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