Good morning from Southern Connecticut Weather.
First, the good news. This is the first time in months we've had a dry Saturday! The first full day of summer is looking pretty good, but temperatures are already rocketing up. Some spots may get close to hitting 90 and starting the heat wave early. Today may be an early test of which guidance to lean on in the coming days.
Now for the bad news. This discussion is not about today, it's about what's coming. You know that here at SCW, we do not sound the alarm unless necessary.
Today's that day. We've been tracking for a week the potential of an expansive and intense ridge of high pressure to build over the eastern half of the country and bring our first heat wave of the year. We get heat waves virtually every year, but this one is different.
Questions even as recent as early yesterday revolved around whether the orientation of the ridge and heights up in Canada would take some of the edge off the heat potential, sparing us a direct hit of warmth that is coming directly from the Desert Southwest. It looks increasingly likely that we're not just in for a standard heat wave, but that we're going to come close to maximizing the potential of the heat, putting June 2025 in rarified air.
The National Weather Service has done a great job thus far of hoisting Extreme Heat Watches yesterday that have been converted into Extreme Heat Warnings for most of the state today. These headlines replace the old excessive heat watches/warnings but have the same meaning. The warnings take effect Sunday and last through Tuesday.
They're up for good reason--the coming heat looks legitimately dangerous.
First, the good news. This is the first time in months we've had a dry Saturday! The first full day of summer is looking pretty good, but temperatures are already rocketing up. Some spots may get close to hitting 90 and starting the heat wave early. Today may be an early test of which guidance to lean on in the coming days.
Now for the bad news. This discussion is not about today, it's about what's coming. You know that here at SCW, we do not sound the alarm unless necessary.
Today's that day. We've been tracking for a week the potential of an expansive and intense ridge of high pressure to build over the eastern half of the country and bring our first heat wave of the year. We get heat waves virtually every year, but this one is different.
Questions even as recent as early yesterday revolved around whether the orientation of the ridge and heights up in Canada would take some of the edge off the heat potential, sparing us a direct hit of warmth that is coming directly from the Desert Southwest. It looks increasingly likely that we're not just in for a standard heat wave, but that we're going to come close to maximizing the potential of the heat, putting June 2025 in rarified air.
The National Weather Service has done a great job thus far of hoisting Extreme Heat Watches yesterday that have been converted into Extreme Heat Warnings for most of the state today. These headlines replace the old excessive heat watches/warnings but have the same meaning. The warnings take effect Sunday and last through Tuesday.
They're up for good reason--the coming heat looks legitimately dangerous.
Above: The European model projections of the heat index across the region Monday afternoon. Heat indices are expected to land between 105-110 on Monday and Tuesday.
Below: The latest advisories, watches, and warnings from the NWS.
Below: The latest advisories, watches, and warnings from the NWS.
The Setup
Everyone paying attention should know it by now. A big ridge of high pressure is just in the right spot to funnel exceptionally warm temperatures aloft and at the surface. If you recall, we faced a near identical situation last June, where a similar kind of ridge made its way to the eastern part of the country. Last year we did not hit 100--illustrating just how hard it is to do any given year, let alone June--but BDL had five consecutive days over 90 degrees and four consecutive days of 95 degrees or higher. Last year's ridge didn't quite orient itself in the "optimal" position to give our region the temperatures aloft to hit 100.
This year looks different, as we should see a more direct flow of 850mb temperatures necessary for upper 90s temperatures at least Sunday-Tuesday, with more heat possible on the edges of the heat wave today (by hitting 90) and on Wednesday (where some spots could reach the low to mid 90s as the ridge breaks down).
Here is the GFS, showing the massive ridge at 500mb develop and intensify over us. This ridge is about as strong as last June--which challenges records for June.
Everyone paying attention should know it by now. A big ridge of high pressure is just in the right spot to funnel exceptionally warm temperatures aloft and at the surface. If you recall, we faced a near identical situation last June, where a similar kind of ridge made its way to the eastern part of the country. Last year we did not hit 100--illustrating just how hard it is to do any given year, let alone June--but BDL had five consecutive days over 90 degrees and four consecutive days of 95 degrees or higher. Last year's ridge didn't quite orient itself in the "optimal" position to give our region the temperatures aloft to hit 100.
This year looks different, as we should see a more direct flow of 850mb temperatures necessary for upper 90s temperatures at least Sunday-Tuesday, with more heat possible on the edges of the heat wave today (by hitting 90) and on Wednesday (where some spots could reach the low to mid 90s as the ridge breaks down).
Here is the GFS, showing the massive ridge at 500mb develop and intensify over us. This ridge is about as strong as last June--which challenges records for June.
This tells us a lot, but you have to look down a little lower to see why we think this heat could be dangerous. We see multiple days on the European model image below of high 850mb temperatures being advected into the region from the Desert Southwest. Now, just like Arctic cold in winter, these temperatures moderate as they travel over the vast expanse of the Earth, but it looks hot enough to give us multiple shots at 100 degrees inland with both Monday and Tuesday. The large whiteout you see is because of the Rocky Mountains.
Dangerous Heat & Humidity
I don't use the term "dangerous" often, but for those wondering whether this is hype, I don't believe so. This does not have the look or feel of a typical summer heat wave. Not even close.
First, the time of year is highly anomalous. Looking back at climate records, Connecticut has seen temperatures reach 100 degrees in June just twice--with the last time being June 30, 1964. We do not get this kind of heat this early, with the overwhelming bulk of our 100 degree days happening in July--the climatological peak of summer heat in Connecticut.
Even more than last year, this matters because if it's already been a hot July and we tack on a 98 or 100 degree day our bodies are acclimated to it. We just had an extended pattern of cool and wet, rinse and repeat, for months. Going from a cooler regime to near record heat and high humidity for an extended period of time can be a shock to the body.
Using the CT Central Climate Division data going back to 1893 (further than the Hartford area records which start in 1905) you can see that the overwhelming number of our 100 degree days are in July, with few in August and September and virtually none in June.
I don't use the term "dangerous" often, but for those wondering whether this is hype, I don't believe so. This does not have the look or feel of a typical summer heat wave. Not even close.
First, the time of year is highly anomalous. Looking back at climate records, Connecticut has seen temperatures reach 100 degrees in June just twice--with the last time being June 30, 1964. We do not get this kind of heat this early, with the overwhelming bulk of our 100 degree days happening in July--the climatological peak of summer heat in Connecticut.
Even more than last year, this matters because if it's already been a hot July and we tack on a 98 or 100 degree day our bodies are acclimated to it. We just had an extended pattern of cool and wet, rinse and repeat, for months. Going from a cooler regime to near record heat and high humidity for an extended period of time can be a shock to the body.
Using the CT Central Climate Division data going back to 1893 (further than the Hartford area records which start in 1905) you can see that the overwhelming number of our 100 degree days are in July, with few in August and September and virtually none in June.
Second, the duration and intensity of the heat is likely to be very rare. To be clear, we can get hot as early as April. The number of 95 degree days, while uncommon, can and certainly do happen this time of year.
But the occurrences become more rare with every degree warmer we get, and the current forecast for Hartford (city) and BDL is for highs greater than 97 degrees Sunday-Tuesday, with temperatures at 100 on Monday and Tuesday.
Even if we failed to hit 100 degrees, having three consecutive days with highs 97 degrees or greater would place this June heat wave in the top 10 of most intense heat waves by temperature.
Even if we failed to hit 100 degrees, having three consecutive days with highs 97 degrees or greater would place this June heat wave in the top 10 of most intense heat waves by temperature.
If the forecast is perfect and we do in fact see two consecutive 100 degree days on Monday and Tuesday, then we're really talking about a generational heat event. The last time BDL had consecutive 100 degree days was 2010, and it has happened 3 times since 1905.
Because Connecticut isn't a desert, this kind of heat can't be achieved without very warm nights and high humidity. In fact, low temperatures the next few nights may be in the mid to upper 70s--not too far off from what our usual high temperature is this time of year.
Impact
The impacts of heat compound on the body, so whether we hit 100 inland and 98 on the shoreline, or 97 inland and 95 at the shoreline, the actual number is little more than an academic exercise because heat indices are likely to be in the 100-110 range each day. In fact, the lower the air temperature is, the more likely that the dew point is oppressive because it will mean we haven't efficiently mixed the air.
Which leads to another important point here. The official stations are at airports. Their dew points will almost certainly be lower than the ones where people live because unlike airport tarmacs, we live in areas with trees and gardens and lawns. Those hold and release moisture.
This is a time where you don't necessarily discount the higher dew points on your weather stations. I can see official stations hitting 105+ heat indices easily on Monday/Tuesday and personal stations surpassing 110.
With that in mind, prepare now. Make sure your AC is functioning (or in my case, installed haha), that you have a plan to check on friends/neighbors/family, and that you cover the paws of your pets if they are outside. Be extra careful in checking to make sure you don't leave kids or pets in the car, and know the signs of heat exhaustion and heat stroke.
Cooling centers will be available across the state. If your or someone you know needs a place to get out of the heat you can find your closest cooling center by dialing 2-1-1 or viewing a list online at 211ct.org.
The impacts of heat compound on the body, so whether we hit 100 inland and 98 on the shoreline, or 97 inland and 95 at the shoreline, the actual number is little more than an academic exercise because heat indices are likely to be in the 100-110 range each day. In fact, the lower the air temperature is, the more likely that the dew point is oppressive because it will mean we haven't efficiently mixed the air.
Which leads to another important point here. The official stations are at airports. Their dew points will almost certainly be lower than the ones where people live because unlike airport tarmacs, we live in areas with trees and gardens and lawns. Those hold and release moisture.
This is a time where you don't necessarily discount the higher dew points on your weather stations. I can see official stations hitting 105+ heat indices easily on Monday/Tuesday and personal stations surpassing 110.
With that in mind, prepare now. Make sure your AC is functioning (or in my case, installed haha), that you have a plan to check on friends/neighbors/family, and that you cover the paws of your pets if they are outside. Be extra careful in checking to make sure you don't leave kids or pets in the car, and know the signs of heat exhaustion and heat stroke.
Cooling centers will be available across the state. If your or someone you know needs a place to get out of the heat you can find your closest cooling center by dialing 2-1-1 or viewing a list online at 211ct.org.
Forecast
There's not as much to say here, but there are things we're still looking at for the Sunday-Tuesday timeframe.
For tomorrow, we're going to be watching to see if cloud debris from a complex of thunderstorms limits high temperatures. It looks unlikely that storms make it here Sunday morning, but we're watching closely. It's a legitimate wildcard as the thunderstorm complex is currently out in the Midwest.
This is one of those rare times where we can forecast a broad 95-100 each day. The shoreline is unlikely to hit 100, but mid to upper 90s look likely Sunday-Tuesday. That's rare in its own right, so the shoreline (outside of far SE CT maybe) is not going to be spared here and if anything the humidity may be worse at the coast.
Inland the question is whether we hit 100 on any of the days. Tomorrow 100 looks unlikely, but very possible on Monday and Tuesday. Nuances make the difference on whether we hit 100. Cloud cover, pop up showers/storms (which appear unlikely) and even the launch pad for temperatures in the morning or how much mixing happens will make the difference.
Overall, a high end heat wave is coming and it may end up being one of the most intense in our record books. Stay hydrated and do not downplay this one. This is legitimately dangerous heat for our region.
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
There's not as much to say here, but there are things we're still looking at for the Sunday-Tuesday timeframe.
For tomorrow, we're going to be watching to see if cloud debris from a complex of thunderstorms limits high temperatures. It looks unlikely that storms make it here Sunday morning, but we're watching closely. It's a legitimate wildcard as the thunderstorm complex is currently out in the Midwest.
This is one of those rare times where we can forecast a broad 95-100 each day. The shoreline is unlikely to hit 100, but mid to upper 90s look likely Sunday-Tuesday. That's rare in its own right, so the shoreline (outside of far SE CT maybe) is not going to be spared here and if anything the humidity may be worse at the coast.
Inland the question is whether we hit 100 on any of the days. Tomorrow 100 looks unlikely, but very possible on Monday and Tuesday. Nuances make the difference on whether we hit 100. Cloud cover, pop up showers/storms (which appear unlikely) and even the launch pad for temperatures in the morning or how much mixing happens will make the difference.
Overall, a high end heat wave is coming and it may end up being one of the most intense in our record books. Stay hydrated and do not downplay this one. This is legitimately dangerous heat for our region.
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
