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In Brief:
Summer plows on. Some moisture countered by some morning cooling may turn into near severe thunderstorms in Longmont Friday late afternoon. Only a few storms are likely to form near the Front Range. We have another chance thunderstorms Saturday before a ridge builds over the state and we approach 100F Sunday/Monday. Beyond that, we'll look it at a day at a time.
10:30am 8/16 Update:
The MCS (mesoscale convective system - a group of self propagating and self sustaining thunderstorms that cover less area than a typical state) that slid to the southeast across the Great Plains last night pushed cool moist air up to the Foothills this morning. The evolution of the hot dry air to the west and above this cool moist layer will dictate who sees severe weather today. The Marginal Risk and Slight Risk (1 and 2 on a scale of 1-5 respectively) zones are just east of I-25. This might be changed later as we see what becomes of this boundary as the day wears on. Be alert that a single severe storm could pop up very quickly later this afternoon, even west of I-25 , no matter where the risk zones are.
End 10:30am 8/16 update.
Forecast Discussion:
The deep tropical moisture flow is mostly cut off, but some Pacific moisture and a bit of tropical water is meandering around NE Colorado (Figure 1). Outflow from earlier storms north and east of the state will cool and stabilize the atmosphere Friday morning to midday. There are short waves traveling by the state Friday (Figure 2) and, if heating returns later in the afternoon we might see some thunderstorms (some severe) later in the day. The SPC has a Marginal Risk (1 on a scale of 1-5) near the I-25 folks (Figure 3).
The Longer Range Forecast:
There is a lesser chance of storms Saturday afternoon (Figure 4) then the ridge builds over the state again and we bake near 100F Sunday and Monday (Figure 4) and get dry again. More later!
