Thereís a lot of moisture this evening being pulled up from the tropics into the eastern part of the United States. The train of showers is mostly stuck in place to our west and thatís where there are flood watches posted. Various counties from South Carolina to New York are in the risk area for flooding. The rainfall in these areas is most intense and will amount over 2 or 3 inches in places.
Ahead of the rain area a plume of humidity has been pulled north into New England. I ended up putting on the central air conditioning to dry out the house. The temperature inside wasnít very warm, but the moisture was going to make it difficult to sleep.
Letís look at couple of maps which really illustrate the rain situation through Sunday. The first map shows how much rain will fall through Friday at 8 PM. This is a total accumulation map of rain from now through tomorrow evening. Notice there is little or no rain accumulation in most of New England, but quite a bit of rain in New York and Pennsylvania as well as parts of Canada.
You probably noticed how variable the sky condition has been today ranging from nearly complete sunshine to a rather ominous sky. This is due to the fact the mechanisms to build the clouds into showers just arenít enough today. However, we do have enough moisture and lift for clouds.
Tomorrow the showers will creep ever so slowly closer while at the same time shrinking in coverage. Eventually, the rain will reach the coastline. The most likely opportunity for rain is Friday night after 10PM through Saturday morning.
The second map I want to show you is for the period from Friday night through Saturday evening. This map again predicts total accumulated rainfall during this 24 hour period. Here you can notice the rain has made it to New England, but also note the heaviest remains west of the coastline. This is just one model, but does indicate a potential outcome.
Earlier this week I thought much of Saturday would be showery. Latest indications are for the bulk of the rain to push off the coastline during the morning meaning we very well could salvage the second half of the day and if Sunday remains mostly shower-free, itís not going to end up being a bad weekend.
This map shows predicted radar for 8AM Saturday. Notice how the main thrust of the rain is just pushing through Boston, but there isnít much if any shower activity to the west of the area. Presently, only morning activities would be affected by rain if this current trend holds.
One the front bringing the rain moves east there will still be some unstable air around the region. This type of pattern brings a chance of afternoon showers and storms, but doesnít create a situation with day long rains. The start of next week will likely see the best and driest weather in the morning with pop-up showers during the afternoon before clearing returns late in the day. Temperatures will be seasonably cool for Sunday and Monday with highs in the 60s.
Iíll be updating the forecast @growingwisdom on Twitter.