August Outlook: New England
Sunday, July 31, 2022
August appears to be another month of above normal temperatures for New England as persistent ridging remains dominant over the central US. Below is the NMME forecast which is an ensemble model generated from a multitude of other ensembles. It is highly regarded because on average it generally verifies better than single ensemble runs. While confidence in any monthly forecast drops mid-month, there doesn't appear to be anything that would indicate below normal temperatures from a synoptic standpoint.
August appears to be another month of above normal temperatures for New England as persistent ridging remains dominant over the central US. Below is the NMME forecast which is an ensemble model generated from a multitude of other ensembles. It is highly regarded because on average it generally verifies better than single ensemble runs. While confidence in any monthly forecast drops mid-month, there doesn't appear to be anything that would indicate below normal temperatures from a synoptic standpoint.
As far as precipitation is concerned, I am anticipating another month of below normal which isn't good for the ongoing drought conditions which is currently moderate to severe. The synoptic pattern that will likely continue isn't favorable for normal to above normal precipitation. In addition, the ongoing lack of soil moisture exacerbates drought conditions because there is no moisture to evaporate so everything just runs hotter and drier. That's not to say we won't get any frontal systems move through but it won't be enough to erase the drought, nor do I think it will be enough to reach average levels for the month.
One external factor that will need to be monitored are the tropics. It has been a very quiet season thus far but climatologically, the Atlantic Basin begins picking up right around now and that is what is being hinted at by ensembles. Below is the EPS 200-hPa Velocity Potential Anomaly plot showing some signs of life in the Atlantic Basin mid-month, likely in the form of convectively coupled Kelvin waves (CCKW) which help generate tropical disturbances. Currently, the lack of tropical waves combined with dry air and strong wind shear over the Atlantic Basin have made it difficult to get anything going but it appears this will change.
The MJO is forecast to remain quiet/weak for at least the next couple of weeks so this shouldn't be much of a factor in stirring up any tropical trouble in the near-term but it still bears watching. We can still get tropical activity without an active/strong MJO. So what does any of this mean for New England? While the chances a tropical system makes it up to New England are climatologically low, these systems can garner enough strength to alter the broad-scale pattern if they move over the right place at the right time. In other words, if a storm were to develop and eventually make it to the US and move inland, it could disrupt the synoptic pattern in such a way that could result in cooler temperatures/wetter conditions for New England for a brief period of time. Chances of this happening are also pretty low, but something else to consider when forecasting beyond two weeks.
VERIFICATION
As expected, New England, especially southern New England, finished the month warmer than normal. Persistent ridging paved the way for another month of above normal temperatures. Precipitation continues to be below normal in large part to the aforementioned synoptic pattern however, Maine had a very productive month, with many locations reporting between 3-6" of monthly rainfall. With the continued lack of rainfall, drought conditions across southern New England continue to worsen. The tropics remained quiet for most of the month despite what models were showing earlier in the month. This is due to continued Saharan dust, dry air and non-conducive synoptic conditions (mainly due to TUTTs).
As expected, New England, especially southern New England, finished the month warmer than normal. Persistent ridging paved the way for another month of above normal temperatures. Precipitation continues to be below normal in large part to the aforementioned synoptic pattern however, Maine had a very productive month, with many locations reporting between 3-6" of monthly rainfall. With the continued lack of rainfall, drought conditions across southern New England continue to worsen. The tropics remained quiet for most of the month despite what models were showing earlier in the month. This is due to continued Saharan dust, dry air and non-conducive synoptic conditions (mainly due to TUTTs).