Weather systems generally move along at a pretty good clip in the mid-latitudes thanks to usually reliable west-to-east winds in the upper part of the atmosphere. Every once in awhile, however, the westerlies become disrupted as a blocking pattern forms in the upper part of the atmosphere. This in turn can lead to the stagnation of surface weather systems with several days of nice weather or several days of poor weather in a given area depending on which part of the upper-air block resides overhead. There are several different types of blocks known to meteorologists and one of these is referred to as the “omega” block since the wind flow pattern in the upper atmosphere resembles the Greek letter by the same name. Indeed, a classic “omega” upper-air blocking pattern is now unfolding across the US and it will soon feature deep upper-level troughs of low pressure along both coasts with strong high-pressure ridging in between. As a result, we’ll be stuck with inclement weather right through Friday and the weekend could also contain some shower activity in the Mid-Atlantic region.
Read More
Our cool, damp unsettled pattern continues right through the work week and even the weekend could have some shower activity to deal with. After occasional showers and drizzle today and tonight, strong surface low pressure will form on Thursday near the east coast and it will meander around for a couple of days given the unfolding classic “omega-shaped” blocking pattern in the upper part of the atmosphere. This coastal storm will produce occasional rain around here on Thursday and Friday and then it will slowly pull away and weaken this weekend. As a result, some sunshine should return to the region on Saturday, but showers cannot be ruled out and a frontal system may bring additional showers on Saturday night and early Sunday.
Read More
Low pressure area is sliding up along the Mid-Atlantic coastline today providing us with more unsettled weather featuring clouds and occasional showers. After a bit of a lull at mid-week, the latter part of the week may feature strong surface low pressure near the Mid-Atlantic coastline. This storm system will likely spin around for a couple of days (Thursday/Friday) as deep upper-level trough forms along the east coast in a classic blocking “omega-shaped” flow pattern in the upper part of the atmosphere. Once this storm system finally pulls away this weekend, it'll turn warmer and the weather will improve noticeably.
Read More
This will be a very unsettled week in the Mid-Atlantic region with multiple chances of rain and numerous low pressure systems will be contributing factors. The latest surface map (not shown) features low pressure sitting just off of the Mid-Atlantic coastline. Another low pressure system will intensify over the Delmarva Peninsula during the next 12 hours or so and it’ll produce more rain around here from early tonight into Tuesday including the threat for strong-to-severe thunderstorms. A third low pressure system will form along the Mid-Atlantic coastline later in the week. That third low pressure system looks like it will meander around for a couple of days (classic "omega" block) as a deep upper-level trough develops along the east coast, and this setup could ultimately result in a strong nor’easter during the late Thursday/Friday time frame. This potential late week nor’easter could bring soaking rains to the I-95 corridor and it could be just cold enough for snowflakes to fly in higher elevation locations from western Pennsylvania to eastern West Virginia.
Read More
Quite an unsettled week is coming to the Mid-Atlantic region with multiple chances for rain. Low pressure and its associated frontal system will continue to affect the region today and tonight with plenty of clouds and additional showers, maybe a thunderstorm. Another low pressure area will slide up along the Mid-Atlantic coastline on Tuesday likely bringing periods of rain to the region. The unsettled pattern will continue during the second half of the week with another low pressure system meandering in the region for days and additional rounds of rain are likely.
Read More
A persistent cool and damp weather pattern has taken over in the Mid-Atlantic region. In fact, the best that can be said about the weather through early next week is that much of Saturday should be rain-free albeit quite cool. Light rain or drizzle is likely today and tonight and then soaking rain is likely late tomorrow night into Sunday and again Sunday night into Monday as low pressure forms in the Mid-Atlantic region. Temperatures throughout the next several days will remain below normal for this time of year.
Read More
Of the next five days only Saturday appears to have any chance at being mostly rain-free. A stalled out frontal system in the Mid-Atlantic region will act as a conduit for moisture over the next couple of days that is now streaming northeastward from the Ohio Valley. The result will be damp and cool weather in the region as we close out the work week with occasional showers. High pressure will bring some clearing to the region on Saturday, but more rain is likely on Sunday and Monday as low pressure forms in the Mid-Atlantic region.
Read More
A cold front has slipped to our south today, and clouds this morning will give way to clearing skies. Low pressure will move along this boundary zone on Thursday and Thursday night and showers are likely to return to the metro region. High pressure should keep us dry on Friday and Saturday, but then more showers are expected to arrive early next week.
Read More
It is nearly May and yet snow is falling today across much of Northern New England and also across portions of the Rockies and western US. These two unusually cold air masses associated with the snow are contributing to increasing atmospheric instability in the Mid-Atlantic region and the central Plains as they clash with neighboring warm, humid air. As a result, scattered strong-to-severe thunderstorms are likely in the DC-to-Philly-to-DC corridor later this afternoon and evening, and a more serious severe weather outbreak is possible from Texas to Nebraska with several tornadoes possible across the U.S. heartland.
Read More
A slow-moving cold front will approach from the north today and the result will be increasing instability in the atmosphere and the threat for showers and scattered strong thunderstorms. Any strong thunderstorm during the mid-day or afternoon hours can contain heavy downpours, damaging winds and small hail. High pressure will bring about some clearing on Wednesday, but then low pressure will approach from the west on Thursday and the threat for showers will increase once again and that threat will linger into Friday.
Read More
