Marine Weather and Tide Forecast for Felton, PA

NEAR TERM /UNTIL 7 AM THIS MORNING/
03Z/11pm EDT Update: Little change in the forecast so far this evening with scattered showers across the southern half of the forecast area. The SPS for fog continues as is; however, localized visibility drops will be possible across Schuylkill County and the south-central mountains overnight. Confidence in this restrictions being as widespread/continuous overnight remains lower; however, so have not issued any additional fog headlines this evening and will continue to monitor trends.

Previous Discussion, Issued 8:42 PM EDT 06/15/2025: Current radar outlines very little in the way of precipitation across central Pennsylvania; however, model guidance shows moderate agreement in rain shower potential persisting across the southern tier overnight. Additional rainfall overnight will generally remain light, generally below 0.10", well-below FFG values with flooding risk on a downward trend overnight. Fog potential will be the bigger story overnight, with higher elevations along the Allegheny Front with recent HRRR probabilities for visibilities dropping below 1/2SM virtually certain across elevations AOA ~2000-2500ft AGL overnight. Have collaborated with WFO LWX to issue a SPS for locally dense fog across higher elevations of the Allegheny Front overnight with some potential for a short-fused Dense Fog Advisory possible should trends worsen overnight. Any motorists overnight will need to monitor visibility trends, and be prepared for rapidly changing conditions as they traverse the higher elevations of central Pennsylvania tonight. Low temperatures overnight will remain fairly uniform, ranging from the mid-to-upper 50s.

SHORT TERM /7 AM THIS MORNING THROUGH WEDNESDAY/
Stationary front stationed near the Greenbrier Valley continues in the short-term allowing for a continued chance for precipitation across the southern half of the forecast area (generally south of Interstate 80) on Monday. Cloud cover will remain fairly persistent, once again, on Monday and will lead to less instability across central Pennsylvania which should keep any thunderstorm elements out of the forecast as a whole. Model guidance does some signal for very marginal instability making way into far western Somerset/Cambria counties that will promote slight chance of afternoon/evening thunderstorm; however, a decreasing trend has been outlined in the Sunday evening forecast package.

PWAT values begin to increase Tuesday morning into Wednesday with best forcing overhead as a surface boundary sets up over central Pennsylvania. Relatively warmer air will work into the western half of the forecast area, allowing for slightly more instability in place on Tuesday to allow for thunderstorm mentions across the western highlands, with some clearing on Wednesday allowing for enhanced destabilization. From a hydrology perspective, rainfall is expected to be efficient across western Pennsylvania (where PWAT values approach 1.75")
which will bring into account flooding concerns, outlined by WPC's D3 MGRL ERO across the western half of the area, with the SLGT risk clipping Somerset/Elk counties. Severe threat on Wednesday remains fairly minimal, with the best shear in place across northern Pennsylvania where cloud cover will likely limit destablization.

LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
Influence of the upper-level trough continues into the long-term period before gradually drifting eastward by Friday. Period of most interest in the long-term will be Thursday, especially in the afternoon/evening hours with some severe potential in the cards across much of central Pennsylvania. Low pressure stationed across southern Canada with warm front stretched into the northern Atlantic and a cold front stationed across the Ohio Valley will allow for some residence time in the warm sector ahead of an afternoon approach by a surface cold front.
Ample moisture will remain in place, with dew points in the upper 60s to lower 70s across the eastern half of the forecast area. This threat is also noted in the Storm Prediction Center D5 Severe Outlook, with a 15% contour. Do want to highlight that some uncertainty does remain with regards to frontal passage time; however, model guidance is continuing to indicate that ingredients will be in place for some severe potential across central Pennsylvania on Thursday.

Cold frontal passage brings in relatively dry conditions for Friday with upper-level heights beginning to increase. Diurnal showers and thunderstorms will remain in the cards for the weekend, as temperatures trend well-above seasonal averages with relatively humid conditions. Sunday will remain the hottest day of the long-term with forecast high temperatures reaching into the mid-to-upper 80s across the northern tier to the lower 90s across the south-central mountains, with heat index values pushing close to the century mark late Sunday PM. HeatRisk values on Sunday outline the warm temperatures/heat index values, with widespread moderate (level 2/4) risk conditions with areas of the south-central mountains and western highlands reaching into the major (level 3/4) risk for heat-related impacts.

AVIATION /06Z MONDAY THROUGH FRIDAY/
High confidence (>80% chance) in long duration low MVFR to LIFR conditions through the 16/0600Z TAF cycle thanks to a moist low level flow from the east/southeast (80 to 150 deg). Cigs near or below alternate minimums. Periods of rain will be focused over the southeast half of central PA airspace through 17/0000Z.

Outlook...

Tue.. MVFR/IFR with fog and periods of rain.

Wed...VFR/MVFR with rain showers and a few thunderstorms possible.

Thu...VFR with strong PM t-storms possible.

Fri...VFR with a slight chance of rain showers.

CLIMATE
Astronomical Summer (solstice) officially arrives on Friday, June 20, at 10:42 p.m.

CTP WATCHES/WARNINGS/ADVISORIES
None.