Raleigh Weather Discussion
We may be on our way to the coldest March in quite some time. So far for the month of March, RDU is 4.29F below normal. The next 10 days at least look to remain much colder than normal, so winter it seems decided to visit North Carolina late this year from late January through March.
In the short term, we will likely see a line of showers and possibly some thunderstorms move through the area this evening and the rain may linger through tomorrow morning. The clouds/rain should clear out as the day progresses and temperatures tomorrow may race into the upper 60s.
But this may be the last day in the 60s for a while as a much colder than normal pattern sets up with even the threat of some wintry precipitation. An upper level disturbance will move through Wednesday night and Thursday morning and this could provide the chance for a shower or possibly a snow flurry Wednesday night into Thursday morning. Cold air will pour in behind this front and the rest of the week into next week will feel more like January/February then late March. Highs will likely be in the 40s/50s.
A complicated weather pattern begins to set up Friday through early next week as the NAO goes very negative with a west-based Greenland block and a strong polar vortex setting up over southeast Canada. At the same time a trough will set up over the southern plains and we may see several disturbances move through the area.
The models are differing over the exact track and nature of these systems with each run. But the gist is that we will see unsettled weather from Friday through Monday most likely. Some of the more extreme scenarios have been for a round of snow or rain/snow mix to move through Friday/Friday night and perhaps a more significant storm Sunday/Monday with heavier snow possible. Some runs of the ECMWF have shown this. In general the GFS has been further north and although even this model argues for some snow to mix in in this period, the precip would likely be mostly rain.
All I can say right now is that all scenarios are on the table. Accumulating snow in the Triangle is not unheard of but very rare by late March. RDU got 7.3 inches on 3/24/83 and several snows in the last 10 days of March in the early to mid 70s. The all-time great late snowstorm in Raleigh was on April 2nd and 3rd 1915 when 10 inches of snow fell. So again, snow this time of year is not unheard of but it has been since 1983 since we have received measurable snow after 3/20, so it has been 30 years.
National Extended Weather Discussion
A general –NAO pattern looks to stick around although it may weaken some. This will keep a general cooler than normal pattern around through at least the first few days of April for the eastern US. Troughiness looks to increase in the west though so we could see a cooler pattern develop there with the Plains perhaps being the warmest spot through time.
With the MJO still hanging out in phase 7 and the ECMWF weeklies keeping the cool pattern going through the first week of April, I think a general cool pattern for the east will continue the next 2-3 weeks. WE could see this break by mid-April and it is possible we could see a warmer pattern set up by the 2nd half of April.