Winter Weather Update 12-24-17
Today’s 12Z model runs continue to show a potential wintry weather event in ENC by late next week.
12Z GFS shows some CAD from the high pressure situated over the Northeast retreating northward into Canada. Low pressure will develop and strengthen off the southeast coast Thursday night into Friday. Moisture will begin to overspread the region Thursday night and continue through Friday morning.
Precipitation type concerns will be the main issue with this approaching system. Forecast soundings show a shallow sub freezing layer at the surface thanks to the retreating high pressure over the northeastern US. Precipitation could start off as light snow over the northern half of ENC before warm air filters in aloft which should transition the precipitation to sleet and freezing rain mainly west of Highway 17.
It is still early in the forecast and changes are possible between now and Thursday night and this system should be monitored throughout the week and necessary actions taken if the forecast verifies.
I will be updating throughout the week with frequent updates regarding this potential system.
Update 8:15 PM: No significant difference in my forecast thinking from the 18Z GFS. Will wait for 00Z GFS later this evening.
Update 8:35 AM (12-25-17): Little change with the 00Z and 06Z GFS but a major shift southward on the 00Z ECMWF. The shift southward on the ECMWF would result in no precipitation at all for all of NC. Due to low confidence, the forecast beyond Wednesday is still up in the air.
Update 6:00 PM (12-25-17): No change in my forecast at this time. GFS and ECMWF still in disagreement on Friday’s system however recent GFS ensemble members are trending towards the ECMWF solution. We will see if this trend continues.
Update 12:00 AM (12-25-17): 00Z GFS is now trending towards the ECMWF solution. I will update later today with any changes to the forecast above.