It's no secret New England has been stuck in a generally dreary and wet pattern for the better part of two weeks now. This pattern will continue through this weekend and into next week, however, a major shift in the pattern is in the works and will begin to change early next week.
EARLY WEEK: THE SAME OLD
Sunday and Monday will remain under the influence of the low pressure system that worked through New England on Saturday. This will keep temperatures cool with unsettled conditions on both days. Some thunderstorms will be possible Monday. Tuesday is when the "heat dome" (which is basically an area of high pressure that traps heat over an area) begins to push eastward.
The dome will still be to New England's west on Tuesday. Temperatures will begin a warming trend on Tuesday, but will still be near or slightly below average. With the dome to New England's west, the western parts of the region will be the warmest. Some isolated showers could also pop on Tuesday as the leading edge of the warmer air pushes into New England.
WEDNESDAY-FRIDAY: SUMMER CONDITIONS
Wednesday will act as the transition day from the cool, unsettled pattern to the hot, drier pattern. Highs will likely be in the upper 70s to low 80s on Wednesday. New England should officially be out of the trough and into a ridge on Wednesday, meaning the days of unsettled weather and daily rain chances will be over.
Thursday is when the heat dome will likely settle into New England. The region will be firmly under the grip of high pressure. Temperatures will have nothing holding them back from shooting well into the 80s with some 90s possible. As of right now, it looks like Friday will be the hottest day with the highest chance of 90 degree readings. Exactly how hot it will get remains a question mark at this time, but confidence is rather high that mid 80s will be achieved.
This will easily be the hottest it has been since the brief warm up New England experienced back on May 31-June 1. The biggest difference is that dew points will be higher, so it will be more humid this time around.
Due to the location of where the high pressure will settle, northern New England is more likely to see well above average temperatures than southern New England at this time. Despite this, confidence has grown that southern New England will get in on this heat by Thursday.
This is reflected in the NOAA's 6-10 day temperature outlook. This set up will allow the entire region to have rather uniform temperatures, in the mid 80s to low 90s. The hottest temperatures will likely be to New England's northwest, across parts of Quebec.
By week's end, the eastern United States could be entrenched in a "Rex Block", or a "high over low". This type of block occurs when a ridge of high pressure is located directly north of a closed low pressure. This set up leads to warmer, drier conditions in the northern area and cooler, unsettled conditions in the southern area. This can also be seen in the 6-10 day outlook above.
Euro weather model showing a high pressure directly over a storm system in the south on Thursday:
Like all blocks, this set up can be stubborn and take a while to break down. How long the hotter weather will last in New England remains to be seen, but it could linger through the weekend due to the fact that blocks are stubborn. Early indications show a breakdown possible by next weekend's end (June 25-26), but this is a very early look.
This is a look at a general Rex Block setup, this isn't necessarily exactly how it sets up for late next week:
DRIVING FACTORS
The biggest factor in this pattern change is the breakdown of the Omega Block. This will finally allow the trough over the northeast to retreat. This will also allow the stifling heat that has gripped the middle part of the country to shift eastward to New England.
On top of this, North Atlantic Oscillation (NAO) is expected to trend back to a positive phase. This supports the persistent troughing over the eastern United States to end.
Along with the breakdown of the blocking pattern and a trend to positive NAO, a heat dome will be pushing into New England. All of this supports New England getting back to summer-like weather by late next week.
Comments