Area Forecast Discussion
Issued by NWS Chicago, IL

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000 FXUS63 KLOT 280832 AFDLOT AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 332 AM CDT MON JUL 28 2014 .DISCUSSION... 251 AM CDT SYNOPSIS...TODAY WILL BE A BEAUTIFUL DRY DAY WITH WELL BELOW NORMAL TEMPS. THE BELOW NORMAL TEMPS CONTINUE THROUGH THE FORECAST PERIOD. WE STAY IN A PATTERN THAT HAS MULTIPLE WAVES OF UPPER LEVEL ENERGY ROTATING THROUGH THE REGION. AS SUCH DIURNAL SHOWERS AND THUNDERSTORMS ARE EXPECTED FROM TUESDAY THROUGH SATURDAY. TODAY AND TONIGHT... THE PATTERN ALOFT WILL NOT CHANGE MUCH OVER THE NEXT WEEK WITH A LARGE LOW/TROUGH TO OUR EAST AND A RIDGE TO OUR WEST. THE SURFACE LOW IS OVER NEW ENGLAND WHILE A HIGH IS BUILDING DOWN THE PLAINS. WE ARE LOOKING AT A DRY AND COOLER THAN NORMAL DAY WITH HIGHS IN THE LOW 70S. TEMPERATURES WILL BE COOLEST ALONG THE LAKESHORE DUE TO STRONG NORTH WINDS. WAVES ALONG THE NORTHWEST INDIANA SHORE ARE VERY HIGH AT 11 FT AT THIS TIME AND STILL EXPECTING DANGEROUS SWIMMING CONDITIONS AT ALL OF THE BEACHES. RIP CURRENTS ARE EXPECTED. WE WILL SEE GUSTS UP TO 35 MPH AGAIN EARLY TODAY WITH WINDS DIMINISHING IN THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS OVERHEAD. CLOUDS CLEAR TONIGHT AND EXPECTING TEMPERATURES TO FALL INTO THE 50S...WITH LOWS AROUND 60 DOWNTOWN. TUESDAY THROUGH THURSDAY... THE SURFACE LOW SHIFTS NORTH INTO QUEBEC WHILE THE PLAINS HIGH SLOWLY SPREADS OVER THE MIDWEST WEDNESDAY NIGHT. THE MAIN THEME FOR THE REST OF THE WEEK WILL BE WEAK VORTICITY STREAMERS ROTATING AROUND THE UPPER LEVEL LOW. THESE STREAMERS MAY PROVIDE ENOUGH FORCING FOR ISOLATED TO SCATTERED AFTERNOON THUNDERSTORM DEVELOPMENT. CONFIDENCE IS MEDIUM-LOW IN COVERAGE AND TIMING SO HAVE LOW END CHANCES OF THUNDERSTORMS EACH AFTERNOON. GIVEN THE WEAK FORCING AND INSTABILITY...NOT EXPECTING SEVERE WEATHER AND THERE SHOULD BE PLENTY OF DRY HOURS. LAKE BREEZES ARE EXPECTED EACH DAY...WITH HIGHS ALONG THE LAKESHORE IN THE MID 70S. HIGHS AWAY FROM THE LAKE WILL BE IN THE UPPER 70S TO AROUND 80. OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO AROUND 60...AND IN THE LOW 60S DOWNTOWN. FRIDAY THROUGH SUNDAY... A LOBE OF UPPER LEVEL ENERGY SWINGS THROUGH THE REGION FRIDAY WHICH WILL BRING US OUR BEST CHANCE FOR SHOWERS AND STORMS. AT THIS POINT INSTABILITY LOOKS WEAK WITH 1000 J/KG OF CAPE OR LESS AND SHEAR DOES NOT LOOK FAVORABLE FOR SEVERE WEATHER. HAVE ANOTHER LESS IMPRESSIVE CHANCE OF AFTERNOON STORMS SATURDAY. TEMPERATURES REMAIN BELOW NORMAL WITH HIGHS IN THE UPPER 70S AND LOWS AROUND 60. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * GUSTY NORTH TO NORTH-NORTHEAST WINDS TODAY. //DISCUSSION...UPDATED 06Z... LOW PRESSURE WILL CONTINUE TO MOVE AWAY ACROSS THE NORTHEAST U.S. WITH NORTHERLY WINDS CONTINUING OVER THE TAF SITES THROUGH TODAY. ON THE LOCAL SCALE AT ORD AND MDW...THE WIND DIRECTION IS LIKELY TO WOBBLE SOME BETWEEN 340 AND 020 THROUGH EARLY MORNING AND THEN BECOME MORE 010-020 FROM MID-MORNING ON DUE TO INFLUENCE OF THE NEARBY LAKE. WIND GUSTS AT TIMES TODAY OF 20 KT OR SLIGHTLY HIGHER ARE LIKELY. SCATTERED CUMULUS ARE LIKELY TODAY BUT NO PRECIPITATION EXPECTED. //ORD AND MDW CONFIDENCE...UPDATED 09Z... * HIGH IN WIND SPEED AND MEDIUM IN WIND DIRECTION...INCLUDING 15Z TIMING OF NORTH-NORTHEAST DIRECTION. //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH SATURDAY...PREDOMINANTLY VFR. MTF/IZZI && .MARINE... 215 AM CDT IMPRESSIVE WINDS AND WAVES FOR JULY ARE OCCURRING EARLY THIS MORNING ACROSS THE SOUTHERN PART OF THE LAKE WITH 2 AM OBSERVATIONS INDICATING THE SOUTH BUOY AT 8.6 FT AND MICHIGAN CITY AT 11.1 FT. NORTHERLY WINDS OF 30 KT WITH OCCASIONAL GALES WILL EVER SO SLOWLY EASE THIS MORNING ACROSS THE SOUTH. THE GRADIENT BETWEEN A DEPARTING LOW IN THE NORTHEAST U.S. AND A HIGH OVER THE NORTHERN PLAINS WILL EASE THIS AFTERNOON AND MORE SO TONIGHT. WAVES WILL BE SLOW TO SUBSIDE ALONG THE INDIANA SHORE BUT ARE EXPECTED TO DROP BELOW SMALL CRAFT ADVISORY CRITERIA BY DAYBREAK TUESDAY. A STRONG UPPER TROUGH ACROSS EASTERN CANADA WILL MOVE LITTLE THROUGH MIDWEEK. AS IS OFTEN THE CASE...WEAKER SECONDARY SURFACE COLD FRONTS WILL MOVE ACROSS THE GREAT LAKES...WITH ONE SUCH FRONT EXPECTED ON TUESDAY AFTERNOON AND NIGHT ACROSS NORTHERN LAKE MICHIGAN. THIS WILL HAVE OVERALL LITTLE INFLUENCE HOWEVER. THE PRESSURE GRADIENT WILL REMAIN LIGHT ACROSS THE LAKE FOR MUCH OF THE WEDNESDAY THROUGH SATURDAY TIME PERIOD WITH AN AFTERNOON LAKE BREEZE ON THE ILLINOIS AND INDIANA SHORES WEDNESDAY AND THURSDAY...AND OVERALL SYNOPTIC ONSHORE FLOW ON FRIDAY AND SATURDAY. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 AM TUESDAY. BEACH HAZARDS STATEMENT...ILZ006 UNTIL 10 PM MONDAY. IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 AM TUESDAY. LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 10 PM MONDAY. SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 AM TUESDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO

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