Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Lincoln Illinois
922 am CDT Tue Sep 23 2014

issued at 920 am CDT Tuesday Sep 23 2014

Still mostly clear across the forecast area this morning, although
some high clouds are starting to spread into the western County Warning Area.
These will increase a bit through the day, but still should be
plenty of sunshine. Temperatures are rebounding nicely from the
cool conditions overnight, and are largely in the mid to upper 50s
as of 9 am. Hourly temperature trend needed some tweaking, but
overall highs in the lower 70s still look good at this point.


Short term...(today)
issued at 343 am CDT Tuesday Sep 23 2014

Large high pressure will slowly shift east today, but still control
the weather over the area. So skies will remain sunny to mostly
sunny and winds will continue to be light. Afternoon high
temperatures will be a tad warmer than yesterday, only reaching into
the lower 70s by this afternoon.


Long term...(tonight through monday)
issued at 343 am CDT Tuesday Sep 23 2014

First half of the forecast remains quiet and rather benign with high
pressure building into and remaining in control of the Midwest.
Surface ridge dominating much of the eastern half of the Continental U.S.
Actually as the pattern stagnates with the best upper level dynamic
and height gradient at h5 to the north. Thermal ridging out to the
west slowly leaking some warm air advection into the region in addition to
increasingly southerly flow as the ridge axis slips to the east.
Max temps continue to go up a couple of degrees each day and
eventually slightly above seasonal normals by late in the week. A
weak trof brings some precip to the plains Wednesday, but the ridge
remains in place and dry air eroding the activity before impacting
central Illinois. In the extended, the GFS and the European model (ecmwf) still in
conflict over dealing with the pattern shift towards the end of the
weekend and beginning of next week. GFS brings a diffuse wave into
the picture Sunday/Monday. Where the European model (ecmwf) was previously dry, it
is starting to pick up on a wave as well, starting as a retrograde
aloft and reorganizing a bit late in the weekend in the Southern
Plains. Overall, the models are having some major issues with when
and how to break up the substantial ridge. Keeping the forecast
conservative for now with only slight mentions until the models
become a little more cohesive.


Aviation...(for the 12z tafs through 12z Wednesday morning)
issued at 620 am CDT Tuesday Sep 23 2014

VFR conditions will continue at all taf sites next 24hrs. Skies
will be clear through most of the day, but then cirrus will advect
into the area from the west. Satellite loop shows that the cirrus
is trying to get into the area, but it will continue to dissipate
as it moves into a dry air mass over central Illinois. Winds today
will be light out of the south to southeast.


Ilx watches/warnings/advisories...


short term...auten
long term...hjs

National Weather Service Glossary of Abbreviations