|3pm Water Vapor imagery with approximate cold front position in blue|
So while the satellite was showing the cold front moving slowly to the east, what did that translate to in regards to precipitation? As you notice on the radar loop below, much of the preciptation has shifted east of the Cascades and Yakima (aside from some isolated showers over western Washington and Oregon) and was making a slow northeast path toward Spokane and northern Idaho. Based on this, it seems certain that rain will fall this evening over these locations, however the front is still expected to weaken during the evening. So where do we expect to see the best chances of rain during the evening between 6 pm and 9 pm?
|Radar Mosaic from 130pm-300pm|
According to the SREF model, the best chances will occur over the extreme northeast portions of Washington and adjacent portions of north Idaho (areas shaded in purples and reds). This would impact trick-or-treaters in Sandpoint, Bonners Ferry, and possibly Colville. However notice the SREF isn't expecting much chance of measurable precipitation over Spokane or Coeur d'Alene(greens are 20% chance of less). This is because the front is still expected to stretch and weaken as it moves to the east this evening. The other area of concern for rain is over the extreme southeast corner of Washington, near the Blue Mountains and Pomeroy. Based on current radar trends, this seems overdone, but bears watching. Let's now check on the hourly HRRR guidance to see if it agrees with the SREF.
|SREF measurable rain chances from 5pm-11pm|
So below you will see the hourly HRRR model data for the period between 6pm-9pm. The images represent what the radar might be showing during those times. Greens and blues show where the model thinks there will be rain. Generally speaking it agrees quite well with the SREF, by keeping most of the rain to the north and east of Spokane. In fact, most of the rain generally remains fixed over northeast Washington and doesn't really hit north Idaho in force until after 8pm, and by then the front looks quite weak. Also notice that over southeast Washington the forecast looks dry until 9pm and then later into the night (not shown here).
|6pm simulated radar from the SREF|
|7pm simulated radar from the SREF|
|8pm simulated radar from the SREF|
|9pm simulated radar from the SREF|
Rain or not, one thing is certain, this will be another mild Halloween. Much more so than what the region endured back in 2002. That evening, the holiday revelers had to endure temperatures in the teens. 2003 was not much warmer. However, since 2007, every Halloween evening has been fairly mild. Here's a look at trick-or-treat temperatures since 2000.
|Halloween temperatures at the Spokane Airport since 2000|