West Chester, PA Weather

What Has Changed

Issued Frost Advisories for portions of southeastern Pennsylvania, southern New Jersey, and Delmarva tonight where the growing season remains active.

Key Messages

1. One more round of frost impacts are expected tonight where the growing season continues.

2. Dry weather continues and above normal temperatures are expected for much of the week into the start of the weekend.

Discussion

KEY MESSAGE 1...One more round of frost impacts are expected tonight where the growing season continues.

Little change in the overall synoptic pattern continues as surface high pressure remains overhead. The high will begin to shift southward tonight allowing a light southwesterly return flow to develop. As a result, temperatures will begin to gradually moderate through Monday.

But before we reach the new week, one more round of chilly temperatures are expected tonight. Ideal radiational cooling conditions look to take place with light/calm winds and clear skies. NBM has been quite poor the past few days with the extent of radiational cooling, so have blended in some colder and better performing guidance over the past couple of nights (MOS/NBM10). This should allow most of the area to again see lows mainly in the mid 30s to low 40s around the region. Have issued one more set of Frost Advisories, mainly across extreme southern New Jersey and the Delmarva where the growing season remains active. Some areas of patchy shallow ground fog is also expected early Monday morning.

KEY MESSAGE 2...Dry weather continues and above normal temperatures are expected for much of the week into the start of the weekend.

As what has been the case for the past week or so, dry weather is expected to prevail over the next 5-7 days. However this time, above-normal temperatures for late October/early November are expected to be accompanied by this dry stretch.

Surface high pressure will largely be in control through much of the week, however there will be one dry cold front that is progged to cross through the area Monday night into Tuesday. From Tuesday and beyond, expansive high pressure is expected to dominate as upper level ridging develops over the majority of the Central-Eastern CONUS with positive 500 mb anomalies.

Aviation

The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas.

Today...VFR/SKC. Southwest winds around 3-6 kt. High confidence.

Tonight...VFR/SKC. A few areas of localized patchy ground fog is possible after 09Z, especially at RDG and MIV so have included a brief tempo group. Winds light and variable to at times calm. High confidence overall, lesser confidence in where areas of ground fog may develop.

Monday...VFR/SKC. West-northwest winds around 5-10 kt. High confidence.

Outlook...

Monday night through Friday...VFR. No significant weather expected.