Thursday, April18, 2019 L-36.com


Marine Weather and Tides
Tolchester, MD

Version 3.4
What's New / NOTES
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 6:22AMSunset 7:47PM Thursday April 18, 2019 12:47 PM EDT (16:47 UTC) Moonrise 5:59PMMoonset 5:16AM Illumination 99% Phase: Waxing Gibbous; Moon at 14 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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ANZ531 Chesapeake Bay From Pooles Island To Sandy Point- 1101 Am Edt Thu Apr 18 2019
.small craft advisory in effect through Friday afternoon...
Rest of today..S winds 5 to 10 kt. Gusts up to 20 kt this afternoon. Waves 1 ft or less...building to 2 ft late. Isolated showers.
Tonight..S winds 10 to 15 kt with gusts to 25 kt. Waves 2 ft.
Fri..S winds 15 to 20 kt. Gusts up to 25 kt... Increasing to 30 kt in the afternoon. Waves 2 to 3 ft. Showers and tstms.
Fri night..S winds 15 to 20 kt with gusts to 30 kt. Waves 3 ft. Showers and tstms.
Sat..S winds 10 to 15 kt with gusts to 25 kt. Waves 2 to 3 ft. A chance of showers.
Sat night..S winds 10 to 15 kt with gusts to 20 kt. Waves 1 to 2 ft.
Sun..W winds 5 to 10 kt. Waves 1 ft. A chance of showers.
Mon..W winds 5 to 10 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 1101 Am Edt Thu Apr 18 2019
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A warm front will cross the waters today. Strong low pressure and its cold front will likely impact the waters Friday and Friday night, with its effects lingering into the weekend. Small craft advisories will likely be needed Friday night through Saturday night, possibly continuing into Sunday. Gale warnings are possible Friday and Friday night.


7 Day Forecast for Marine Location Near Tolchester, MD
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location: 39.21, -76.25     debug


Area Discussion for - Philadelphia/Mount Holly, PA
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Fxus61 kphi 181619
afdphi
area forecast discussion
national weather service mount holly nj
1219 pm edt Thu apr 18 2019

Synopsis
A warm front will slide northward across our area today into
tonight. Low pressure tracking up the ohio valley Friday will slowly
push a strong cold front toward our area. As the strong energy aloft
arrives later Saturday into Sunday, the strong cold front will move
through. High pressure will then build into the region from the
south Sunday night into Monday, followed by a cold front moving
through late Monday into Tuesday. High pressure then builds to our
north Tuesday into Wednesday.

Near term until 6 pm this evening
1230 update...

bumped temperatures up a few degrees as areas that are seeing
clearing have risen into the 70s, and parts of DELMARVA appear
poised to challenge 80. Otherwise no significant changes with
the stratus deck breaking out on schedule from south to north.

930 update...

very little change needed as going forecast is in good shape. Still
going to be some uncertainty this afternoon as a sharper temperature
gradient zone will eventually set up as daytime heating increases
and the warm front slowly makes its way north. Keeping an eye on a
cluster of showers and even some thunder over western va and eastern
wv moving northeastward. Short range guidance doing a very poor job
with that. On its trajectory this may clip our western zones, but
for now will continue to keep a dry forecast for the afternoon with
the belief that this activity will fade out. Previous discussion
follows.

A few sprinkles or light showers will be possible through this
morning, especially across the lehigh valley, southern poconos, and
nw nj as weak upslope flow continues ahead of the warm frontal
passage. Warm air is already advecting across the area at the 850 mb
level, however, it will be slow to work its way northward at the
surface across the northern half of the cwa. There will likely be a
fairly stark temperature gradient as the warm air works its way
northward by this afternoon with surface temperatures warming into
the low 70s from roughly i-195 and southward where the front passes
north. On the other hand, kept temperatures on the cool side in the
low 60s for highs in the higher terrain of the poconos and far NW nj
as cooler upslope flow will be stubborn to break. Winds will turn
southerly through the afternoon as the front works its way northward.

Short term 6 pm this evening through 6 am Friday
The warm front will finally work its way through the rest of the
region tonight. Will be a quiet night with only a few scattered
light showers or sprinkles across the northern third of the
forecast area as the front lifts across the rest of the region.

Southerly flow will continue through the night, advecting warmer
and moister air northward. Lows will be on the milder side
ranging from the low 60s from the philadelphia metro southward
to the mid 50s across the poconos and northern nj.

Long term Friday through Wednesday
Summary... Warm air ahead of a strong system Friday and Saturday then
some cooling Sunday. Heavy rain and potentially some gusty
thunderstorms move through later Friday into Saturday. Another surge
of warm air Monday before some cooling takes place again Tuesday and
Wednesday.

Synoptic overview... A ridge in the western atlantic ocean Friday
while a highly amplified trough from the great lakes to the lower
mississippi valley closes off during Friday. This feature will roll
east-northeastward and drive surface low pressure up the ohio
valley. A strong short wave rolls northward just ahead of the closed
low Friday night and Saturday morning, and a secondary surface low
moves northward into the vicinity of western pennsylvania. The
amplified and slow motion of this storm will delay the arrival of
the strong cold front into our area, with the actual frontal passage
becoming more of an occlusion with time. This closed low will cross
our area Sunday before opening up as it lifts to our northeast
Sunday night into Monday. The flow aloft then becomes more zonal for
a time early next week.

For Friday and Saturday... A rather active time as an upper-level
trough closes off as it slowly arrives into the east. The
amplification of this system results in deep southerly flow
increasing substantially well ahead of the cold front, and this will
result in ample warm air advection and eventually ascent. Southerly
surface winds should gust to 30-40 mph Friday afternoon and evening
especially in the coastal plain with an increase in the low-level
jet. Where the boundary layer warmth is maximized, then the vertical
mixing will be more efficient. Friday however may start with areas
of low clouds especially across the northern areas.

Large scale ascent ahead of the closed low and strong short wave
will team up with a strong low-level jet and potentially drive an
embedded squall line eastward Friday night. The system overall
continues to look slower given that is closes off. The initial
surface low is forecast to track up the ohio valley, however a new
surface low should develop near the triple point ahead of strong
short wave energy associated with the closed low. This low should
generally track west of our area, and this all may tend to delay the
bulk of the forcing and therefore showers thunder until late Friday
afternoon and especially overnight Friday. Overall the daytime hours
of Friday may have more scattered showers and perhaps some thunder
within the warm sector, then the more organized convection arrives
Friday night.

The severe weather potential depends on the amount of instability as
lapse rates aloft do not look as steep along with perhaps some lower
clouds beneath an inversion. The timing looks later and therefore
not as favorable regarding peak instability, however deep southerly
flow may compensate somewhat even at night and the shear looks
impressive. The strength of the shear alone can certainly compensate
for the lower instability especially as convection encounters the
low-level jet, therefore a squall line or a broken band of lower
topped convection may roll through Friday night with locally strong
to damaging wind gusts. The greatest severe threat continues to be
delmarva southward, however further north the strong shear may still
result in some robust convective winds reaching the surface. As
such, SPC has expanded the marginal risk northward.

The guidance indicates a narrow but intense plume of moisture ahead
of this closed low resulting in pw values increasing to 1.5-2.0
inches. The freezing level is forecast to be rather high, therefore
warm rain processes will result in more efficient rainfall rates.

The flow increasingly more meridional will result in heavy rain and
potentially some flash flooding especially if cells tend to train in
a south to north fashion. Given uncertainty on the more focused area
of heaviest rain, held off on any watches for now. A mention
continues in hazardous weather outlook. The surface system is
forecast to lift east and north of our area Saturday, however the
closed low aloft will be arriving therefore after a wet start to
Saturday there may still be some instability showers during the
afternoon and at night.

For Sunday and Monday... The upper low moves across our area Sunday,
then it should gradually be weakening and lifting to our northeast
Sunday night. There should still be some instability showers around
especially on Sunday. High pressure then starts to build in from the
south, however a weak cold front moves through later Monday into
Tuesday. The timing of this front will depend on how fast the closed
low opens up and lifts out. It will turn much warmer again Monday
ahead of the front assuming the closed low has already exited the
region.

For Tuesday and Wednesday... High pressure is forecast to build to
our north during this time frame resulting in more of an onshore
flow. There is some timing details that need to be worked out
regarding the cold front mentioned above, as some guidance is slower
with it and brings it through on Tuesday. We leaned closer to the
wpc timing. A short wave trough may start to arrive by later
Wednesday, therefore kept some low pops for possible showers in for
both days.

Aviation 16z Thursday through Monday
The following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.

Today... MVFR CIGS this morning. A brief light shower or sprinkle
is possible at rdg, abe, or ttn. Improvement toVFR conditions
by early afternoon as the warm front lifts across the region
from south to north. Southeasterly winds from 5 to 10 knots
turning southerly to even southwesterly around 10 knots this
afternoon. Some higher gusts up to 15 knots possible, especially
at acy.

Tonight... GenerallyVFR with strengthening southerly winds expected.

Marginal MVFR CIGS possible toward Friday morning. Low level
wind shear is expected to develop overnight for the delaware
valley and coastal TAF sites.

Outlook...

Friday and Saturday... Areas of MVFR ceilings Friday becoming
widespread MVFR to ifr Friday night into Saturday morning, then
improving toVFR by later Saturday. A southerly low-level jet should
result in low-level wind shear Friday night especially for the i-95
terminals on eastward.

Showers and some thunderstorms especially later Friday afternoon
into Saturday morning will result in ifr visibilities at times.

Southerly winds 10-20 knots with gusts of 25-35 knots.

Sunday...VFR ceilings may transition to MVFR ceilings at times with
some showers around. South to southwest winds 10-15 knots, becoming
west-southwest at night.

Monday...VFR. West-southwest winds 5-10 knots.

Marine
Today... SCA conditions with easterly winds 15 to 20 knots. Winds
turning to a southerly direction through the afternoon. Gusts up to
25 knots possible over the ocean waters and over the bay. Seas
between 4 to 6 feet.

Tonight... Southerly winds increasing to 20 to 25 knots, with gusts
up to 30 knots possible. Seas building to 5 to 7 feet.

Outlook...

Friday... Small craft advisory conditions expected as seas build well
above 5 feet and winds gust to around 30 knots. Southerly gale force
gusts are possible, however this will be within a warm air advection
regime limiting mixing over the colder waters. For now, extended the
advisory through 22z 6pm for now and also added delaware bay.

Despite the winds, areas of marine fog may develop for a time as
warm moist air moves over the cooler waters.

Saturday... Small craft advisory conditions with gusts of up to 25
knots, however winds diminish at night. Seas 6-10 feet on the ocean
waters.

Sunday... Winds below advisory criteria, however seas remaining
elevated on the ocean zones although due slowly subside at night.

Monday... Conditions (seas) dropping below advisory criteria.

Tides coastal flooding
East to southeast surface flow turns more southerly and increases by
later today and continues through Friday night. This will increase
the surge above astronomical tide.

Minor tidal flooding is anticipated, and localized moderate tidal
flooding is possible with the high tide tonight and especially
Friday night. With the full moon on Friday, the astronomical tide
both tonight and Friday night is less than one foot below minor
flooding thresholds. The surge is expected to be at least one foot
on the ocean front despite more of a southerly wind component.

Spotty minor tidal flooding is possible with the daytime high tide
today. However, water levels with this tide cycle are expected to
remain below advisory level.

There are a few factors that could further increase tidal flooding
concerns. First, heavy rain is possible Friday night. While the
heaviest rain should be west of the coastal plain, any higher
rainfall rates near the time of the Friday night high tide could
enhance tidal flooding above the current forecast. Secondly, though
the Friday morning high tide is a lower astronomical tide and there
won't be much flooding on the oceanfront, there could be impacts on
the back bays as there will be limited opportunity for water to
evacuate after the Thursday night high tide given strong southerly
winds.

For the northeastern shore of the chesapeake bay, this area will be
slower to see any tidal flooding with this system. However, if the
current model trends continue then minor tidal flooding will be
possible with the Saturday morning high tide.

Phi watches warnings advisories
Pa... None.

Nj... None.

De... None.

Md... None.

Marine... Small craft advisory until 6 pm edt Friday for anz450>455.

Small craft advisory until 6 pm edt Friday for anz430-431.

Synopsis... Gorse
near term... Davis o'brien
short term... Davis
long term... Gorse
aviation... Davis gorse
marine... Davis gorse
tides coastal flooding...



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
TCBM2 - 8573364 - Tolchester Beach, MD 0 mi47 min WSW 7 G 8.9 58°F 58°F1016 hPa (-1.1)
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 15 mi47 min ESE 1.9 G 2.9 60°F 1015.7 hPa (-0.9)
FSNM2 15 mi53 min E 1.9 G 4.1 60°F 1015.3 hPa
CPVM2 17 mi47 min 57°F 57°F
BLTM2 - 8574680 - Baltimore, MD 18 mi47 min E 1.9 G 2.9 60°F 57°F1015.3 hPa (-0.9)
APAM2 - 8575512 - Annapolis, MD 20 mi47 min 60°F 1015.3 hPa (-1.0)
TPLM2 - Thomas Point, MD 24 mi47 min SSE 5.1 G 6 56°F 55°F1016.7 hPa (-0.7)56°F
CHCM2 - 8573927 - Chesapeake City, MD 32 mi47 min SSW 2.9 G 11 69°F 59°F1015.5 hPa (-1.7)
DELD1 - 8551762 - Delaware City, DE 43 mi47 min SE 4.1 G 8 62°F 53°F1015.7 hPa (-1.5)
RDYD1 - 8551910 - Reedy Point, DE 43 mi47 min 1015.1 hPa (-1.4)
CA2 - 8571892 - Cambridge, MD 45 mi47 min 71°F 60°F1015.6 hPa (-0.8)
SJSN4 - 8537121 - Ship John Shoal, NJ 47 mi47 min ESE 12 G 14 56°F 57°F1015.6 hPa (-1.4)
WASD2 - 8594900 - Washington, DC 47 mi47 min SSE 4.1 G 5.1 62°F 62°F1015.6 hPa (-1.2)

Wind History for Tolchester Beach, MD
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Baltimore / Martin, MD13 mi57 minESE 57.00 miMostly Cloudy63°F59°F88%1016.6 hPa
Bay Bridge Field, MD17 mi67 minWSW 55.00 miFog/Mist61°F59°F94%1015.9 hPa
Phillips Army Air Field / Aberdeen, MD18 mi62 minVar 57.00 miPartly Cloudy66°F57°F73%1015.9 hPa
Baltimore, Inner Harbor, MD20 mi53 minno data mi63°F54°F73%1015.8 hPa
Annapolis, United States Naval Academy, MD20 mi1.9 hrsESE 77.00 miOvercast61°F55°F81%1016.4 hPa
Baltimore, Baltimore-Washington International Airport, MD22 mi53 minSW 49.00 miMostly Cloudy65°F55°F70%1015.4 hPa

Wind History from MTN (wind in knots)
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1 day agoSW10
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S5W10SE6SE8SE4SE5SE5S5CalmCalmCalmCalmCalmN3NE4NE5NE7NE11NE14E14
2 days agoW22
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Tide / Current Tables for Tolchester Beach, Chesapeake Bay, Maryland
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Tolchester Beach
Click for Map
Thu -- 12:33 AM EDT     0.18 feet Low Tide
Thu -- 06:15 AM EDT     Moonset
Thu -- 06:24 AM EDT     Sunrise
Thu -- 06:40 AM EDT     1.79 feet High Tide
Thu -- 01:21 PM EDT     0.00 feet Low Tide
Thu -- 06:59 PM EDT     Moonrise
Thu -- 07:23 PM EDT     1.43 feet High Tide
Thu -- 07:45 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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0.20.20.40.71.21.51.71.81.61.30.90.50.2000.30.611.31.41.41.20.90.6

Tide / Current Tables for Baltimore Harbor Approach, Maryland Current
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Baltimore Harbor Approach
Click for Map
Thu -- 01:36 AM EDT     0.00 knots Slack
Thu -- 04:55 AM EDT     1.08 knots Max Flood
Thu -- 06:15 AM EDT     Moonset
Thu -- 06:24 AM EDT     Sunrise
Thu -- 08:09 AM EDT     -0.00 knots Slack
Thu -- 11:19 AM EDT     -1.03 knots Max Ebb
Thu -- 02:35 PM EDT     0.00 knots Slack
Thu -- 05:26 PM EDT     0.81 knots Max Flood
Thu -- 06:59 PM EDT     Moonrise
Thu -- 07:45 PM EDT     Sunset
Thu -- 08:19 PM EDT     -0.00 knots Slack
Thu -- 11:22 PM EDT     -0.89 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-0.7-0.30.20.611.10.90.60.1-0.4-0.8-1-1-0.7-0.30.20.60.80.80.50.1-0.3-0.7-0.9

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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.