September’s Here But Rain Continues

By John McGinley

Last week our atmospheric models were forecasting a shift in the upper level high to the west that would have cut off the monsoon and given us a hot, dry week. Well, it started out that way, but quickly went astray as the high moved over the plains and the great moisture pump started up again. This was aided by an upper level low over the southwest that created strong southerly winds and sent abundant moisture northward toward a cold front over norther nColorado that had created upslope. Rain began on Sunday and continued through Tuesday and Wednesday. Heavy rain was widespread over the mountains and metro area. pea-sized hail up to 3 feet (!) deep occurred in Wheatridge. Rainfall amounts around the Foothills were 1.0 to 2.5 inches. Starting last Wednesday we had daily highs in the 80s with dry southwesterly winds. By Monday the front moved through and serious thunderstorms blossomed over the area.  Temperatures fell from the 70s to the 50s by Tuesday giving the area a taste of fall. I need to amend last week’s rainfall totals for August. Despite many years of math I made an error totaling up the monthly rain :  it turned out to be 3.72 instead of 4.62…..still above normal but not among the wettest August totals.

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Day     Date                High    Low     Precip              Comments

Wed    Sep 4               81        55

Thu      Sep 5               81        53

Fri        Sep 6               81        54        0.02L               Shower

Sat       Sep 7               79        50

Sun      Sep 8               77        49        0.26L               Thunderstorms

Mon     Sep 9               68        51        0.83L               Thunderstorms                       

Tues     Sep 10             54        51        0.33L               Rain                            

Forecast

We’ll see a continuance of the monsoon  pattern Thursday and Friday with a high probability of showers. Saturday precipitation probabilities decrease a bit but Sunday will see recharged showers after a cold front passage. After Monday the moisture shifts east and the temperatures will rise back to September normals.

Thursday-Sep12: Cloudy with rain and occasional thunderstorms. High in the low 50s with lows in the mid 40s.

Friday-Sep 13: Much like Thursday.

Saturday- Sep14: Partly cloudy with afternoon showers, Highs in the mid 60s after lows in the upper 40s. Frontal passage late.

Sunday-Sep 15: Cloudy with more showers. Highs back into the upper 50s with lows in the low 40s.

Monday-Sep 16: Partly cloudy with only isolated showers. Warmer with highs in the mid 60s after lows in the mid 40s

Tuesday-Sep 17: Fair and warmer with highs in the low 70s with lows in the upper 40s.

 Wednesday-Sep 18: Like Tuesday. Gusty winds late.