Area Forecast Discussion
Issued by NWS Central Illinois

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KILX 180456
AFDILX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1156 PM CDT FRI APR 17 2015

.UPDATE...
ISSUED AT 859 PM CDT FRI APR 17 2015

HIGH PRESSURE OVER THE MIDWEST RESULTING IN RELATIVELY CLEAR
SKIES OVER CENTRAL IL THIS EVENING ALONG WITH LIGHT WINDS. HIGH
CLOUDS WILL GENERALLY INCREASE ACROSS THE AREA TONIGHT AS A LOW
PRESSURE SYSTEM OVER THE ROCKIES SLOWLY APPROACHES FROM THE
WEST...BUT NO MAJOR IMPACTS FROM THIS SYSTEM ARE EXPECTED
OVERNIGHT DUE TO THE RELATIVELY SLOW APPROACH OF THIS SYSTEM. WITH
AFTERNOON DEWPOINTS IN THE LOW TO MID 50S...FOG SHOULD BE MINIMAL
AS LOWS IN THE MID 50S ARE EXPECTED. NO UPDATES NEEDED AT THIS
TIME AS FORECASTS ARE IN GOOD SHAPE WITH THESE FEATURES.

&&

.SHORT TERM...(TONIGHT) ISSUED AT 256 PM CDT FRI APR 17 2015

QUIET WEATHER IS EXPECTED ACROSS CENTRAL AND SOUTHEAST ILLINOIS
TONIGHT WITH HIGH PRESSURE AND THE ASSOCIATED DRY AIRMASS IN
CONTROL. WE`VE HAD MORE INSOLATION TODAY THAN YESTERDAY, DESPITE
THE ROBUST CU FIELD, AND FORECAST SOUNDINGS SUGGEST THE LOW LEVEL
MOISTURE WILL BE FAIRLY WELL MIXED OUT. SO, DO NOT EXPECT FOG TO
BE AS MUCH OF PROBLEM LATER TONIGHT AS IT WAS IN SOME AREAS THIS
MORNING. OTHERWISE, LIGHT WINDS AND MINIMAL CLOUD COVER SHOULD
ALLOW FOR GOOD RADIATIONAL COOLING TONIGHT. EXPECTING OVERNIGHT
LOWS MAINLY IN THE MID 50S, WARMER THAN LAST NIGHT, THANKS TO
AIRMASS MODIFICATION/HIGHER DEW POINTS.

.LONG TERM...(SATURDAY THROUGH FRIDAY) ISSUED AT 256 PM CDT FRI
APR 17 2015

THE CUTOFF UPPER-LEVEL LOW, CURRENTLY BEGINNING TO LIFT NORTHEAST
OUT OF THE FOUR CORNERS REGION, IS STILL EXPECTED TO GRADUALLY
SPREAD SHOWERS AND A FEW THUNDERSTORMS INTO THE REGION AS IT MOVES
THROUGH. HOWEVER, AS IS OFTEN THE CASE WHEN DEALING WITH CUTOFF
UPPER LOWS, THE MODEL GUIDANCE HAS BEEN TRENDING SLOWER WITH ITS
EXPECTED ARRIVAL (SOME SOLUTIONS ARE STILL FASTER THAN OTHERS).
GIVEN THE SLOWER EXPECTED ARRIVAL, HAVE PRETTY MUCH REMOVED POPS
FROM SATURDAY, AND GREATLY LOWERED THEM SATURDAY NIGHT. IF SLOWER
TRENDS PERSIST, THEY WILL NEED TO BE LOWERED FURTHER THROUGH AT
LEAST SATURDAY NIGHT. STILL LOOKS LIKE SUNDAY AND SUNDAY NIGHT
SHOULD END UP FAIRLY WET AS THE UPPER LOW REMNANTS GET ABSORBED IN
TO A DIGGING NORTHERN STREAM TROF. WHILE ONE MIGHT EXPECT THE
SURFACE LOW TO WEAKEN AS THE UPPER FEATURE IT IS TIED TO DIMINISHES,
THE LATEST MODEL RUNS SUGGEST THAT WILL NOT HAPPEN IN THIS CASE.
RECENT GUIDANCE DIGS THE NORTHERN STREAM TROF MORE THAN PREVIOUS
SOLUTIONS, AND THE JET STREAKS ASSOCIATED WITH THE DIGGING TROF AND
DISSIPATING UPPER LOW ARE WORKING IN CONCERT TO STRENGTHEN THE
SURFACE LOW. THAT BEING SAID, THE CONSENSUS TRACK UP THE EASTERN
BORDER OF ILLINOIS IS NOT CONDUCIVE TO US GETTING INTO THE WARM
SECTOR AND/OR SEVERE WEATHER ON SUNDAY.

SOME POST SYSTEM SHOWERS ARE POSSIBLE ON MONDAY, POSSIBLY A GREATER
RISK THAN BEFORE IF THE SYSTEM SLOWS MUCH MORE THAN CURRENT
INDICATIONS. HOWEVER, OTHERWISE MONDAY SHOULD BE THE FIRST DAY OF
WHAT LOOKS TO BE A PROLONGED PERIOD TEMPERATURES ON THE COOLER SIDE
OF NORMAL. THE WEEKEND SYSTEM CONTINUES TO EVOLVE AFTER IT LEAVES
THE AREA, TAKING UP A FAIRLY STEADY RESIDENCE AS A RELATIVELY DEEP
TROF OVER EASTERN NORTH AMERICA FOR THE REST OF THE WEEK. PERIODIC
DISTURBANCES MOVING THROUGH THIS TROF MAY POSE AN OCCASIONAL RISK OF
SHOWERS, BUT GUIDANCE AGREEMENT WITH RESPECT TO THESE DISCRETE
FEATURES IS POOR AT BEST. HAVE KEPT POPS ON THE LOW SIDE THROUGH THE
EXTENDED RANGE OF THE FORECAST AS A RESULT.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1156 PM CDT FRI APR 17 2015

VFR CONDITIONS ACROSS CENTRAL IL THIS EVENING AS HIGH PRESSURE
REMAINS OVER THE REGION. LOW PRESSURE APPROACHING FROM THE WEST
STARTING TO INITIATE S-SE FLOW OVER THE REGION WHICH WILL CONTINUE
AND INCREASE TO 8-15 KTS THROUGH 00Z. DEWPOINTS GENERALLY IN THE
LOW-MID 50S ALONG WITH SOME SUBTLE MIXING DUE TO LIGHT S WINDS
OVERNIGHT SHOULD ALLOW FOR ONLY LIGHT FOG/HAZE IN MVFR CATEGORY
DEVELOPING OVERNIGHT. FOR SATURDAY...INCREASING CLOUD COVER
EXPECTED ALONG WITH INCREASING SOUTHEASTERLY BREEZES...BUT VFR
CONDITIONS EXPECTED THROUGH 00Z. AFTER 00Z...CHANCES FOR
PRECIPITATION DEVELOPING MAINLY KPIA-KSPI SOUTHWESTWARD THROUGH
06Z...ALTHOUGH TIME HEIGHTS PRESENTLY SHOWING ENOUGH DRY AIR TO
OVERCOME THAT ANY SHOWERS SHOULD REMAIN IN VFR CONDITIONS UNTIL
06Z.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...ONTON
SHORT TERM...BAK
LONG TERM...BAK
AVIATION...ONTON


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.