wxgeek's weather-Drier and Warm Weather-update July 20

Fri July 20

A hot and mostly dry weekend in store for CO east of the Divide. Temps will approach record levels in many areas of eastern CO. Precip should remain mostly west of the Divide through at least Monday, with only a very slight chance for isolated showers in the foothills.

Models keep the large upper ridge centered over the central Rockies this weekend, and then begin to move it slightly east into the central Plains early next week. As the ridge moves east, slightly better chances for afternoon storms east of the Divide early next week. Models then indicate a weak disturbance will move along the south side of the upper ridge towards the end of next week, and will create a better monsoon flow and instability, so precip chances should get better from Wednesday through next weekend. We are getting to the time of year when the flow aloft is quite weak, so any storms that do form tend to be very slow moving, and thus can create localized flooding.

Long range models keep the persistent upper ridge over the central portion of the U.S. which will keep our temps at or above seasonal norms, as well as keep a large part of the central U.S. under hot and dry conditions, worsening an already severe drought over much of the U.S. With 100 degree temps forecast today and this weekend in Denver, it is very likely Denver will set a new record for the number of 100 degree days in a year (10 so far). 2012 has already set a number of heat related records, and it appears it will continue to do so at a blistering pace. Already this year the Arctic has lost a record amount of sea ice. Seems heat records will become the norm.
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"Climatology is what you expect, Weather is what you get".

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

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After a nice break spent fishing on the upper Klamath river near the CA/OR border with my sons, always nice to be back in Colorado.

Upper ridge currently centered over MO/AR is forecast to move west back over CO later this week and into the weekend. As this occurs, the monsoonal moisture will be pushed farther west as well. Today, more showers and thunderstorms likely over the High Country and foothills with isolated storms over the Plains. On Thursday as the upper ridge begins to move west, moisture will also move primarily west of the Divide over CO. Foothills could still see some isolated storms, but limited precip. This pattern will remain in place over the weekend with vast majority of storms west of the Divive, and temps above seasonal norms. AZ and UT will see the majority of activity from monsoonal moisture over the weekend.

Long range models keep the upper ridge centered over the central Rockies and 4 Corners region through most of next week, which will keep temps warm and limit precip to isolated afternoon and evening thunderstorms over most of CO, with highest chances over the High Country and southwest mountains.

So far in July I have recorded about 2.75 inches of rain, which is slightly above average for the month, but we have not made up for our deficit in moisture from earlier this year in March-June. Long range progs indicate we may only see light precip through the end of July until a better monsoon flow appears. The Climate Prediction Center forecast for August -October is calling for above average temps and near normal precip for CO. Looking further ahead, we currently have El Nino conditions building in the equatorial eastern Pacific. Most prediction models continue this trend into the Fall and upcoming Winter and predict a weak to moderate El Nino. Each El Nino is different, but in general this bodes well for average to above average snowfall for the foothills and Plains of CO. Unfortunately, the central and northern mountains usually receive below average snowfall during El Nino seasons. The southwest mountains can go either way. As always, long range predictions are not very accurate, so would not count on this at this time. We should know better by September or October how strong the El Nino event will actually be. During a typical El Nino event (which there really is not), the foothills tend to receive above average snow in the Fall (especially October), average amounts in the Winter months, and then above average in the Spring.
_________________
"Climatology is what you expect, Weather is what you get".

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

Bump for July 20 update