This article is from the source 'guardian' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.
You can find the current article at its original source at http://www.guardian.co.uk/world/2013/mar/04/us-storm-moves-east-snow
The article has changed 7 times. There is an RSS feed of changes available.
| Version 1 | Version 2 |
|---|---|
| US storm moves east with snow forecast – but uncertainty remains | US storm moves east with snow forecast – but uncertainty remains |
| (about 1 month later) | |
| Meteorological spring may have officially started on Friday, but someone forgot to tell Old Man Winter. A large winter storm is currently developing over the Dakotas and is expected to spread east over the US in the the next three days. Snow is possible from Minneapolis all the way to Boston, though much uncertainty remains in the track of this storm system. | Meteorological spring may have officially started on Friday, but someone forgot to tell Old Man Winter. A large winter storm is currently developing over the Dakotas and is expected to spread east over the US in the the next three days. Snow is possible from Minneapolis all the way to Boston, though much uncertainty remains in the track of this storm system. |
| The most confidence I have in the forecast is in the northern midwest including in Minneapolis and Chicago. Winter storm warnings are in effect throughout the region for 6-12in of snow for Monday through Tuesday evening. Snowfall could fall at rates from 1-2in per hour Monday night into Tuesday. Winds on Tuesday could be between 15mph and 30mph – creating near blizzard conditions. | The most confidence I have in the forecast is in the northern midwest including in Minneapolis and Chicago. Winter storm warnings are in effect throughout the region for 6-12in of snow for Monday through Tuesday evening. Snowfall could fall at rates from 1-2in per hour Monday night into Tuesday. Winds on Tuesday could be between 15mph and 30mph – creating near blizzard conditions. |
| The storm will then move onto the northern Indiana and western Ohio, where winter storm warnings are in effect. Starting tomorrow and falling through Wednesday could be between 5 and 10in. Sleet may mix in within the snow south of Route 30. The snow should mostly miss Cleveland and Indianapolis. | The storm will then move onto the northern Indiana and western Ohio, where winter storm warnings are in effect. Starting tomorrow and falling through Wednesday could be between 5 and 10in. Sleet may mix in within the snow south of Route 30. The snow should mostly miss Cleveland and Indianapolis. |
| The snow should move into the Washington metropolitan area on Tuesday Night and last well into Wednesday. All models have the storm essentially stalling near here. The GFS model has 1.7in and the NAM 2in of forecasted liquid precipitation at the National airport, while the European has only around 1.2in. | The snow should move into the Washington metropolitan area on Tuesday Night and last well into Wednesday. All models have the storm essentially stalling near here. The GFS model has 1.7in and the NAM 2in of forecasted liquid precipitation at the National airport, while the European has only around 1.2in. |
| The biggest uncertainty in the forecast for the DC area is temperature. The temperature profile at National airport suggests that the surface could stay around 35F, even as all other layers of the atmosphere are at or below 32F. With precipitation rates well over 0.1in per hour (or 1in on a 10 to 1 ratio if it were snow), my guess that the dynamics should be able to overcome the shallow warm layer of the surface as modeled. We saw a similar phenomenon in New York during February's blizzard. | The biggest uncertainty in the forecast for the DC area is temperature. The temperature profile at National airport suggests that the surface could stay around 35F, even as all other layers of the atmosphere are at or below 32F. With precipitation rates well over 0.1in per hour (or 1in on a 10 to 1 ratio if it were snow), my guess that the dynamics should be able to overcome the shallow warm layer of the surface as modeled. We saw a similar phenomenon in New York during February's blizzard. |
| That's why you see snowfall maps put out by the models having significantly more precipitation set to fall as snow in DC than one might expect, given the surface temperature is never forecast to fall below 32F. Exactly where the eventual rain/snow line ends up is still up in the air. Either way, any preciptiation that starts as rain in DC should transition to snow, which is why a winter storm watch is currently issued for the area. | That's why you see snowfall maps put out by the models having significantly more precipitation set to fall as snow in DC than one might expect, given the surface temperature is never forecast to fall below 32F. Exactly where the eventual rain/snow line ends up is still up in the air. Either way, any preciptiation that starts as rain in DC should transition to snow, which is why a winter storm watch is currently issued for the area. |
| At this point, the best call is say to say 3+ in Washington DC and Baltimore, with the possibility of significantly more. To the north and west of the city in places such as Charlottesville and the Appalachian areas of Cumberland and Martinsburg, temperatures should be less of an issue. Six inches plus should fall in these areas with more than 12in possible. | At this point, the best call is say to say 3+ in Washington DC and Baltimore, with the possibility of significantly more. To the north and west of the city in places such as Charlottesville and the Appalachian areas of Cumberland and Martinsburg, temperatures should be less of an issue. Six inches plus should fall in these areas with more than 12in possible. |
| Up the coast to New York and eventually Boston, the final outcome is far from known. The GFS has been consistent on bringing major liquid precipitation to New York and Boston on the day of Wednesday and through Thursday morning. The GFS individual ensemble members don't have a single miss among them, which is quite unusual. The latest average the GFS ensembles has 1.25in liquid into New York and 3in (or 30in of snow if all precipitation fell as snow) in Boston! | Up the coast to New York and eventually Boston, the final outcome is far from known. The GFS has been consistent on bringing major liquid precipitation to New York and Boston on the day of Wednesday and through Thursday morning. The GFS individual ensemble members don't have a single miss among them, which is quite unusual. The latest average the GFS ensembles has 1.25in liquid into New York and 3in (or 30in of snow if all precipitation fell as snow) in Boston! |
| The GFS is joined by the Short-Range Ensemble Forecast model which continues to bring an inch or more of precipitation to both cities. Other models have been less enthusiastic including the European. | The GFS is joined by the Short-Range Ensemble Forecast model which continues to bring an inch or more of precipitation to both cities. Other models have been less enthusiastic including the European. |
| The European model –statistically the best – had been adamant about keeping the storm mostly south of Atlantic City. It did come north its most recent run, delivering a little over 0.5in of liquid precipitation to both New York and Boston. Still, it remains south of the GFS. | The European model –statistically the best – had been adamant about keeping the storm mostly south of Atlantic City. It did come north its most recent run, delivering a little over 0.5in of liquid precipitation to both New York and Boston. Still, it remains south of the GFS. |
| The difference between the two models is how they are handling an upper level low pressure system in upstate New York. The GFS merges the upper level low with the low pressure delivering the snow to DC quite well and drags it up the coast. The European does not do so as much. I'm not sure which is right, though the GFS has held serve the last few model runs. | The difference between the two models is how they are handling an upper level low pressure system in upstate New York. The GFS merges the upper level low with the low pressure delivering the snow to DC quite well and drags it up the coast. The European does not do so as much. I'm not sure which is right, though the GFS has held serve the last few model runs. |
| In terms of amounts, I expect some minor accumulation in both cities if the GFS or European have a clue. Obviously more if the GFS is right. Amounts are likely to be less than the pure liquid amounts as surface temperatures expected to be borderline. That's especially the case if the European model is correct, and heavier snow does not cool the atmosphere. | In terms of amounts, I expect some minor accumulation in both cities if the GFS or European have a clue. Obviously more if the GFS is right. Amounts are likely to be less than the pure liquid amounts as surface temperatures expected to be borderline. That's especially the case if the European model is correct, and heavier snow does not cool the atmosphere. |
| Snow, however, may not be the big story in the New York City area. Winds are expected to be quite strong along the coast line. We can't be too sure on wind direction yet, though wind speeds could be in excess of 40mph. This should cause rough surf and high waves in many areas still recovering from Sandy. Coastal flood advisories and warnings are likely to be issued for coastal areas in New Jersey, Long Island, and southern New England. | Snow, however, may not be the big story in the New York City area. Winds are expected to be quite strong along the coast line. We can't be too sure on wind direction yet, though wind speeds could be in excess of 40mph. This should cause rough surf and high waves in many areas still recovering from Sandy. Coastal flood advisories and warnings are likely to be issued for coastal areas in New Jersey, Long Island, and southern New England. |
| I'll being watching the models as this storm developed. Please keep an eye out for updates here and from the National Weather Service. | I'll being watching the models as this storm developed. Please keep an eye out for updates here and from the National Weather Service. |
| Our editors' picks for the day's top news and commentary delivered to your inbox each morning. | |
| Our editors' picks for the day's top news and commentary delivered to your inbox each morning. Enter your email address to subscribe. |