Marine Weather and Tides
5/20/2018 -- NOAA is having problems with the data feed that I use to draw the graphs. They are aware of the issue and working to resolve it. Sometimes changing the location by about a mile will give a correct graph. 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.
|Sunrise 5:41AM||Sunset 8:18PM||Monday May 21, 2018 10:19 PM EDT (02:19 UTC)||Moonrise 11:05AM||Moonset 12:26AM||Illumination 47%|
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|ANZ530 Chesapeake Bay North Of Pooles Island- 732 Pm Edt Mon May 21 2018 |
Tonight..SE winds around 5 kt. Waves flat. A slight chance of showers and tstms after midnight.
Tue..S winds 5 to 10 kt. Waves 1 ft or less. A chance of showers and tstms. Patchy fog.
Tue night..SW winds 5 kt. Waves less than 1 ft. A chance of showers and tstms.
Wed..NW winds 5 to 10 kt. Waves 1 ft.
Wed night..NW winds 5 to 10 kt. Waves 1 ft or less.
Thu..N winds 5 kt. Waves less than 1 ft.
Thu night..SW winds around 5 kt. Waves flat.
Fri..SW winds 5 to 10 kt. Waves 1 ft.
Sat..S winds 5 to 10 kt. Waves 1 ft. A chance of tstms. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
|ANZ500 732 Pm Edt Mon May 21 2018 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A cold front stalled to the south and west of the waters tonight will slowly return north as a warm front Tuesday. A cold front will pass through the waters Wednesday and high pressure will build overhead Thursday. High pressure will move offshore Friday through the weekend. Small craft advisory conditions are possible Wednesday.
7 Day Forecast for Marine Location Near Chesapeake City, MDHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 220108|
area forecast discussion
national weather service mount holly nj
908 pm edt Mon may 21 2018
A weak area of low pressure will develop and move eastward across
the saint lawrence valley Tuesday through Wednesday bringing a weak
cold front through the region late Tuesday into early
Wednesday. High pressure builds in behind this exiting system
through the end of the week. Uncertainty then becomes rather
high for the next potential system to affect our area by
memorial day weekend; however, it does appear that another
frontal system will impact the region bringing unsettled
Near term until 6 am Tuesday morning
High pressure remains just offshore with the mid-level ridge
across the central appalachians. As this ridge gradually breaks
down overnight, cloudiness will increase across the area. With
added low-level moisture within in a southeasterly flow regime,
the approach of a mid-level shortwave, and more favorable jet
dynamics, maintained a chance of showers in the forecast over
the eastern shore of maryland and northeast of the fall-line.
Despite the convection to the south and west, the atmosphere
remains stable north of the front, so do not expect thunder
Updated hourly temperatures and dew points with lamp and
continuity, otherwise, remainder of forecast is on track.
a very nice afternoon in progress across the region, however it
is cooler toward the coast due to a breeze off the ocean and a
sea breeze front making inland progress. An upper-level trough
over the midwest is forecast to gradually shift eastward tonight
and be in the great lakes region by daybreak Tuesday.
Meanwhile, a west-east ridge is across the southern states to
the southwestern atlantic ocean. This will allow surface high
pressure to gradually shift eastward and become more centered
off the southeastern new england coast by daybreak.
As the upper-level trough shifts eastward, a weak area of low
pressure will shift eastward as well and be located near the eastern
great lakes as we approach daybreak. A frontal zone to our south
will gradually shift northward as a warm front, however this feature
looks to remain south of our area through tonight. The flow aloft is
more zonal therefore short wave energy will easily roll eastward
especially across our northern areas later tonight.
As the flow increases some out of the southwest in the lower levels,
warm air advection increases. The bulk of this through the night is
forecast to be focused to our west, however the leading edge of it
nears northeast pennsylvania late tonight. There is also a surge in
theta-e advection especially late tonight. In addition, parts of our
region start to be within the right entrance region of an upper-
level jet. This all leads to some increase in lift later tonight and
clouds will increase, therefore some showers should arrive
especially in parts of eastern pennsylvania. We cannot rule out a
few showers in DELMARVA near the incoming surface front, however the
greater concentration of showers toward morning should be near
northeastern pennsylvania. As a result, focused the highest pops
there late tonight.
The hourly temperature, dew point and wind grids were adjusted based
on the latest observations, then the lamp and some hi-res guidance
was blended into this evening to assist with trends. Low
temperatures are mostly a blend of continuity and mos.
Short term 6 am Tuesday morning through 6 pm Tuesday
An upper-level trough is forecast to amplify some across the great
lakes region during Tuesday. This will drive weak surface low
pressure northeastward, with a warm front lifting into our area and
then a weak cold front approaching from the west late in the day.
An area of warm air advection ahead of this system will also help in
advecting more moisture across our region within a south-southwest
flow. An initial area of showers in the morning especially north and
west of the i-95 corridor should lift northeastward by early
afternoon as the initial surge in warm air theta-e advection occurs.
A stronger short wave is forecast to move across the area in the
afternoon, and this should result in renewed shower development from
west to east. The surface flow looks to remain more backed from the
southeast during the day, keeping the low-levels more stable. Some
of the forecast soundings show the potential for decent elevated
instability especially toward late afternoon, with the better chance
of some surface-based instability across portions of delmarva. The
shear looks to be 30 knots or less, however wind profiles are such
that convection in the afternoon may develop into some bands from
the west. There is some drier air aloft, and therefore if convective
cores are able to be strong enough then locally gusty winds are
possible especially in the west southwest zones which is further
away from the cooler ocean influence.
It appears that an abundance of clouds though will be around for
much of the region through the day with a lack of a true warm sector
surging northward. As a result, high temperatures will be on the
Long term Tuesday night through Monday
Main challenges in the long term are the residual precipitation
chances Tuesday night and very poor model continuity agreement
this weekend and beyond.
Vort MAX will be moving through new england on Tuesday night
with a predecessor perturbation moving off the mid-atlantic
coast during the evening. Scattered convection should be ongoing
in the central southern mid-atlantic, possibly affecting central
and especially southern portions of the CWA Tuesday evening.
Convection should also exist along the main cold front to our
northwest, but most of the high-resolution guidance indicates
these storms will dissipate as nocturnal cooling develops and
the stronger ascent progresses north northeast of the region by
Tuesday night. However, there remains some debate on when this
will occur, with the wrf-nmm and rgem suggesting more prolonged
convection during the evening night along this front, making it
well into northern central portions of the cwa. The 12z nam
nest is not as optimistic, but does suggest storms may persist
into the poconos and vicinity at least. Coarser guidance is more
aggressive in producing QPF in much of our area during the
evening, and with large-scale lift and considerable elevated|
instability remaining well into the evening hours, felt that
keeping pops at least in the chance category was wise. Included
some likely pops north of the mason-dixon line, with the more
aggressive coarse output along with modest support from
mesoscale models enough to boost pops.
The environment is not altogether unfavorable for a strong storm
or two given the presence of 1000+ j kg of MUCAPE in the
evening, dry air aloft, and some potential cold-pool linear
organization. The shear remains weak through the evening, though
i would not be too surprised to see small hail with the
strongest cores. This threat should be short-lived, as a
nocturnal lowering of instability should preclude a more
substantive longer-duration threat. The cold front is expected
to move through the area by Wednesday morning.
High pressure will build into the northeast for the rest of the
week, setting up a dry and fairly pleasant period. Midlevel
ridging will develop to our west, but the northeast will remain
on the periphery of eastern canada troughing, so temperatures
will not get too out of hand during this period (though they
should be a few degrees above seasonal averages, in general).
Kept the temperature forecast close to a model consensus blend
through this period.
Model agreement deteriorates rapidly this weekend, as the 12z
gfs deepens a reinforcing trough over eastern canada, with the
ecmwf cmc maintaining more progression. This has ramifications
on the ejection of a western u.S. Upper low and the evolution of
the low trudging northward in the gulf, not to mention the
strength speed of a cold front and upstream surface high
pressure associated with the eastern canada trough. Owing to the
stronger deeper trough, the GFS blasts a cold front through the
area this weekend, bringing a cooler end to memorial day
Meanwhile, the cmc ECMWF are considerably slower with this
front, leaving the mid-atlantic ohio valley in long-
duration moist southerly fetch as the gulf low approaches the
mid-south and southeast. These models are much closer to each
other than the gfs, so weighted the forecast much more strongly
to these solutions Saturday onward. This would lead to
increasing chances of showers storms Saturday onward (especially
Sunday and Monday) and temperatures remaining above seasonal
averages, though I did trend them downward somewhat Sunday and
Monday for at least a nod to the GFS (and to the increasing
precipitation chances). This period bears watching, not only for
the strong model disagreement but also for the potential for
heavy rainfall, should the ECMWF cmc solutions be in the more-
Aviation 01z Tuesday through Saturday
The following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
Tonight...VFR with an increase in clouds and gradual lowering. Light
and variable winds at most terminals.
Tuesday...VFR ceilings lowering to MVFR (locally ifr possible late
in the day). Some showers and perhaps a few thunderstorms,
especially in the afternoon. South or southeast winds less than 10
knots. Low confidence regarding the timing of the MVFR ceilings.
Tuesday night: sub-vfr conditions possible with a chance for
showers storms, especially in the evening. South winds becoming
west northwest as a cold front moves through the area, with
speeds 5 to 15 kts (possibly with some gusts near the frontal
passage). Low confidence.
Wednesday through Friday:VFR, though patchy fog may occur
nightly in rural valley locations. Winds generally northwest
Wednesday and Thursday (10 to 15 kts during the day; below 10
kts at night) becoming south southwest Thursday night and Friday
(probably with some gusts 20+ kts on Friday). Moderate
Friday night and Saturday: predominantlyVFR, though chances for
showers storms begin to increase on Saturday. Winds
south southeast 10 to 15 kts with higher gusts during the day
Saturday. Low confidence.
The conditions are expected to remain below small craft advisory
criteria through Tuesday. An onshore wind this afternoon is
generally below 10 knots, however some gusts up to 20 knots are
occurring nearshore due to a sea breeze that has moved inland. A
southeasterly wind is anticipated tonight through Tuesday with
speeds around 10 knots. Some showers and possible thunderstorms on
Tuesday, especially in the afternoon.
Tuesday night: chance of showers storms in the evening, with
potential for some gusty winds and locally higher waves. Outside
of storms, sub-advisory winds seas expected.
Wednesday through Friday: sub-advisory winds and seas and fair
Friday night and Saturday: may see marginal advisory conditions
develop as winds become southeasterly and strengthen.
Predominantly fair weather expected, though the chance of storms
will be increasing gradually during the weekend.
Phi watches warnings advisories
near term... Gorse lf
short term... Gorse
long term... Cms
aviation... Cms gorse lf
marine... Cms gorse lf
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
|Stations||Dist||Age||Wind||Air Temp||Water Temp||Waves||Pressure||DewPt|
|CHCM2 - 8573927 - Chesapeake City, MD||6 mi||50 min||E 1.9 G 4.1||65°F||69°F||1021.9 hPa|
|DELD1 - 8551762 - Delaware City, DE||18 mi||50 min||SSE 5.1 G 9.9||64°F||65°F||1021.7 hPa|
|RDYD1 - 8551910 - Reedy Point, DE||19 mi||50 min||64°F||68°F||1021.3 hPa|
|TCBM2 - 8573364 - Tolchester Beach, MD||26 mi||50 min||S 2.9 G 5.1||70°F||71°F||1021.3 hPa|
|MRCP1 - 8540433 - Marcus Hook, PA||34 mi||50 min||67°F||66°F||1021.4 hPa|
|FSNM2||37 mi||74 min||S 7 G 11||73°F||1020.4 hPa|
|DRSD1 - Delaware Reserve, DE||38 mi||110 min||ESE 4.1||63°F||1022 hPa||61°F|
|BLTM2 - 8574680 - Baltimore, MD||38 mi||50 min||S 5.1 G 7||73°F||71°F||1020.3 hPa|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||38 mi||50 min||SSE 11 G 11||71°F||1020.6 hPa|
|CPVM2||43 mi||50 min||69°F||64°F|
|APAM2 - 8575512 - Annapolis, MD||46 mi||50 min||70°F||1020.6 hPa|
Wind History for Chesapeake City, MD(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Phillips Army Air Field / Aberdeen, MD||13 mi||82 min||SE 4||10.00 mi||Fair||69°F||61°F||76%||1021.3 hPa|
|Wilmington, New Castle County Airport, DE||21 mi||29 min||SSE 10||10.00 mi||Fair||64°F||57°F||78%||1021.8 hPa|
Wind History from APG (wind in knots)
|1 day ago|
|2 days ago|
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Old Town Point Wharf |
Click for Map
Mon -- 01:25 AM EDT Moonset
Mon -- 03:24 AM EDT 2.48 feet High Tide
Mon -- 05:44 AM EDT Sunrise
Mon -- 09:11 AM EDT 0.79 feet Low Tide
Mon -- 12:05 PM EDT Moonrise
Mon -- 03:42 PM EDT 3.25 feet High Tide
Mon -- 08:16 PM EDT Sunset
Mon -- 10:42 PM EDT 0.66 feet Low Tide
Mon -- 11:50 PM EDT First Quarter
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|Chesapeake and Delaware Canal |
Click for Map
Mon -- 12:27 AM EDT 1.75 knots Max Flood
Mon -- 01:25 AM EDT Moonset
Mon -- 02:40 AM EDT -0.09 knots Slack
Mon -- 05:44 AM EDT Sunrise
Mon -- 06:17 AM EDT -2.11 knots Max Ebb
Mon -- 09:57 AM EDT 0.07 knots Slack
Mon -- 12:04 PM EDT Moonrise
Mon -- 01:11 PM EDT 2.22 knots Max Flood
Mon -- 04:38 PM EDT -0.08 knots Slack
Mon -- 07:12 PM EDT -1.65 knots Max Ebb
Mon -- 08:15 PM EDT Sunset
Mon -- 10:50 PM EDT 0.03 knots Slack
Mon -- 11:50 PM EDT First Quarter
Tide / Current data from XTide NOT FOR NAVIGATION
Weather Map and Satellite Images(on/off)  HelpWeather Map
GOES Local Image of Mid-Atlantic EDIT
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Wind Forecast for Philadelphia/Mount Holly, PA (22,6,7,8)(on/off)  Help
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