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ANZ530 Chesapeake Bay North Of Pooles Island- 933 Pm Est Sun Dec 3 2023
Rest of tonight..W winds 10 kt. Waves 1 ft. Areas of dense fog late this evening with vsby 1 nm or less.
Mon..W winds 5 to 10 kt. Waves 1 ft.
Mon night..NW winds 5 to 10 kt. Waves 1 ft.
Tue..W winds 5 kt. Waves less than 1 ft.
Tue night..N winds around 5 kt. Waves 1 ft.
Wed..NW winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft.
Wed night..NW winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft.
Thu..SW winds 5 to 10 kt. Waves 1 ft.
Fri..SW winds 5 to 10 kt. Waves 1 ft.

ANZ500 933 Pm Est Sun Dec 3 2023
Synopsis for the tidal potomac and md portion of the chesapeake bay..
a frontal system will cross the waters through Monday. A clipper system will impact the area Tuesday into Wednesday. High pressure will return to the waters Thursday and Friday. Small craft advisories may be needed Monday night and Wednesday.

FXUS61 KCTP 040234 AFDCTP

Area Forecast Discussion National Weather Service State College PA 934 PM EST Sun Dec 3 2023

SYNOPSIS
Upper level troughing is expected over the region through the middle of this week, with a pair of weak Alberta Clippers passing south of Pennsylvania. Upper level should build over Pennsylvania late next week, with low pressure potentially tracking west of the state next weekend.

NEAR TERM /UNTIL 7 AM MONDAY MORNING/
Radar loop at 02Z shows the bulk of the rain has lifted north of PA associated with low pressure tracking across upstate NY.
Gusty west winds behind the trailing cold/occluded front have driven drier air into most of Central PA, but satellite imagery indicates lingering low clouds/fog over parts of the Lower Susq Valley. As the front sweeps through, expect these low clouds/fog to be scoured out between 02Z-04Z.

Large scale subsidence overspreading the region behind the departing upper level shortwave should result in rain-free conditions for most of the region the rest of the night.
However, low level moisture and upslope flow should yield lingering light rain showers/patchy drizzle over the NW Mtns.
By late tonight, the arriving airmass is progged to become cold enough for the rain showers to mix with snow showers over the NW Mtns. Surface temps should remain above freezing and preclude any snow accums. Expect diminishing west winds toward dawn, as the pressure gradient relaxes. Min temps still expected to range from 35-40F over the forecast area.

SHORT TERM /7 AM MONDAY MORNING THROUGH WEDNESDAY/
A potent-looking shortwave and associated batch of precipitation over Missouri this evening is progged by all model guidance to remain too far south to affect the forecast area as it passes south of PA Monday. However, low level moisture pooling ahead of a weak surface trough over the Lower Grt Lks, should support spotty, light upslope rain/snow showers over the NW Mtns.
Progged temps aloft remain a bit too mild for lake effect and surface temp well above freezing should preclude any snow accums.

Forecast soundings support a mainly cloudy Monday due to the presence of low level moisture trapped beneath a subsidence inversion. Model RH profiles indicate the best chance of breaks should be over the Lower Susq Valley and the least chance over the NW Mtns. Model soundings become fairly well mixed to 900mb, where temps of -1C to -2C support highs from the upper 30s NW Mtns to upper 40s over the Lower Susq Valley.

Surface ridging building into the region should cause any lingering rain/snow showers across the NW Mtns to dissipate Monday night, with lows dipping into the upper 20s to low 30s areawide.

Latest guidance tracks a weakening Alberta Clipper well south of PA Tuesday PM. This moisture-starved system appears likely to produce a period of light snow across the Laurel Highlands Tuesday evening, where a light accum of an inch or less is possible. Elsewhere, a bit of light snow/flurries is possible, but ensemble guidance indicates the chance of measurable precip is <50pct.

Wednesday looks like a chilly day with a breezy NW wind developing behind the departing clipper.

LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
Medium range guidance maintains a chance of snow showers on Wednesday with a slow to depart upper trough axis propogating east of the Commonwealth by Wednesday night, and an inverted sfc trough/weak clipper low passing south of the Mason Dixon line.
Northerly flow and upper level ridging builds over the region on Thursday maintaining fair and cool conditions before zonal flow pattern resumes late in the week.

Coldest conditions expected Wed/Thu before rebounding above climo levels by next Friday/Saturday. Might have to watch potential for some light overrunning precipitation along the NY border Thursday or Thursday night, if temps are still cold enough, that could result in light mixed precip. But for now consensus keeps most precip north of the PA/NY border.

Otherwise, rising 500mb heights ahead of organized storm over the west- central U.S. should also keep mild conditions into next weekend. GFS/ECMWF displaying their usual fast/slow bias with this system with CMC a middle ground with round of precip for later Sunday/Sunday night (very low confidence on timing).

AVIATION /02Z MONDAY THROUGH FRIDAY/
IFR conditions remain widespread into this afternoon as warm front sluggishly lifts but buckles along the Allegheny Front.
Central and Eastern airfields should remain stuck with persistent lower cigs and vsbys (fluctuating between IFR and MVFR into this afternoon).

Brief improvement to MVFR conds spreading over the western Laurel Highlands (Cambria and Somerset) currently, and model soundings indicate 150-250+ J/kg of elevated MUCAPES propogate across the Alleghenies late this afternoon and evening. Cold front approaching this evening with aforementioned instability ahead of it will support scattered to numerous showers to last into the evening over the west and northwest. A few rumbles of thunder can't be ruled out with these showers over the Mtns of Western PA where the marginal destabilization occurs ahead of the cold front. LLWS also possible at the western TAF sites (KJST, KAOO, KUNV) into this evening as llvl inversion ~2k feet persists. The threat for LLWS may continue to expand and impact KIPT, KMDT and KLNS for up to several hours between 00-05Z Monday as the axis of the westerly low-level jet continues to move east.

Outlook...

Mon...MVFR/IFR western 1/3 with snow showers.

Tue-Wed...Light rain/snow with sub-VFR likely.

Thu...Chance of rain or snow.

CTP WATCHES/WARNINGS/ADVISORIES
None.

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Port Deposit
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Sun -- 02:37 AM EST     2.49 feet High Tide
Sun -- 07:07 AM EST     Sunrise
Sun -- 10:48 AM EST     0.52 feet Low Tide
Sun -- 12:09 PM EST     Moonset
Sun -- 02:41 PM EST     1.48 feet High Tide
Sun -- 04:40 PM EST     Sunset
Sun -- 09:24 PM EST     0.14 feet Low Tide
Sun -- 10:35 PM EST     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION

Port Deposit, Susquehanna River, Maryland, Tide feet

Havre de Grace
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Sun -- 01:06 AM EST     2.08 feet High Tide
Sun -- 07:07 AM EST     Sunrise
Sun -- 08:29 AM EST     0.13 feet Low Tide
Sun -- 12:09 PM EST     Moonset
Sun -- 02:18 PM EST     1.53 feet High Tide
Sun -- 04:40 PM EST     Sunset
Sun -- 08:02 PM EST     0.32 feet Low Tide
Sun -- 10:35 PM EST     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION

Havre de Grace, Susquehanna River, Maryland, Tide feet

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