004 FXUS61 KCTP 050321 AFDCTP Area Forecast Discussion National Weather Service State College PA 1121 PM EDT Wed Jun 4 2025 .SYNOPSIS... * Cold front approaches from the west overnight into Thursday morning with rain expected after sunrise on Thursday. * A marginal risk of severe weather across the NW PA Thursday afternoon, with damaging winds being the main hazard. * Unsettled pattern continues into the first half of next week with episodic showers and thunderstorms. && .NEAR TERM /THROUGH THURSDAY NIGHT/... Cumulus field this evening gradually decreasing as it loses daytime heating and will gradually scatter out over the next couple of hours. Some period exists where the bulk of central Pennsylvania will observe clear skies; however, expect clouds to begin filling in overnight as moisture ahead of a weak cold front approaches the area overnight. Given current observed dewpoint depressions, have slightly increased patchy fog mentions overnight, which agrees with RAP model RH cross- sections for increasing low-level moisture overnight. Showers are expected to begin during the mid-to-late morning hours across northwestern Pennsylvania. Some model guidance exists with respect to how dry the lower-levels will be so have trended precipitation onset slightly back this evening, pushing it closer to the 10am to 12pm timeframe for first returns entering the furthest reaches of NW Warren County. Precipitation gradually overspreads the area through Thursday, gradually approaching the I-81 corridor by sunset. Precipitation continues into Friday morning for areas north/west of I-81, with best chances for precipitation across far SE PA coming late Friday. With respect to the severe threat on Thursday, favorable instability approaching the 1500-2000 J/kg mark, coupled with ample moisture and lift during the afternoon hours will promote continues severe threat across NW half of the CWA. Model soundings do continue to outline the favored inverted-V shape along with fairly dry mid-levels for damaging wind. Shear remains the most marginal of parameters; however, sufficient shear remains in place for some storms to become developed enough for hail concerns, too. With all these factors in mind, SPC has continues to outline the NW PA with a marginal risk for severe weather on Thursday. PWAT values approaching 1 inch will also promote some potential for heavier downpours in thunderstorms especially given weak low-level flow that could allow for training thunderstorms. Flooding impacts would likely be isolated/localized with higher potential in the typical urban and poor drainage locations. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... The aforementioned cold front will be slow-moving and continue to provide a focus for showers and thunderstorms through the end of the week with a developing area of low pressure west of the area becoming more of a factor by Saturday. As moisture continues to pool along the frontal zone, the Weather Prediction Center continues to show a marginal EROs with potential for repeat rounds of rain to potentially cause some runoff issues. Further rainfall over areas that potentially encounter training on Thursday will be at the most risk for flash flooding on Friday, thus trends will need to be continuously monitored ahead of afternoon thunderstorms on Friday that could, once again, bring locally heavier rainfall. It is noted that heaviest rainfall in the short-term also remains fairly reliant on the track of the surface low near or directly over central Pennsylvania. The exact track of the low remains uncertain, so there remains some uncertainty with respect to where the axis of heaviest rainfall will occur. Cloud cover and the high likelihood for showers will drop high temperatures by 5-10 degrees on Friday towards the 70F-80F range, very close to climatological averages. Friday night will be mild with low temps in the upper 50s to mid 60s or +10-15F above normal, while Saturday night pushes closer to climatological averages, but still +5-10F above average for the early stages of June. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Still looks like Sunday will have the best chance to be the main part of the weekend to be mainly dry. After that, will have to wait to later next week for the return to dry weather. Temperatures next week cooler than what we have now, although the average temperature today was not all that high, as the low temperature this morning offset the very warm aft. Anyway, temperatures next week will be closer to normal. Earlier discussion below. The active front from the short term period finally pushes east of Pennsylvania on Sunday and upper-level ridging attempts to build in behind it, bringing a period of drier weather with seasonable temperatures to end the weekend. Rain chances return to the forecast on Monday and look to persist through Wednesday, as a trough approaches from the west. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... Late evening update. Current fcst in good shape. Main change was to have a gusty wind at IPT for a few more hours. The gusty wind there keeping the temperature up there, compared to most of the area. Earlier discussion below. Other than some fair weather CU and a few high clouds, looking at mainly clear skies into early Thursday. A cold front will bring a chance of showers and storms to the the northern and western sections of PA Thursday afternoon. The main chance will be mainly limited to BFD. Outlook... Fri...Numerous SHRA/TSRA, esp NW. Brief reductions to MVFR and IFR in the TSRA. Sat...Showers/PM TSRA continue, gradually tapering off across NW PA late. Sun...VFR/no sig wx expected. Mon...Showers and storms, especially late across the north and west. && .CLIMATE... The high temperature at Altoona reached 89 degrees at 2:22pm on June 4th. This broke the record of 86 degrees set back in 1971 and 2024. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...NPB NEAR TERM...NPB SHORT TERM...Bauco/NPB LONG TERM...Martin/NPB AVIATION...Martin/Bauco CLIMATE...Martin