(On or around the first Monday of each month I’ll review the previous month’s weather over the CONUS. These posts aren’t meant to be especially insightful, but rather to provide a basis of useful maps and other graphs to refer back to when appropriate.)
The following maps show a quick overview of the dynamics averaged over most of February.
The maps below show, in order: the total jet (1a) and the anomalous jet (1b) over the globe; the anomalous 500 hPa heights (1c) over the globe and the anomalous surface temperature (1d) and precipitation (1e) over the CONUS during February.
Most of the country ended up warm, largely as predicted in my February forecast post. My precipitation forecast was pretty far off though, with significant rain along the West Coast and a small deficit in the southeastern CONUS.
(This is the second in a series of monthly forecasts, which I will update on (roughly) the last Monday of each month. Each of these posts will be paired with a short retrospective of the past month, which will function as less of an analysis and more of a place to put maps/graphs for future reference.)
February has turned out to be mostly as expected; very warm in the east and less warm in the west. The million dollar question, then, is what happens next month?
Figure 1, below, shows the AO, NAO, and PNA archives and CFS forecasts for the next three months. I’ve marked March for easy referencing. Visually, the CFS forecast averaged over March seems to yield a fairly neutral AO and NAO, and a negative PNA.
A negative PNA implies ridging over the east and troughing over the west, which would extend the warmth we’ve seen along the East Coast this winter. Predictably, this corresponds with a CFS temperature forecast that shows precisely that, as well as some incredible warmth over eastern Europe and western Asia.
If this warmth keeps up during the next few weeks, it’s possible that grapes will begin growing for the season in the East. About half of the nights at the end of February have temperatures at or below freezing in DC, and the possibility of a March frost is quite high. This could have a negative impact on wine yields if the vineyards can’t keep their temperatures high enough.