22 FEB 2011 Long Range
Forecast updated 2:00pm EST - 22 Feb 2011
Looking ahead into the next week there is a significant chance for a major precipitation
next Monday. An intense surface low is moving into the Illinois/ Indiana region Sunday
going into Monday morning and with it a lot of moisture and instability.
With spring nearing temperatures will begin to flucuate from freezing to non-freezing within
the next week and by Monday the thickness lines are indicating above freezing temperatures
to correspond with this low pressure system. The first weather graphic below shows the
location of the 540 thickness line (1000-500mb thickness) and the areas of strong precipitation
(measurements are for the 3 day totals). The areas of concern are the southern and northern
boundaries of Indiana. These large amounts will bring the threat of river flooding.
The following graphics are the 12Z run of the GFS looking into the forcings for Monday at 12Z.
There is a significant Vorticity maximum that lies directly southwest and north of the surface
low's center and along with that Omega values in the -19 range. However looking at temperature
advection by the wind there seems to be little if any advection in the region of high vorticity and
negative omega values.
Judging from these findings and the observations of recent precipitation events over the past few weeks
it's safe to say that any minor changes in the track of this surface low will determine the severity of
events for the Indiana region.
Today's long-range forecast graphic was produced by Brittany Davila and Brian Doogs