Sunrise 6:11 AM   Sunset 8:04 PM Moonrise 12:17 AM   Moonset 9:06 AM

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ANZ538 Patapsco River Including Baltimore Harbor- 443 Am Edt Mon Apr 29 2024
Rest of the overnight - W winds 5 kt. Waves flat. Today - SW winds around 5 kt - .becoming se late. Waves 1 ft or less. Tonight - S winds 5 to 10 kt. Waves 1 ft. Tue - SW winds 5 to 10 kt. Waves 1 ft. Tue night - W winds 5 to 10 kt. Waves 1 ft or less. A chance of showers and tstms. Wed - NW winds 5 kt. Waves flat. A chance of showers. Wed night - NE winds around 5 kt. Waves flat. Thu - SE winds 5 to 10 kt. Waves 1 ft. Fri - SE winds 5 to 10 kt. Waves 1 ft. A chance of showers through the night.
winds and waves higher and visibilities lower in and near tstms.

ANZ500 443 Am Edt Mon Apr 29 2024
Synopsis for the tidal potomac and md portion of the chesapeake bay -
high pressure building across the area through tonight will bring very warm temperatures and dry conditions. A cold front crosses the waters Tuesday into Wednesday bringing chances for showers and Thunderstorms. High pressure briefly returns Thursday before another front crosses the local waters over the weekend. Small craft advisories may be needed Tuesday afternoon to evening, and again on Friday.

FXUS61 KCTP 291127 AFDCTP

Area Forecast Discussion National Weather Service State College PA 727 AM EDT Mon Apr 29 2024

SYNOPSIS
-Patchy fog possible in northern PA around sunrise, especially in locations that received rain Sunday afternoon/evening.
-Well above average temperatures persist this week with highs in the 70s and 80s; near-record highs possible today.
-Cold fronts Tuesday and Friday-Saturday bring showers and storms. Potential for a few heavy downpours.

NEAR TERM /UNTIL 6 PM THIS EVENING/
Currently any dense fog has been confined to far northern PA where rain fell on Sunday afternoon. Will monitor as we get close to sunrise to see if foggy conditions become more widespread.

Today will be the warmest day of this upcoming week as the ridge of high pressure reaches its maximum northward extent this afternoon. Surface high pressure to the south of PA will result in ample sunshine and west-southwest flow characteristic of a true summer day. Recent model guidance continues to suggest MaxTs in the 80s nearly everywhere and an outside chance at 90 near the Mason and Dixon line. Some afternoon convection across mainly northern PA does appear plausible given embedded shortwaves within the ridge axis. If convection manages to occur, MaxTs across northern PA could be limited to the upper 70s but will still be well above seasonable averages.

SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/
Monday night will be similar to Sunday night with temperatures falling near the dewpoint temperature (upper 50s to low 60s).
Some increasing high clouds will begin streaming in overnight ahead of an approaching cold front. A few high res models try to develop a cluster of showers and maybe an embedded storm moving across the central mountains later this evening, but dry conditions should prevail for most.

By Tuesday morning, low pressure from the Central Plains will move northwest of the area, bringing a weak sfc cold front across the area during the morning and early afternoon hours.
Showers are expected at the onset Tuesday morning across NW PA.
The surface low will transfer its energy to a developing coastal low on Tuesday evening. This will help focus moisture advection and elevated instability across eastern PA where a few stronger showers and thunderstorms are possible. PWAT values of 1.25" are near the 99th percentile for this time of year and will support torrential rainfall. With storm motions in a northeasterly direction, some training is possible and could lead to isolated flash flooding, which as prompted a Marginal Risk of Excessive Rainfall from the Weather Prediction Center.
Recent dry conditions may mitigate any major concerns.

Showers will gradually weaken overnight Tuesday into Wednesday morning, but a lingering stationary boundary will keep cloudiness and unsettled weather around into the first part of Wednesday. Another mild night is in store across the southeast where clouds will stay put and temperatures remain in the low 60s. Some clearing appears possible in northwest PA and could support lows touching the upper 40s.

LONG TERM /WEDNESDAY THROUGH SUNDAY/
Showers become more scattered in nature Wednesday afternoon with dry conditions expected by the evening hours as an upper- level ridge takes hold over the region.

Model solutions have started to latch onto a stronger upper- level ridge solution, providing fair weather on Thursday and into the first half Friday. It is of note that a slightly weaker shortwave could allow for some shower activity, but given successive runs of guidance brining about a stronger shortwave, have opted to cut PoPs out from this timeframe.

A low-pressure stationed over the Great Lakes will bring about the next sfc cold front across central PA later on Friday and throughout the day on Saturday. There is fairly good agreement with deterministic model guidance in regards to precipitation associated with the frontal passage, although timing remains the biggest uncertainty at this time. The timing is likely to have a big impact on observed temperatures on Saturday. In the warmer scenario, a slower frontal passage would allow temperatures to reach the mid to upper 70s areawide. A faster arrival of precipitation and clouds could keep temperatures in the upper 50s to middle 60s. Have opted for a middle of the road scenario at this point with highs in the 60s to low 70s.

After the frontal passage Saturday, the upper pattern trends more zonal supporting seasonable temperatures with occasional chances for rain for the first full week of May.

AVIATION /12Z MONDAY THROUGH FRIDAY/
Visibility restrictions due to fog will continue at IPT for the next few hours. Once the fog dissipates, high pressure will allow for VFR conditions across the area with scattered clouds between 5000 and 8000 feet during the afternoon. Winds will generally be light, though there could be some gusts to 15 knots. An isolated shower or thunderstorm cannot be ruled out this afternoon across the north, but any impacts would be brief.

Upper level ridging begins to break down Monday evening and mid level cloud cover will begin to increase ahead of an approaching cold front. A few showers will be possible after 00Z Tuesday.
Some fog could develop once again tonight, though there is considerable disagreement in the guidance regarding this. As of now it seems like BFD and IPT would again be the most likely to see fog develop, but other sites could see visibility restrictions as well.

Outlook...

Tue...Isold PM tsra impacts Eastern PA. Evening low cigs poss W Mtns.

Wed...Early AM low cigs possible W Mtns.

Thu...No sig wx expected.

Fri...Evening showers/cig reductions possible.

CLIMATE
Monday will be the warmest day of the week and high temperatures could approach record levels. Here are the current record high temperatures for April 29th at several climate sites in Central PA:

SITE RECORD YEAR Altoona 83F 1974 Bradford 76F 1984 Harrisburg 90F 1974 Johnstown 88F 1974 State College 89F 1942 Williamsport 86F 1974

CTP WATCHES/WARNINGS/ADVISORIES
None.

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Chain Bridge
Click for Map
Mon -- 12:51 AM EDT     2.83 feet High Tide
Mon -- 01:09 AM EDT     Moonrise
Mon -- 06:12 AM EDT     Sunrise
Mon -- 07:08 AM EDT     0.63 feet Low Tide
Mon -- 10:06 AM EDT     Moonset
Mon -- 12:53 PM EDT     3.35 feet High Tide
Mon -- 07:59 PM EDT     Sunset
Mon -- 08:17 PM EDT     0.54 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Chain Bridge, D.C., Tide feet

Chain Bridge
Click for Map
Mon -- 12:46 AM EDT     2.83 feet High Tide
Mon -- 01:09 AM EDT     Moonrise
Mon -- 06:12 AM EDT     Sunrise
Mon -- 07:03 AM EDT     0.63 feet Low Tide
Mon -- 10:06 AM EDT     Moonset
Mon -- 12:48 PM EDT     3.35 feet High Tide
Mon -- 07:59 PM EDT     Sunset
Mon -- 08:12 PM EDT     0.54 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Chain Bridge, one mile below, D.C., Tide feet

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