Cooling Trend into this Weekend for the Northeast, Warming Up Again Next Week!

Good morning! Our warm and muggy pattern comes to end today. A cold front has passed through early this morning. Temperatures may hold steady or slowly falling for rest of morning, before rising again into the mid-upper 70s with lower humidity this afternoon. Plenty of sunshine and breezy conditions are expected today. Northerly winds will be sustained around 15 to 20 mph with higher gusts up to 30 mph possible this afternoon and early this evening.

Mostly clear skies will continue into tonight. As a cooler, Canadian airmass begins to settle into the Northeast, temperatures will drop into the mid-upper 50s over more urban and coastal areas and upper 40s to lower 50s over Interior areas. Winds will also gradually diminish overnight, as the pressure gradient over the Northeast weakens. But more ideal radiational cooling conditions aren’t expected. On Friday, weak high pressure over the Northeast will support plenty of sunshine for most of the day. But a cooling trend will continue, with high temperatures only into the upper 60s to lower 70s. Which is actually closer to seasonal levels for this time of year.

Then a weak area of low pressure or cold front associated with a shortwave trough coming out the Great Lakes will move through the Northeast during Friday night and Saturday. Some scattered showers are possible, as this system moves through. But moisture is limited, thus not alot of rainfall is anticipated. Overnight lows Friday night are likely to be similar to Thursday night, as clouds increase late. More cloud cover, limited sunshine and cooler mid-level temperatures may keep temperatures from rising out mid-upper 60s on Saturday.

NAM model showing shortwave trough and low pressure with some showers around Saturday morning over Northeast

NAM model showing shortwave trough and low pressure with some showers around Saturday morning over Northeast

Stronger high pressure from Central Canada builds in behind this system for the rest of the weekend. This will result in clearing skies and calmer winds, that will support more ideal radiational cooling on Saturday night. Temperatures will likely drop into lower 50s over many urban areas. While many of the suburbs and interior valleys may will see lows down into 40s.  Then more sunshine is expected on Sunday with high temperatures more in the upper 60s to lower 70s again. Overall this weekend, will feel more like Autumn. Sunday appears to be the best day for outdoor plans.

The upper-level pattern begins changing again early next week, as the pacific jet becomes more active again over West Coast. This will cause more ridging to build again the Plains to the East Coast with some much warmer than normal temperatures returning. But some confluence over Northeast will support high pressure to be positioned nearby with more onshore winds, early in the week. So we anticipate high temperatures only in lower to middle 70s on Monday and Tuesday over the Northeast.

By Wednesday and Thursday high pressure will far enough south too for more southwest winds. Temperatures should likely warm up at least into the upper 70s to lower 80s. Which is around 10 to 15 degrees above normal for the first of week of October. No significant precipitation is expected underneath ridging for much of next week. Next chance for any showers may come with a weak cold front from the north by Thursday. Temperatures may cool down somewhat again afterwards.

ECMWF ensembles showing 2m temperatures several degrees above normal over the Northeast by Wednesday

ECMWF ensembles showing 2m temperatures several degrees above normal over the Northeast by Wednesday

But overall, as we look further ahead, no significant changes to upper-level pattern are currently foreseen. Troughiness will reside largely over the West Coast of the US with more ridging and progressive flow dominating over Central and Eastern US. So temperatures are expected to average above normal into the second week of October in the Northeast. Stay tuned for more updates on the forecast for this upcoming weekend and pattern for the rest of the October.