Popcorn showers; that is an isolated shower or thunderstorm that could pop up most anywhere and is largely due to the daytime heating. As you can see from the map on the right courtesy of the OK Mesonet, they are few and far between. But, if one happens to move over you, they are capable of brief periods of pretty heavy rainfall and even some locally damaging winds. Since they are so few and far between, the chances of any one location receiving measurable rainfall is around the 10% level. That will be the case this afternoon and again Sunday afternoon and evening.
Otherwise, we will have mostly sunny skies both days and afternoon temperatures near triple digits as well. Light S to SE winds at the surface will generally be less than 10 mph with a few higher gusts so not much of a cooling breeze out there either. At least the light winds and fair overnight skies will allow temperatures to drop into the 70s during the early morning hours.
Also, our dew point temperatures are so far staying in the 60s and have been mixing out with somewhat drier air aloft during the daytime. As a result the relative humidity levels have been dropping into the 20-30% range during the heat of the day keeping the heat index close to the actual air temperature. That means that although we will be around 100 degrees today and Sunday, the heat index should remain below the dangerous 105 level, but it will be close. Strongly suggest taking it easy with the outdoor activities, lots of fluids, etc....
By Monday, for the July 4 festivities, there will be a better chance of showers and storms, particularly late in the day. Some subtle changes in the winds aloft will allow for a weak boundary to drift down from Kansas to near the Ok/Ks state line. This should provide a better focus for showers and storms to form and will also pool higher dew point temperatures across NE Ok. Bottom line: a 20% chance of showers and storms, some of which will be locally strong so Mother Nature may be providing a few fireworks of her own that evening.
There will also be a few more clouds in the sky which together with a few cooling storms should keep us below triple digits on Monday. That should be the case for the rest of the week as well. We will be much warmer than normal, but at least for now it appears that we will be below triple digits with some popcorn showers or storms possible on any given day.
So, stay cool, stay tuned, and check back for updates.