT     Sunrise
Tue -- 08:41 AM EDT     0.00 knots Slack
Tue -- 10:07 AM EDT     0.33 knots Max Flood
Tue -- 12:08 PM EDT     -0.00 knots Slack
Tue -- 04:00 PM EDT     -0.76 knots Max Ebb
Tue -- 05:47 PM EDT     Moonset
Tue -- 07:42 PM EDT     0.00 knots Slack
Tue -- 08:17 PM EDT     Sunset
Tue -- 10:15 PM EDT     0.72 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.1-0.2-0.6-0.8-0.9-0.9-0.8-0.5-0.20.10.30.30-0.2-0.5-0.7-0.8-0.7-0.5-0.20.10.50.70.7

Weather Map and Satellite Images
       (on/off)   Help
Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Mid-Atlantic    EDIT
Geos

Wind Forecast for Wakefield, VA (20,4,5,8)
      (on/off)   Help

Ground Weather Radar Station Dover AFB, DE
   (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.