Forecast Discussion: The dog days of Summer, red flags and rogue parcels


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“Welcome to the party, pal!” – the heat is on and the pressure cooker is locked in place for the Black Hills Region.

The West has been dealing with this heat and dry air for quite some time, so we’re arriving a little late to the dog days of summer. 80s, and widespread 90s should be expected through this week – with plenty of sunshine and dry, dry conditions.
Climatologically speaking, this is very normal for this region. Drought is a cyclical occurrence and nobody should be surprised that we have finally arrived here.

We have experienced 25 days of 90°+ temperatures in Rapid a City so far in 2020. Last year we had 7 Total days of 90°+ days. Seven!… now THAT was unusual. We were almost a foot of rain above normal in precipitation by the time we reached December – a very green and rainy year.
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Now, the fact that we are usually drier around here does not mean it’s any easier on ranchers and folks who live off the land and depend on the rain. It costs money, time, energy and resources when Mother Nature doesn’t come through.

This is happening in a big way out towards Sheridan County and the Bighorn Mountains ⛰– I traveled out that way this past weekend and to say the area is dry is an understatement. If you got friends or neighbors out that way living off the land – keep rainy thoughts for them, a little would go a long, long way at this point.

NOW…. having that said, we are operating under a pressure cooker, (large scale meteorological high pressure). Sinking air is suppressing storm activity and encouraging dry conditions to persist. Two things comes to mind for me when I look at the morning metrics.
-wildfire potential 🔥
-explosive rogue thunderstorms ⛈

Red flag warnings are important to pay attention to, as it indicates region with critical fire danger. Low relative humidity, dry brush, gusty winds, etc…


Today, we don’t have red flag warnings 🚩….. only because we’re just below a critical level in ingredients. So maybe we’re not at 100% critical fire criteria… we’re still at 90, or 95, or even 80% on those lucky few days. We’re going to be at this level for the next couple of weeks … until we get significant moisture reintroduced to the region – so buckle up and be ready to stay vigilant for the long haul here. Do it for your neighbors, friends and wildlife companions that rely on the non-burnt land to make a living.

To the subject of afternoon rogue boomers ⛈– it’s more of a curiosity than a serious concern over the next couple weeks.

Any rising parcel that breaks the high pressure lockdown, sinking air, tough inversion, dry conditions and 500 other negative factors will find itself king of the castle – much like shooting the moon if you’ve ever played the card game hearts.

These storms are familiar as the lone wolf on the prairie, or a singular looking mushroom cloud of water filled cumulonimbus clouds arching over the Black Hills on a hot and otherwise blue-sky day. These storms can be troublesome, using the otherwise inert surface heat to blossom into powerful isolated thunderstorms that can take that “10% chance of thunderstorms” and blow up your afternoon plans with lots of lightning, large hail and gusty winds.

The good news – they’re generally very isolated, and most days you’re staring at clear blue skies. Dominant high pressure usually wins out in these situations, and only the most devious and stubborn of rising parcels reaches the happy hunting grounds of the upper atmosphere.
The moral of the story – thunderstorms have distinct personalities. Any rising air parcel that can break out of a maximum security high-pressure prison has to be at least a LITTLE bit crazy. Keep an eye out for these summer storms over the next week.


Southeasterly surface winds pick up around 10:30 AM Monday in Rapid City

Some days we’ll have better chances for rogue storms than others – take today and Wednesday for example. Southeasterly winds Monday afternoon and evening may be just enough to give air parcels and edge of moisture and heat to break the cap. Will be interesting to see how this afternoon develops.

Stay safe out there, respect our nature filled backyard and it will pay dividends in the future. Use the clear evenings to observe our stunning night skies. Stay healthy!


Categories: Local News, Weather Daily