wxgeek's weather-Cooler and Wetter Weather Ahead-Update 9/13

Update Fri Sep 13 the

Historic flooding across the Front Range will continue today, but we will begin to see some relief this evening and this weekend. We are not quite out of the woods just yet, radar shows band of moderate to heavy rain moving across JeffCo at this time. Flow aloft slightly more from the south southwest today, which is drier versus the south southeast flow of the past 2-3 days that pushed precip up against the foothills of Boulder and Larimer counties. Models showing overall decrease in precip after 10:00 am today, but we could still see some heavy bands and cells through this evening as plume of monsoon moisture still streaming north across NM and CO. Rainfall totals from Monday are incredible, with some areas of Boulder county receiving up to 14 inches of rain since Monday, nearly the annual average in 1 week. Areas near Aurora received up to 12 inches of rain since Monday. Really a historic and unprecedented event as far back as records exist. Certainly the wettest September on record for many areas. Rivers and creeks may continue to rise through tonight and Saturday morning, then begin to recede.

Drier weather on tap for the weekend, but some showers will still be possible each day, but the more typical afternoon and evening variety with some sunshine finally. Next week continues to look much drier with temps back near seasonal norms, which many areas need to dry out.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

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Update Thu Sep 12

Serious flooding still occurring mostly in Boulder county. Heaviest rain this morning will continue along and north of I-70, especially in Boulder and Weld counties. Rain will persist but taper off through the morning and early afternoon, then re-intensify later this afternoon and evening and persist into the night once again. As ground is saturated and reservoirs are at capacity, any additional rainfall will create more flooding, so expect more flood warnings and evacuations in areas already experiencing flooding. So far areas around Conifer have only received about 1.5-2.0 inches of rain the past 72 hours. Areas near Boulder have received 5-8 inches of rain over the past 24 hours. Additional amounts of 1-3 inches are likely over the next 24-48 hours. Even areas that have not experienced flooding yet, may see flooding and rock and mud slides as saturated soils continue to receive additional rainfall. Be careful driving in areas where standing water exists, as water levels may rise rapidly. More road closures likely into Friday morning. Be careful driving, and please remember to turn your lights on when driving in the rain, the lights are not for you, they are for other cars to see you. Lots of standing water on roads with hydroplaning possible to likely.

Fairly unprecedented rainfall event for CO. Most of our flooding comes from thunderstorm events, so 2-4 days of near steady rain is quite rare. Reminds me much more of flood events along the west coast during winter months. Heavy rain expected through tonight, and then we should see more showery type precip on Friday as the upper level low causing this moves farther north in NV. The upper low then is forecast to become an open tough and move east over the weekend, so we should see more typical shower and thunderstorm pattern in the afternoon and evening hours Saturday and Sunday, with even some sunshine during the day, hence warmer temps. Conditions dry out and warm up next week.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

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Update Mon Sep 9

Showers and thunderstorms beginning to move across the foothills and into adjacent plains this afternoon. This activity will persist into this evening and likely into nighttime hours with periods of brief heavy rain and thunderstorms that may contain small to medium hail and frequent lightning. Flash Flood Watch is in effect for northern foothills, and may be extended south this evening. Flash flooding will be possible, especially in the foothills today and Tuesday, and especially across recent burn scar areas. Many areas across the state could receive 1-3 inches or more of rain this week. This activity is being fueled by a late Monsoon plume of moisture being advacted northward into CO as upper ridge has moved east, upper low has formed near the NV/CA/AZ border and cold front moving into the state from the northwest. This combination will bring deep moisture from Mexico and wring it out across CO through Friday. Heaviest rain will be from this afternoon into Tuesday night, but isolated heavy storms will be possible Wednesday through Friday as well. Temps will remain at or below seasonal norms through the weekend due to cooler air and lots of cloud cover and rain.

Conditions will begin to warm back to near seasonal norms and dry out by early next week, although isolated afternoon and evening storms will be possible, especially from the foothills west. The North American Monsoon is still going strong, with average daily dew points in Tucson in the mid 60's. Today marks the average end date of the North American Monsoon, but it will likely persist into at least this weekend. Beyond that, conditions look to be more seasonal through the end of September with passing upper troughs bringing slight cool downs and some precip. At this time, still does not appear to be any hint of an early season snowfall in September for our foothills.

_________________
"Climatology is what you expect, Weather is what you get".

"It is better to be roughly right than precisely wrong".

Bump for Sept 12 update

Bump for sept 13 update