Category Archives: Weather Outlook


A chance of showers on Saturday has been advertised, and the GFS FV3GFS are somewhat pessimistic for Saturday’s weather.

However, I think the global models may be over-predicting showers and rain.

The NAM has been quite conservative regarding showers for Saturday and based on that model, I think just cloudy conditions for Saturday and  mostly cloudy on Sunday is the most likely scenario.    Certainly, a widely scattered shower is possible, but much of the day may be rain-free.

Thurs 10:30 pm update:  Tonight’s NAM shows a lot more showers during the day Saturday than previous NAM model runs.  So Saturday may be as unsettled and wet as forecast by the GFS.  Stay tuned 

An easterly wind will be responsible for the cloudiness.   I’ll update Friday evening.


Fri Morning Update: The latest models have shifted the showers to late Saturday and most of Sunday into Sunday night.  So Saturday is looking like a better day, especially from PHL and northward. I’ll do an updated weekend forecast Friday evening.

The weather for this weekend is again looking unsettled.  There are huge differences between the NAM and GFS models for Saturday with the NAM being much wetter than the GFS.

Basically, there are timing differences with the disturbances that are expected to move along a frontal boundary. The position of the front is also in question.

Perhaps there’s insight in the fact that the new GFS model under development (referred to as the GFS FV3- “Finite Volume Cubed Sphere” ) has a similar forecast for Saturday as the NAM.  By the way, I’ve been looking at the GFS FV3 more and more.

That would mean that Saturday would be the wettest and Sunday would be dry.  Too soon to be sure.

As for the cool weather so far this season, it’s not been a surprise— the nadir in the solar cycle is known for cool weather.  The secondary effects of a solar cycle nadir results in  a lower solar wind  causing more cloudiness.


This weekend’s weather is shaping up to be somewhat similar to last weekend’s Sunday-Monday forecast.  Less than perfect weather for the start of June.

Low presssure developing near the Delmarva coast along with the moisture remnants of Tropical Storm Alberto will bring rainy conditions for much of Saturday. It will be warm and humid, with high temperatures in the low 80s.  There may be some sun mid-day.

Sunday afternoon
Fri PM updated outlook for Sunday afternoon

Like last weekend, high pressure will nose down from the northeast on Sunday suppressing rain to our south.  An easterly flow will bring cool, mostly cloudy and damp conditions but much of the day Sunday will be rain-free. High temperatures 68.

Friday 11PM Update: Tonight’s NAM shows showers returning late morning on Sunday; Sunday doesn’t look dry as previously forecast .

There’s the chance of showers returning Sunday evening.


GFS forecast for Saturday evening
GFS forecast Saturday evening

The outlook for this weekend’s weather is looking remarkably similar to last weekend’s weather.  (Not a good thing!)

Like last weekend, high pressure nosing in from the northeast will result in an easterly wind flow that will keep things damp and cool. Moisture from the remnants of Alberto transported into the Midwest will also be pulled in.  Weak low pressure is also expected to develop near the Delmarva and remain blocked from moving away, also resulting in low clouds and showers/thunderstorms.

Like last weekend, there are differences between the GFS and NAM with the GFS having heavy rain on Sunday, but the NAM not so much.  I think the NAM did best last weekend.

So there’s uncertainty about how much rain and when.   Right now Saturday looks like the wettest day, based on the NAM.  Sunday may turn out drier.