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In Brief:
Nearly perfect weather continues through Monday midday. Drop mic.
A cold front and deep upper air trough move in Monday afternoon and a long period starting with thunderstorms continuing with rain and nighttime snow at times runs Tuesday through next Monday and beyond.
Forecast Discussion:
High pressure (with some clouds) continues today. The ridge will build a bit more overhead - so temperatures will warm a touch more. West winds at the surface will warm things a bit to the upper 70'sF.
The Longer Range Forecast:
With the next trough coming in just a bit sooner, and with clouds increasing, we will probably only see the lower 70'sF on Monday. The front should slide down the front range increasing our chances of rain and thunderstorms around sunset (big blue line Figure 2). We probably won't see severe thunderstorms along I-25 and westward, but we may see a marginal or slight risk out on the eastern plains. I'll update you on that as we get closer.
A quick check on the GFS 10-day total water has us in, what is probably, a down slope notch again, but we do get 1 to 1.25 inches of water. The bullseyes of heaver precipitation are staying consistent to our west and east (Figure 3). The GFS has no Longmont snow but the GEM (Figure 4) does give us 1-2 inches (or a touch more) snow over the next 10 days. If anything accumulates, it should 'wash' away in the daytime rain and temperatures that follow.