Tuesday afternoon technical discussion

Tuesday Afternoon Technical Discussion

Synopsis: Cold front ousts the warm air currently in place over much of the state. Expecting temperatures to fall well below normal as trough deepens. The brunt of the cold air will occur after a strong cold front passes around Thursday.

Short-term: Most of the area experienced fair weather along with warm temperatures today as can be seen in Visible Satellite Imagery. The weaker of two cold fronts is currently positioned near the Ohio Valley. It will make its way through tonight which could spark showers and thunderstorms overnight. Both the GFS, and the NAM have the precipitation dissipating as it crosses central Pennsylvania. 12Z models show weak PVA, with relative humidity's fairly weak in the mid to upper atmosphere.  Convection along the front is still possible as it enters the state. Temperatures will fall to around average. Dry air will provide a short break between fronts leading to mostly sunny conditions across much of the state during the day Wednesday.

Long-term: The second and stronger of the two cold fronts, as the trough impacts the area, will fuel widespread showers, and thunderstorms late Wednesday into Thursday. Behind it, very cold temperatures for this time of year will follow along with fair weather as a high pressure system dominates the Northeast. Highs will be in the 60's Thursday and into the weekend. Parts of the state especially north may find near freezing temperatures during the evenings as the 540 height line makes one of its closest encounters since the spring. Welcome back autumn!

-Doc Ray

Matthew Ray
Penn State Meteorology