textproduct: State College

WHAT HAS CHANGED

* Introduced a bit more in the way of valley fog for early Tuesday and Wednesday mornings.

KEY MESSAGES

1) Unseasonably mild and dry weather will continue until late Wednesday or Wednesday Night prior to a few periods of showers preceding and accompanying a cold frontal passage. Cooler and a return to mainly dry conditions will follow for Friday through Sunday.

DISCUSSION

KEY MESSAGE 1: Unseasonably mild and dry weather will continue until late Wednesday or Wednesday Night prior to a few periods of showers preceding and accompanying a cold frontal passage. Cooler and a return to mainly dry conditions will follow for Friday through Sunday.

Latest satellite loop and regional obs showing lower-based altocu advecting ENE across the western half of the CWA with some light refl returns from virga near the Western edge of our CWA.

09z temps in the upper 40s to low 50s were as much as 10-13 deg F above normal across the SW zones where the cloud cover is the thickest, while some periods of thin cirrus across the North and East has allowed the mercury to into the upper 30s to low 40s (4-5F above normal).

The close proximity of the large, 1032 MB surface high located just east of KACY will keep winds light from the SE or South.

A sprinkle isn't out of the question over the North tonight - much like the very small and brief shower they had two nights ago. We'll keep the forecast at 0 PoP since there is no risk of 0.01" accumulating. That isn't great news for northern PA where BFD only accumulated 0.85" through all of Oct, and is currently on a run of 14 straight days without measurable (0.01") rain.

Upper level ridging builds back into the region for the first half of this week, helping to prolong our dry stretch and keeping high temperatures 10 to 15 degrees above normal for much of week followed by a moderate cooldown of 8-15 deg F in the Thursday to Sunday period.

Highs in the lower 70s are in store for all but the higher elevations on Wed.

Chances for widespread rainfall return for the second half of the week. Very late Wed or Wed night is the earliest anyone will see precip as a complex system develops over the middle of the country. There is still a lot of uncertainty regarding the evolution of the upper air pattern and phasing of energy aloft that will decide the development and progression of this system. The more weighted/favored (per WPC) ECMWF solution yields only a brief 12-18hr window of precip as the cold front moves through (longer in the eastern half of the CWA than over the west) Wed night and Thurs. Cold air under a sharp trough could make the first part of the weekend a little chilly and damp with instability showers.

AVIATION /12Z MONDAY THROUGH FRIDAY/

Good VFR with light wind continues today as high pressure remains a stronghold over the eastern U.S. Cirrus clouds between FL180-FL250 will have no impact on flight planning weather. Toward the end of the forecast period, -SHRA may creep into northwest PA so a VCSH was added to KBFD. Chances now remain less than 20%.

Patchy valley/river fog is possible overnight but over two weeks of dry air will help keep most of this at bay with the best chance (20%) over the southeast region.

Outlook...

Tue...Patchy AM valley fog; otherwise, VFR prevails.

Wed-Thu...Rain showers, especially in the PM hours on Wednesday and continuing into Thursday. Sub-VFR conditions become more likely in showers.

CTP WATCHES/WARNINGS/ADVISORIES

None.