Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Lincoln Illinois
257 PM CDT Monday Apr 27 2015

Short term...(tonight)
issued at 256 PM CDT Monday Apr 27 2015

High pressure dominating central Illinois again for
tonight. Northerly winds will become light and somewhat variable
tonight as the ridge axis moves over the region. Efficient
radiational cooling set up expected as temperatures drop into the 30s yet
again. Southwestern portions of the County Warning Area may reach towards a low of 40,
limiting the potential for frost. Northestern County Warning Area not as warm and patchy
frost still likely. Will have to watch xover temperatures later this
afternoon, but winds should stay up a little bit and prevent a big
drop in visible.


Long term...(tuesday through monday)
issued at 256 PM CDT Monday Apr 27 2015

North-northeasterly flow continues to push cooler than normal air
into central Illinois and will keep a very slow warming trend going
through Wednesday. After a cool morning Tuesday with lows in the
upper 30s in much of central Illinois...highs will reach the middle 60s
Tuesday and again Wednesday...with light north-northeast breezes.

Fairly complicated pattern setting up for Wednesday into Thursday as
a deep upper low passes by through the southern states and a
Canadian shortwave looks as though it will drop rapidly southward as
it becomes blocked by a deep low off the Nova Scotia coast. Current
models are in fairly good agreement moving the upper low south
through Indiana Wednesday night...pushing a cold front into
Illinois...and perhaps producing some light precipitation in the
region. Given the wide variations in model handling of this feature
the past few days...have held off introducing probability of precipitation into the forecast
but have trimmed back highs for Thursday as this could turn out to
be a cool breezy day.

Through the weekend...moderately strong zonal will set up over the
northern U.S. While southerly low level flow over the plains
transports Gulf moisture northward. Enough moisture and instability
will move into central Illinois for chances of showers and thunderstorms
developing Friday night through the weekend as upper level
disturbances interact with the moisture and instability. Warm
temperatures expected through this period with highs in the 70s and
lows mainly 50s.


Aviation...(for the 18z tafs through 18z Tuesday afternoon)
issued at 104 PM CDT Monday Apr 27 2015

VFR and breezy north-northeast winds through the afternoon, becoming light
and variable in the overnight. Little expected in the way of
ceilings...with a scattered cumulus field developing between 4500 and 5000 feet. Will
watch closely for the xover values this afternoon, but so far,
winds should stay up just enough to counter fog development
tonight, similar to last night. Keeping VFR throughout.


Ilx watches/warnings/advisories...


Short term...hjs
long term...Onton

National Weather Service Glossary of Abbreviations