Area Forecast Discussion
Issued by NWS Chicago, IL

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000
FXUS63 KLOT 040537
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1237 AM CDT TUE AUG 4 2015

.SHORT TERM...
229 PM CDT

THROUGH TONIGHT...

UPPER LEVEL LOW PRESSURE IS ANCHORED SOUTH OF HUDSON BAY...KEEPING
A COOLER NW FLOW ACROSS THE REGION. AT THE SURFACE...HIGH PRESSURE
IS ANCHORED JUST TO OUR WEST...WITH A WEAK SURFACE TROUGH CROSSING
LAKE MICHIGAN. THE RESULT IS MUCH QUIETER WEATHER ACROSS THE AREA
TODAY. READINGS ARE HOLDING IN THE UPPER 70S TO LOW 80S UNDER
MODEST NORTHWEST WINDS. THERE IS A LAKE BREEZE KEEPING ONSHORE
WINDS IN PLACE...BUT THIS IS CONFINED TO FAR NORTHWEST INDIANA
WITH AN AREA OF CUMULUS CLOUDS. ADDITIONAL CLOUDS ARE CONFINED TO
WISCONSIN CLOSER TO THE LOW. THIS PATTERN HOLDS THROUGH THE NIGHT.
WITH GENERALLY CLEAR SKIES AND WEAKENING WINDS TONIGHT...A COOL
NIGHT IS ON TAP WITH MANY LOCATIONS OUTSIDE OF THE URBAN CORRIDOR
FALLING INTO THE MID TO UPPER 50S. EXPECT 60S IN AND CLOSER TO
CHICAGO.

KMD

&&

.LONG TERM...
326 PM CDT

TUESDAY THROUGH MONDAY...

QUIET WEATHER WILL PERSIST ON TUESDAY AS THE AREA REMAINS IN
BETWEEN THE STRONGER WESTERLIES USHERING IN MID LEVEL ENERGY TO
THE SOUTHWEST...AND STRONGER ENERGY WELL TO THE NORTH/NORTHEAST
TIED TO LARGE UPPER LEVEL CENTER. AFTER A PERIOD OF CAA...A MORE
NEUTRAL SETUP WILL BE IN PLACE ON TUESDAY AND WITH SUNNY SKIES
ONCE AGAIN IN PLACE...MOST LOCATIONS WILL OBSERVE HIGH TEMPS IN
THE LOW 80S. GENERALLY QUIET/DRY CONDITIONS WILL LIKELY PERSIST
INTO TUESDAY NIGHT...BUT AREAS ACROSS THE SOUTHERN CWA WILL SEE AN
INCREASE IN MID/HIGH LEVEL CLOUD COVER.

STILL SOME UNCERTAINTY IN PLACE WITH REGARDS TO POSSIBLE SYSTEM
DURING MIDWEEK...WITH GUIDANCE STILL VARYING FROM COMPLETELY DRY
CONDITIONS TO MORE WIDESPREAD PRECIP. MAIN TIME FRAME OF
UNCERTAINTY IS FROM WEDNESDAY INTO THURSDAY/THURSDAY NIGHT WITH
THE GFS/SREF STILL THE MORE AGGRESSIVE OF THE MODELS...BRINGING A
WETTER PATTERN ACROSS THE REGION. THE EXTENT OF THE NORTHERLY PUSH
OF THE STRONGER MID LEVEL ENERGY THIS WEEK WILL DICTATE OUR
WEATHER THIS WEEK AND FOR THE GOING FORECAST...HAVE MAINTAINED
HIGHEST CHANCE POPS ACROSS AREAS SOUTH OF INTERSTATE 80 WITH
SLIGHT CHANCE FURTHER NORTH DURING THIS TIME. INSTABILITY AXIS
LOOKS TO REMAIN ALONG/NEAR THE SOUTHERN CWA...AND HAVE ALSO
CONTINUED SLIGHT CHANCE THUNDER.

RODRIGUEZ

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 06Z...

* WEST TO NORTHWEST WINDS ARND 6-8KT...INCREASING TO ARND 10KT
  AFTER DAYBREAK WITH GUSTS DEVELOPING AFT 15Z TO 17KT.

BEACHLER

//DISCUSSION...UPDATED 06Z...

HIGH PRESSURE WILL REMAIN CENTERED WEST OF NORTHERN IL/NORTHWEST
IN...ALLOWING A CONTINUED FEED OF LIGHT WINDS THROUGH DAYBREAK
FROM THE WEST TO SLIGHTLY NORTHWEST. MIXING WILL INCREASE MID TO
LATE MORNING...AND ALLOW SOME GUSTS TO DEVELOP UP TO 18KT. THIS
SHOULD BE STRONG ENOUGH WINDS TO PREVENT A LAKE BREEZE FROM
PUSHING INLAND. WINDS DIMINISH SHORTLY AFTER SUNSET...BUT REMAIN
WESTERLY ARND 6-10KT. DRY AIR WILL CONTINUE TO LIMIT THE CLOUD
COVER TODAY...WITH ONLY A FEW CIRRUS CLOUDS FLOATING OVERHEAD.

BEACHLER


//ORD AND MDW CONFIDENCE...UPDATED 06Z...

* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.

BEACHLER

//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...

WEDNESDAY...SLIGHT CHANCE SHRA IN THE EVENING...OTHERWISE VFR.
WINDS BECOMING EAST.

THURSDAY...CHANCE SHRA/SLIGHT CHANCE TSRA...OTHERWISE VFR. EAST-
NORTHEAST WINDS.

FRIDAY...CHANCE SHRA/TSRA...OTHERWISE VFR. EAST-NORTHEAST WINDS.

SATURDAY...PRIMARILY VFR.

SUNDAY...PRIMARILY VFR. SLIGHT CHANCE SHRA/TSRA AT NIGHT.

RC

&&

.MARINE...
444 PM CDT

WESTERLY WINDS IN PLACE THIS AFTERNOON AND EVENING WILL BECOME
MORE NORTHERLY WITH LOW PRESSURE TO THE NORTHEAST...AND HIGH
PRESSURE EXTENDING FROM THE NORTHERN PLAINS THROUGH THE OHIO
VALLEY. THIS HIGH WILL SPREAD OVER THE WESTERN GREAT LAKES THIS
EVENING AND SHIFT EAST OF THE LAKE BY MID WEEK...WHILE WINDS ARE
EXPECTED TO REMAIN RELATIVELY LIGHT DURING THIS PERIOD. GUIDANCE
VARIES SIGNIFICANTLY WITH REGARDS TO SURFACE PATTERN FROM MID WEEK
TO THE END OF THE WORK WEEK...WITH CHANGES TO CURRENT WIND
SPEED/DIRECTION FORECAST LIKELY IN THE COMING DAYS.

RODRIGUEZ

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&

$$

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