We are in the midst of a quiet and rather sunny period of weather here in central New York. Jet stream winds aloft are buckling with high pressure forecast be close to us for the foreseeable future.
If everything turns out as we are forecasting, we will end up with a stretch of dry weather for a full week. That begs the question: how unusual is it for dry weather this long during the month of September in Syracuse? The numbers say pretty often. Just over the last 10 years we’ve had four Septembers with at least a week’s worth of dry weather. In 2009 we actually had 10 straight days! Looking back over a longer period of time (60 years) you find Syracuse has such a stretch once every four years. It kind of makes sense that we can get these periods of drier weather. We are moving out of the heat and humidity of summer so systems moving through the northern tier of states have less moisture available to them. If you look back at the monthly records since 1949, some of our driest months on record have occurred during the early fall.
It looks our next chance for rain comes next Monday and the culprit is either a cold front moving in from the west or low pressure moving north along the Northeast coast. This low is kind of a ‘wildcard’ to the forecast because there are differing solutions from our computer models as to the strength and, more importantly, the track of the low. To give you a sense of what we are dealing with here are forecast maps from both the GFS and the European models on next Monday.
European Forecast Monday 8 AM
GFS Forecast Monday 8 AM
As you can see, there is quite a bit of difference which means our confidence in Monday’s forecast is lower than on the other 7 days of our forecast. We are keeping our chances for rain low for Monday for now (30%) because of that uncertainty. That ‘wetter’ solution from the European model is new within the last day or so but even with this change we have to respect what it is sayinging because it tends to be the most accurate computer model we use.
So the bottom line is even with the uncertainty for Monday, this will be our best chance for showers over the next 7 days. Even if the coastal low is too far east there is the cold front approaching from the west. You can see those showers to our west Monday morning on both the models above.