Area Forecast Discussion
Issued by NWS Chicago, IL

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000
FXUS63 KLOT 271149
AFDLOT

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

.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 12Z TAFS...

HIGH END IFR TO LOW END MVFR STRATUS IS OVER ALL OF THE TERMINALS
EXCEPT RFD. SATELLITE AND GUIDANCE CONTINUE TO SUGGEST MVFR
STRATUS WILL HANG AROUND INTO THIS AFTN. NORTHEAST TO EAST WINDS
BEGIN GUSTING TO 25 KT LATE THIS MORNING. HAVE MEDIUM-HIGH
CONFIDENCE THAT THE MVFR CIGS WILL SCATTER OUT THIS AFTN AHEAD OF
THE ADVANCING LOW AND ASSOCIATED PRECIP. HAVE HIGH CONFIDENCE IN
RAIN OCCURRING TONIGHT...AND MEDIUM-HIGH CONFIDENCE IN TIMING.
GUIDANCE VARIES ON TIMING BUT MOST MODELS FEATURE THE MAIN SWATH
OF RAIN ROTATING THROUGH EARLY THIS EVENING FOR RFD AND THEN MID
EVENING FOR THE EASTERN TERMINALS. DECIDED TO ADD VCTS AS WELL.
HAVE MEDIUM CONFIDENCE THAT EMBEDDED THUNDERSTORMS WILL BE IN THE
REGION BUT LOW CONFIDENCE IN COVERAGE AND EXACT LOCATIONS THIS
EVENING. THINKING MVFR CIGS WILL ACCOMPANY THE SHOWERS AND THERE
IS A CHANCE IFR CIGS MAY ALSO CREEP OVER THE TERMINALS. DID NOT
HAVE A LOT OF CONFIDENCE IN IFR CIGS SO KEPT THEM AS A SCT LAYER
FOR NOW.

JEE

&&

.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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