Post by tornado on Dec 21, 2017 11:10:40 GMT -5
This is why we need ground observers: radar does not detect all precipitation. This case involves ASOS
but not CWOs.
2 sites in SW Nebraska with 900-foot overcast layers, were reporting light freezing rain. Those sites were
KIML (Imperial) and KMCK (McCook). Another site in NW Kansas, KGLD (Goodland), had light freezing rain
with an 800-foot ceiling. Radar showed no precipitation over those 3 sites. So either 3 ASOS sites were
reporting incorrect weather, or weather radar doesn't detect all precipitation. Since Goodland KS is the
site of a NWS Forecast Office; except for the fact that ASOS is reporting freezing rain instead of freezing
drizzle, it appears they believe ASOS over the radar:
Winter Weather Advisory
URGENT - WINTER WEATHER MESSAGE
National Weather Service Goodland KS
713 AM MST Thu Dec 21 2017
...FREEZING DRIZZLE ACROSS THE TRI STATE AREA...
COZ090>092-KSZ001>004-013>015-027-028-NEZ079>081-212215-
/O.NEW.KGLD.WW.Y.0006.171221T1413Z-171222T0000Z/
Yuma County-Kit Carson County-Cheyenne County-Cheyenne-Rawlins-
Decatur-Norton-Sherman-Thomas-Sheridan-Wallace-Logan-Dundy-
Hitchcock-Red Willow-
Including the cities of Yuma, Wray, Burlington, Arapahoe,
Cheyenne Wells, St. Francis, Bird City, Atwood, Oberlin, Norton,
Goodland, Colby, Hoxie, Sharon Springs, Oakley, Benkelman,
Culbertson, Trenton, Stratton Ne, Palisade, and McCook
713 AM MST Thu Dec 21 2017 /813 AM CST Thu Dec 21 2017/
...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 PM MST /6 PM CST/
THIS AFTERNOON...
* WHAT...Freezing drizzle occurring. The ice will result in very
slippery conditions on sidewalks, roads and bridges. Additional
ice accumulations of a light glaze are expected. The freezing
drizzle will change over to light snow or flurries this
afternoon. Snow amounts of less than an inch are expected.
* WHERE...Portions of east central Colorado, northeast Colorado,
northwest Kansas, west central Kansas and southwest Nebraska.
* WHEN...Until 5 PM today.
* ADDITIONAL DETAILS...a few accidents have already been reported
on Interstate 70 in northwest Kansas. Use extreme caution if
travel is necessary.
--------
As of 1600Z, 2 more sites reported light freezing rain, where radar did not indicate
precipitation. Those sites are Ord/Evelyn Sharp Field (KODX) in Nebraska, and Hill City
(KHLC) in Kansas.
Neither the NWS forecast office in Goodland KS, or Hastings NE, have yet extended the
Winter Weather Advisory to cover Hill City, Kansas. Let's see if they do so.
17Z edit:
Of course, it's hard for forecasters at Goodland to forecast, when ASOS goes belly-up:
SPECI KGLD 211636Z AUTO M06/M06 A2993 RMK AO2 PK WND 35034/1609
FZRAE10 P0000 I1001 T10561061 PWINO FZRANO $
METAR KGLD 211653Z AUTO A2995 RMK AO2 PK WND 35034/1609 FZRAE10
PRESRR SLPNO P0000 I1/// PWINO FZRANO $
METAR KGLD 211753Z AUTO A2996 RMK AO2 SLPNO 6//// I6/// 51031
PWINO FZRANO PNO $
METAR KGLD 211853Z AUTO A2995 RMK AO2 SLPNO PWINO FZRANO $
At least Goodland extended the WWA to cover Hill City KS:
Hastings, Nebraska radar still doesn't show precipitation over Hill City:
