Forecast updated 1:00pm EST - 15 Feb 2011
Moving into Thursday and Friday our warming trend will continue as a ridge builds over the Great Plains. High pressure stationed over the Southeast will continue to bring warm air northward into the Ohio Valley region. The first plot below shows the progression of the 5520m 1000-500mb thickness line for the next 7 days. As you can see a slight ridge will be stationed over the Great Plains but will continue eastward over the East Coast as we head into next week.
Our best chance for rain in the 5 days comes on Thursday night and Friday in the morning hours. There was no sign of vorticity advection during this time period but the warm air advection should be able to support the vertical motion for precipitation. The second plot below is a plot of the temperature advection by the geostrophic wind at 850mb at 00Z Friday, forecast hour 60. Also shown are the winds at 850mb as well as the heights. This plot shows a concentration of warm air advection in the area centered over southern Illinois at this time. The next time periods have this warm air advection decreasing as we move forward but still should be enough to support a chance for rain on Friday.
With the warm air advection in the air on Friday we expect temperatures to continue to be in the mid-40s or low 50s after a high around 60 on Thursday. The third plot below shows the 2-m temperatures and 10-m winds for 00Z Saturday, forecast hour 84. Temperatures are in the mid-40s with winds out of the northwest. This situation would support cold air advection at the surface which also is visible at the mid-levels (850mb and 700mb). This forecast has a cooling of temperatures during the weekend back into the low 30s and high 20s.
Today's long-range forecast graphic was produced by Kevin Van Leer and Matthew Rudkin.