254 AM CDT
MAIN FORECAST CHALLENGE THIS MORNING IS WITH POTENTIAL FOR FROST
AGAIN TONIGHT.
THE POWER-HOUSE STORM THAT PUT ON ONE HECK OF A SHOW ALONG THE LAKE
MICHIGAN SHORE IS WEAKENING AND MOVING AWAY WITH HIGH PRESSURE
MOVING INTO THE REGION. PUSH OF CHILLY AIR IN THE WAKE OF THIS
STORM IS ALREADY BEING REPLACED WITH WARM AIR ADVECTION ALOFT TO
OUR WEST...WHICH SHOULD BEGIN TO SPREAD EAST INTO THE AREA TODAY.
WITH FULL/NEARLY FULL SUNSHINE AND DRY AIR MASS IN PLACE WOULD
ANTICIPATE A HEALTHY REBOUND IN TEMPS THIS AFTERNOON.
TEMPS AND SUBSEQUENT FROST POTENTIAL IS TRICKY FOR TONIGHT. MOSTLY
CLEAR SKIES AND REASONABLY GOOD CHANCE OF WINDS GOING NEARLY CALM
WOULD CERTAINLY FAVOR STRONG RADIATIONAL COOLING. HOWEVER...ALOFT
TEMPERATURES WILL BE WARMING RAPIDLY...WITH MODEL PROGGED 925MB
TEMPS NEARLY 10C WARMER THAN THIS MORNING...SO AM SOMEWHAT CONCERNED
ABOUT JUST HOW COLD/DECOUPLED WE WILL BECOME. WE STAND A REASONABLY
GOOD CHANCE OF AREAS OF FROST OVER OUR SE CWA...BUT WILL LET THE DAY
SHIFT RE-ACCESS AND PULL THE TRIGGER ON ANY POSSIBLE HEADLINES.
REALLY LOOKING LIKE A SPECTACULAR LATE OCT WEEKEND ALL THINGS
CONSIDERED WITH UPPER RIDGE BUILDING IN AND TEMPS RECOVERING BACK TO
ABOVE SEASONAL NORMS. WEAK SHORTWAVE AND ASSOCIATED FRONT APPROACH
FROM THE NORTHWEST LATER SUNDAY AND HAVE CONTINUED WITH LOW CHANCE
POPS WITH THIS FEATURE. MOISTURE LOOKS TO BE FAIRLY LIMITED...BUT
WITH STEEP LAPSE RATES HARD TO COMPLETELY RULE OUT SOME SCATTERED
CONVECTION ALONG THE FRONT.
MORE SIGNIFICANT SHORTWAVE PROGGED TO ARRIVE TUESDAY...BUT MEDIUM
RANGE MODELS CONTINUE TO BOUNCE AROUND WITH RESPECT TO THE TRACK
OF THE SURFACE LOW. SHOULD IT GO NORTH...WE COULD BE QUITE MILD
WITH SOUTHERLY WINDS...CONVERSELY IF IT GOES FARTHER SOUTH LIKE
THE GFS/DGEX SUGGEST THEN STIFF EAST WINDS SHOULD KEEP IT CHILLY.
UNTIL THE MODELS SETTLE ON A SOLUTION PROBABLY BEST TO MAKE NO
MAJOR CHANGES TO GOING FORECAST FOR NOW.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 10Z...
* NO CONCERNS.
BMD
//DISCUSSION...UPDATED 06Z...
NO SIGNIFICANT CONCERNS FOR THE LATEST FORECAST. LINGERING VFR CLOUD
COVER FROM DEPARTING LOW WILL GRADUALLY ERODE FROM THE WEST AS
ANTICYCLONIC FLOW PUSHES EAST ACROSS THE FORECAST AREA. GUSTY WINDS
HAVE ENDED ACROSS THE AREA AND WINDS WILL GRADUALLY BACK TO THE WEST
THEN SOUTHWEST THROUGH THE FORECAST PERIOD AND REMAIN LIGHT...LESS
THAN 10 KT...AS THE RIDGE AXIS MOVES THROUGH THE AREA. BMD
//ORD AND MDW CONFIDENCE...UPDATED 10Z...
* HIGH CONFIDENCE IN ALL ELEMENTS OF FORECAST.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY...VFR
* SUNDAY...CHANCE SHRA
* MONDAY...VFR
* TUESDAY AND WEDNESDAY...CHANCE SHRA
SHEA
&&
.MARINE...
321 AM...LOW PRESSURE OVER QUEBEC WILL CONTINUE TO SLOWLY WEAKEN
AS IT LIFTS NORTHEAST TODAY AND TONIGHT. A RIDGE OF HIGH PRESSURE
EXTENDING FROM WESTERN ONTARIO SOUTH INTO THE PLAINS...WILL MOVE
SOUTHEAST ACROSS THE WESTERN LAKES THIS AFTERNOON INTO THIS
EVENING. THUS THE GRADIENT WILL CONTINUE TO SLOWLY WEAKEN THROUGH
THE DAY...THOUGH SOME GUSTS TO 30 KT ARE STILL POSSIBLE ACROSS FAR
NORTHERN LAKE MICHIGAN EARLY THIS MORNING. A WEAK TROUGH OF LOW
PRESSURE WILL MOVE ACROSS THE WESTERN LAKES SATURDAY AND THEN IS
EXPECTED TO DISSIPATE AS LOW PRESSURE MOVES ACROSS MANITOBA
SATURDAY NIGHT AND THEN ACROSS ONTARIO SUNDAY AND SUNDAY NIGHT.
APPEARS THE GRADIENT WILL TIGHTEN ENOUGH FOR WINDS TO INCREASE
BACK INTO THE 15-25 KT RANGE SUNDAY/SUNDAY NIGHT AHEAD OF A COLD
FRONT THAT WILL TURN WINDS WESTERLY BY MONDAY MORNING. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FROST ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032 UNTIL 9 AM FRIDAY.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 1 PM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 PM FRIDAY.
&&
$$
