NEAR TERM /UNTIL 8 AM THIS MORNING/
Another mainly clear and comfortable night ahead with min temps 45-60F and radiational fog in the usual river/stream valleys.
Low stratus may also try to sneak into the extreme southeast zones thanks to developing southeast flow.

SHORT TERM /8 AM THIS MORNING THROUGH FRIDAY NIGHT/
A persistence forecast is a good bet with high pressure firmly in control providing more nice weather through the end of the week. A southeast flow should result in a slight uptick in humidity and may also try to advect some low stratus into parts of the southern tier and Lower Susq Valley during the overnight hours.

Daytime highs will be in the upper 70s to low 80s over most of the forecast area. Guidance continues to indicate nighttime fog formation in the favored valleys of north central PA. The HRRR Smoke model also continues to show an increase in vertically integrated smoke, which will make skies look more hazy/milky by Friday.

LONG TERM /SATURDAY THROUGH WEDNESDAY/
Medium range guidance supports a high confidence of warm and dry weather this weekend into early next week associated with persistent upper ridging. Abundant sunshine and ensemble mean 850mb temps in the 14-15C range support highs in the upper 70s to mid 80s. However, surface ridging and associated dry air should result in decent radiational cooling each night, with min temps near seasonal levels. Although the air will be dry, patchy river valley fog remains possible each morning.

As the remnants of Francine over the Mississippi Valley run into building high pressure over the Northeast US late Sat into Sun, its forward motion will slow significantly. Medium range guidance shows the associated midlevel low opening into a trough extending from the Mississippi Valley to the waters off the Southeast US. Subsequently, a developing coastal low off the South Carolina coastline becomes the dominant feature later Sunday into Monday. Although the coastal low will start off non- tropical, the NHC gives it a 20 pct chance of becoming tropical or subtropical early next week. As the high over the Northeast US pushes east late Tue into Wed, this will ultimately allow the coastal low to drift westward and northward, with the potential for a period of unsettled weather in central PA from Tuesday through the end of the week.

AVIATION /06Z THURSDAY THROUGH MONDAY/
Influence of high pressure will allow for valley fog potential across all of central Pennsylvania (except potentially JST)
overnight into Thursday morning. The highest chances will be at BFD/AOO/UNV, where dewpoint depressions already running in the 0-3F range. This, coupled with persistence, have lead to adding mentions of VCFG with visibility restrictions at BFD/AOO in the 07-12Z Thursday timeframe. There is slightly less confidence at UNV, so have kept restrictions minimal at this time. There is also higher (60-70%) confidence at LNS given with HRRR/SREF guidance indicating IFR visibilities in the 08-13Z Thursday timeframe. There is lower confidence in any restrictions at MDT (20-30%) due to lower probabilities in all model guidance coupled with local climatology of fog at MDT. If any restrictions are to occur at MDT, generally expect MVFR visibilities (4-6SM) in the 09-11Z Thursday timeframe.

All airfields across central Pennsylvania are expected to prevail VFR by 13Z Thursday with very high (> 90%) confidence.
The influence of high pressure will continue to bring light surface winds, generally below 5 kts with higher elevation sites 5-10 kts sustained). Valley fog potential will once again be the main concern aviation-wise Thursday PM into Friday morning.

Outlook...

Fri-Mon...AM valley fog north & central; otherwise, no sig wx.

CTP WATCHES/WARNINGS/ADVISORIES
None.