Monthly Forecasts

1.13.2021 - Made adjustments to long range outlook today as some of the major global signals have changed. La nina hanging on longer. AMO has stayed near neutral last two months. Latest analogs suggest wetter & colder than average January for Wisconsin but still feel previous forecast maps are good. Be prepared for much colder than avg temps developing in the second half of January enough to offset early month warmth. It's been dry to this point but doubtful it remains that way.

12.21.2020 - Latest long range outlook today is suggesting that the DEC upper trough tendency in the eastern US will slide westward into western North America in January. In summary, no major changes from previous forecast except to emphasize temp forecast. This is far from certain but what we're going with for now.

300mb height anomaly based on analogs shows more troughing across western NOAM.

TEMPS - Above average temperatures expected across the eastern US including Wisconsin.

PRECIP - Storm track through the Ohio valley is favorable for near or locally above average precipitation trends across Wisconsin in January. Maybe not exclusively...but by the end of the month you'll should see it. I'm keeping Wisconsin in a the NEAR-NORMAL category for now...my feeling is for a "typical winter-like January". Wetter across the Ohio valley.

Confidence remains LOW. AMO might be flipping to neu-neg and PDO forecast is less certain following 11-2020 neg spike...in other words long term trends could be more consistent. Looking at CFS monthlies, the temp forecast is in general agreement.

11.25.2020 - Near average January for both precipitation and temperature. Perhaps some winter storms that bring above avg precipitation on a local basis.

1.13.2021 - Removed below average temp forecast for Wisconsin. Latest analogs suggest AVG-BELOW AVG temps in Wisconsin during February but didn't feel it was significant enough to map in. Might end up like a typical February. Precipitation forecast staying mostly the same with small adjustments. ABOVE AVG precip signal for central WI.

12.21.2020 - If we assume that the AMO will weaken this winter, heading back towards neutral (slightly pos for this forecast) and PDO follows same trend....

300mb height anomaly based on analogs shows more troughing across western NOAM.

TEMP - Backing off on below avg temp signal over the US this update...but keeping it for Wisconsin and western US. I excluded Upper Michigan from the below avg temp signal. Again this requires a tendency toward upper level trough over the western half of north America as suggested by global patterns.

PRECIP - Global pattern favors a storm track through the Great Lakes in Feb, with above average precip through Wisconsin. This could mean more rain AND/OR snow than average.

The risk is that we've been in +AMO for a long time and you'd have to predict a rare flip towards neu/neg this winter to make it happen. Thus confidence remains low.

11.25.2020 - Below average temperatures are likely in February across much of the country as the La nina weakens. Near average precipitation but likely a couple winter storms like normal.

1/13/2021 - No changes.

12/21/2020 - Somewhat depends on FEB 2021...if indeed is snowier/colder than average it would greatly increase the likelihood of a colder MAR. The global pattern suggests colder than average temps across much of the country. I pulled back to what is more likely...below avg temps across the north & central US. The precip forecast is close to average/normal.

POST MORTEM

Dec 2020 was drier than expected. Temperatures were on target.

FORECAST

Above average temperatures are favored across the Great Lakes region, especially into the north-central US. Near average precipitation. Based on ONI, QBO, AMO signal.

CFS forecast for DEC 2020

CFS Dec 2020 temperature forecast