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  • Between the mornings of May 15 and 19, a strange phenomenon was detected by the National Weather Service Radar in Spokane (located 3 miles north of Fairchild AFB).
  • This phenomenon developed each day at approximately the same time (around 430 am) and over the same location, near the Turnbull National Wildlife Refuge south of Cheney.
  • Each day the phenomenon seemed to fan out with the prevailing low-level winds and disperse by 5 am. 
     

May 15th

May 15 radar loop

  • The first morning detection occurred shortly after 425 am near point "A".
  • The radar echoes (originally blue and green colors) fanned out to the northwest and north-northeast.
  • Prevailing low-level winds were out of the southeast.

May 16th

 

May 16 Radar Loop

  • On the morning of the 16th, the echoes first appeared around 434 am, again near point "A".
  • The radar echoes fanned out to the northwest, ending up somewhere near Edwall and Reardan.
  • Prevailing low-level winds were out of the southeast.

May 17th

May 17 Radar Loop

  • A day later, the echoes appear at 431 am.
  • The echoes again fan to the northwest.
  • Prevailing winds were from the southeast.

May 18th

May 18 Radar Loop

  • Unlike the previous three mornings, there were showers falling in the general vicinity.
  • Also unlike the previous 3 mornings, the strange echoes moved off to the east-northeast.
  • The prevailing low-level winds were out of the south to southeast.

May 19th

May 19 Radar Loop

  • The morning was clear and fairly cool.
  • This morning also saw the echoes moving to the northeast.
  • This was similar to the low-level winds, which were from the southwest.
  • Officials at Turnbull Wildlife Refuge, under the radar echo, reported nothing unusual at the time.

Daily Location of this phenomenon

Turnbull NWR topo

  • Point "A" on the previous radar images correlates with the green arrow on the image to the right.
  • This places the origin near Long Lake in the Turnbull Wildlife Refuge, southwest of Cheney.
  • On other days, the echoes originated slightly east, near Turnbull Slough.

How Deep are the Radar Echoes?

Radar Cross Section

  • Using a radar cross-section, we can estimate how deep or thick these returns are.
  • The based of the radar beam is around 2250 ft MSL.
  • The top of the green (or most dense echoes) is around 4000 ft, and the darker blue echoes extend to nearly 5000 ft MSL.

  • After some very cold temperatures (below freezing on the mornings of May 21-25), the echoes returned to the area in June.
  • The weather during this period was cooler and wetter than what occurred in May.
  • On one occasion, the odd echoes originated from two additional locations.

June 6th

June 6 Radar Loop

  • The morning was clear and cool.
  • The low-level winds were from the east.

June 7th

Jun 7th Radar Loop

  • This was a wet morning, at least northeast of the site. Notice the showers (yellow and green echoes over the Spokane Valley and Coeur d'Alene).
  • The echo near Marshall late in the loop was a rapidly forming shower.
  • Low-level winds were from the southwest.

June 8th

June 8 Radar Loop

  • This was a clear and dry morning. Cool temperatures prevailed.
  • Low-level winds were from the south.
  • The echo splits late in the loop.

June 10th

June 10 Radar Loop

  • The morning weather was cloudy with numerous showers north and east of the site (not seen on this loop).
  • Low-level winds were from the southwest.
  • Radar echoes formed near Reardan and extreme NW Spokane County.

June 10th Locations

 

  • On the morning of June 10th, additional echoes originated over extreme NW Spokane County, and near Reardan.
  • Both sites were near bodies of water.

NW Spokane County Reardan        

 

By Jonathan Fox