Thursday, April27, 2017 L-36.com


Marine Weather and Tides
Lancaster, PA

Version 3.4
What's New / NOTES
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.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 6:07AMSunset 7:58PM Thursday April 27, 2017 12:52 PM EDT (16:52 UTC) Moonrise 6:17AMMoonset 8:27PM Illumination 3% Phase: Waxing Crescent; Moon at 2 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
ANZ530 Chesapeake Bay North Of Pooles Island- 1031 Am Edt Thu Apr 27 2017
.small craft advisory in effect through this evening...
Rest of today..SE winds 5 kt...becoming S 15 kt with gusts to 20 kt this afternoon. Waves 1 ft or less...building to 2 ft late. Patchy fog late this morning with vsby 1 to 3 nm.
Tonight..S winds 10 to 15 kt with gusts to 20 kt. Waves 1 to 2 ft. A chance of showers. Patchy fog. Vsby 1 to 3 nm.
Fri..SW winds 5 to 10 kt. Waves 1 ft.
Fri night..S winds 5 to 10 kt. Waves 1 ft.
Sat..SW winds 5 to 10 kt. Waves 1 ft.
Sat night..N winds 5 to 10 kt. Waves 1 ft or less. A chance of showers.
Sun..SE winds 5 to 10 kt. Waves 1 ft. A chance of showers in the morning.
Mon..SW winds 10 to 15 kt. Waves 1 to 2 ft. A chance of showers and tstms in the afternoon. Showers and tstms likely through the night. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 1031 Am Edt Thu Apr 27 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A weak cold front will cross the waters tonight. A backdoor cold front will move south across the chesapeake bay region Sunday morning. A stronger cold front will cross the region from the west Monday night. A small craft advisory is possible Monday into Tuesday.

7 Day Forecast for Marine Location Near Lancaster, PA
   Hourly   EDIT   Help
location: 40.04, -76.3     debug


Area Discussion for - State College, PA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 kctp 271459
afdctp
area forecast discussion
national weather service state college pa
issued by national weather service binghamton ny
1059 am edt Thu apr 27 2017

Synopsis
A strong subtropical ridge over the western atlantic will
dominate our weather through Monday. A front will weaken as it
moves into the ridge late today, triggering thunderstorms. Then
ridge will build westward over the weekend. We will be on the
warm, moist western side of the ridge most of the weekend. A
classic dirty warm up with warm moist air and potential diurnal
thunderstorms. Alas, a strong trough should bring cooler drier
weather to the region for the second part of next week.

Near term /through tonight/
1030 am update...

goes-16 red band visible imagery continues to show a stubborn
marine layer that was "stuck" in the ridge and valley region of
central pa up to the north central mountains and into east
central and northeast pa. In addition, the clouds were covering
a large portion of the lower susquehanna valley. West of the
allegheny front from the northern mountains to the laurel
highlands, skies were pretty much clear under a cirrus layer.

The low-level flow will remain from the south to southeast
through the afternoon. This will keep this marine layer in
place. Insolation from the strong late april Sun is expected to
break up this cloud layer but looking at the 1 minute satellite
data, this cloud layer looks very stable especially in central
pa. So we have backed way off on clearing in much of the county
warning area and lowered maximums in these areas as well. We may
have to adjust this even more with the 18z update. Rest of
forecast has not been changed as waiting for more 12z guidance.

See previous discussion below.

Previous discussion...

goes-16 3.9-11.2um loop at 09z showing stratus becoming more
extensive over eastern pa, as boundary layer cools. It looks
like most of the region east of the allegheny divide will begin
the day either cloudy or foggy. Model soundings/sref prob charts
suggest patchy low clouds could linger until midday over the
eastern half of the state. Eventual clearing and very warm air
at 850mb should result in temps rising to near 80f this
afternoon.

Main forecast issue remains the potential of a few strong to
severe tstorms this evening associated with arrival of a
weakening cold front. All guidance timing convection into the
western counties between 21z-00z. Model soundings showing fairly
impressive shear, both 0-6km and 0-1km. However, only modest
low level moisture return ahead of front and thus marginal cape
values expected. SPC has placed roughly the western half of pa
in a marginal risk this evening. Given the strong winds aloft
and borderline cape, expect isolated damaging wind gusts to be
the greatest threat, rather than large hail. Not sure how much
weight to place on 00z naefs, which is indicating a high
probability of stp>1 across the north-central counties as front
comes through around 00z, suggesting a brief tornado can't be
ruled out.

Short term /Friday through Friday night/
Diminishing frontal showers/storms should push through eastern
pa after dark, as CAPE diminishes and bulk of large scale
forcing with parent shortwave lifts north of the region.

A dry and slightly cooler Friday is expected, as surface ridging
builds in behind cold front. 850 hpa temps remain above normal
across the lower susq valley, where readings could again push
80f. Model rh profiles support a mostly sunny forecast for most
of the area Friday. Some increasing mid level cloudiness appears
likely across the northwest counties during the afternoon, as
waa aloft spreads in ahead next shortwave working across the
grt lks.

Long term /Saturday through Wednesday/
A weak shortwave passing across southern ontario/quebec is
progged to push a shallow cold front through pa Saturday. Timing
of this front will favor diurnally-driven convection across the
southern counties, where pre-frontal heating could potentially
push temps into the mid 80s based on model 850mb temps near 15c.

A cold air damming scenario expected Sunday, as dying frontal
boundary slips south of the border and sfc high over new england
directs a cool southeast flow into central/eastern pa. Have
nudged MAX temps several degrees below national blend guidance
Sunday. Much warmer/unstable airmass west of the mountains could
lead to pm tstorms across western pa, potentially affecting our
western counties.

Max pops during the extended period remain centered on
Monday/may 1st associated with passage of a potent cold front.

A severe weather threat may evolve downstream from the oh
valley into the mid atlantic late Monday before temperatures
decline to near normal behind the cold front for next Tuesday
and Wednesday.

Aviation /15z Thursday through Monday/
Goes-16 shows the low clouds than spread westward across pa
overnight. This feature is associated with a strong gradient in
the potential temperature field. This marine front is stuck sort
of north-south along the mountains. Mainly MVFR/ifr to east of
it andVFR to the west. This low cloud boundary should erode
west to east this am restoringVFR to kunv and kipt before kmdt
and klns.

Winds a few thousand feet up are over 20kts. When we mix in the
15 to 18 utc timeframe winds will get a bit gusty.

The frontal system to our west is in ohio and ky. It is forecast
in most models to bring showers and thunderstorms to western
areas in the 20 to 22 utc timeframe and later as one moves east.

Initially, there could be some strong storms with this front.

But they should weaken as they move into eastern areas mainly
after 0000 to 0200 utc.

Any rain and low-level moisture will triggers some low clouds
and patchy fog. Most likely to the east, closer to the front and
higher moisture values. Some pretty moist air still stuck in se
pa in the 0600 utc timeframe Friday am. Much drier to the west.

MainlyVFR behind the front in west MVFR/ifr in east especially
southeast.

Friday looks like shortly after sunrise the dry air should make
for a great flying day.VFR should dominate.

The chance of showers and rain increases Friday night into
Saturday.

Outlook...

fri... No significant weather.

Sat-sun... A few showers possible. Mainly dry withVFR
conditions for much of the time.

Mon... Breezy with showers and thunderstorms likely with fropa.

Ctp watches/warnings/advisories
None.

Synopsis...

near term...

short term...

long term...

aviation...



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
44057 - Susquehanna, MD 37 mi42 min Calm G 1.9 68°F 1011.2 hPa
CHCM2 - 8573927 - Chesapeake City, MD 44 mi52 min ENE 6 G 11 71°F 59°F1011.1 hPa
DELD1 - 8551762 - Delaware City, DE 49 mi52 min S 11 G 16 67°F 58°F1011.9 hPa
MRCP1 - 8540433 - Marcus Hook, PA 50 mi52 min 71°F 1011.3 hPa

Wind History for Chesapeake City, MD
(wind in knots)    EDIT      (on/off)   Help
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
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
Last
24hr
W3
N3
NW4
W4
W4
SW2
SW3
S3
--
W3
W2
NW1
--
--
--
E1
NE1
--
NE1
NE3
E4
G8
E7
G11
E4
G8
NE6
G11
1 day
ago
NE14
G23
NE11
G19
NE8
G11
NE10
G18
NE12
G20
NE13
G22
NE11
G17
NE9
NE7
G11
NE6
G10
N7
G14
N4
G10
N5
G8
N5
G8
NE6
G9
NE7
G11
NE7
G11
NE4
G7
N5
G9
N4
G8
NE5
N4
N2
G5
NW3
2 days
ago
NE9
G13
NE7
G10
NE13
NE11
G16
NE9
G13
NE11
G16
NE9
G14
NE11
G16
NE7
G11
NE10
G16
NE10
G13
NE12
G15
NE9
G12
NE9
G13
NE7
G10
NE8
G11
NE8
G13
NE10
G17
NE11
NE10
G17
N8
G17
NE12
G17
NE16
G21
NE13
G21

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Lancaster, Lancaster Airport, PA6 mi59 minSSE 710.00 miA Few Clouds73°F66°F79%1010.9 hPa
Chester County Airport, PA23 mi57 minSSE 710.00 miFair72°F62°F73%1012.5 hPa

Wind History from LNS (wind in knots)
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
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
Last 24hrN3CalmCalmCalmW3SE3SW6S3S3CalmCalmE5E3CalmCalmCalmCalmE3E3E3E7E8SE8SE7
1 day agoNE15
G22
E15
G22
NE14
G22
E14
G23
E19
G27
E15
G20
E14E13E11E14E14NE9NE10NE8NE5NE8N7NE6NE9NE7NE6NE7NE5NE5
2 days agoE8E6E9--NE12E9E3E5E7E9E10E9E9E7E8E10E8NE11E13E15E14
G21
E15E13
G22
NE17
G22

Tide / Current Tables for Port Deposit, Susquehanna River, Maryland
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Port Deposit
Click for Map
Thu -- 06:10 AM EDT     Sunrise
Thu -- 06:29 AM EDT     0.28 feet Low Tide
Thu -- 07:17 AM EDT     Moonrise
Thu -- 11:59 AM EDT     3.70 feet High Tide
Thu -- 07:54 PM EDT     Sunset
Thu -- 08:04 PM EDT     0.33 feet Low Tide
Thu -- 09:25 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.52.21.81.40.90.50.30.30.81.72.73.43.73.53.12.61.91.40.80.50.30.51.21.9

Tide / Current Tables for Havre de Grace, Susquehanna River, Maryland
   EDIT      (on/off)   Help   One Week of Data
Havre de Grace
Click for Map
Thu -- 05:11 AM EDT     0.18 feet Low Tide
Thu -- 06:10 AM EDT     Sunrise
Thu -- 07:17 AM EDT     Moonrise
Thu -- 10:59 AM EDT     2.97 feet High Tide
Thu -- 06:15 PM EDT     0.15 feet Low Tide
Thu -- 07:54 PM EDT     Sunset
Thu -- 09:25 PM EDT     Moonset
Thu -- 11:38 PM EDT     2.25 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.11.71.30.80.40.20.30.81.52.32.832.82.41.91.40.80.40.20.20.71.31.82.2

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 State College, PA (12,3,4,5)
      (on/off)   Help

Ground Weather Radar Station Philadelphia, PA
   (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.