10 02-2013 marta nelson's forecast

Friday Forecast: October 4, 2013

Forecast period: Thursday noon through Saturday

noonForecast area:

Front Range (Boulder-Longmont)

Weekend Forecast• Rain will begin to fall Thursday around 3pm after the wind shifts from south to

southeast. Thunder and lightning are possible during the early hours of the storm, from 3:00pm to 6:00pm. Rain rate will increase after 5:00pm and change to snow around midnight*.

• Snow accumulation will be less than one inch and the ground will not get cold enough to produce black ice, though a slippery Friday morning commute is not out of the question. Snow will turn back into rain Friday before noon and all precipitation will cease by Friday around 6pm, as the winds shift and become westerly.

• The remainder of the weekend will be the bright, crisp, clear fall weather that we like: – Saturday a bit chilly, with a high around 55 and a low of 30. – Sunday, expect a high of 65 Sunday with a low around 31. Winds will be light and westerly;

skies will be mostly clear.

*There is a possibility to see some thunder snow with this storm. If Thursday morning is sunny and warm and the cold snow-making air descends early we could see a convective snowstorm Thursday afternoon.

Radiometers

• I would expect that the RDX rooftop radiometer will begin to pick up increased moisture signals before the Denver NOAA radiometer, as the moisture from this storm is being transported from the Pacific northwest.

• I also expect a good deal of supercooled liquid water (liquid water at below-freezing temperature, ripe for snowflake production) will be present and will ‘pool’ against the Front Range. Hence, I expect to see more liquid in the RDX radiometer than the NOAA radiometer.

Precipitation: Noon Thursday

Precipitation: 6pm Thursday

Precipitation: 12am Friday

Precipitation: noon Friday