Thursday, April 19, 2018

Jack D's Email Re Bizarre Point Forecasts

I know they (HQ) are wanting more automation in forecasts so “staff can dedicate more time to warnings and community outreach”. In AFDs around here (southern Illinois), they pull no punches. I have heard “Forecast Builder” mentioned many times as well as “Forecast guidance” from Central Region HQ.  Today is the first time I have seen a forecaster ADMIT they have been constrained by automation.  He clearly favors the drier solution based on his expertise, but has to be “beholden” to the “consensus model blend” and POP values into the weekend.  I have heard “CONSALL” thrown around lately and I would bet this acronym is this blend he is talking about..........   
  Area Forecast Discussion 
  .LONG TERM...(Thursday through Sunday)
  Issued at 327 AM CDT Mon Mar 26 2018
  Forecast confidence continues to deteriorate through the extended
  portion of the forecast. Confidence is especially poor for the 
  weekend into next Monday. 
  Due to the disparity in timing of surface features,
*******and the  consensus model blend we are beholden to these days,*********
  the forecast details, especially winds, are not very representative of any 
  solution through the weekend. We have lots of PoPs all the way 
  through the weekend, but the drier ECMWF is the favored model at 
  this point. Look for lots of showers/rain Thursday, Friday into 
  Friday evening, and then late Sunday into Monday. Saturday through 
  most, if not all, of Sunday should be dry.
 Note - southern Illinois was dry and mostly clear on the Sunday mentioned above (Easter Sunday).

Jack Henz sent this link which provides some insights:

Examples of bizarre point point forecasts with meteorologically improbable changes in sensible weather at short time intervals (1 to 2 hours) are shown below:

Beckley WV
Snow and sleet likely before noon, then rain, snow, and sleet likely between noon and 2pm, then rain likely after 2pm.

Scattered rain showers before 9pm, then a chance of rain and snow showers between 9pm and 10pm, then a chance of snow showers after 10pm.

Sun Apr 15 forecast for Wed Apr 18th for Madison WI
Freezing rain and sleet likely before 9am, then rain likely, possibly mixed with freezing rain between 9am and 10am, then rain likely after 10am.

FCST point NE Montana
Rain showers and sleet likely, possibly mixed with freezing rain before 2am, then snow showers likely, possibly mixed with sleet between 2am and 3am, then snow showers after 3am.

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