Area Forecast Discussion
Issued by NWS Chicago, IL

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756
FXUS63 KLOT 271736
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
1236 PM CDT WED APR 27 2016

.UPDATE...

1110 AM CDT

THE MAIN CONCERNS THIS MORNING CONTINUE TO CENTER AROUND TIMING
OF SHOWERS THIS AFTERNOON INTO TONIGHT. CURRENTLY IT APPEARS THE
AREA OF SHOWERS TO OUR SOUTHWEST WILL CONTINUE TO GRADUALLY WORK
THEIR WAY TO THE NORTHEAST THROUGH THE AFTERNOON. AREAS ACROSS THE
CHICAGO METRO LOOK TO REMAIN DRY THROUGH AT LEAST 3-4 PM THIS
AFTERNOON...IF NOT LATER...BEFORE THE THREAT OF RAIN SHOWERS
BEGINS TO INCREASE. THE THREAT OF THUNDER WITH THIS INITIAL SURGE
OF MOISTURE LOOKS LOW. HOWEVER...ANOTHER ROUND OF THUNDERSTORMS
EXPECTED TO DEVELOP THIS AFTERNOON OVER NORTHERN MISSOURI COULD
TRACK EAST-NORTHEASTWARD AND POSSIBLE IMPACT SOUTHERN SECTIONS OF
THE AREA THIS EVENING BEFORE THEY WEAKEN.

OVERALL...WE HAVE NOT MADE ANY MAJOR CHANGES TO THE
FORECAST...JUST SOME MINOR TWEAKS TO TIMING OF PRECIPITATION THIS
AFTERNOON. OTHERWISE...PERSISTENT EASTERLY FLOW AND CLOUD COVER
SHOULD KEEP AREAS NEAR THE LAKE IN THE MID 40S...AND ONLY INTO THE
LOWER 50S INLAND.

KJB

&&

.SHORT TERM...
320 AM CDT

THROUGH THURSDAY

PRIMARY SHORT TERM CONCERN REVOLVES AROUND TIMING THE PRECIP
ARRIVAL AND OF COURSE TEMPS. WHILE LOW CLOUDS WILL PROBABLY CLEAR
OUT IN SPOTS AT TIMES...HIGH CLOUDINESS LIKELY TO KEEP CHARACTER
OF THE DAY CLOUDY. STIFF NORTHEAST WINDS WILL CONTINUE TO ADVECT
DRY AIR INTO THE LOW LEVELS WHICH COMBINED WITH THE VERY SLOW
MOVEMENT OF THE APPROACHING UPPER LOW WILL LIKELY KEEP MOST OF THE
AREA DRY THROUGH EARLY TO MID AFTERNOON. AN ARC OF SHOWERS AND
PERHAPS A THUNDERSTORM WILL LIFT NORTHEAST ACROSS THE AREA VERY
LATE THIS AFTERNOON AND TONIGHT.

CLOUDINESS AND COOL NORTHEAST FLOW WILL CONTINUE THURSDAY WITH
SOME FOG POTENTIAL EVEN NEAR THE LAKE AS HIGHER DEWPOINTS ATTEMPT
TO SPREAD NORTH AND INTERACT WITH THE CHILLY MARINE LAYER. UPPER
LOW SHOULD MOVE ACROSS THE CWA THURSDAY AND SHOULD BE ENOUGH TO
SUPPORT ISOLD TO SCTD SHOWERS EVEN THOUGH IT WILL BE WEAKENING
QUICKLY. ANY SHOWERS SHOULD END THURSDAY EVENING AS THE SYSTEM
MOVES EAST OUT OF THE AREA.

IZZI

&&

.LONG TERM...
320 AM CDT

FRIDAY THROUGH WEDNESDAY...

FRIDAY AND PERHAPS A GOOD CHUNK OF SATURDAY LOOK TO BE DRY BEFORE
THE NEXT CLOSED LOW WOBBLES OUT OF THE SOUTHERN PLAINS AND TOWARD
THE AREA. AS IS TYPICALLY THE CASE...THERE CONTINUES TO BE SOME
RUN TO RUN VARIABILITY IN THE TIMING AND TRACK OF THIS SYSTEM AND
RESULTANT RAIN CHANCES HERE. LATEST MEDIUM RANGE GUIDANCE HAS
TRENDED SOUTH SOME AND GFS SLOWER...BUT DIDN`T REALLY MAKE TOO
MANY CHANGES TO GOING FORECAST WHICH HAS INCREASING SHOWER CHANCES
OVER THE WEEKEND.

THE NORTHEAST LOW LEVEL FLOW LOOKS TO BE LOCKED IN THROUGH THE
REST OF THE WEEK AND PROBABLY THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK AS WELL. THE RESULT SHOULD BE A CONTINUATION OF BELOW
AVERAGE TEMPERATURES ACROSS THE AREA...THOUGH NO WHERE WILL THOSE
BELOW AVERAGE TEMPS BE AS PRONOUNCED AND DRAMATIC AS ALONG THE
LAKE FRONT. IT CONTINUES TO LOOK PLAUSIBLE THAT TEMPS MAY NOT
REACH 50F ALONG THE LAKEFRONT THROUGH THE UPCOMING WEEKEND!

IZZI

&&

.AVIATION...
FOR THE 18Z TAFS...

A STORM SYSTEM TO OUR WEST WILL GRADUALLY SPREAD SHOWERS
NORTHEASTWARD ACROSS THE TERMINALS LATE THIS AFTERNOON THROUGH EARLY
THIS EVENING. MAIN CHANGE TO THE TAFS WAS TO REMOVE THE VCTS
MENTION...AS IT APPEARS MOST OF THE THUNDERSTORM ACTIVITY MAY REMAIN
SOUTH OF THE TERMINALS. THERE IS STILL A SMALL CHANCE OF STORM AT
THE TERMINALS THIS EVENING...BUT THE PROBABILITY AND DURATION OF IT
IS TO LOW TO CONTINUE A MENTION IN THE TAFS AT THIS TIME. SHOWER
ACTIVITY SHOULD MOVE INTO KRFD BY EARLY THIS AFTERNOON...AND ACROSS
THE EASTERN TERMINALS AFTER 21-22 UTC. THESE SHOWERS WILL CONTINUE
INTO THIS EVENING BEFORE ENDING BY LATE EVENING. ADDITIONAL SHOWERS
ARE POSSIBLE ACROSS THE AREA LATER TONIGHT INTO THURSDAY...BUT DUE
TO UNCERTAINTIES ON THE EXACT TIMING...WITH JUST LEAVE A VCSH IN THE
FORECAST.

EXPECT WINDS TO CONTINUE TO BE GUSTY AT TIMES OUT OF THE EAST-
NORTHEAST THROUGH THE PERIOD. CIGS WILL IMPROVE SOME THIS
AFTERNOON...BUT LOWER MVFR CIGS AROUND...OR JUST BELOW 1,000 FT AGL
ARE LIKELY AGAIN BY THURSDAY MORNING.

KJB

&&

.MARINE...
250 AM CDT

HEADLINES...THE SMALL CRAFT ADVISORIES LOOK GOOD AS IS.

LOW PRESSURE OVER KANSAS WEAKENS AND PASSES OVER CENTRAL IL
THURSDAY. MEANWHILE HIGH PRESSURE OVER CENTRAL CANADA REMAINS
STATIONARY THROUGH THE END OF THE WEEK AND THEN SHIFTS EAST OVER
QUEBEC EARLY NEXT WEEK.  NORTH TO EAST WINDS ARE EXPECTED OVER THE
LAKE THROUGH MONDAY. THE ONSHORE FLOW RESULTS IN HAZARDOUS WAVES FOR
SMALL CRAFT INTO THURSDAY FOR THE IL NSH WATERS.  ANOTHER WEAK LOW
PASSES SOUTH OF THE LAKE SUNDAY...AND THEN HIGH PRESSURE SPREADS
OVER THE LAKE MONDAY. A LOW PRESSURE SYSTEM MOVES ACROSS SOUTHEAST
CANADA MONDAY NIGHT INTO TUESDAY...AND WINDS ARE FORECAST TO BECOME
SOUTH OR SOUTHWEST AS THE HIGH SHIFTS EAST OF THE LAKE TUESDAY.

JEE

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 PM WEDNESDAY.

     SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 PM THURSDAY.

&&

$$

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