The hot weather returns to Pittsburgh on Friday and lasts through the weekend
PITTSBURGH (KDKA) - The heat is back today and I have highs near 90. I am keeping Pittsburgh's high at 89 degrees with plenty of sunshine.
Our airmass isn't exactly the hottest with 850mb temps just at 16°C. In fact this would be the "coolest" 90° days in regards to our 850mb temps if we hit it. Most model data has pulled back highs to the upper 80s, and that's where I have been all week long. The National Blend of Models has Pittsburgh's high at 88°. The high-resolution HRRR model has us at 90 for the high today. I had Pittsburgh hitting 89° for the past two days and I had our high today at 88° on Monday and Tuesday. I am going to keep us at 89° for the daily high.
The heat settles in for the weekend and early next week. I have us in the low 90s for highs on both Saturday and Sunday. Our next rain chance comes on Sunday but tracking and timing of the system that is located near Winnipeg, Canada is uncertain at this time.
Most model data shows us seeing scattered fast-moving storms from this system which would give us a storm chance. We are currently not on the Storm Prediction Center's severe risk but I expect this will change.
Monday has a solid shot of being the hottest day of the year so far.
It may also end up being the hottest day of the year. I have us hitting 96° for the high. This is the perfect time to mention new data that was released earlier this week that details the impact of "heat islands."
The heat island effect occurs due to cities being a collection of things that absorb and then radiate heat. In scientific terms, we talk about these things as having 'low albedo'. A great way to think about this is when it snows. Fresh snow reflects lots of sunlight back off the surface. It's bright outside due to light energy being reflected. Suppose you wait two days though dirt has mixed with the snow lowering the albedo.
The sunlight is still the same but it is being absorbed.
Urban areas have more things that absorb sunlight compared to rural areas. As urban areas collect and then eventually release this heat, it causes temperatures in these 'micro-climates' to soar. The data out this week attempts to put a number on the difference with some parts of Pittsburgh seeing high temperatures upwards of 9 degrees hotter than what you can expect at the Pittsburgh airport. That means on sunny days if I am forecasting a high of 90 degrees in Pittsburgh, some parts of the city will approach 99 degrees for their actual high. According to the data, up to 50 thousand people in Pittsburgh would be impacted at the highest level and could see a difference of more than 9° on some of the hottest days.
You can check out the map here. If you're wondering what goes into the data that determines where the hottest weather in the city may occur, there are three things they look at.
- Density of buildings along with the height of buildings
- Concrete versus greenery
- How many people live in an area
Looking over the data the places most likely to be the hottest in the city weren't a surprise to me.
Stay up to date with the KDKA Mobile App – which you can download here!
