Good evening from Southern Connecticut Weather. 

This is just a brief discussion covering what is already turning into an exceptional heat wave. Sunday we had the curveball of morning clouds and convection, but that did not stop most stations from reaching the low 90s. Today we saw truly exceptional heat by way of air temperatures and humidity producing truly high end heat indices over most of the day and even into tonight. Tomorrow will feature even higher air temperatures, and some guidance is showing a legitimate chance to tie or break all time high temperatures. 

Above: RTMA analysis of heat indices in the eastern part of the country during the peak of the heat/humidity earlier today. While some official stations reached intra-hour heat indices of up to 115 degrees--truly exceptional--it was the communities that bore the brunt of the heat, with some places showing heat indices over 120 degrees. Heat indices reaching over 100 reached deep into Canada today, speaking to the immense geographic scope of the ridge responsible for this heat. 

Day Two--Big Heat. Bigger Humidity 
Today was high end in every sense of the term. New Haven first recorded a heat index of 100 at 8:15am. With records going back to 1948, this likely smashed the earliest New Haven has seen a heat index that high that early. 

It doesn't stop there. Using ASOS data from around the state: 

• Bridgeport (BDR) recorded a daily record air temperature and more impressively, tied the sixth highest heat index with records going back to the 1940s. 
• New Haven (HVN) tied for sixth highest heat index with records going back to the 1940s. Interestingly, the record came last year.
• Meriden (MMK), which goes back to 1975, recorded its second highest heat index ever, with the record being set in 2000. 
• Bradley Airport (BDL), with records going back to the 1940s, tied its 7th highest heat index. 
• Hartford (city HFD) tied for 3rd all time with records going back to the 1940s. Note that it had an intra-hour maximum of 115 degrees, which would have put it second all time. 

The more moisture in the air, the harder it is to warm the surface. That's what makes today so impressive, we had high temperatures in the mid to upper 90s in most spots (especially inland) and still had heat indices between 105-115 at official stations. That means that dew points were in the upper 70s to low 80s and it didn't matter for insulating the surface. 

In areas that saw dew points fall due to more mixing in the atmosphere, we saw temperatures reach 100. Plattsburgh, NY saw its warmest temperature in 50 years today, and both Hartford and BDL reached 98 late as mixing allowed for more late day heat. 

Tonight will be hot and humid--setting the stage for the peak tomorrow. 

Day Three--Historic Heat on the Table
Tomorrow we have two significant changes that should take place. First, the wind direction will be more westerly, which should block the sea breeze that has protected the shoreline from high end air temperatures. The second is that the ridge peaks and brings in the warmest temperatures yet aloft. Some guidance is seeing the potential for historic heat. 

Above: the NOAA Model Blend, which takes the best of our guidance and produces a forecast. Temperatures are expected to top 100 tomorrow across most of CT with the blend. 

But using the blend only gets you so far. Given the impressive heating today, a wind shift tomorrow, and the highest end 850mb and 925mb temperatures we get in the region, the forecast if it verifies would tie all time records from 2011 at HFD and BDL. 

Above: the NWS expects highs above 100 in parts of the state tomorrow. Daily records and all time June records are in jeopardy, and all time heat records could be tied or broken tomorrow. This is truly extraordinary, made even more so by the fact that it's happening in June. 

The "saving grace" is that with more mixing, we get rid of some of these dew points. We'll see how much we mix out tomorrow but it won't be too much of a reprieve, if any. Expect heat indices between 100-110 once again at the official sites, and higher elsewhere. 

The impact of heat compounds on the body. Take it easy tomorrow and stay hydrated. 

A​s 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.
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Thank you for reading SCW. 

​-DB

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. 

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. 

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. 

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. 

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. 

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.

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.

​A​s 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.
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Thank you for reading SCW. 

​-DB

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. 

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. 

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. 

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

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. 

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). 

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. 
​
A​s 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

Good morning from Southern Connecticut Weather! 

I actually wrote this late last night, but it was too late to post. 

After another wet Saturday, we hope everyone had a happy Father's Day! In keeping with the incredibly persistent pattern, our wet Saturday was replaced with a decent Sunday. At the midpoint of the month, a consistent summer pattern is yet to reveal itself. At BDL (Hartford) temperatures are right around normal, with a +0.4 degree departure. At Bridgeport, its dead on for normal with a 0.0 degree departure! 

Half the days have been below normal. We've had plenty of cloudy days, but we actually haven't had much rain. Both stations are below normal to date with June rainfall. At BDL, there has only been one clear day this month officially. 

After some hints, we finally have some real indications that the pattern is changing toward a real summer pattern. We're in transition this week, and while it's still too far ahead the following week could bring even more significant heat. For now though, let's look at the week ahead. 

Above: the 12z European Ensemble (EPS) showing the 500mb pattern through the week. Note how the latter part of the week brings a ridge over the eastern part of the country. This will usher in our summer pattern. 

Monday-Tuesday
The start of the week is unsettled but far from a washout, as a decaying high pressure system loosens its grip on our region. Monday doesn't look too bad and should be mostly dry. I'm not expecting anything more than isolated to scattered showers at worst. Temperatures will rise a bit compared to Sunday, but highs will still remain cooler than normal. This time of year the average high is 80 at Hartford and 78 at Bridgeport, with average temperatures rising steadily as we move into astronomical summer. 

Tuesday will bring more clouds and a greater chance of showers. Once again, I'm not expecting a washout, but scattered to widespread showers are possible, especially later in the day and evening. With mostly cloudy conditions, high temperatures also remain below normal. 

Wednesday-Friday
Temperatures jump on Wednesday as ridging begins to build in. Wednesday will bring a chance of pop up showers and thunderstorms, but unlike early week, we should look at these like standard summer fare. It will feel like summer, with a flip to more humidity as well. 

Thursday looks like them most active day of the week. There is a good signal for heat as the ridge continues to build, and the day is looking hazy, hot, and humid with inland temperatures in the upper 80s to low 90s. In addition, we will see a weak cold front move into the region. This will trigger the potential for thunderstorms, some of which could be strong to severe. It doesn't encompass our region, but the SPC has 15% odds of severe weather in the Mid-Atlantic at this range, which is very unusual. This is something we'll be watching closely. 

In the wake of the front on Thursday, temperatures and humidity should come down some on Friday. Because this is a weak front in a broader pattern of ridging, it looks like there won't be troughing nosing into CT as we head into the weekend...

Above: the 18z Euro showing chances of showers and storms Wednesday and Thursday. Note how Thursday keeps the strongest storms to our south. That is something we will be watching closely. 

Saturday-Sunday
Finally, we head into a Saturday without me putting significant rain chances attached to the forecast! Our gradual pattern change opens the door for ridging to continue to dominate. This would mean that we finally have a dry weekend. We still need to watch for a chance of the usual summertime pop ups, but for now, I feel good about the weekend with temperatures that are lower than Thursday, but still in the low to mid 80s--good stuff for this time of year. Summer is likely to start on time this year. 

The Dailies
Monday: Partly cloudy with a chance of isolated showers. Highs in the low to mid 70s. Chance of rain 20%. 

Tuesday: Mostly cloudy with showers. Highs in the low to mid 70s. Chance of rain 50%. 

Wednesday: Partly cloudy with more warmth and humidity. Highs in the low to mid 80s. Chance of rain 20%. 

Thursday: Hazy, hot, and humid with a chance of thunderstorms. Some storms could be strong to severe. Highs in the upper 80s to low 90s. Chance of storms 40%. 

Friday: Mostly sunny. Highs in the low to mid 80s.

Saturday: Mostly sunny. Highs in the low to mid 80s.

Sunday: Partly sunny with a chance of showers. Highs in the low to mid 80s. Chance of showers 30%.  

A​s 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.
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Thank you for reading SCW. 

​-DB

Good evening from Southern Connecticut Weather! 

June 1 is a big day in the weather world. It heralds the start of meteorological summer, which runs until the end of August, marks the first day of the Atlantic hurricane season, which is expected to be another active one, and also signals a climatological shift toward more active weather as our pattern usually begins to evolve toward a more summery disposition. 

Our May was a gloomy one, with an abundance of cloud cover and a barrage of wet weekend systems. At the official Hartford station (BDL) temperatures finished right around normal, but we had our 3rd wettest May on record. At Bridgeport, looking back at meteorological spring, 44 out of 90 days had at least light rain. 

On cue, our rinse, dry, and repeat pattern is cycling right back to dry. Although tonight we have some lingering showers, the next few days look predominantly sunny and dry. This time however, we will have a ridge of high pressure building in that will take our temperatures up and give us a taste of summer. Our first 90 degree day is on the table later in the week. That said, our wet pattern is not breaking yet. More rain is in the forecast for the upcoming weekend. Let's dive in.

Above: European Ensemble (EPS) depiction of the 500mb pattern in the week ahead. The week is dominated by a transient ridge that will introduce our first real summer heat of the season. 
​
Monday-Tuesday
Although Sunday was nice for most, we finally get rid of the showers and warm up some for Monday. We should have partly to mostly sunny skies, though there will likely be a haze as wildfire smoke from the west lingers over the region. Fortunately, models project the smoke to stay well above the surface and not significantly impact air quality Monday, and temperatures tomorrow should land in the upper 60s to low 70s. 

Tuesday looks like an even better day, with temperatures warming up to the upper 70s and low 80s with more sunshine as high pressure begins to nose in. 

Above: In the daylight images of the gif above you can see the expanse of wildfire smoke over the eastern U.S. creeping its way into the region. That impacted our sunset tonight and is likely to remain over or nearby the region at least through tomorrow, though I'm thinking the smoke is with us for much of the week ahead. The key is how low it gets to the ground. 

Wednesday-Friday
The peak of the warmup happens during this period of the week, as the ridge dominates our weather. Wednesday temperatures are likely to reach well into the 80s, with humidity rising but not looking too bad at this time. Inland areas as usual this time of year will be most likely to record the warmest temperatures. 

Thursday and Friday are the days when we have the greatest shot at widespread 90s, and will have higher humidity. Thursday could be the best chance of 90 of those two days, but I'm still a bit skeptical especially if smoke is around filtering some of the sunlight and we have thunderstorms. 

While Wednesday looks dry, we will start to see increasing shower and thunderstorm chances on Thursday and Friday--pretty typical of summer weather--which will increase as a boundary attempts to reach the region. Given the heat and humidity likely, we will need to pay attention to possible severe storms. 

Above: 18z Euro depicting shower and thunderstorm chances Thursday and Friday afternoon as a boundary tries to approach. This boundary will influence our weekend. 

Saturday-Sunday
Stop me if you've heard this before: rain chances this weekend. It has been an incredible unlucky stretch with our "rinse" portion of our pattern occurring on weekends, and it's looking like that stretch may continue in the weekend ahead. The aforementioned boundary may get hung up over the region, bringing the chance of rain showers and thunderstorms on Saturday and/or Sunday if the boundary doesn't clear. Nothing's set in stone yet, but it's something to watch. With both the GFS and Euro showing the boundary nearby, the odds of at least some precipitation on the weekend seem high. 

The Dailies
Monday: Partly to mostly sunny. Highs in the upper 60s to low 70s. 

Tuesday: Mostly sunny. Highs in the upper 70s to low 80s. 

Wednesday: Mostly sunny and warmer. Highs in the mid to upper 80s. Touch cooler at the shoreline. 

Thursday: Hazy, hot, and humid. Highs in the upper 80s to low 90s inland. Mid to upper 80s at the shoreline. Chance of thunderstorms 40%. 

Friday: Hazy, hot, and humid. Highs in the upper 80s to low 90s inland. Mid to upper 80s at the shoreline. Chance of thunderstorms 40%. 

Saturday: Mostly cloudy with a chance of showers and thunderstorms. Highs in the upper 70s to low 80s. Chance of storms 50%. 

Sunday: Mostly cloudy with a chance of showers and thunderstorms. Highs in the mid to upper 70s. Chance of showers 30%. 

A​s 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.
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Thank you for reading SCW. ​