128
FXUS63 KILX 181818
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
ISSUED BY NATIONAL WEATHER SERVICE CHICAGO IL
1218 PM CST MON NOV 18 2024
KEY MESSAGES
- STRONG WINDS WILL DEVELOP LATE THIS AFTERNOON THROUGH TUESDAY
MORNING AS A POWERFUL STORM SYSTEM LIFTS NORTHWARD THROUGH THE
PLAINS. SOUTHWESTERLY WIND GUSTS WILL REACH 40-50MPH.
- AFTER TWO MORE DAYS OF ABOVE NORMAL TEMPERATURES, SHARPLY COLDER
CONDITIONS WILL BE IN STORE WEDNESDAY THROUGH FRIDAY. IN FACT,
PORTIONS OF CENTRAL ILLINOIS MAY SEE THE FIRST SNOW FLURRIES OF
THE UPCOMING SEASON WEDNESDAY NIGHT INTO THURSDAY.
SHORT TERM
(TODAY TROUGH TUESDAY)
ISSUED AT 329 AM CST MON NOV 18 2024
A 996MB LOW OVER WEST TEXAS WILL DEEPEN TO AROUND 986MB AS IT
TRACKS NORTHEASTWARD TO NEAR OMAHA, NEBRASKA BY EARLY THIS
EVENING. A LARGE SHIELD OF LIGHT TO MODERATE RAIN AHEAD OF THE
ASSOCIATED WARM FRONTAL BOUNDARY IS CURRENTLY NOTED UPSTREAM
ACROSS THE OZARKS. THIS RAIN AREA WILL LIFT INTO CENTRAL ILLINOIS
THIS MORNING, WITH THE STEADIEST AND MOST WIDESPREAD PRECIP
FOCUSING WEST OF THE I-57 CORRIDOR. FURTHER EAST, ONLY SCATTERED
SHOWERS WILL BE OBSERVED NEAR THE INDIANA BORDER. CAMS HAVE SPED
UP THE ARRIVAL/DEPARTURE OF THE RAIN AS MOST SOLUTIONS NOW SHOW A
PERIOD OF DRY WEATHER ACROSS MUCH OF THE KILX CWA FROM MID-AFTERNOON
INTO EARLY EVENING. ONCE THE RAIN ENDS AND SE WINDS INCREASE,
AFTERNOON HIGH TEMPERATURES WILL CLIMB WELL INTO THE 60S...WITH
READINGS REACHING THE 70-DEGREE MARK ACROSS THE FAR SOUTH NEAR
FLORA AND LAWRENCEVILLE.
AS THE PRESSURE GRADIENT TIGHTENS IN ADVANCE OF AN OCCLUDED
FRONTAL BOUNDARY APPROACHING FROM THE WEST, SE WINDS WILL STEADILY
INCREASE AS THE DAY PROGRESSES. GUSTS WILL REACH 30-35MPH
ALONG/WEST OF I-55 AFTER 21Z/3PM. EVEN STRONGER WINDS WILL DEVELOP
DURING THE EVENING WITH THE HRRR CONSISTENTLY SHOWING GUSTS
INCREASING TO 40-50MPH. FORECAST SOUNDINGS INDICATE 200-300J/KG OF
ELEVATED INSTABILITY AND WINDS INCREASING TO 50KT AT JUST 1500FT
ALOFT. THINK A BROKEN LINE OF SHOWERS AHEAD OF THE FRONT WILL MIX
SOME OF THIS MOMENTUM DOWN TO THE SURFACE, PRODUCING WIND GUSTS
UP TO AROUND 50MPH. EVEN AFTER THE SHOWERS PASS, STRONG/GUSTY
WINDS WILL PERSIST THROUGH THE REMAINDER OF THE NIGHT AND INTO
TUESDAY MORNING. DESPITE A GRADUALLY LOOSENING PRESSURE GRADIENT,
INCREASED MIXING AFTER SUNRISE WILL HELP KEEP THE GUSTS GOING.
GIVEN THE DEEP LOW ACROSS THE PLAINS AND A CONSISTENT SIGNAL FROM
THE HRRR, HAVE OPTED TO ISSUE A WIND ADVISORY FOR LOCATIONS NORTH
OF THE I-70 CORRIDOR FOR TONIGHT THROUGH TUESDAY MORNING.
SHOWERS AND ISOLATED THUNDERSTORMS WILL ACCOMPANY THE OCCLUDED
FRONT THIS EVENING. ONCE THE FRONT EXITS INTO INDIANA, DEEP-LAYER
MOISTURE WILL DECREASE OVERNIGHT: HOWEVER, A SATURATED LAYER BELOW
800MB WILL PERSIST INTO TUESDAY MORNING...RESULTING IN SCATTERED
LIGHT SHOWERS OR DRIZZLE. STORM TOTAL RAINFALL BETWEEN THE SURGE
OF WAA PRECIP THIS MORNING AND THE CONVECTIVE LINE ASSOCIATED WITH
THE OCCLUDED FRONT THIS EVENING WILL RANGE FROM 0.10-0.25 NEAR THE
INDIANA BORDER...TO 0.75-1.00 ALONG/WEST OF THE ILLINOIS RIVER.
BARNES
LONG TERM
(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 329 AM CST MON NOV 18 2024
A SHORT-WAVE TROUGH EVIDENT ON LATEST WATER VAPOR IMAGERY OFF THE
COAST OF WASHINGTON/OREGON WILL PHASE WITH A SEPARATE WAVE LIFTING
NORTHEASTWARD ACROSS THE PLAINS...CREATING A DEEP UPPER LOW OVER
THE UPPER MIDWEST/GREAT LAKES BY WEDNESDAY/THURSDAY. PREVIOUS RUNS
OF THE GFS AND ECMWF HAD SHOWN SURFACE CYCLOGENESIS NEAR OR JUST
EAST OF ILLINOIS ASSOCIATED WITH THE UPPER PHASING THAT WOULD
HAVE PRODUCED PRECIPITATION ACROSS THE KILX CWA. THE 00Z NOV 18
SUITE OF MODELS HAS BACKED OFF ON THIS SOLUTION AND NOW FEATURES
THE SURFACE LOW FORMING MUCH FURTHER E/NE. THE END RESULT WILL
LIKELY BE VERY LITTLE PRECIP ACROSS CENTRAL ILLINOIS AS THE COLDER
AIRMASS ARRIVES. WILL STILL HANG ON TO LOW CHANCE POPS ON
WEDNESDAY AS THE PHASING OCCURS...AS WELL AS WEDNESDAY NIGHT AND
THURSDAY AS THE SYSTEM PIVOTS INTO THE GREAT LAKES. HOWEVER, HAVE
LOWERED POPS AND LIMITED SNOW MENTION TO WEDNESDAY NIGHT INTO
MAINLY THURSDAY MORNING. WOULD NOT BE SURPRISED TO SEE SOME SNOW
FLURRIES, BUT THE CHANCES FOR ANY ACCUMULATION ARE SLIM TO NONE.
THE MAIN WEATHER STORY WILL BE THE SHARPLY COLDER TEMPERATURES AND
BRISK WIND-CHILLS. WITH AIR TEMPERATURES ONLY IN THE LOWER 40S AND
NW WINDS GUSTING 30-35MPH, WIND-CHILL VALUES WILL HOVER IN THE
UPPER 20S AND LOWER 30S ON THURSDAY.
ONCE THE UPPER LOW LIFTS FURTHER NORTHEAST, WINDS WILL DECREASE
AND TEMPERATURES WILL SLOWLY MODERATE BACK INTO THE MIDDLE TO
UPPER 40S BY SUNDAY.
BARNES
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1218 PM CST MON NOV 18 2024
LOW CLOUDS AND SHOWERS CONTINUE TO SPREAD NORTHWARD ACROSS
CENTRAL ILLINOIS EARLY THIS AFTERNOON. HOWEVER, MOST OF THE RAIN
AND LOW CIGS ARE SHOWING SIGNS OF SHIFTING NORTH OF SOME OF THE
SOUTHERN TERMINALS AT THIS TIME. THE EXPECTATION IS THAT CIGS
WILL CONTINUE TO UNDERGO IMPROVEMENT BY (IF NOT PRIOR) TO 20Z
THIS AFTERNOON AS THE SURFACE WARM FRONTAL PRECIPITATION
CONTINUES ITS NORTHWARD MIGRATION INTO NORTHERN IL EARLY THIS
AFTERNOON. OUR NEXT PERIOD OF RAIN IS THEN EXPECTED TO SHIFT
EASTWARD ACROSS THE AREA MID TO LATE THIS EVENING THROUGH THE
EARLY OVERNIGHT HOURS IN ADVANCE OF AN APPROACHING COLD FRONT. A
LOW (5-15% CHANCE) OF A RUMBLE OF THUNDER ALSO EXISTS WITH
THESE SHOWERS TONIGHT. HOWEVER, GIVEN THE LOW POTENTIAL, THERE
IS NOT FORMAL MENTION FOR TS IN THE TAFS.
WINDS WILL BECOME INCREASINGLY GUSTY (30+ KT) FROM THE
SOUTHEAST THIS EVENING AND TONIGHT AS A STRONG SURFACE LOW
TRACKS NORTHEASTWARD ACROSS THE MID-MISSOURI VALLEY. WINDS WILL
THEN SHIFT SOUTH-SOUTHWESTERLY AFTER 09Z TONIGHT AS A SURFACE
COLD FRONT SWEEPS EASTWARD ACROSS THE AREA. A PERIOD OF STRONG
WIND GUSTS (35+KT) IS POSSIBLE (40-50% CHANCE) WITH THE PASSAGE
OF THIS FRONT. THESE STRONG GUSTY WINDS WILL GRADUALLY EASE
THROUGH THE AFTERNOON AS THEY TURN WEST- SOUTHWESTERLY.
ILX WATCHES/WARNINGS/ADVISORIES
WIND ADVISORY FROM 6 PM THIS EVENING TO NOON CST TUESDAY FOR
ILZ027>031-036>038-040>057-061.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page