Archive‎ > ‎EAS 434 - Spring 2013‎ > ‎Mar 21 briefing‎ > ‎

Long Range Web Ind



GFS 211 has precipitation forecasted on March 25 for 00Z.  The most intense area of precipitation is indicated by the low pressure symbol.  Based on the 6-hour total, South-east Indiana will partake in the heavier precipitation (~1 in), but the rest of Indiana will see not as heavy precipitation (~0.10 in).  Looking at the 850mb streamlines for this time period, there appears to be strong deformation over the northeast coast that could have aided in this precipitation.  The axis of contraction is stronger in the north than in the south, but there is a clear axis of dilation.  This is indicative of frontogenesis.  Since frontogenesis increases the magnitude of the potential temperature(theta) gradient, the potential temperature plotted at the 850mb height for this time period shows how tight the Theta becomes in the south part of the axis of contraction and further near the center of the low pressure.  The axis of contraction, dilation, and theta gradient help explain why precipitation has been forecasted for this time period in the Midwest, and specifically southeasterm Indiana.


Image created by Andrea Orton


 
Comments