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High Winds Creating Critical Fire Weather Threats in California; Heavy Rains Along Gulf Coast

Strong to high winds are creating critical fire weather conditions across much of California, and explosive fire growth in Southern California. Wind gradients gradually weaken Sunday and through mid next week. Conversely, very wet conditions will develop this week as week along the Gulf Coast; and unsettled weather pattern to the north with snow from the Great Basin to the High Plains. Read More >

Astronomical Data and Information

Lake of the Woods - Copyright 1999 M.Fuhs

 The July setting sun casts its brilliance
over Lake of the Woods, Ontario


The principle of Rayleigh Scattering explains the red or orange sunsets.  As the sun moves lower in the sky, its light has to travel through "more" of the atmosphere since the sun is at a much lower angle.  In fact at the horizons on a level plane, the atmosphere is about 40 times more thick than it is directly overhead.  Particles and molecules in the atmosphere will scatter out the shorter wavelengths (blue in the color spectrum) more easily than longer ones (red).  Thus, we are left with the reddish portion of the light spectrum to see. 





Season Starting Dates and Times
Mar 20
5:29 AM CDT
Jun 20
11:24 PM CDT
Sep 22
3:02 PM CDT
Dec 21

10:28 AM CST



2017 Major Meteor Showers
Peak Dates
Jan 3-4
Peak is in the pre dawn hours, in fact the best viewing is just before sunrise.  Waxing crescent moon will set in the evening and provide no interference.  This meteor shower always favors northerly latitudes in the northern hemisphere due to its radiant being near the handle of the Big Dipper asterism, but its peak only lasts for a few hours.  Therefore most observers see rates much less then 50-100 per hour.


Very early morning Apr 22


Look between midnight and sunrise, with the peak viewing just before sunrise.  A thin, waning crescent moon for all practical purposes will not give any interference.  The radiant for this shower is near the border of the constellations Lyra and Hercules.     

Eta Aquariids

May 5-6


Peak time occurs for a couple of hours just before sunrise.  Waxing gibbous moon will provide no interference as it will set before the pre dawn hours.  This shower favors the southern hemisphere and the southern latitudes of the northern hemisphere as the radiant is from near the star Eta in the constellation Aquarius.  In the northern U.S. and Canada, less than 10 to 20 meteors per hour can be expected whereas the shower is quite spectacular in the southern hemisphere.

Delta Aquariids
July 28-30
Peak time occurs for a couple of hours just before sunrise.  Waxing crescent moon will provide no interference.  This shower favors the southern hemisphere and the southern latitudes of the northern hemisphere as the radiant is near the star Delta in the constellation Aquarius.  In the northern U.S. and Canada, less than 15 to 20 meteors per hour can be expected and the meteors are typically rather faint.

Aug 12-13

The peak of the Perseids occurs from 9 am CDT August 12th through 9:30 pm August 12th.  That's daylight, so watch for the Perseids from the late evening hours of August 11th through the pre dawn hours of August 12th, and again from the late evening of August 12th through the early morning hours of August 13th.  The radiant is in the constellation Perseus but meteors from the Perseids are seen all over the sky.  Unfortunately, a waning gibbous moon only a few days past full will provide major interference. 


Oct 21


Peak viewing is in the early morning hours of October 21.  A new moon will provide no interference.  The radiant is north of Orion's red giant star, Betelguese.    


Nov 17-18


 Look before dawn on November 17th or 18th, with the radiant emanating from the constellation Leo.  A new moon will provide no interference. 

Evening Dec 13 to early morning Dec 14
The peak viewing time will be 12:30 am CST, (just past midnight) on December 14th.  In addition, a thin waning crescent moon will provide little to no interference.  The Geminids provide on average the best meteor shower of the year as the radiant is near the twin's heads in Gemini.  


*ZHr is the maximum numbers of meteors expected per hour at Zenith (straight up in sky) and under a very dark sky.  Average meteor rate can be expected to be less (much less in an urban environment.)

Radiant:  A point in the sky in which meteors appear to originate.



These pages were developed in response to public inquiries concerning astronomical data.