Happy Thursday to all you weather fans and afficionados in the tri-state :-)
Showers and storms have been here and there around the region since yesterday, but our primary focusing mechanism (that pesky slothful cold front we've been talking about) finally sags farther south, hopefully giving us a breather. But, it won't be for everyone though-- here's what some of the models are indicating:
|GFS - 2pm Thursday||CMC - 2pm Thursday||WRF - 2pm Thursday|
Note that there's a fair amount of agreement as to where the line sets up of rain vs. no-rain, however, it's going to be a sharp line. The models are indicating an arriving clear-out not far behind this frontal boundary that will be draped in the south. A little jog here and there can take someone who was initially expecting sunshine, and instead give them showers (or vice verse). The threat for flooding should be a litlte lower today. Despite more areas with wet, saturated ground, the bulk of the rain that could get us over the line will instead be much to our south.
Local modeling of our anticipated rainfall situation:
|HAS Precipitation Forecast||HPC Precipitation Forecast|
The heavier stuff progresses to our south.
Now we have to turn our attention to the cooler weather that comes with the clearing skies. Yesterday we were talking about the below-normal weather riding in for the rest of the week once this front sags through, and it looks like that is becoming a reality. Several counties in the north are under frost and freeze advisories (see the maps below). Locally, most of the threat is for temperatures in the mid-to-upper 30s, which may end up being more of an annoyance for those waiting out for the school bus than many of the plans out there-- but anything grown too early out of season isn't going to like it :-)
---Looking Ahead Weather Tangent (feel free to skip past)---
[Cue Dire Music]
Recall a little while back that I pointed out the back end of many of these mid-range forecast models like to generate large, ominous storms, and that often they simply modify into something anticlimactically less worrisome by the time they get here. Well, this may well be another one of those cases.
|GFS - Surface Map / Atmospheric Thickness - Tuesday PM
||CMC - Surface Map / Atmospheric Thickness - Tuesday AM|
|GFS - Precipitation / 850mb Temperatures - Tuesday PM||CMC - Precipitation / 850mb Temperatures - Tuesday AM|
Okay, so this may be a bunch of gobbledy-gook comin at you, so let me break down a little of this. The top row of graphics contain the surface map (where you typically see areas of high pressure and low pressure), and the atmopsheric thicknesses (a measurement of how thick, in decameters-- tens of meters, the atmosphere is from one pressure level to the other). The reason why the atmospheric thickness is a good measurement to have is because you can get a general impression of the temperature of a whole column of air with one number, because the generally warmer columns of air would be a little thicker than the colder ones. So looking at the top row of maps, the "540" line is dashed and in red. This represents a measurement of 5400 meters, but more importantly is typically associated with a temperature profile capable of bringing snowfall to locations at sea level. Notice how far south this line has plunged to at the times indicated by the model. There is a little disagreement between the two on timing, but it is interesting to see the kind of game-changing cold they want to advertise. Add to that the information given by the maps on the bottom row. The contours in blue represent precipitation, and the thick black line represents the 0°C line at 850mb (a just-above-the-surface temperature measurement). With these maps we see that (a) Thicknesses will be cold enough to support snow; (b) a Surface low pressure system will be off-shore and a northerly wind-flow will come off the Great Lakes toward our location; (c) Temperatures at 850mb will be below freezing (actually in a 'sweet spot' for snow formation); (d) Precipitation is being advertized on both models.
So basically it's got your attention. :-) However, models can make a spectacularly good case for a forecast that just happens to be wrong. Let's just keep this in mind, and see how things go in the coming days. Oh, and one more map to show you on this tangent...
|GFS - Temperature Anomaly - Tuesday PM|
Talk about game-changing... How about temperatures 10-15° below normal for the afternoon, with lots of heat out west (a virtual flip-flop from most of the last month)
...Let's just see if this same thing holds true on the model runs a few days from now... I have my doubts. But at the very least it's important to be aware of the long-range possibilities.
Let's just take care of the couple of days we have on our plate right now... Track the showers as they slide to the south, and see how far the colder air penetrates into our valleys. Sunshine should eventually work its way in soon enough, providing for some great Easter Egg hunting weather-- hopefully right up through your sunrise services (but you might want to think about some chilly morning clothing options, just in case) ;-)
|Regional Radar/Satellite with Warnings Tracking||
From the Storm Prediction Center (below): Click For a Larger Image
|Activity Overview||Storm Outlook||Watches||Potential Watches||Storm Reports|
|Temperatures||HD Doppler Radar||Estimated Rainfall||Active Warnings|
|Click For Larger||Click For Interactive Radar||Click For Larger||Click For Larger|
Have a great day everyone!