Area Forecast Discussion
Issued by NWS Chicago, IL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KLOT 012005
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
305 PM CDT WED JUL 1 2015

.SHORT TERM...
1101 AM CDT

THIS AFTERNOON AND EVENING...

SURFACE RIDGE CONTINUING TO BUILD SOUTH WITH ELONGATED HIGH PRESSURE
AREA LOCATED ACROSS CENTRAL AND WESTERN LAKE SUPERIOR. A
NORTHERLY LOW LEVEL FLOW IS HELPING TO SCOUR OUT RESIDUAL LOW
LEVEL MOISTURE AS EVIDENT BY THINNING LOW CLOUDS OVER NRN IL.
EXPECT THIS TREND TO CONTINUE THIS AFTERNOON WITH RAP/SREF/HRR
TRENDING DRIER IN THE LOW LEVELS. STILL CANT RULE OUT A SHOWER
FAR SOUTH CWFA BUT FEEL CHANCES OF THAT WILL HOLD OFF TILL EVENING
GIVEN CURRENT RADAR TRENDS AND RAP/HRR/SERF AND HAVE DROPPED
MENTION OF SUCH IN THE GRIDS/ZFP. GOING TEMPS ON TARGET WITH
ONSHORE FLOW HOLDING TEMPS SIGNIFICANTLY DOWN NEAR THE
LAKEFRONT... QUITE CHILLY BY JULY 1 STANDARDS. AVERAGE HIGH TEMP
FOR THE DAY IS 84 AT ORD AND RFD. SHAVED A DEGREE OR TWO OFF
MAXES WEST AND SOUTH CWFA AS TEMPS STRUGGLING COMPARED TO AVERAGE
DIURNAL TREND FOR THE TIME OF YEAR AND MID-HIGH CLOUDINESS.

RAP PICKING UP ON LOW LEVEL MOISTURE ASSOCIATED WITH LOW CLOUDS
UPSTREAM OVER LAKE MICHIGAN AND LARGELY SHUNTS THIS MOISTURE OFF
TO THE EAST THIS EVENING. HENCE EXPECT MAINLY SCT-BKN MID-HIGH
CLOUDS TO CONTINUE THIS AFTERNOON AND EVENING AS MODEST DRYING IN
THE LOW LEVELS CONTINUES.

ED F

&&

.LONG TERM...
330 AM CDT

THURSDAY THROUGH TUESDAY...

LITTLE CHANGE TO THE PATTERN IS EXPECTED THROUGH THE REMAINDER OF
THE WEEK. UPPER TROUGH RESPONSIBLE FOR OUR COOL AND DRY WEATHER
WILL GRADUALLY WEAKEN AND SURFACE RIDGE WILL SLOWLY MIGRATE
EASTWARD ALLOWING FOR VERY SLOWLY MODERATING TEMPERATURES AND
GRADUAL WEAKENING OF THE LAKE BREEZES AND ASSOCIATED LAKE COOLING.
BY THE WEEKEND...TEMPS SHOULD MODERATE BACK CLOSER TO SEASONAL
NORMS AS GRADIENT FLOW TURNS MORE SOUTHERLY AND WARM AIR ADVECTION
KICKS IN. FLOW LOOKS WEAK ENOUGH SATURDAY TO ALLOW WEAK ILLINOIS
LAKE BREEZE TO FORM...AND CAN`T EVEN RULE IT OUT SUNDAY
EITHER...THOUGH THE MAGNITUDE OF ANY POSSIBLE LAKE COOLING LOOKS
TO BE FAR LESS OVER THE WEEKEND.

MEDIUM RANGE MODELS HAVE SLOWED THE ARRIVAL OF COLD FRONT AND
ASSOCIATED SHOWER/STORM CHANCES UNTIL MONDAY/MONDAY NIGHT TIME
FRAME NOW...SO OUTSIDE OF A SLIGHT CHANCE OF A SHOWER OR TWO
SNEAKING INTO OUR FAR SOUTHERN CWA AT TIMES THROUGH FRIDAY...IT
LOOKS LIKE DRY WEATHER WILL BE THE RULE THROUGH THE HOLIDAY
WEEKEND.

IZZI

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* LAKE BREEZE/NORTHEAST WINDS APPROACHING 10 TO 12KT THIS
  AFTERNOON.
* MVFR CIGS POSSIBLE BRIEFLY THURSDAY MORNING.

ED F

//DISCUSSION...UPDATED 18Z...

CLEARING LINE APPROACHING FROM THE NORTH THIS AFTERNOON WILL
STRIP AWAY MVFR CIGS AND INCREASE WINDS BY AROUND 19Z. BRIEF WIND
OBS SHOWING NORTH SHOULD QUICKLY CHANGE BACK TO NORTHEAST UNDER
THIS WEAK HIGH PRESSURE REGIME. WHILE VFR CONDITIONS ARE
FORECASTED FOR MOST OF THE PERIOD...THERE IS A CHANCE FOR MVFR
CIGS AGAIN TOMORROW MORNING. NORTHEAST WINDS OFF OF LAKE MICHIGAN
WILL STREAM IN ADDITIONAL MOISTURE...LEADING TO SCT TO BKN CLOUDS
AT 2KFT FROM 11-14Z. DAYTIME HEATING AND ADVANCING HIGH PRESSURE
SHOULD LIFT THOSE TO JUST FAIR WEATHER CUMULUS BY MID MORNING.

WINDS REMAIN FROM THE NORTHEAST THURSDAY AND WILL APPROACH THE
10KT MARK BY 18Z. HIGHER CONFIDENCE IN THE WINDS THURSDAY AS THIS
IS A PRESSURE DRIVEN WIND WITH LITTLE LAKE INFLUENCE.

MM

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* MEDIUM CONFIDENCE IN TIMING OF NORTHEAST WINDS...HIGH IN WIND
  SPEED.
* LOW CONFIDENCE IN MVFR DEVELOPMENT THURSDAY MORNING.

ED F

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

THURSDAY NIGHT THROUGH SATURDAY...DRY AND VFR. NE WINDS.
SUNDAY...DRY AND VFR. SE WINDS.
MONDAY THROUGH TUESDAY...CHC TSRA. SW WINDS.

BMD

&&

.MARINE...
314 AM CDT

NORTH WINDS HAVE PICKED UP INTO THE 15 TO 25 KT RANGE AT TIMES IN
BETWEEN AN AREA OF LOW PRESSURE OVER THE EASTERN GREAT LAKES AND A
RIDGE OVER ONTARIO AND THE UPPER MIDWEST. THE HIGH WILL BUILD SOUTH
OVER LAKE MICHIGAN WITH WINDS GRADUALLY ABATING FROM THE NORTH
TODAY THROUGH THURSDAY. THE HIGH SHOULD PROVIDE QUIET WEATHER AND
RELATIVELY LIGHT WINDS FRIDAY THROUGH THE WEEKEND. SOUTHWEST WINDS
LOOK TO FRESHEN UP AGAIN MONDAY AHEAD OF AN APPROACHING COLD
FRONT.

BMD

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ002 UNTIL 8 PM WEDNESDAY.

LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 8 PM WEDNESDAY.

&&

$$

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.