Looking at the latest numbers, I'd say things are leaning slightly in Martha Coakley's direction. No, I don't mean the poll numbers, I mean temperature numbers.
The Forecast Forecast: 36.1F (Coakley +3.1) More Clouds than Sun -- Lean Coakley
It's a widely held belief that the higher the turnout on Tuesday, the higher the chances that Coakley will win the election. The thought is that Brown's voters are more motivated right now and will come out to vote no matter what, while Coakley's support is a little softer, and rain, sleet, snow or cold might depress her numbers.
So in the fine tradition of pollster.com, fivethirtyeight.com, swing state project, and others who try to predict elections based on poll aggregation, I am introducing the Forecast Forecast, which will predict turnout (and therefore chances of winning) based on an aggregate of forecasts from eight sources.
The median temperature over the last 31 days is 33F, so a prediction above 33F would suggest a higher turnout, and a prediction of under 33 would suggest lower turnout. Precipitation would drive turnout down, where lots of sun would move it up.
So here is the data, as of 10:00pm, January 14:
Channel 4: 34F Mostly Cloudy
Channel 5: 34F Mostly Cloudy
Channel 7: 33F Sunny
Channel 25: 40F Mostly Cloudy, 30% chance of rain/snow late
NECN: 39F Mostly Cloudy
NWS: 37F Partly Sunny
TWC: 36F Mostly Cloudy
WUND: 36F Partly Cloudy
Based on the eight forecasts available Thursday evening, the Forecast Forecast predicts a temperature of 36.1 with more clouds than sun, and a very tiny chance of rain. Which means the forecast for Tuesday is Lean Coakley.
(NECN: New England Cable News; NWS: National Weather Service; TWC: The Weather Channel; WUND: Weather Underground)