Rain, snow, and a possible tropical low are in our future through next week (notice the ‘rhyme’ with the lack of iambic pentameter? lol). Glancing at our HAMmodel extended GFS products a formation similar to what occurred during the last snow event is starting to take shape. As i’ve previously discussed, using GFS this far out tends to be problematic at best, yet it is still an essential and exciting thing to do.
Today let’s begin by examining our HAMmodel 180 hour Liquid Precipitation Forecast product at 3 hour intervals (below).
A few things are immediately apparent, the first being that precipitation will begin entering the western United States from central California northward to the Pacific Northwest. This will begin as early as this evening and tomorrow morning. So take your galoshes and umbrellas for the kids if you plan to search for goulies and goblins on Halloween, or for those Harry Potter fans “All Hallows Eve.”
As the rain begins moving further inland we can expect some snow in the upper elevations, with some excitement showing itself by midweek and especially by next Thursday in the great plains. As you view the animation above, do you notice a familiar pattern in the distribution of the forecast precipitation? =)
Let’s examine this from a different perspective with our HAMmodel GFS 180hr Forecast Snowdepth product (below).
Notice as our HAMmodel 180hr Forecast Snowdepth product begins (please refer to this post for descriptions of the product) no snowdepth is shown (also recall that GFS is a low resolution product), however as the days progress, most notably beginning around Monday, showdepth (projected snowfall) propogates easterly into the Rockies and eventually into the Great Plains by midweek.
The last two times since the advent of fall that GFS has displayed a similar pattern, we received respectable snowfalls in the general area, and around the general times forecast. What is most exciting about the combination of liquid precipitation forecast product and forecast snowdepth product are the clearly delineated outlines defining the potential for an ‘event.’ Let us see if it is so.
Depending upon model transition for the above, and with respect to tropical activities, there is some strong disagreement with emphasis upon a strongly tilted negative trough into next week, in and around the southern Mississippi Valley. However, there does seem to be a general agreement with the possibility of a tropical or hybrid low developing in an area from the Western Carribean out along aline heading towards Bermuda. It will be fun to see if anything can pull together.
As always stay tuned to your favorite weather outlet, stay informed, and stay safe!