Thursday, February 6, 2014

Quick Rant/Minor Weekend Snows/Next Week's Storm Potential

Quick Rant
Ever since the middle to later half of last week into this past weekend, there's been a lot of buzz going around about a significant winter storm to impact the area this coming weekend (2/8-2/9).  Besides there being 2 real wintry events (2/3 northern VA snow and 2/5-2/6 western VA Ice storm) in the meantime, the fact that this talk began 7+ days away is quite frustrating.  Any specific storm over 5 days away isn't going to get much attention from me.  We can only observe weather to a certain degree.  These observations are assimilated into computer models which use the data to come up with a forecast.   There are approximately 5 billion cubic kilometers of air in the Troposphere (where all of Earth's weather occurs).  To be able to have a 100% accurate forecast all the time would mean we'd have to know how all this volume of air was behaving at every second.  Of course we will never have the capability to do that, so we technically start with error in our forecast models from the moment they start running.  As the model goes further in time, these errors accumulate rapidly.  Errors in the 1-5 day period have much lesser implications than those in the 5+ day period. With that being said, I do think it's possible to look past the 5 day mark and note the overall pattern we're heading into.  If it was up to me, I'd just get rid of the snow maps (known as clown maps because of how ridiculous they are) for any period over 5 days away.  Bottom line, long range model guidance should be used to recognize patterns-not look for storms.  I've noticed a lot of degreed meteorologists are even posting these images with a headline something to the effect of "This is not a forecast. Just one run of a computer model".  If it's over 5 days away and it's not a forecast, why post an image that shows extreme totals?  I know a lot of times parts of the general public see these maps and run with them.  I have a friend up in New York who said there were signs on gas pumps today saying "Fill up your car.  Major Snow-Storm Coming this Weekend."  The only reason I can think of for these maps being posted are page likes and shares.  The sad part is, those first to post a random model snow-map that shows Richmond to Boston seeing a 12-24" blizzard 9 days away are usually the ones with 100k+ followers and 1,000+ shares per post.  Once these far off threats far apart, its just wash, rinse, repeat.  This probably won't ever end but you can do your part by not sharing these long shot events or contributing to the hype surrounding them.  End of rant.

2 Minor Snows Through This Weekend\
Our next weather maker is currently coming into California bringing some much needed rains to that area.  This system will swing across the southwest into Texas before working its way across the Carolinas and out to sea.  The reason this won't be a major storm is because the southern stream is way too far out ahead of the northern stream; preventing a phase between the two and a larger storm.

Instead, we will be dealing with two separate chances of snow (1 shot with each stream).  The southern stream will swing through during the day on Saturday.  This may bring a period of light snow across portions of central and southeast VA, where temperatures will be marginal.  I'm not expecting much from this since heaviest precipitation will stay across the Carolinas closer to the low.  There may be an inch or two along the far northern edge.

We will then watch the northern stream energy that was left behind swing through during the early morning hours on Sunday.  This will be the typical clipper like system where western slopes of the Allegheny Mountains may see a few inches with light flurries and snow showers breaking out in some areas across the Shenandoah Valley and northern Virginia.  I'm not expecting much of any accumulation in these areas.  If these two streams could have phased, we could have been talking about a more significant storm.  It's very tough to pinpoint the timing of two moving pieces so far out.

Next Week's Storm Potential
Earlier on the facebook page, I posted this image from the 00z Euro last night showing a split flow pattern setting up for next week.  The Gfs and the Canadian model looked very similar at 500 millibars.  This occurs when the jet stream breaks into two separate branches.  It often times presents a good chance for the mid Atlantic to see significant storms because of the moist flow out of the Pacific along with an active stream of northern disturbances.  It only takes one of these northern stream shortwaves to meet up with a piece of energy coming out of the Pacific to get a significant storm.  I'm not going to try and pinpoint any exact time frame, but the early to middle part of next week looks like it may present the best opportunity for a significant mid atlantic storm that we have seen so far this year.  It's time to sit back, wait, and watch as models come into closer range over the next few days.  It is worth noting that the Euro ensembles and Gfs ensembles both show this pattern setting up as well.

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