What is Cap? And why it means minimal rain chances for Texoma Tuesday night

Rain and storms limited to areas east of HW 81 late Tuesday night and Wednesday morning

What is Cap? And why it means minimal rain chances for Texoma Tuesday night
Strong capping inversion in place Tuesday night limiting shower & storm coverage for Texoma (Source: KSWO)

LAWTON, Okla. (TNN) -

The capping inversion, sometimes referred to as a lid, is defined as a layer of warm air high in the atmosphere, usually this is several thousand feet above the ground. A warm and moist air parcel rises with height, so as the air parcel moves upwards normally this would help to create a storm as it rises very high. However, this layer of warm air helps to delay, or suppress, thunderstorms from developing.

Strong capping inversion in place Tuesday night limiting shower & storm coverage for Texoma
Strong capping inversion in place Tuesday night limiting shower & storm coverage for Texoma (Source: KSWO)

For example, the cap stops the warm and moist air parcel from rising high in the atmosphere and cools it down. Once the air parcel begins to cool down, it allows the clouds to sink (cool air is more dense), therefore inhibiting storm development across a specific region.

A capping inversion can also increase the amount of potential instability due to the air above the cap being able to cool further into the atmosphere. The warm air near the surface can become strong enough to suddenly, and violently, rush upwards, breaking the cap, leading to storms to become organized and strong within a short period of time. When there is no cap in place the fuel for storms including moisture, heat and cool air aloft all gets used up quickly. Typically, this yields to fewer storms and storms that are short-lived.

When there is a cap in place here are the two main scenarios:

1. A strong cap holds warm moist air and cool dry air apart, air parcels air not strong enough to break through the Cap. Therefore, weather conditions remain quiet, but well above average.

- In our case, the western and central half of southwest Oklahoma and northwest Texas will be strong on Tuesday leading to rain chances to stay east of Highway 81.

Strong Cap in place allows for a dry and warm Tuesday for much of Texoma.
Strong Cap in place allows for a dry and warm Tuesday for much of Texoma. (Source: KSWO)
Cap allows well above average temperatures for much of our area.
Cap allows well above average temperatures for much of our area. (Source: KSWO)

2. Cap in place allows conditions at the surface to destabilize and as instability increases throughout the day air parcels can become strong enough to rise and break through cap. Once this happens storms develop quickly and typically strengthen thanks to enhanced instability.

- The air parcels are expected to break the cap across eastern Oklahoma and in Kansas leading to possible strong/severe storms.

Severe Weather Outlook Tuesday
Severe Weather Outlook Tuesday (Source: KSWO)

There are always more than one reason for severe weather, or no severe weather. But having a Cap in place and the strength associated with it allows meteorologists to prepare for severe storm potential.

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