WxWatcher007 Posted July 28, 2023 Share Posted July 28, 2023 1 hour ago, HIPPYVALLEY said: More gross than hot. Today will be pretty bad but nothing we haven’t seen before. This. The dews have been notable, the temps have not. 1 Link to comment Share on other sites More sharing options...
Typhoon Tip Posted July 28, 2023 Author Share Posted July 28, 2023 90/70 here ... 90/66 next door at KFIT ... 1 Link to comment Share on other sites More sharing options...
Typhoon Tip Posted July 28, 2023 Author Share Posted July 28, 2023 My present extraordinary boredom led me to display this extraordinary example of Sonoran/SW heat release event on the GFS's farthest extended range ... despite the extraordinary unlikeliness of it happening. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted July 28, 2023 Author Share Posted July 28, 2023 what's interesting about that image is that PWM-DCA is probably already 95(mid aug)-100(mid jul), prior to that Venetian plume's arrival from the GL 1 Link to comment Share on other sites More sharing options...
tamarack Posted July 28, 2023 Share Posted July 28, 2023 1 hour ago, HoarfrostHubb said: Yup. High dew point driven. I don’t know if New England ever gets dews higher than yesterday. I'd nominate August 1988 as a contender. 1 Link to comment Share on other sites More sharing options...
STILL N OF PIKE Posted July 28, 2023 Share Posted July 28, 2023 The fact that heat index is measured in the shade basically negates how hot it actually feels in the sun on a hot and Dewey day and then Of course you want to incorporate a wind component . Not sure why heat warnings Are not correlated to Wet Bulb Global temperature Link to comment Share on other sites More sharing options...
dendrite Posted July 28, 2023 Share Posted July 28, 2023 3 minutes ago, STILL N OF PIKE said: The fact that heat index is measured in the shade basically negates how hot it actually feels in the sun on a hot and Dewey day and then Of course you want to incorporate a wind component . Not sure why heat warnings Are not correlated to Wet Bulb Global temperature Temp and dew are measured in full sun. Link to comment Share on other sites More sharing options...
STILL N OF PIKE Posted July 28, 2023 Share Posted July 28, 2023 7 minutes ago, dendrite said: Temp and dew are measured in full sun. Ummm...Everything I look up shows heat index temps are measured in shade . This is from weather.gov. What am I missing https://www.weather.gov/ict/wbgt#:~:text=It is the traditional measurement,degrees to the heat index. Link to comment Share on other sites More sharing options...
Typhoon Tip Posted July 28, 2023 Author Share Posted July 28, 2023 8 minutes ago, STILL N OF PIKE said: Ummm...Everything I look up shows heat index temps are measured in shade . This is from weather.gov. What am I missing https://www.weather.gov/ict/wbgt#:~:text=It is the traditional measurement,degrees to the heat index. Brian said T and DP are measured in the sun - not sure he was commenting on the HI derivatives? Link to comment Share on other sites More sharing options...
dendrite Posted July 28, 2023 Share Posted July 28, 2023 Just now, STILL N OF PIKE said: Everything I look up shows heat index temps are measured in shade . This is from weather.gov. What am I missing https://www.weather.gov/ict/wbgt#:~:text=It is the traditional measurement,degrees to the heat index. Okay I think I know what you’re saying. Heat index only encompasses temp and dew and those are both measured in full sunshine albeit with proper shielding. You want something that factors in temp, solar radiation, humidity, and wind. There are equations to calculate that, but you’re not going to get it on an ASOS without a pyranometer to measure the solar rad. Davis uses an equation to calculate THW index or THSW index if you have a solar sensor so I can do that here. But it changes wildly during the day depending on clouds and wind speed. Here’s my THSW index chart for the day. You can see where the sun started hitting the solar sensor and each cloud we had. 3 Link to comment Share on other sites More sharing options...
STILL N OF PIKE Posted July 28, 2023 Share Posted July 28, 2023 1 minute ago, dendrite said: Okay I think I know what you’re saying. Heat index only encompasses temp and dew and those are both measured in full sunshine albeit with proper shielding. You want something that factors in temp, solar radiation, humidity, and wind. There are equations to calculate that, but you’re not going to get it on an ASOS without a pyranometer to measure the solar rad. Davis uses an equation to calculate THW index or THSW index if you have a solar sensor so I can do that here. But it changes wildly during the day depending on clouds and wind speed. Here’s my THSW index chart for the day. You can see where the sun started hitting the solar sensor and each cloud we had. They (heat index ) are measured in shade on everything I have read , I haven’t found a link that says full sunshine Link to comment Share on other sites More sharing options...
dendrite Posted July 28, 2023 Share Posted July 28, 2023 Just now, STILL N OF PIKE said: They are measured in shade What is measured in shade? Link to comment Share on other sites More sharing options...
STILL N OF PIKE Posted July 28, 2023 Share Posted July 28, 2023 2 minutes ago, dendrite said: What is measured in shade? Heat index is a measure for how hot it feels outside in a shaded area , not full sunshine Do you have anything that links heat index being described to measure how how the body feels in the sunshine Link to comment Share on other sites More sharing options...
kdxken Posted July 28, 2023 Share Posted July 28, 2023 1 hour ago, HoarfrostHubb said: This summer has been noticeably calm. Eric Fisher @ericfisher · 22m A lot of days that have looked like this. Weak sea breezes. I believe we're on pace for the least windy summer on record...or very close to it 1 Link to comment Share on other sites More sharing options...
dendrite Posted July 28, 2023 Share Posted July 28, 2023 Shade to me means under trees or on the north side of a building. 2m temps and dews are measured in open areas with full sun, but they are shielded to protected from solar contamination. We’re trying to get the true air temperature and dewpoint of the air at 2m…not the temp the probe is being heated to due to solar effects. 1 Link to comment Share on other sites More sharing options...
STILL N OF PIKE Posted July 28, 2023 Share Posted July 28, 2023 9 minutes ago, dendrite said: Shade to me means under trees or on the north side of a building. 2m temps and dews are measured in open areas with full sun, but they are shielded to protected from solar contamination. We’re trying to get the true air temperature and dewpoint of the air at 2m…not the temp the probe is being heated to due to solar effects. This isn’t complicated really heat index measures how hot it feels in a shaded area . That’s why I think it’s flawed bc it doesn’t account for sunshine if the NHC wanted to use your Davis (and others ) which gives a good estimation of temp in sun that would be great and I wouldn’t have made my original point but they ..don’t so my point was it seems flawed (obviously for official stations ) Link to comment Share on other sites More sharing options...
powderfreak Posted July 28, 2023 Share Posted July 28, 2023 8 minutes ago, dendrite said: Okay I think I know what you’re saying. Heat index only encompasses temp and dew and those are both measured in full sunshine albeit with proper shielding. You want something that factors in temp, solar radiation, humidity, and wind. There are equations to calculate that, but you’re not going to get it on an ASOS without a pyranometer to measure the solar rad. Davis uses an equation to calculate THW index or THSW index if you have a solar sensor so I can do that here. But it changes wildly during the day depending on clouds and wind speed. Here’s my THSW index chart for the day. You can see where the sun started hitting the solar sensor and each cloud we had. 4 minutes ago, STILL N OF PIKE said: Heat index is a measure for how hot it feels outside in a shaded area , not full sunshine Do you have anything that links heat index being described to measure how how the body feels in the sunshine That graph he posted is what you are looking for. It spikes in full sun and then drops 15F when a cloud comes in. Sounds like you are looking for an unshielded thermometer just getting blasted by sun? The temp/dew is measured in the sun but it’s shielded, so sort of like “shade” as the actual instrument is not getting torched by solar. Link to comment Share on other sites More sharing options...
weatherwiz Posted July 28, 2023 Share Posted July 28, 2023 3 minutes ago, STILL N OF PIKE said: This isn’t complicated really heat index measures how hot it feels in a shaded area . That’s why I think it’s flawed bc it doesn’t account for sunshine This doesn't make any sense. For example, BDL is 88/70 that yields a HI of 93 (either by using dewpoint or relative humidity which is 55%). The temperature and dewpoint being used to calculate the HI or not coming from the shade. Link to comment Share on other sites More sharing options...
dendrite Posted July 28, 2023 Share Posted July 28, 2023 2 minutes ago, STILL N OF PIKE said: Heat index is a measure for how hot it feels outside in a shaded area , not full sunshine Do you have anything that links heat index being described to measure how how the body feels in the sunshine Not off hand but those equations are complicated and there’s some disagreement about how the variables are all factored in to come up with an estimate. All of these indices are just estimates. The wind chill one was wrong for decades as well. 1 Link to comment Share on other sites More sharing options...
dendrite Posted July 28, 2023 Share Posted July 28, 2023 Pickles just wants the affect of the sun on the skin being factored in. But you’re just going to confuse the public more. “It’ll feel like 120 in the sun with calm wind, but 110 in the sun with a breeze, and only 100 under a cloud.” Our heat index is basically a humidex. Just accept you’re going to feel hotter in the sun and that wind will increase cooling effects. 1 Link to comment Share on other sites More sharing options...
weatherwiz Posted July 28, 2023 Share Posted July 28, 2023 1 minute ago, dendrite said: Pickles just wants the affect of the sun on the skin being factored in. But you’re just going to confuse the public more. “It’ll feel like 120 in the sun with calm wind, but 110 in the sun with a breeze, and only 100 under a cloud.” Our heat index is basically a humidex. Just accept you’re going to feel hotter in the sun and that wind will increase cooling effects. I think one time I was drinking a 40 at school and I was bored and I tried to calculate a HI by hand with one of the equations and ended up with some crazy number and gave up. 2 Link to comment Share on other sites More sharing options...
STILL N OF PIKE Posted July 28, 2023 Share Posted July 28, 2023 8 minutes ago, dendrite said: Pickles just wants the affect of the sun on the skin being factored in. But you’re just going to confuse the public more. “It’ll feel like 120 in the sun with calm wind, but 110 in the sun with a breeze, and only 100 under a cloud.” Our heat index is basically a humidex. Just accept you’re going to feel hotter in the sun and that wind will increase cooling effects. Not really but lol I’m moving on . The public (not this board although some may ) assumes the heat index on a sunny day measures the effective temperature in the Sunshine where they are playing sports outside or at lake or pool etc. They would be confused why it actually doesn’t . They aren’t hiding under trees 1 Link to comment Share on other sites More sharing options...
dendrite Posted July 28, 2023 Share Posted July 28, 2023 3 minutes ago, STILL N OF PIKE said: Not really but lol I’m moving on . The public (not this board although some may ) assumes the heat index on a sunny day measures the effective temperature in the Sunshine where they are playing sports outside or at lake or pool etc. They would be confused why it doesn’t . They aren’t hiding under trees They do? I’ve never heard of anyone thinking the heat index factors in sun, but rather just the temp with humidity factored in. Maybe find smarter milfs? Link to comment Share on other sites More sharing options...
STILL N OF PIKE Posted July 28, 2023 Share Posted July 28, 2023 5 minutes ago, dendrite said: They do? I’ve never heard of anyone thinking the heat index factors in sun, but rather just the temp with humidity factored in. Maybe find smarter milfs? It’s flawed unless the folks who created the heat index anticipated measuring how how it feels out in sunshine with everyone wearing sombrero hats. Mexican dilfs . 1 Link to comment Share on other sites More sharing options...
dendrite Posted July 28, 2023 Share Posted July 28, 2023 How long is anyone outside in direct sun this time of year anyway? I start burning in about 2 minutes. Link to comment Share on other sites More sharing options...
STILL N OF PIKE Posted July 28, 2023 Share Posted July 28, 2023 5 minutes ago, dendrite said: How long is anyone outside in direct sun this time of year anyway? I start burning in about 2 minutes. Without a pool very little time During 11-5 . I can’t imagine having to do football practice or all the town camps that are running on days like this or doing roofing Link to comment Share on other sites More sharing options...
Typhoon Tip Posted July 28, 2023 Author Share Posted July 28, 2023 2 hours ago, STILL N OF PIKE said: Heat index is a measure for how hot it feels outside in a shaded area , not full sunshine Do you have anything that links heat index being described to measure how how the body feels in the sunshine Hmm. The sun on the skin' is a different kind of therm than ambient kinetic air temperature, though - including the ability to radiate heat away from the skin that is involved in the complex equations of Heat Index. In other words, there may not be a direct way to "combine" sun into the same HI manifold of metrics. Maybe indirectly? sure ...like, infrared adds converted energy, so, that increase in turn increases what needs to radiate away. Then, we have utility over that energy budget and can due the deltas. But alone, sun "heat" on the skin is short wave/infrared radiation. What we feel when we feel hot air is after it has been converted to kinetic temperature (by conduction physics with black body objects..etc). Check this, but I'm pretty sure we feel hot air differently. That's a heat source sink relationship. Hot doesn't bleed off to hot as quickly as it does to cold. So that is detected through biological nerves somehow interacting with conduction with the surrounding air. Basically ...air that is already hot is limiting the heat escaping from our person. There may be some 2ndary infrared responses, if say the gas ( air ) gets so hot that it starts radiating in the infrared at a high enough registry. Anyway, infrared is a measure of electromagnet frequency, which humans can sense within a certain bandwidths... like, infrared, through the visible range of the spectrum. However, it's a different energy state; I'm not sure it can be included into the same (ambient kinetic temperature + saturation) gaining up on the ability of the human body to radiate its own heat away...with out first may converting it to post-conduction heat that is gain, and then adding it. 1 Link to comment Share on other sites More sharing options...
weathafella Posted July 28, 2023 Share Posted July 28, 2023 24 minutes ago, dendrite said: How long is anyone outside in direct sun this time of year anyway? I start burning in about 2 minutes. Never. I go out completely zinced up and generally avoid any time before 6pm. I walk tons at night though. Link to comment Share on other sites More sharing options...
Go Kart Mozart Posted July 28, 2023 Share Posted July 28, 2023 2 hours ago, Typhoon Tip said: My present extraordinary boredom led me to display this extraordinary example of Sonoran/SW heat release event on the GFS's farthest extended range ... despite the extraordinary unlikeliness of it happening. Link to comment Share on other sites More sharing options...
Go Kart Mozart Posted July 28, 2023 Share Posted July 28, 2023 1 hour ago, weatherwiz said: This doesn't make any sense. For example, BDL is 88/70 that yields a HI of 93 (either by using dewpoint or relative humidity which is 55%). The temperature and dewpoint being used to calculate the HI or not coming from the shade. Wiz, are you gonna fire up a thread for tomorrow? According to Upton, 2,500 j/kg of CAPE, yowza! Link to comment Share on other sites More sharing options...
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