Storm-weary U.S. residents pounded by Superstorm Sandy may have a new storm to contend with on Wednesday: an early-season Nor’easter is expected to impact the mid-Atlantic and New England with strong winds and heavy rain. Our two top models, the European (ECMWF) and GFS (run by the U.S. National Weather Service), are now in agreement on both the track and intensity of the storm. The storm will move off the coast of South Carolina/Georgia on Tuesday evening. Once over the warm waters off the coast, the low will intensify, spreading heavy rains of 2 – 3″ over coastal North Carolina on Tuesday night and Wednesday morning. The storm will accelerate to the north-northeast on Wednesday and pull in cold air from Canada, intensifying into a medium-strength Nor’easter with a central pressure of 984 mb by Wednesday evening. The European model, which did an exemplary job forecasting Hurricane Sandy, is slower, predicting the Nor’easter’s highest winds will begin affecting New Jersey on Wednesday night. The GFS model is about 12 hours faster, predicting the strongest winds will arrive on Wednesday morning. A 12-hour period of strong winds of 40 – 45 mph will likely affect the coast from Maryland to Massachusetts, accompanied by a swath of 2 – 3″ of rain. The heaviest rains will likely fall over Eastern Massachusetts and Rhode Island. The storm also has the potential to bring more than a foot of snow to mountain areas of New England. The storm is still four days away, and four-day forecasts of the path and intensity of Nor’easters usually have large errors. Nevertheless, residents and relief workers in the region hit by Sandy should anticipate the possibility of the arrival on Wednesday of a moderate-strength Nor’easter with heavy rain, accompanied by high winds capable of driving a 1 – 2 foot storm surge with battering waves. The surge and waves will potentially cause moderate to severe erosion on New Jersey coast, where Hurricane Sandy pulverized the protective beach dunes.

Figure 1. Predicted wind speed for Thursday morning, November 8, 2012, from the ECMWF model (left) and predicted wind speed for 2 pm EST on Wednesday, November 7, from the GFS model (right). Both models runs were done beginning at 12Z (8 am EDT) on November 3, 2012. Winds tropical storm-force (39+ mph) are predicted to extend from coastal Virginia to Massachusetts. The GFS model brings the Nor’easter to a point off the New Jersey coast about 12 hours faster than the ECMWF model.

Figure 2. Forecast track error for four of our top models used to predict Hurricane Sandy. The GFS model performed the best for 1 – 3 day forecasts, but the European (ECMWF) model far out-performed all models at longer-range 4 – 5 day forecasts. This may be due to the fact the model was able to successfully predict the timing of the arrival of a trough of low pressure over the Eastern U.S. that acted to steer Sandy to the north and then northwest. Image credit: Morris Bender, NOAA/GFDL.

Charities mobilize for Sandy
Sandy’s death toll of 109 in the U.S. makes it the 25th deadliest hurricane in U.S. history, and the 2nd deadliest since 1972, when Hurricane Agnes killed 122 in the Northeast U.S. The main owners of The Weather Channel have agreed to match donations of up to $1 million to the American Red Cross, with all donations to benefit people in the hard-hit areas of the U.S. To have your donation matched, please visit www.redcross.org/sandy, or text SANDY to 90999. I also recommend my favorite disaster relief charity, Portlight.org. They are focusing their response efforts exclusively on the post-Sandy needs of people with disabilities.Check out the Portlight blog to see what they’re up to. Sandy’s greatest devastation occurred in Haiti, where rains of up to 20 inches in 24 hours unleashed rampaging flood waters that killed at least 54, left 200,000 homeless, wiped out thousand of acres of crops, and killed massive numbers of livestock. For impoverished families in Haiti still struggling to recover from the earthquake in 2010 and Hurricane Isaac in August, Sandy was devastating. These crops are the very essence of rural Haitian’s livelihoods, and there are fears widespread starvation will result. A disaster relief charity in Haiti that I’ve contributed to for many years, The Lambi Fund of Haiti, is seeking donations to help farmers purchase local seeds so that they can replant their crops in the wake of this latest terrible Haitian catastrophe.

I’ll have an update Monday, unless there’s some major change in the model forecasts for the coming Nor’easter.

from:    http://www.wunderground.com/blog/JeffMasters/article.html