Mary Ellen Pann

South-central Pennsylvania will have sunny but sticky conditions with highs in the mid-80s before clouds and humidity increase. Showers are expected late tonight and Thursday, with isolated thunderstorms possible Thursday afternoon. Friday should be dry and more comfortable, while the weekend may bring additional showers and thunderstorms. Cooler, less humid weather is forecast for the following week, with temperatures mostly in the upper 70s to near 80 degrees.

A cold front and northwest winds will reduce humidity overnight, bringing sunnier and more comfortable conditions Tuesday, with highs in the low to mid-80s. Wednesday will remain warm and somewhat sticky before showers and thunderstorms become possible Thursday as another cold front moves through. Humidity is expected to fall again Friday, while additional showers and storms may affect the Susquehanna Valley over the weekend. Early next week is forecast to be dry, cooler, and less humid.

High humidity and temperatures in the mid-80s are expected, with showers and thunderstorms most likely between 3 p.m. and 7 p.m. A cold front should bring brief heavy rain but no severe weather threat, followed by lower humidity and more comfortable conditions Tuesday and Wednesday. Additional showers and storms are possible Thursday and over the weekend, while early next week is expected to be drier and cooler.

Mostly sunny and seasonable conditions are expected across south-central Pennsylvania today, with lower humidity and highs in the mid to upper 80s. Rain and thunderstorms will return Sunday as a warm front moves north, bringing increased humidity, a marginal risk of isolated severe storms, and a slight risk of flash flooding, particularly near the Pennsylvania-Maryland line. Drier, sunnier conditions are expected Tuesday before humidity rises again midweek, with additional storm chances Thursday and Friday.

A flash flood warning for central Franklin County in south-central Pennsylvania was canceled after thunderstorms produced heavy rain, with 1 to 2 inches reported and additional rainfall possible. The warning covered areas including Chambersburg, Guilford, St. Thomas, Fayetteville, Scotland and Fort Loudon, where flooding could affect creeks, streams, roads and low-lying areas. Residents were advised not to drive through flooded roads.

A second round of thunderstorms is expected across south-central Pennsylvania and the Susquehanna Valley Monday afternoon and evening, with potential for wind gusts over 60 mph, quarter-size hail, heavy rain, isolated flash flooding and a low but nonzero tornado risk. Storms should weaken around sunset. Additional, generally less severe thunderstorms are forecast Tuesday and Wednesday, followed by lower humidity and mostly drier weather late in the week before storms return Sunday.

A mostly sunny and drier day is expected after morning clouds, with highs reaching the upper 80s to lower 90s and slightly lower humidity. Monday is designated an Impact Day because strong to severe thunderstorms could bring damaging winds, frequent lightning, heavy rain and isolated flash flooding across the Susquehanna Valley. A cold front will bring additional showers and storms Tuesday into Wednesday, followed by cooler, less humid and more comfortable conditions later in the week and into the following weekend.

Hot and humid conditions will continue across south-central Pennsylvania, with afternoon and evening thunderstorms bringing risks of damaging wind gusts, heavy rain and isolated flash flooding. Severe-weather risk is generally marginal, with a slight risk in parts of York and Lancaster counties. Sunday and Monday will remain warm near 90 degrees with limited storm chances, while a cold front Tuesday into Wednesday should bring additional showers and storms, lower temperatures and more comfortable humidity.

A persistent tropical airmass will bring higher humidity and daily chances of showers and thunderstorms across the Susquehanna Valley. The risk of heavy downpours and localized flash flooding increases Thursday and Friday, with scattered storms continuing through Saturday; isolated severe storms with damaging winds are possible. Drier conditions are expected Sunday and Monday, followed by another chance of showers and storms with a cold front Tuesday into Wednesday.

South-central Pennsylvania will have mostly clear skies and cooler temperatures overnight, followed by a sunny Tuesday with low humidity and highs in the mid-80s. Heat and humidity will increase from Wednesday onward, bringing daily chances of showers and thunderstorms, with temperatures nearing 90 degrees from Friday through the weekend. Storm chances should decrease Sunday and Monday before another system brings additional storms Tuesday into Wednesday.

The Susquehanna Valley is expected to become increasingly humid, with isolated showers and thunderstorms late today and additional storms Monday. Tuesday presents the greatest risk for scattered strong to severe thunderstorms as frontal systems move through, with damaging winds, hail and heavy rain possible. Southern Franklin, Adams, York and Lancaster counties are under a Slight Risk, while surrounding areas face a lower Marginal Risk. Storm chances continue Wednesday before drier, seasonable weather arrives Thursday and Friday; another increase in showers and storms is possible Sunday.

Shifting winds from a warm front are expected to clear heavy wildfire smoke in south-central Pennsylvania, improving air quality from unhealthy to moderate by afternoon. An enhanced risk of severe storms is forecast for later in the day, with damaging winds, heavy rain, isolated flash flooding, hail, and a low tornado risk. Storm chances persist into the evening before clearing overnight, followed by drier, less humid conditions Sunday and Monday. Another round of storms is possible Tuesday as a new cold front approaches.

A heatwave beginning Tuesday brings temperatures in the mid-to-upper 90s, with heat index values near or above 100 degrees and the hottest conditions expected Wednesday. Heat advisories are in effect across multiple Pennsylvania counties, with the possibility of an upgrade to an extreme heat warning. Humidity rises through midweek before easing as temperatures fall slightly Thursday and Friday. Storm chances increase late in the week, with weekend temperatures returning to the 80s and more seasonable conditions expected next week.

Humidity decreases across south‑central Pennsylvania as high pressure brings drier conditions and sunshine, with seasonable temperatures in the mid‑80s. Heat and humidity rise beginning Tuesday, bringing several days in the 90s and potentially dangerous heat indices near 100 degrees on Wednesday. Storm chances remain low until late in the week, with brief relief in humidity by Thursday and Friday before thunderstorms become more likely heading into next weekend.

A Flood Watch from 2 p.m. to 8 p.m. accompanies slow‑moving showers and storms capable of producing excessive runoff and localized flooding across the Susquehanna Valley. Southern Franklin, Adams, and York counties face a marginal severe weather risk, though the main severe threat has shifted south. Cooler temperatures in the upper 70s to low 80s follow recent heat, with additional unsettled weather and periodic showers continuing through midweek and increased storm chances toward the weekend.

A flood watch is in effect from Sunday afternoon through Monday evening in South-Central Pennsylvania, with slow‑moving thunderstorms expected to bring heavy rain, damaging winds, hail, and localized flash flooding. Storms are most likely late Sunday afternoon and evening, followed by lingering showers overnight. Cooler but still humid conditions continue Monday, with additional showers and flooding risks despite a lower chance of severe weather. Unsettled conditions persist Tuesday, before temperatures rise and weather trends somewhat drier later in the week, though periodic storm chances remain.

Strong, slow‑moving thunderstorms are expected from Sunday afternoon through Monday, producing heavy rainfall exceeding two inches per hour, damaging winds, and possible large hail. A Flood Watch is in effect due to the risk of excessive runoff and flooding in low‑lying and poor‑drainage areas across the Susquehanna Valley. Temperatures reach the upper 80s before cooler conditions return Monday, with additional showers and storms continuing into Tuesday and recurring chances through the week as another system approaches next weekend.

Dangerous heat persists across South‑Central Pennsylvania with temperatures in the upper 90s and heat index values up to 110 degrees. Counties remain under an Extreme Heat Warning or Heat Advisory, and the WGAL Storm Team has designated Saturday as an Alert Day and Sunday as an Impact Day. Scattered storms are expected this afternoon and evening, some capable of producing damaging winds and heavy rain, with additional storm chances Sunday as the heat dome shifts. Relief arrives early next week as temperatures return closer to seasonal averages.

An extreme heat warning is in effect for the Susquehanna Valley from Wednesday through Friday as temperatures near or exceed 100 degrees with heat index values of 105 to 110. A heat dome is driving the prolonged heat and humidity, with overnight temperatures remaining unusually warm. Storm chances increase over the weekend as the ridge begins to break down, offering some relief by Sunday. Independence Day will still be hot under a heat advisory, and dry conditions persist with June ranking among the driest on record.