Special Weather Discussion
Latest Weather Discussion by Eric Horst
11:30am Tuesday, January 21, 2020
* Milder Pattern Returns...With Rain More Likely Than Snow *
It's been relatively cold the last few days...but it won't last. The large-scale pattern, though not as warm trending as a few weeks ago, still isn't aligned right for persistent cold and frequent snow in the East. Despite some subtle shifts, there remains a bias towards troughing over Greenland and Alaska...both of which signal mild conditions winning over cold conditions here.
The warming trend begins Wednesday with a high near 40....leading to a high ~46 Thursday and Friday. Overnight lows will remain chilly given clear skies and light winds, until clouds increase Thursday night into Friday.
The weekend will bring a slow-moving storm as an upper-level low rolls from the Ohio Valley across the Northern Mid-Atlantic. The exact track is not locked in, but with no fresh Arctic air in place this is more likely to be a rain event in the low elevations...with accumulating snow likely in parts of central and northern PA. One thing to watch, however--this kind of storm can pull cold air in on the back side...and in fact cool top-down as the upper-level system moves overhead. So it's possible that after a rainy Saturday, the precipitation could end as a period of wet snow Saturday night or Sunday morning. This is FAR from a sure bet...so let's wait a few days to see how things set up.
Looking ahead to next week, a chilly (but not cold) start will lead to another warming trend...with a shot at hitting 50 degrees the middle or end of next week. Even into the opening days of February the pattern looks mild, though Arctic air may return to the northcentral US around February 3rd or 4th...and just maybe some blocking will begin to develop around Greenland. If so, there's a chance for a more wintry spell for here mid-February. We'll see.