Good evening from Southern Connecticut Weather!
Well, if you were waiting for the pattern to change, it has finally arrived. Our clouds and fog this morning gave way to a mix of clouds and sun, and more humidity. That humidity heralds what's coming. As I mentioned in the forecast earlier this week, we are moving into a "deep summer" pattern for the foreseeable future. Tomorrow kicks things off with highs that are expected to land in the upper 80s to low 90s, and with humidity factoring in, some spots could have heat indices top our near 100. Tomorrow brings heat advisories, air quality alerts, and a chance of severe thunderstorms. Let's take a closer look at tomorrow and the potential heat wave that's coming.
Well, if you were waiting for the pattern to change, it has finally arrived. Our clouds and fog this morning gave way to a mix of clouds and sun, and more humidity. That humidity heralds what's coming. As I mentioned in the forecast earlier this week, we are moving into a "deep summer" pattern for the foreseeable future. Tomorrow kicks things off with highs that are expected to land in the upper 80s to low 90s, and with humidity factoring in, some spots could have heat indices top our near 100. Tomorrow brings heat advisories, air quality alerts, and a chance of severe thunderstorms. Let's take a closer look at tomorrow and the potential heat wave that's coming.
Above: the Storm Prediction Center Day 2 (D2) outlook for the region. About two thirds of the state is under a slight risk, while SE CT has the least risk of seeing severe thunderstorms.
Thursday
Tomorrow is a multi-hazard kind of day. The first hazard is the heat. You don't need major heat to cause health issues. If you're outside tomorrow working or engaging in activity, make sure you are taking lots of breaks and staying hydrated. For our furry friends, make sure they have their paws protected if they're outside on concrete, and make sure you are checking on neighbors and family that may not have access to cooling.
Thursday
Tomorrow is a multi-hazard kind of day. The first hazard is the heat. You don't need major heat to cause health issues. If you're outside tomorrow working or engaging in activity, make sure you are taking lots of breaks and staying hydrated. For our furry friends, make sure they have their paws protected if they're outside on concrete, and make sure you are checking on neighbors and family that may not have access to cooling.
Above: NWS graphic on practicing heat safety.
Highs tomorrow will reach the upper 80s to low 90s, with the exception of the immediate coast wherever a southwest breeze is able to persist off the water. Humidity looks to be high to oppressive across the state regardless. With a hazy, hot, and humid day, air quality will also be less than ideal, leading to air quality alerts in parts of the state.
Severe Risk
Tomorrow also brings a risk of severe thunderstorms. We see these kind of days from time to time, where an approaching cold front (in this case it's not that cold) serves as a trigger in a hot and humid environment. In this case, it's a pre-frontal trough in advance that may serve as the trigger.
Highs tomorrow will reach the upper 80s to low 90s, with the exception of the immediate coast wherever a southwest breeze is able to persist off the water. Humidity looks to be high to oppressive across the state regardless. With a hazy, hot, and humid day, air quality will also be less than ideal, leading to air quality alerts in parts of the state.
Severe Risk
Tomorrow also brings a risk of severe thunderstorms. We see these kind of days from time to time, where an approaching cold front (in this case it's not that cold) serves as a trigger in a hot and humid environment. In this case, it's a pre-frontal trough in advance that may serve as the trigger.
Above: the 18z high resolution NAM that shows very little activity in the region at 6pm tomorrow.
Below: the 18z HRRR which shows a more robust period of storms but not until after approximately 7pm
Below: the 18z HRRR which shows a more robust period of storms but not until after approximately 7pm
The severe risk looks real tomorrow, but it is conditional. We need a strong enough trigger earlier in the day to break the cap and initiate convection. The models have been all over the place with how many, if any, storms we get, so we will just need to watch how tomorrow goes. Stay tuned. The best timing for any storm potential is between 2-10pm.
The Coming Heat Wave
Despite the heat on Thursday, that doesn't start the heat wave, which is defined as three consecutive days of 90 degree temperatures. The "cold" front tomorrow drops our heat and humidity down on Friday (only into the 80s for temperature), but we start warming right back up on Saturday and Sunday is modeled to be the start for most of inland CT with highs in the low 90s.
This is because of a big ridge that is expected to develop over the region, one that is a near lock to occur based on ensemble guidance.
The Coming Heat Wave
Despite the heat on Thursday, that doesn't start the heat wave, which is defined as three consecutive days of 90 degree temperatures. The "cold" front tomorrow drops our heat and humidity down on Friday (only into the 80s for temperature), but we start warming right back up on Saturday and Sunday is modeled to be the start for most of inland CT with highs in the low 90s.
This is because of a big ridge that is expected to develop over the region, one that is a near lock to occur based on ensemble guidance.
Above: the coming ridge on the EPS. Note that after Friday's reprieve we have the dominant ridge develop, and it is unusually strong for this time of year. The devil is in the details on how long the heat wave will last, and if we will get "Big heat" or a more run of the mill heat wave.
It should be noted that with this kind of ridge orientation, we can get "ridge runners", that is, storms that ride the periphery of the ridge and move into the region. Some of that is showing up for late Saturday night into early Sunday, and that's something to watch as it could bring severe weather. We're too far out to know much for sure, but it's worth noting.
The key in the week ahead is whether we have the model depictions reveal themselves to be accurate in the orientation and intensity of the ridge. If we have lower heights in Canada that can nudge back on the ridge, our heat wave could be broken up in two, or come in much less intense than the more doom-like forecasts you may have seen online. You would see that nudge back in the form of backdoor cold fronts that shunt the worst heat to our southwest.
However, if there is nothing to our north providing real resistance, we could have a longer duration heat wave that gives us multiple days with highs in the mid to upper 90s. That combined with the humidity would be good for heat advisories at the least. I have been less of a believer in a historic ridge and heat wave given our climatology in June, but a higher end heat wave is on the table next week.
I never like posting these, but they will give you a clearer view of what we're seeing on the ensemble guidance. Both images are for Hartford (city).
It should be noted that with this kind of ridge orientation, we can get "ridge runners", that is, storms that ride the periphery of the ridge and move into the region. Some of that is showing up for late Saturday night into early Sunday, and that's something to watch as it could bring severe weather. We're too far out to know much for sure, but it's worth noting.
The key in the week ahead is whether we have the model depictions reveal themselves to be accurate in the orientation and intensity of the ridge. If we have lower heights in Canada that can nudge back on the ridge, our heat wave could be broken up in two, or come in much less intense than the more doom-like forecasts you may have seen online. You would see that nudge back in the form of backdoor cold fronts that shunt the worst heat to our southwest.
However, if there is nothing to our north providing real resistance, we could have a longer duration heat wave that gives us multiple days with highs in the mid to upper 90s. That combined with the humidity would be good for heat advisories at the least. I have been less of a believer in a historic ridge and heat wave given our climatology in June, but a higher end heat wave is on the table next week.
I never like posting these, but they will give you a clearer view of what we're seeing on the ensemble guidance. Both images are for Hartford (city).
Above: to make it readable, here are the latest ensemble projections for temperatures. These will change, but this gives you a sense of the strength of the heat signal.
Stay tuned.
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Thank you for reading SCW.
-DB
Stay tuned.
As always, please like, share, and interact with us on our social media--on Facebook to share our discussions, and follow us on Twitter @southernctwx to retweet our posts. Hit the buttons below to join.
Thank you for reading SCW.
-DB
