Good Morning Bloggers!
By 6am this morning, a weak cold front was approaching KC from the northwest. The very light winds had shifted to the northwest behind the front in northern Kansas and far northwestern Missouri. Near that surface low, fog and mist were reported early this morning across Iowa.
Early morning temperatures behind the front had dipped into the 20s in St. Joseph and Manhattan, KS. Ahead of the front, KC was in the 40s and the downtown airport was just shy of 50° at 6 am.
The front sneaks into the metro later in the morning, then lifts back north of the metro tonight as a warm front. The winds, although light, will be able to shift from the west later today, then out of the southeast tonight. Despite this front, we still warm to the low 60s today.
After a 70° Sunday, a second cold front will drop Tuesday’s daytime temperatures into the 50s. More 60° days will then follow. This is much warmer than our average high of mid-40s for early December.
Here’s the key to our extended period of warmer than average weather. It’s the upper level flow pattern, which parallels the white lines on the map below.
The flow is mainly west-to-east. It’s called a “zonal” flow and can be very efficient at keeping the cold air locked up to the north. The zonal flow dominates our weather pattern for now, which is why we have at least a week’s worth of warmer than average temperatures ahead of us.
When the flow develops segments more ”meridional” or north-to-south and south-to-north, these flow lines appear more wavy. These long waves in the jetstream allow cold blasts of air to plunge southward and drop our temperatures. After all, you’d expect a north-to-south flow to advect cold air southward, wouldn’t you?
Below is the European Model’s forecast for next weekend (9 days from now):
This is a distant forecast and there is disagreement on the timing of this upper level trough between the European Model and the GFS model. We’ll see if these different models can converge on a solution that show a cold blast by the end of next week or shortly thereafter. Could it spell rain as well in this time frame? We’ll be talking about it on future blogs and on the midday and 4:30/5/6 pm newscasts.
Have a great weekend.