Our next weathermaker, Winter Storm "Nirvana", is poised to being some light snow accumulations, perhaps 1 inch, starting early tomorrow morning.
The National Weather Service has issued a Winter Weather Advisory for Southeast Missouri from 3 AM to 6 PM tomorrow. Usually 1 inch of snow isn't enough to trigger an Advisory, but the forecasters are worried that the snow combined with high winds could cause travel problems. The advisory states:
* TIMING: LIGHT SNOW WILL SPREAD EAST INTO PORTIONS OF SOUTHEAST MISSOURI AFTER MIDNIGHT...AND POSSIBLY INTO FAR WEST KENTUCKY BEFORE DAYBREAK. ACCUMULATING SNOW WILL BE POSSIBLE THROUGH THURSDAY MORNING...GRADUALLY TAPERING OFF FROM WEST TO EAST THURSDAY AFTERNOON.
* MAIN IMPACT: SNOW IS EXPECTED TO ACCUMULATE ON ROADWAYS AND CAUSE TRAVEL ISSUES...WITH AROUND 1 INCH POSSIBLE.
* OTHER IMPACTS: GUSTY NORTHWEST WINDS AT 15 TO 25 MPH WITH GUSTS OF 30 TO 35 MPH WILL CAUSE BLOWING SNOW AT TIMES...WHICH MAY FURTHER REDUCE VISIBILITIES. WIND CHILL READINGS WILL DROP INTO THE TEENS AND POSSIBLY EVEN SINGLE DIGITS.
The GFS computer model cranks out 1+ inch of accumulation for Cape Girardeau. (Source: Earl's Computer Models page)
However, the NAM model is less bullish, suggesting that Cape won't see much. Based on recent history, it wouldn't surprise me if we got squat.
Indeed, the official forecast leaves open the possibility that we won't see anything:
TONIGHT: MOSTLY CLOUDY. A 30 PERCENT CHANCE OF SNOW AFTER MIDNIGHT. LOWS IN THE LOWER 30S. WEST WINDS AROUND 5 MPH IN THE EVENING SHIFTING TO THE NORTHWEST 10 TO 15 MPH AFTER MIDNIGHT.
THURSDAY: CLOUDY. SNOW LIKELY IN THE MORNING THEN A CHANCE OF SNOW IN THE AFTERNOON. SNOW ACCUMULATION UP TO 1 INCH. HIGHS IN THE LOWER 30S. TEMPERATURE STEADY OR SLOWLY FALLING IN THE AFTERNOON. NORTHWEST WINDS 10 TO 20 MPH WITH GUSTS TO AROUND 35 MPH. CHANCE OF PRECIPITATION 60 PERCENT.
THURSDAY NIGHT: MOSTLY CLOUDY WITH A 20 PERCENT CHANCE OF SNOW IN THE EVENING...THEN PARTLY CLOUDY AFTER MIDNIGHT. LOWS AROUND 18. WEST WINDS AROUND 15 MPH.
If the chance of precipitation is 60%, then the chance that we don't get any snow tomorrow must be 40%.
With all of this in mind, here's the first Dartboard Forecast for 2012: