I’ve been talking all week about the great September weather through the weekend. We still have a mostly great week, but tomorrow is now looking wet for some of us. Earlier this week it appeared a storm system off the east coast would stay far enough east to only bring some clouds to the Cape and Islands. Now, it look as if the storm will come close enough to bring rain and even some high surf to those areas and the rain shield could penetrate as far north as Boston, west to Worcester.
North of the Massachusetts turnpike there will be clouds, but there is a chance the rain won’t make it that far north. I’ll be updating the extent of the rain here and on Twitter @growingwisdom
The amount of rain will range from close to an inch along extreme south coast to a trace in northern areas. It looks like there will be a very sharp cut-off to the rain line much like a sharp distinction between accumulating snow and no snow in the winter.
Actually many of the forecast challenges with this storm are similar to winter. How close to the coast will the storm come, how long with the precipitation last and what is the strength of the storm. In early fall we don’t have the extremes of temperature winter storms have to work with, therefore these September nor’easters can be a bit fickle.
With the clouds and rain tomorrow it’s going to be cool. Highs will range from 61-66, coolest where it rains the most.
Tomorrow evening the radars will show the rain pivoting south and heading out to sea. The rain will be slowest to leave the outer portions of Cape Cod, while it may have ended in Worcester not too long after sunset. Areas of west and south of Boston which need rain will be right on the edge of getting significant water and I’ll have much more tomorrow morning.
Friday brings clearing with sunshine returning. If it’s cloudy in the morning south of Boston it will become sunny by the afternoon and temperatures will be much warmer than the previous day. Highs Friday reach back towards 70F or a bit higher if we see the sun early. This sets up the glorious weekend of weather with highs around 80F and abundant sunshine. It will be in the lower 70s along parts of Cape Cod, but the rest of the region can expect a weekend return to summer, albeit a temporary one.