Best weekend of the year? Early frost late next week?

Clear the calendar this weekend. Cancel all indoor plans. This is a red alert.

This weekend's weather may be the best of the year in the eyes of many Minnesotans.

A delightfully dry and clean Canadian air mass sails through Minnesota this weekend.

Abundant sunshine? Highs in the upper 60s north and 70s central and south? Lows in  the 40s and 50s with excellent sleeping weather? No AC? Lakes still warm enough for a September dip?

In my 30 years of informal, completely unscientific feedback from Minnesota weather consumers, I can confidently say about 90% of Minnesotans will consider this weekend's weather some of the year's finest.

Somebody alert the media. Oh wait, I am the media.

Our delightful weekend comes to you courtesy of the Royal Canadian Chamber of  Weather Commerce. We curse bitter southbound Canadian air masses often enough in winter. We might as well give praise when they send us near weather perfection in early September.

Here's a look at the pleasant high pressure blob setting up shop in the central US this weekend.

Here's a close up look at the metro forecast this weekend. I can't recall a weekend this summer with this combination of all sun and moon symbols, no threat of rain and more pleasant temps.

Can you?

October preview late next week

You knew it would happen sooner or later. Temps in the 70s hold into early, then the jet stream buckles southward from it's annual summer Canadian vacation late next week.

Here's a look at the jet stream roaring over the Upper Midwest by next Friday courtesy of Climate Reanalyzer from the University of Maine.

Yes, it will have the look and feel of (late) October late next week. High in the 50s. Bonfires. Football weather.

Here's a look at temperature anomalies by next Friday, which may approach 20 degrees below average in these parts.

Here's a look at the week as a whole. Temps start out in the typical 70s, then crash a full 20 degrees according to the Euro model runs. The Euro may be overly aggressive, but lows in the 30s and spotty frost are not out of the question in the metro suburbs late next week.

Early frost?

The prospect of frost in early to mid-September is not unheard of for central Minnesota, but it is notably early for the Twin Cities outer suburbs.

Here's a look at average first frost (32-degrees) for areas around the Twin Cities from the Minnesota Climate Working Group.

Stay tuned as we tweak the numbers for late next week, but expect to say hello to some of your favorite sweaters and fleece for the first time in a few months.

Fall color splashes up north

Yes it's that time again. Some early reports show splashes of  fall color in parts of northern Minnesota already. Here's the early fall color report from the Minnesota DNR, which shows a few colorful spots "up Bemidji."

Typical dates for "peak" fall color?

Still a few weeks away.

"Heat burst" and high dew points

My MPR colleague Dr. Mark Seeley elaborates on this week's tropical moisture surge with high dew points, and a rare heat burst in western Minnesota Thursday.Here's a snippet form this week's Weather Talk.

Topic: High dewpoints and a heat burst

September 3-4 brought very high dewpoints to many parts of the state, with readings of 70 degrees F or higher. Montevideo reported a 73 degrees F dewpoint on the 3rd and 77 degrees F on the 4th, while the University of Minnesota-St Paul Campus reported a dewpont of 75 degrees F on the 3rd and 79 degrees F on the 4th of September. These are near record values for the date. On Thursday (Sept 4th) the high dewpoints pushed the Heat Index readings into the 90s F by afternoon for many southern Minnesota communities, making for a very uncomfortable day.

In addition early in the morning hours on September 4th, decaying thunderstorms over western portions of Minnesota produced an overnight "heat burst" for some areas. This is produced by compressional heating of sinking air from aloft. In Marshall, MN the air temperature at 5:00 am was 66 degrees, but rose to 72 degrees F by 6:30 am, while at Slayton, the air temperature was 66 degrees F at 4:00 am and rose to 72 degrees F by 4:30 am.

Supermoon #3

This weekend's fine weather comes with a sky show bonus. The 3rd consecutive "Supermoon" waxes toward full Monday night.

Her's a snippet from the International Business Times. 

The final supermoon, completing the trio of supermoons that began in July, may not be the biggest of the bunch but will be the last one of 2014. August's supermoon occurred within the hour the moon reached perigee, the closest point to Earth in its elliptical orbit, while September's supermoon occurs on the same day as perigee.

Due to the close proximity to Earth, the full moon appears roughly 30 percent brighter and 14 percent larger than a regular full moon. September's supermoon takes place on Sept. 9 and stargazers won't need ideal viewing conditions or a telescope to enjoy. September's full moon will be a Harvest Moon as it occurs closest to the autumnal equinox, notes the Old Farmers Almanac.

El Nino Update: A big maybe?

This week's El Nino update from NOAA is not exactly brimming with confidence about the potential for a warm event this winter. NOAA puts the chances at 60 to 65% which is down from earlier this year.

Warmer water is slowly building, but having a hard time taking firm hold in the tropical Pacific.

Here's the latest from NOAA on the potential for a developing El Nino this winter.

ENSO Alert System Status: El Niño Watch

Synopsis: The chance of El Niño is at 60-65% during the Northern Hemisphere fall and winter.

During August 2014, above-average sea surface temperatures (SST) continued across much of the

equatorial Pacific (Fig. 1). Most of the Niño indices warmed during the month with values of +0.5°C in

Niño-4, +0.4°C in Niño-3.4, +0.4°C in Niño-3, and +0.8°C in Niño-1+2 (Fig. 2). Subsurface heat content

anomalies (averaged between 180º-100ºW) also increased during the month (Fig. 3) as above-average

subsurface temperatures developed across the central and east-central equatorial Pacific (Fig. 4). This

warming is associated with the downwelling phase of an equatorial oceanic Kelvin wave triggered in July

by low-level westerly wind anomalies. Westerly wind anomalies continued in the central and eastern part

of the basin early in August, but weakened by the end of the month. Enhanced easterly upper-level wind

anomalies have prevailed during much of the month, and the Southern Oscillation Index has been

negative. However, convective cloudiness remained generally near average over most of the region,

except for below average cloudiness observed across the central and western Pacific (Fig. 5). The lack of

a coherent atmospheric El Niño pattern and near-average SSTs in the central Pacific indicate a

continuation of ENSO-neutral.

Most of the models continue to predict El Niño to develop during September-November and to

continue into early 2015 (Fig. 6). A majority of models and the multi-model averages favor a weak El

Niño. At this time, the consensus of forecasters expects El Niño to emerge during September-October

and to peak at weak strength during the late fall and early winter (3-month values of the Niño-3.4 index

between 0.5°C and 0.9°C). The chance of El Niño is at 60-65% during the Northern Hemisphere fall and

winter (click CPC/IRI consensus forecast for the chance of each outcome).

If El Nino fails to materialize, chances for a milder than average winter in Minnesota drop significantly. Will we need to brace for the return of the Polar Vortex this winter?

Stay tuned.