Memorial Weekend Heat Wave

[SpartyOn]

I was not paying attention to the weather conditions much as I wasnt around the computer, only saw the final high temps, so I do believe you about the lake breeze. And trust me, when I say something about DTW vs DET/rest of SE MI, it has to do with the suspicious nature of how DTW is always warmer than everyone (including a wunderground weather station located in Romulus RIGHT by the airport), not being suspect of DET being too low. DTW has been racking up plenty of stat-padding degrees in an already above-avg temperature regime the last many months, though as said with several others 95s yesterday, I wouldnt consider yesterday one of those stat-padding days.

I've always been under the impression that DTW gets a little downsloping.

[michsnowfreak]

I've always been under the impression that DTW gets a little downsloping.

I never really thought of that. I suppose its possible. As said above, check out the asos readings for Ypsilanti during a warm afternoon (any time of year) or Ann Arbor during a cool night (again, any time of year) and the readings are so funky its crazy. Whats weird is the two are so close yet they routinely will have the warmest (YIP) and coldest (ARB) readings in SE MI on many days.

[Stebo]

I never really thought of that. I suppose its possible. As said above, check out the asos readings for Ypsilanti during a warm afternoon (any time of year) or Ann Arbor during a cool night (again, any time of year) and the readings are so funky its crazy. Whats weird is the two are so close yet they routinely will have the warmest (YIP) and coldest (ARB) readings in SE MI on many days.

There is downsloping from the West with respect to the Irish Hills, which is why YIP/DTW tend to be warmer than most, also due to the fact that there is a lot of concrete out here and at Willow Run this adds to the warmth. ARB tends to be colder at night due to the Huron River Valley with cold air settling into the valley.

[Powerball]

I've always ben under the impression that DTW gets a little downsloping.

Yes. If you look on Google Maps, the area just to the SW of Metro Airport and Willow Run is slightly higher in elevation.

The tarmac helps too.

Ann Arbor is also slightly higher in elevation, about 200 feet, which likely explains the slightly cooler lows than other locales.

[Trent]

One thing to remember with any reporting site is that it is subject to extreme local conditions, that can vary within 1/4 mile.

ARB always has notoriously overnight lows. This is because the airport sits in a tiny little bowl. The elevation is higher on all four sides so any clear nights allow for radiational cooling to take place and allow the colder denser air to sink down to that spot. Check out any of the coop observers within a couple miles and you will not find similar temps. So the overnight lows for that spot are indicative of that spot, not necessarily the city/county they represent.

Same can be said for DTW, the temps at DTW are indicative of the temperature at that spot. It's a flat huge expanse of airport. You have no natural water features on the premises, virtually no trees, a mish mash of concrete runways, expanses of mostly dead grasses, parking garages, hangars, and so forth. The temperatures for that spot are indicative of that spot, not necessarily the city/county/region that they represent.

Temperatures are going to vary based on where one is precisely located. Case in point, stand in a sunny field, then walk a few yards to the tree line and stand in the woods. Which is warmer, which is cooler? Chances are there's going to be a degree or two difference in a matter of 50 yards.

Pretty much any temperature has to be taken with a bit of local knowledge and understanding that not all thermometers are calibrated equally. Just because Jimmy McLightning bolt puts up a personal weather station online, doesn't mean it's at the right spot above ground, far enough from buildings, etc, etc. A temperature taken at 2 feet above ground versus 6 feet can cause a degree or two of error.

Not saying that either ARB, YIP, or DTW are accurate or inaccurate. We all know their micro climates and they have been consistent, they are what they are.

[michsnowfreak]

There is downsloping from the West with respect to the Irish Hills, which is why YIP/DTW tend to be warmer than most, also due to the fact that there is a lot of concrete out here and at Willow Run this adds to the warmth. ARB tends to be colder at night due to the Huron River Valley with cold air settling into the valley.

Cool info, thanks.

[michsnowfreak]

One thing to remember with any reporting site is that it is subject to extreme local conditions, that can vary within 1/4 mile.

ARB always has notoriously overnight lows. This is because the airport sits in a tiny little bowl. The elevation is higher on all four sides so any clear nights allow for radiational cooling to take place and allow the colder denser air to sink down to that spot. Check out any of the coop observers within a couple miles and you will not find similar temps. So the overnight lows for that spot are indicative of that spot, not necessarily the city/county they represent.

Same can be said for DTW, the temps at DTW are indicative of the temperature at that spot. It's a flat huge expanse of airport. You have no natural water features on the premises, virtually no trees, a mish mash of concrete runways, expanses of mostly dead grasses, parking garages, hangars, and so forth. The temperatures for that spot are indicative of that spot, not necessarily the city/county/region that they represent.

Temperatures are going to vary based on where one is precisely located. Case in point, stand in a sunny field, then walk a few yards to the tree line and stand in the woods. Which is warmer, which is cooler? Chances are there's going to be a degree or two difference in a matter of 50 yards.

Pretty much any temperature has to be taken with a bit of local knowledge and understanding that not all thermometers are calibrated equally. Just because Jimmy McLightning bolt puts up a personal weather station online, doesn't mean it's at the right spot above ground, far enough from buildings, etc, etc. A temperature taken at 2 feet above ground versus 6 feet can cause a degree or two of error.

Not saying that either ARB, YIP, or DTW are accurate or inaccurate. We all know their micro climates and they have been consistent, they are what they are.

Yeah those are good points too. As you said, its an airport, so lots of flat land, grass, and runways. Just outside the airport there are some wooded areas, so it would be interesting to see the difference in temp.

[Geos]

Interesting discussion on the different observation stations and temperature differences. Around here some stations that usually stand out with the lowest temperatures for overnight lows is Aurora/Sugar Grove, Burlington Municipal Airport, and nearby at Waukegan Airport.

Radiational cooling is maximum at these locations. From listening to Tom Skilling, the Aurora site is adjacent to open farmland and fields. Burlington airport near the Racine/Walworth County line is in a bowl area surrounded by undeveloped land. Waukegan airport doesn't have heavy development around it with plenty of open, flat spaces in around the airport. Of course at Waukegan there is a lake influence, but when skies and clear and winds are light it tends to be a good 5-10° colder than ORD. I think at all these sites, fog tends to develop over them from radiational cooling as well.