Sunrise 5:42 AM   Sunset 8:22 PM Moonrise 5:46 PM   Moonset 3:24 AM

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ANZ530 Chesapeake Bay North Of Pooles Island- 134 Pm Edt Tue May 21 2024
This afternoon - SW winds 10 kt. Waves 1 ft. Tonight - S winds 5 to 10 kt. Waves 1 ft. Wed - S winds 5 to 10 kt. Waves 1 ft. Wed night - S winds 5 to 10 kt. Waves 1 ft. Thu - SW winds 5 kt. Waves less than 1 ft. A chance of showers and tstms. Thu night - W winds 5 kt. Waves less than 1 ft. A chance of showers and tstms. Fri - SW winds around 5 kt. Waves 1 ft. A chance of showers. A chance of tstms. Sat - S winds 5 kt. Waves less than 1 ft. A chance of tstms.
winds and waves higher and visibilities lower in and near tstms.

ANZ500 134 Pm Edt Tue May 21 2024
Synopsis for the tidal potomac and md portion of the chesapeake bay -
high pressure will build over the waters today. A strong cold front will approach the waters Wednesday into Thursday. This frontal system will settle south of the area Friday before retreating back toward the waters this weekend. Small craft advisories may be needed for portions of the waters Wednesday.

FXUS61 KCTP 211643 AFDCTP

Area Forecast Discussion National Weather Service State College PA 1243 PM EDT Tue May 21 2024

SYNOPSIS
*Surge of summerlike warmth and humidity through midweek *Strong to severe t-storms possible Wednesday afternoon *Seasonably warm & unsettled Thursday through Memorial Day

NEAR TERM /THROUGH TONIGHT/
Mostly sunny skies are firmly in place today as temperatures have surged into the upper 70s and low 80s at noon. A scattered deck of fair weather cumulus will develop at higher elevations across the Laurel Highlands and northwest mountains this afternoon as temperatures rise into the mid 80s, which is ~10-15F above late May climo. Can't rule out a stray shower or thunderstorm across the west where a narrow plume of ~500 J/kg MLCAPE will develop this afternoon. Have added mention of isolated showers/storms to the forecast, but expect most locations to stay dry. Dewpoint temperatures will stay in the mid to upper 50s, which will help keep the humidity at a manageable level today.

Fair weather cumulus will collapse tonight with the loss of daytime heating and a few high clouds may still drift overhead.
The gradual advection of higher dewpoints through daybreak Wednesday along with clear skies will likely result in patchy fog again tonight. Highest fog potential based on SREF and HRRR probabilities will be the central ridge and valley region where deeper valleys can effectively decouple. A comfortable night is in store as temperatures bottom out in the upper 50s to low 60s.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
Wednesday will be the warmest day of the week with summerlike to near record max temps forecast in the mid to upper 80s. See the climate section of the AFD to find out which sites have the best shot at tying or setting a new daily record high for 5/22.
In addition to anomalous heat, dewpoint temperatures will rise into the low 60s making for a noticeable uptick in humidity compared to today. The newly-released NWS HeatRisk product (available at www.weather.gov/ctp/heat) indicates the potential for heat-related impacts to those especially sensitive to heat, especially those without effective cooling and/or adequate hydration.

The combination of summerlike warmth and dewpoints in the low/mid 60s will support moderate destablization Wednesday afternoon with MLCAPE values progged in the 1000-1500 J/kg range. While 0-6km shear values are fcst to remain <30kts over most of CPA, the instability/steep lapse rates may be sufficient to support isolated strong to locally damaging wind gusts with t-storms into the early evening. SPC has upgraded the northwest 1/2 of the CWA to a Slight risk or severe t-storm risk level 2 out of 5. If the Slight risk remains in place for the Day 1 forecast tomorrow, it will be the first Day 1 SLGT in our area since April 17th! Latest hi- res models show t-storm clusters developing ahead of an eastward advancing cold front/near a leading pre frontal trough and moving west to east across the area from around midday through the late evening. This convection could be enhanced by remnant MCVs associated with Day 1/Tue convection as they propagate into the Lower Great Lakes within southwesterly flow aloft.

The morphology of storms into Wednesday night and Thursday morning remains a bit fuzzy at this time. A break in the shower/storm activity is probable Wednesday evening with subsequent activity ranging from stratiform rain showers to a continued severe threat through midnight. Much will depend on the evolution of storms in the Plains today and their progression eastward over the next 24 to 36 hours. By daybreak Thursday, some patchy fog is once again possible, especially if any breaks in the clouds help promote more efficient radiational cooling overnight.

More showers and t-storms are likely on Thursday as the primary cold front slowly moves through the area and settles near the MD line Thursday night. The focus for stronger storms shifts into far southeastern PA on Thursday afternoon with the D3 MRGL SWO just clipping Lancaster County. High temps will cool off a bit over most of CPA on Thursday into the mid 70s to lower 80s, but remain above climo for this time of year. Low temps Thursday night/AM Friday in the 55-65F range will not be as warm/humid as Wednesday night.

LONG TERM /FRIDAY THROUGH MONDAY/
Temperatures should remain on the mild side through the end of the week. The cold front will come through on Thursday and then stall just south of PA on Friday. The proximity of the stalled front will result in a continued chance of scattered showers and t-storms for at least southern PA.

There remains some uncertainty in the forecast heading into the Memorial Day weekend, but it appears that Central PA's weather could remain mild but showery.

AVIATION /16Z TUESDAY THROUGH SATURDAY/
Minor update late this morning. Fog is gone, and just some high clouds. The airmass is not real moist, thus CU and showers will be very limited. Thus backed off on timing of showers at BFD by a few hours.

Earlier discussion below.

Patchy fog is present across some of the Lower Susquehanna Valley for the early morning hours today. These visibility restrictions should rise quickly after 8 AM.

VFR and calm winds will prevail for most of Tuesday after the early morning fog lifts out of the region. There are a few scattered showers possible for the NW PA, but their coverage remains low and confidence is too low to include them in the BFD TAF other than a mention of VCSH. The next chance for significant convection will be Wednesday night with a slight risk for severe weather in place across NW PA.

Outlook...

Wed...Scattered t-storms, stronger storms NW.

Thu...Chance of t-storms.

Fri-Sat...Mainly VFR, slight chance of showers.

CLIMATE
Daily record maximum temperatures for 5/22:

Harrisburg 96/1941 Williamsport 95/1941 Altoona 88/2013 Bradford 84/2013 State College 89/1975

CTP WATCHES/WARNINGS/ADVISORIES
None.

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Port Deposit
Click for Map
Tue -- 04:14 AM EDT     0.68 feet Low Tide
Tue -- 04:23 AM EDT     Moonset
Tue -- 05:44 AM EDT     Sunrise
Tue -- 10:12 AM EDT     3.41 feet High Tide
Tue -- 06:18 PM EDT     1.06 feet Low Tide
Tue -- 06:43 PM EDT     Moonrise
Tue -- 08:17 PM EDT     Sunset
Tue -- 10:08 PM EDT     2.06 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Port Deposit, Susquehanna River, Maryland, Tide feet

Havre de Grace
Click for Map
Tue -- 03:06 AM EDT     0.57 feet Low Tide
Tue -- 04:23 AM EDT     Moonset
Tue -- 05:44 AM EDT     Sunrise
Tue -- 09:16 AM EDT     2.58 feet High Tide
Tue -- 04:28 PM EDT     0.51 feet Low Tide
Tue -- 06:42 PM EDT     Moonrise
Tue -- 08:17 PM EDT     Sunset
Tue -- 09:55 PM EDT     1.94 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Havre de Grace, Susquehanna River, Maryland, Tide feet

Full Color Weather Map

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