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ANZ530 Chesapeake Bay North Of Pooles Island- 746 Am Edt Sat Sep 23 2023
.gale warning in effect through this evening...
Today..NE winds 25 kt with gusts to 45 kt. Waves 3 ft. Rain. Vsby 1 to 3 nm.
Tonight..NE winds 25 to 30 kt...diminishing to 15 to 20 kt with gusts to 30 kt late. Waves 3 ft. Rain. Vsby 1 to 3 nm.
Sun..E winds 10 to 15 kt. Gusts up to 25 kt until late afternoon. Waves 1 to 2 ft. Rain.
Sun night..N winds 10 kt. Waves 1 ft. A chance of showers.
Mon..N winds 10 kt. Waves 1 ft. A chance of showers.
Mon night..NE winds 10 kt with gusts to 20 kt. Waves 1 ft. A chance of showers.
Tue..NE winds 15 to 20 kt...diminishing to 10 kt after midnight. Waves 1 to 2 ft. A chance of showers.
Wed..NE winds 10 to 15 kt. Waves 1 ft. A chance of showers after midnight.

ANZ500 746 Am Edt Sat Sep 23 2023
Synopsis for the tidal potomac and md portion of the chesapeake bay..
tropical storm ophelia will approach the area from the south, moving across the mid-atlantic this weekend. Strong wind gusts in excess of 40 to 50 knots are expected over the waters through Sunday morning. The remnant low pressure system will move north of the area by late Sunday, with high pressure building in from the north by Monday, continuing through mid-week. Small craft advisories will likely be needed Sunday, and again early next week.

FXUS61 KCTP 231143 AFDCTP

Area Forecast Discussion National Weather Service State College PA 743 AM EDT Sat Sep 23 2023

SYNOPSIS
The slow moving remnants of Tropical Storm Ophelia will lift north into the Mid Atlantic region this weekend into early next week. A blocking pattern is anticipated the rest of next week, caused by an anomalous upper ridge centered east of Hudson Bay.
Over Pennsylvania, a stalled front is likely to be in the vicinity of southwest PA much of the week, while a large surface high noses southward into the rest of the state.

NEAR TERM /UNTIL 6 PM THIS EVENING/
Clouds now cover all of the CWA, but thin spots are seen here and there. Most are still higher than 10kft. The first rain band from this storm has moved into the SErn counties.
Measurable (0.01") rain has registered at THV and LNS, but this initial rain band is already thinning out a bit on radar/reflectivity. Dewpoint depressions are still around 10 degrees at this point. We'll see the clouds continue to lower and thicken as the day progresses. But, the rain may not get much farther to the NW than a UNV-IPT line before noon. The rain will struggle to get into the NWrn 5 counties by day's end. QPF from the major models is a little lighter on the whole than last night's runs had. This should change very little of what we were thinking back then. Namely, that the rain will be largely beneficial to the driest parts of Central PA. The wind continues to look tame, too. Max gusts this aftn will be in the L30s (KTs) over the far SE, but 20+ KT gusts shouldn't reach much past IPT-UNV-JST today (and tonight). Maxes will be pretty close to the current 08Z values in the SE (if not cooler), so we've made a rather flat T fcst there. Elsewhere, temps should rise a couple of degs in the ridge and valley region and 10-15F over the Alleghenies and Laurels.

SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/
Latest NHC guidance keeps Ophelia as a TS until the center moves up to the NC/VA border this evening. The focus of the heaviest rain for Central PA will remain over the southeast part of the forecast area, with the heaviest rain falling tonight. Model consensus and NHC track is for the low center of the (expectedly) downgraded depression to inch poleward and a little to the east, only reaching DOV by Sun evening.

Again, the rainfall is now looking a little lighter, but totals of >2" should still occur in the Lower Susq where some instability (mainly aloft) is possible. SPC general thunder area now extends well into the CWA for Day1. Beneficial rainfall is the story of this system for central Pennsylvania as the areas likely to receive the heaviest rain are sorely needing it, namely the Lower Susquehanna River Valley. FFG of 4+"/6hrs means the flood threat is unusually low for a decaying tropical system over PA.

Winds will be less than remarkable for Central PA, even in the Lower Susq. The higher gusts into the L-M30s will be S/E of Harrisburg. Gusts >20KT will be rare N/W of IPT-UNV-JST.

Temps won't drop more than 2-3F tonight in the SE due to the clouds and almost-saturated environment. But, a more-normal drop of 15F is expected in the far NW.

Rain continues, but probably lighter over the CWA on Sunday. It starts to taper off on Sun night, even though the sfc low will be as close as it will be. As the pressure fills, the wind will actually get lighter on Sunday and continue to do so on Mon.
Precip may linger into Monday, but likely be very light and confined to the SE, drying up thru the day. Considered lowering PoPs quite a bit for Sun night and Mon, but we'll pass it along to the next shift in order give us more time to make sure it's the best move. Max temps should be up 5-8F from Sun.

LONG TERM /TUESDAY THROUGH FRIDAY/
11 pm Friday update... On the large-scale, once the remenants of Ophelia exit stage right early next week, we'll be left with a weak upper trough axis over the OH Valley and Mid-Atlantic region, amidst an overall blocky regime. Generally speaking, this system looks ill-defined, with the best moisture availability to the south of the Commonwealth. As a result, we'll carry relatively low chances (30-40% or less) of showers through about mid-week, with the highest probabilities from about US-22/I-78 southward.

Later next week, the above mentioned trough gradually fills, with an upper ridge axis approaching from the middle of the country. This should mean drier weather, with slowly moderating temperatures.

Readings for most of next week should range in the 60s by day, with cloudiness at night keeping lows in the upper 40s-50s range. Towards the end of the week, daytime highs back into the lower 70s should make an appearance for at least the southern valleys.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
A steady deterioration from south to north is expected on Saturday for most of the central PA terminal sites. MVFR cigs, along with light rain, should first impact KLNS and KMDT just after daybreak (around 12-13z). Similar restrictions will impact KAOO, KJST, and KUNV by midday (15-16z), then reach KIPT by mid to late afternoon (20-21z). By late morning or the midday hours, IFR ceilings and more persistent, perhaps heavier rains will edge towards KLNS and KMDT. Confidence on this worsening trend in conditions is high, but there is uncertainty in the timing of IFR arrival.

A tight moisture gradient across northwestern PA, plus downsloping E-SE flow, may well keep KBFD restriction free through Saturday, with MVFR cigs possible Sat night. There is medium confidence here.

As for the surface winds, an easterly breeze of 5-10 kt should be prevalent for most of the overnight period, with perhaps some 15-20 kt gusts impinging on KLNS and KMDT towards daybreak.
Saturday, easterly winds will become gusty area-wide, with 20-25 kt gusts common by afternoon. At KMDT and KLNS, some 30-35 kt gusts are possible late in the day. There is fairly high confidence in this wind gust scenario Saturday afternoon into the early evening.

Winds will be even stronger at 2kft AGL, where NE flow is progged to increase to 35-50 kts Saturday. Some LLWS is possible, but left it out of some TAFs for now due to mixing of momentum due to gusts. However, if low levels are more stable and prevent mixing via frequent gusts, LLWS may need to be added to all of the TAFs.

Outlook...

Sun...Restrictions are likely area-wide, with persistent light rain, and embedded areas of heavier rain in the vicinity of KLNS and KMDT.

Mon-Tue...Improvement is expected this period, although brief restrictions in hit and miss showers are still possible each afternoon.

Wed...VFR.

CLIMATE
The Fall Equinox passed earlier in the night. Welcome to astronomical autumn. No winter on the horizon, as the 8-14 day outlook is for above normal temps, and the October outlook (updated on the 21st) is also for above normal temps over all of the eastern U.S.

The normal first freeze at BFD is the 21st of Sept. We're past then, and with that forecast of above normal temps, sub- freezing temps may not occur at BFD for quite a while. Everyone else usually follows BFD's first freeze by many days to more than a month. MDT's mean first freeze isn't until very late Oct (29th).

CTP WATCHES/WARNINGS/ADVISORIES
None.

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Port Deposit
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Sat -- 05:13 AM EDT     3.72 feet High Tide
Sat -- 06:52 AM EDT     Sunrise
Sat -- 02:04 PM EDT     1.41 feet Low Tide
Sat -- 03:40 PM EDT     Moonrise
Sat -- 05:23 PM EDT     2.12 feet High Tide
Sat -- 07:00 PM EDT     Sunset
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Port Deposit, Susquehanna River, Maryland, Tide feet

Havre de Grace
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Sat -- 03:56 AM EDT     2.66 feet High Tide
Sat -- 06:52 AM EDT     Sunrise
Sat -- 11:37 AM EDT     0.52 feet Low Tide
Sat -- 03:40 PM EDT     Moonrise
Sat -- 05:02 PM EDT     1.68 feet High Tide
Sat -- 07:00 PM EDT     Sunset
Sat -- 10:52 PM EDT     0.48 feet Low Tide
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Havre de Grace, Susquehanna River, Maryland, Tide feet

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