Aurora watch, frost advisories, October-like weekend

The MPR News Weather Lab has declared an Aurora Watch this weekend.

Okay, there's no such thing, at least not yet. But a hyperactive sun has spawned twin geomagnetic storms that have been pummeling earth's magnetosphere and the effect will likely peak over the weekend.

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NOAA

Here are some details on the massive Coronal Mass Ejections hurtling earthward this weekend from the National Oceanic and Atmospheric Administration.

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A PAIR OF CMES

G2 (Moderate) geomagnetic storms remain in the forecast for September 12th as a result of the coronal mass ejection (CME) associated with the R1 (Minor) solar flare observed on the 9th. The latest WSA-Enlil model run has the CME associated with yesterday's R3 (Strong) solar flare arriving mid to late day on that same day.

A G3 (Strong) Geomagnetic Storm Watch has been issued for September 13th due to the combined influence of these two events with G1 (Minor) storming anticipated to continue into September 14th. In addition, the S1 (Minor) solar radiation storm that is in progress as a result of the eruption yesterday is expected to persist for the next few days.

Keep in mind that the forecast periods listed are in Universal Time so aurora watchers in the northern U.S. should be looking for possible activity both Thursday and Friday nights. Stay tuned for updates.

The first salvo of northern lights arrived early Friday morning over Alaska and northern lights were reported as far south as Minnesota.

http://www.youtube.com/watch?v=L3taBvdvGOc Be alert for possible auroras this weekend. Best viewing as always away from city lights and low on the north horizon. Early frost this year As if our half  "summer" wasn't short enough already? Most locations in Minnesota will wake up to early frost Saturday morning. The inner core of the Twin Cities metro area may escape a hard frost, but temperatures in the lower 30s are likely in the outer suburbs.

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Twin Cities NWS

The twin Cities Urban Heat Island may keep temps near 40 degrees downtown, but not in the suburbs especially outside the Interstate 494/694 loop.

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NOAA

The warming trend kicks in next week, and temps should reach the 70s once again.

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Weatherspark