We have near normal to slightly above normal temperatures through the weekend with daily chances of afternoon thunderstorms moving off the mountains (yes I’m sounding like a broken record). There is a cool down slated for Sunday.
The SPC has expanded the Marginal Risk (1 on a scale of 1-5 in severity) of severe weather to just include Longmont (Figure 2 update). Figure 3 update is a close-up that just happens to exclude Airport Road but does include Main St. in the Marginal Risk. That map is not intended to be scrutinized THAT closely – it is an artifact of how the larger graphic boundary is drawn, but I though it was funny.
The primary risk for the widely separated cells (less severe than yesterday in Colorado) will be for hail and strong gusty winds. Very few will experience these along I-25, but be aware.
End 8:30am Update.
The low chance of severe weather around Longmont Monday PM has diminished to zero. Enjoy your evening.
It is really interesting to see the line of thunderstorms stretching north south ahead of the west coast trough from central Mexico up to Canada ( purple blobs in Figure 1 update).
End 8pm Update.
Every day will start clear, then cloud up in the afternoon as thundershowers move off the higher elevations to hit a few people with lightning and heavier rain (and small hail) – Figure 1. The risk that a thunderstorm or two gets stronger on Monday will be due to that west coast trough, that we’ve watched for a week or more, as it finally drifts by us down in New Mexico (Figure 2).
Longmont is just on the edge of a Marginal Risk of severe weather Monday afternoon (this is posted early – Figure 3). For Tuesday, that risk should remain further out east as the trough migrates a bit further east as well.
The Longer Range Forecast:
The trough cools us a bit Wednesday and Thursday (but not much, just to the upper 70’sF) then it is back to the 80’sF for the end of the week and weekend. Another trough approaches Sunday and we cool to the 60’s with a bit better chance of rain. Next week will be a bit cooler than average with those daily chances of afternoon showers.