Ski Denton Snow Report

469 FXUS61 KCTP 180727 AFDCTP Area Forecast Discussion National Weather Service State College PA 327 AM EDT Sat Jul 18 2026 .WHAT HAS CHANGED... * Tornado risk is still 5% chc of a tornado w/in 25 miles of a point), but the conditional intensity group 1 has been introduced S & E of Harrisburg * Damaging wind gust threat is high (45% chc of wind damage w/in 25 miles of any point) over almost all of the CWA && .KEY MESSAGES... 1) Severe thunderstorms with damaging winds and heavy rainfall are possible from mid-day into late evening. Tornadoes also possible. 2) Sunday & Monday quiet but Tues looks active again with severe and flood risks returning. && .DISCUSSION... KEY MESSAGE 1: Severe thunderstorms with damaging winds and heavy rainfall are possible from mid-day into late evening. Tornadoes also possible. SPC has kept the Enhanced risk of severe weather expectation for all of Central PA today. They have also added a special (conditional intensity group or CIG) hatching to SErn PA (including areas S & E of Harrisburg. The CIG designation means that tornadoes that do develop in that area could be stronger than just EF0/1. A reasonable maximum intensity of EF2-strength tornadoes is possible today - again, mainly in SE PA. Early showers and even a thunderstorm or two will occur near/along a pair of warm fronts moving north and east through the area this morning and early afternoon. The vort max moving into western PA at 07Z is expected to continue to touch off showers this morning. Some lightning is possible, mainly across the S. There should not be a threat for severe weather until at least late this morning after we can get the clouds and showers away and get some heating/pump up the CAPE. The timing of that vort max and the SHRA/TSRA it helps generate look like they will be early enough in the day that ample heating should then occur as the main warm front pushes into the srn counties and across the CWA late this morning and early this afternoon. As the CAPEs climb, and the wind profiles/hodographs become rounded, the risk for deep convection that would also take advantage of the high helicity to produce supercells increases. This convection could start a couple hours earlier than climatologically-favored timing...more like a noon kickoff than early- to mid-aftn. The risk for discrete, spinning cells is highest over the Lower Susq, but is possible anywhere across the CWA with the warm front(s) and varied boundaries from earlier rain and differential heating playing roles to make the near storm llvl/blyr environment favorable. 70F+ dewpoints will arrive in the S with the first warm front, and the LCLs should be low and favorable for tornado development. The Sig Tor Parameter (STP) is highest over the SE, esp in Lancaster Co. Lower (l-m60s) dewpoints hang on across the N for much of the day. The NW will have the next-best chance for severe storms to develop. However, the increasing moisture and moderate-high shear and moderate-high CAPEs will mean we`ll have to watch all of the CWA for storm initiation in early and mid afternoon. These could also be supercells away from the SE - at least early in the event. The wind profile becomes more-aligned/straight hodographs that would be more favorable for storm clusters or a broken line, esp if a pre-frontal trough materializes. The cold front moving down from the NW should arrive late in the day and could continue to provide lift for storms in the NW half of the area into the evening. But, it may arrive in most places too late (after stabilization from other/earlier precip) to make a wide threat for severe wx to occur along it as it passes. Expect precip along the cold front to weaken and fall apart the deeper it gets into the CWA (into the central mtns). If there is a chance for a bust or weakness in the severe forecast it is over the central mtns/ridge-and-valley region. Potent storms are likely/certain in the SE and the NW, but are less certain in the Laurels and ridge and valley counties. ---------------------------------------------------------- KEY MESSAGE 2: Sunday & Monday quiet but Tues looks active again with severe and flood risks returning. A drying trend is expected Sunday with noticeably lower humidity allowing for a pleasant day and relatively cool night. However, latest RRFS shows some near sfc smoke returning to CPA from the Great Lakes. This could result in reduced air quality and hazy sky conditions. Additional bouts of rain/t-storms are possible into the workweek. The first of which will be around Tuesday (Day4) as a well-developed synoptic storm moves through the Great Lakes and NE CONUS. SPC has been highlighting a 15% prob (equivalent to SLGT risk, level 2/5) for Central PA. Forcing/support for this medium range severe outlook appears fairly robust and would take stock in this risk manifesting at shorter ranges. WPC is also highlighting Tuesday for heavy rainfall and possible flooding with the synoptic system generating multiple chances for rain with high atmos moisture in place. Temperatures will trend near to slightly below historical averages through late week into month-end with some noticeably cooler nights possible. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... There will be two major areas of concern for the next 24 hours. The first will be the continued visibility restrictions at all terminals due to heavy surface smoke concentrations. Visibilities will continue to remain less than 6 miles across most of the Commonwealth through the early morning hours. Anticipate widespread IFR and MVFR restrictions until after 16Z Saturday. A surface center of low pressure is expected to move over the Mid- Atlantic region today, and this will usher out the smoke this afternoon while also bringing convection to the region. The timing of this convection remains the second point of concern. The consensus thinking is there will be two rounds of storms today. The first will come this morning as a cluster of showers will develop along the leading moisture edge ahead of the front (PWATs increasing to 1.5"-2.0") as moisture filters in ahead of the Great Lakes system, with a few thunderstorms being possible as this activity progresses west to east across the Commonwealth. This activity should largely end from west to east between 16 and 18Z. The second round of storms will kick off later in the afternoon with a main line of storms along the front developing between 20 and 22Z. Convection is expected to exit the southeastern terminals of KLNS and KMDT by 06Z Sunday. These storms today will be strong to severe and may produce gusty winds, heavy rain, and flight restrictions. Outlook... Sun...Lingering -SHRA with restrictions possible early (primarily driven by low ceilings), with VFR favored otherwise. Mon...Mainly VFR. Tue-Wed...Restrictions possible in showers/t-storms with cold FROPA expected between Tuesday/Wednesday. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ WHAT HAS CHANGED...Dangelo KEY MESSAGES...Dangelo DISCUSSION...Dangelo/Steinbugl AVIATION...Bowen