Joe’s Weather Blog: Surging towards 90° for a day…then relief (MON-6/5)

Good morning…not sure how many weather blogs there will be this week…another one on Wednesday perhaps…maybe another on Friday and then I’ll be taking an extended vacation and I’m somewhat under orders NOT to take my laptop with me. No laptop…no blogs. I’ll tell you more about that later in the week. Meanwhile after a “weird” day yesterday with the downpours or lack thereof…today will be a summer day for temperatures but it’s a one day affair before we get some more seasonable air to move into the area.


Forecast:

Today: Mostly sunny and hot with highs approaching 90°. The hottest so far this season is 88° last month…let’s see if we can better that…not a lot of wind either which is a bit strange with the hot forecast.

Tonight: You’ll notice the lower dew points and more pleasant “feel” to the air. Lows down to the lower 60s…even some upper 50s out there.

Tuesday: Nicer and more of a seasonable day with highs in the lower 80s

Wednesday: Beautiful although there may be some more clouds around with highs around 80°


Discussion:

After a foggy start in some areas this morning…today will be a brighter and hotter day…again near 90° is likely with some getting hotter than that. Yesterday’s rain in spots was intense…but there was a whole lot of feast or famine when it came to the rain. At the station we didn’t have a drop…4 miles away at the downtown airport…they had close to 2″. That thunderstorm, helped to create an outflow boundary (rain cooled air flowing away from the storm) and that helped to trigger additional rains in the metro. There were other factors at play as well…so there was a bit more rain around the I-70 corridor than anywhere else. areas more south and farther north had little to nothing either. Those types of events happen during this time of the year…where one storm helps to initiate dozens of other showers and storms.

Today nothing of the sort should happen. Despite the heat and a wind shift moving through, I’m expecting mainly dry conditions in the area. I guess there could be something very isolated popping up with the push of lower dew points coming into the region…but it would be VERY isolated.

Dew points through lunch or so will be moderate. That means with rapidly rising temperatures, it will be a rather muggy morning into early to mid afternoon BUT the dew points will be dropping off this afternoon and by this evening should be down into the 60° range. Dew points are a bit of a tough thing for many too understand. I typically don’t talk “on the air” about the dew point because folks have a tough time wrapping their heads around it. They mostly understand relative humidity…but not the dew point. The thing is…if you think about dew points differently (especially during this time of the year) they can make some sense.

The “official” explanation of dew points goes like this…dew points indicate the amount moisture in the air. The higher the dew points, the higher the moisture content of the air at a given temperature. Dew point temperature is defined as the temperature to which the air would have to cool (at constant pressure and constant water vapor content) in order to reach saturation. A state of saturation exists when the air is holding the maximum amount of water vapor possible at the existing temperature and pressure.

That’s a lot to wrap your mind around…

There’s more to this though…via the University of Illinois…”When the dew point temperature and air temperature are equal, the air is said to be saturated. Dew point temperature is NEVER GREATER than the air temperature. Therefore, if the air cools, moisture must be removed from the air and this is accomplished through condensation. This process results in the formation of tiny water droplets that can lead to the development of fog, frost, clouds, or even precipitation.

Relative Humidity can be inferred from dew point values. When air temperature and dew point temperatures are very close, the air has a high relative humidity. The opposite is true when there is a large difference between air and dew point temperatures, which indicates air with lower relative humidity. Locations with high relative humidity indicate that the air is nearly saturated with moisture; clouds and precipitation are therefore quite possible. Weather conditions at locations with high dew point temperatures (65 or greater) are likely to be uncomfortably humid.”

So you need a dew point value to calculate relative humidity.

Here’s a different way of using dew point that is a bit simpler to understand. When the dew point is high during the summer months..it “feels” muggy. For example we will often during this time of the year use a graphic that relates to a “comfort” scale or something along those lines…”comfort” is subjective to people. Some like the muggies many hate the thick air of summer heat and humidity. When the dew point is below 65°…it’s rather bearable around here…above 65° and it starts feeling uncomfortable with temperatures in the 80s+ especially. Dew points in the 70s are somewhat common during the summer in the KC area…that is the “air you can wear” type feeling outside.  Dew points above 80° can occasionally happen too…and that is just nasty.

So think of the dew point for the purpose of this discussion today as a value that when it goes higher…it feels muggy…when lower…not too bad.

Today the dew point will be well into the 60s for awhile…as temperatures go higher it will “feel” more muggy. 90° with dew points 65°+ “feels” muggy. 90° with dew points in the 40s doesn’t “feel” as muggy. That’s why desert heat can be more tolerable for many because the air is so dry…lower dew points. I’ll take 105° with dew points in the 20s (Arizona summer weather) over the Plains 90° with dew points around or above 70° anytime.

From these values we calculate the heat index as well…but that is a whole other discussion.

That is what I refer to as a tangent!

The dew points will be coming down tonight and especially Tuesday into Wednesday. Probably down into the 50s with some 40s dew points possible. This will make the air “feel” more pleasant. The temperatures will be coming down too so it’s a win win.

Notice what is going to be happening to the surface wind flow tomorrow…it will be more form the NE to the SW…there will be a decent area of higher pressure passing towards the north of the region…this will switch the winds around this afternoon and allow more seasonable air and drier air (lower dew points to move into and through the region)

So this all will result in a more “pleasant” feel to the air after today and it will continue through Thursday. Towards the weekend though the drier air and the lower dew points will have moved away and as more of a southerly flow sets up…the dew points come up…the temperature comes up and the heat and humidity are back.

This is also a dry flow for the region as well with limited rain chances it appears for quite some time. as a matter of fact the rain totals off the model data aren’t very good for awhile as we swing through the end of the typical part of the wettest time of the year period. For the next week or so it’s going to be mostly dry it appears. There should be an opportunity for rain/storms on a more widespread basis perhaps towards the early or middle part of NEXT week. That’s a long ways off though.

OK that’ll do it for today…have a great Monday and stay cool and hydrated this afternoon.

Our feature photo comes from Kevin Shelter out in Independence, MO. Thanks Kevin!

I’ll be filling in for Mike today…see you at 5/6/9/10

Joe

 

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