343 PM CDT
FOR THE REMAINDER OF THE AFTERNOON AND EVENING...MILD CONDITIONS
CONTINUE ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA.
TEMPERATURES WILL CONTINUE TO INTO THE MIDDLE TO UPPER 70S ACROSS
THE NORTHERN PORTIONS OF THE CWA NEAR THE WISCONSIN BORDER...TO
AROUND 80 TO THE FAR SOUTH. A WEAK LAKE BREEZE HAS PUSHED INLAND
FROM DOWNTOWN CHICAGO TO NWRN LAKE COUNTY...ALLOWING THE LAKE FRONT
LOCATIONS NORTH OF CHICAGO TO REMAIN A LITTLE COOLER...WITH HIGHS
TOPPING OUT TODAY IN THE LOWER 70S. OVERNIGHT...EXPECT SKIES TO BE
MOSTLY CLEAR. AS SFC DEWPOINTS HAVE REBOUNDED INTO MIDDLE 50S
TODAY...EXPECT THAT OVERNIGHT LOWS WILL NOT BE QUITE AS LOW AS
RECENTLY...THIS TEMPERATURES ONLY DROPPING GENERALLY INTO THE MIDDLE
50S.
THE UPPER LEVEL PATTERN IS FINALLY SHOWING SOME SIGNS OF EASTWARD
PROGRESSION...SIGNALING A CHANGE IN THE WEATHER. THE PERSISTENT
UPPER LEVEL RIDGE IS BEGINNING TO MOVE EASTWARD AS AN UPPER LOW
RIDES NWD THROUGH THE NRN PLAINS AND INTO SCNTRL CANADA. CONDITIONS
ACROSS THE AREA SHOULD REMAIN PLEASANT FOR A COUPLE MORE DAYS AS THE
UPPER RIDGE SLOWLY BUILDS EWD AND HIGH AMPLITUDE...FULL-LATITUDE
TROUGHING DEVELOPS OVER THE CNTRL PLAINS. EXPECT LITTLE CHANGE IN
THE SENSIBLE WEATHER CONDITIONS FOR TUESDAY AS A RIDGE OF SFC HIGH
PRESSURE EXTENDS FROM SERN CANADA...THROUGH THE ERN GREAT LAKES...TO
THE MIDDLE MISSISSIPPI VALLEY. LOW LEVEL FLOW WILL REMAIN
SELY-SSELY THROUGH THE DAY...WITH FOR TUESDAY REMAINING VERY SIMILAR
TO RECENT DAYS...WITH ONLY PERHAPS SOME INCREASING MID AND HIGH
CLOUDINESS.
WEDNESDAY IS SHAPING UP TO BE CHANGE DAY AS A COLD FRONT ASSOCIATED
WITH THE APPROACHING...DEVELOPING TROUGH TRACKS THROUGH THE CNTRL
PLAINS. THERE ARE STILL SOME MODEL DISAGREEMENTS...ESPECIALLY WITH
THE TIMING OF THE FRONTAL PASSAGE. HAVE GENERALLY FOLLOWED THE
GFS/SREF SOLUTION WHICH HAS BEEN VERY CONSISTENT IN TIMING OF THE
FROPA WITH RECENT RUNS...ALTHOUGH OVERALL...THE TIMING DIFFERENCES
AMONG THE MODELS IS NOT VERY LARGE. GENERALLY...EXPECT THE FROPA TO
OCCUR IN THE LATE EVENING HOURS. HAVE NOT MADE MUCH CHANGE TO THE
ASSOCIATED PCPN FORECAST AND STILL EXPECT A PERIOD OF SHOWERS
WITH...WITH PCPN POSSIBLY MOVING INTO THE ROCKFORD AREA AS EARLY AS
LATE WEDNESDAY AFTERNOON. EXPECT THAT THE PCPN WILL NOT CLEAR THE
EASTERN PORTIONS OF THE CWA UNTIL LATE THURSDAY NIGHT OR FRIDAY
MORNING. STILL EXPECT THAT THERE MAY BE A CHANCE FOR SOME
ISOLD...EMBEDDED THUNDER WITH THE FRONT...BUT INSTABILITY IS
EXPECTED TO BE RATHER MODEST...SO HAVE TRIMMED BACK THE SLIGHT
CHANCE THUNDER AREAS IN THE GRIDS...AND HAVE CONFINED IT MORE
CLOSELY WITH THE FRONTAL BOUNDARY.
TEMPERATURES SHOULD DROP OFF SIGNIFICANTLY FOLLOWING THE FROPA WITH
850MB TEMPS DROPPING TO ARND 2C BY FRIDAY MORNING. BY
THURSDAY...HIGHS SHOULD BE IN THE MIDDLE 60S. AS THE COLD ADVECTION
REALLY KICKS IN OVERNIGHT THURSDAY AND FRIDAY...HIGHS BY FRIDAY
SHOULD BE MUCH MORE SEASONABLE...IN THE UPPER 50S TO LOWER 60S.
FOR THE REMAINDER OF THE LONGER TERM FORECAST PERIOD...FOR SATURDAY
THROUGH MONDAY...CONDITIONS WILL MODERATE THROUGH THE WEEKEND AS
ANOTHER UPPER RIDGE BUILDING OVER THE WRN CONUS MOVES OUT OVER THE
PLAINS. RISING HEIGHTS OVER THE MIDWEST SHOULD ALLOW FOR GENERALLY
DRY WEATHER THROUGH THE WEEKEND AND TEMPERATURES REBOUNDING BACK
INTO MIDDLE 60S...TO LOWER 70S BY SUNDAY.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* NO CONCERNS OVERNIGHT
* WEAK LAKE BREEZE POTENTIAL THIS EVENING
SHEA
//DISCUSSION...UPDATED 06Z...
SURFACE WIND FEATURES SET UP AND WILL ALLOW LIGHT SOUTHERLY FLOW
THROUGH THE OVERNIGHT PERIOD. DENSER CIRRUS THIS EVENING SHOULD
PRECLUDE ANY BR/VISBY RESTRICTIONS AS SEEN YESTERDAY
MORNING...OTHERWISE OVERALL WEATHER PICTURE FOR THE DAY IS
SIMILAR TO YESTERDAY. EXPECT ANOTHER WEAK LAKE BREEZE TO DEVELOP
AND POTENTIALLY MOVE ACROSS THE TERMINALS LATE IN THE EVENING
AGAIN. WOULDNT EXPECT ANYTHING OVERLY STRONG AGAIN...AND HEDGED IN
THAT DIRECTION WITH WINDS JUST TO THE SOUTH OF EAST AROUND 22Z.
WEAK FRONTAL BOUNDARY WILL CONTINUE TO SLOWLY ENCROACH FROM THE
WEST AND PRECIP POTENTIAL WILL BEGIN TO INCREASE. AT THIS
POINT...ALL EASTERN TERMINALS ARE STILL LOOKING DRY FOR THE 24/30
HOUR TAFOR. RFD ON THE OTHER HAND IS SHOWING THE BETTER CHANCES
INTO THE OVERNIGHT HOURS. CONFIDENCE IS STILL LOW WITH TIMING AND
OVERALL IMPACT AND WILL CONTINUE WITH A PROB30 AT THIS
POINT...UNTIL BETTER SPECIFICS CAN BE ZEROED IN ON. THUNDER
POTENTIAL STILL LOOKS LOW WITH ONLY WEAK ELEVATED INSTABILITY
NOTED ON FORECAST SOUNDINGS...WITH MINIMAL FORCING/MOISTURE
AVAILABLE. OTHERWISE CIGS WILL SLOWLY BEGIN TO TREND DOWNWARD AND
EVEN WITH THE RAINFALL POTENTIAL...FORECAST SOUNDINGS CONTINUE TO
INDICATE THAT BASES WILL STILL REMAIN VFR.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* MEDIUM-HIGH CONFIDENCE IN THE WIND FORECAST
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS
SHEA
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
* WEDNESDAY AND THURSDAY...OCCASIONAL SHRA WITH MVFR OR EVEN
BRIEF IFR POSSIBLE ESPECIALLY WED NGT/THURS MORNING.
* FRIDAY AND SATURDAY...SLGT CHC SHRA FRI...OTHERWISE VFR.
* SUNDAY...SLGT CHC SHRA WITH MVFR CIGS.
RATZER
&&
.MARINE...
231 AM CDT
BROAD RIDGE OF HIGH PRESSURE CONTINUES TO PROVIDE AN INFLUENCE ON
THE WEATHER FOR THE WESTERN GREAT LAKES REGION. THIS RIDGE OF HIGH
PRESSURE IS EXPECTED TO STEADILY SLIDE EAST/NORTHEAST...AS AN AREA
OF LOW PRESSURE LIFTS NORTHEAST FROM MANITOBA INTO WESTERN
ONTARIO LATER TODAY. THEN A SECOND AND STRONGER AREA OF LOW
PRESSURE IS EXPECTED TO DEVELOP LATE IN THE WEEK ACROSS AND
PROVIDE A SIGNIFICANT INFLUENCE ON THE WEATHER OVER LAKE MICHIGAN
FRIDAY THROUGH EARLY SATURDAY...WITH A VERY TIGHT PRESSURE
GRADIENT. IN ADDITION WINDS ARE EXPECTED TO APPROACH GALE CRITERIA
FRIDAY THROUGH EARLY SATURDAY. AT THIS TIME HAVE OPTED TO HOLD OFF
ON ANY HEADLINES...HOWEVER IF MODEL SOLUTIONS CONTINUE TO
STRENGTHEN THIS SYSTEM...A GALE WATCH MAY BE ISSUED.
MUCH COOLER AIR WILL ARRIVE...ALLOWING WAVES TO STEADILY BUILD
LATE IN THE WEEK INTO EARLY THIS WEEKEND BEFORE THE PRESSURE
GRADIENT SLACKENS.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
