358 AM CDT
MAIN FORECAST CONCERNS ARE WITH PRECIP CHANCES TODAY AS WELL AS
INTO THE END OF THE WEEKEND...WITH A POSSIBLE BRIEF WARM UP EARLY
NEXT WEEK.
LATEST SATELLITE IMAGERY SHOWING A LARGE AREA OF HIGH LEVEL CIRRUS
MOVING ACROSS PORTIONS OF NORTHERN ILLINOIS AND NORTHWEST INDIANA
EARLY THIS MORNING...WITH SOME MID/LOW LEVEL CLOUD COVER MOVING
EAST ACROSS THE LAKE. ALTHOUGH...THIS HIGH LEVEL CIRRUS IS RATHER
THIN AND STILL RESULTING IN MOSTLY CLEAR CONDITIONS. WITH THESE
CLEAR SKIES AND CALM CONDITIONS...TEMPERATURES HAVE BEEN ABLE TO
FALL INTO TO THE LOW AND MID 30S THIS MORNING WITH WARMER TEMPS
NEAR THE LAKE. WITH THESE FALLING TEMPS...HAD INCLUDED THE
REMAINDER OF THE CWA IN THE FROST ADVISORY THIS MORNING WITH THE
EXCEPTION OF COOK COUNTY. THERE ALSO REMAINS SOME ISOLATED AREAS
OF FOG THIS MORNING...WITH VISIBILITIES HOLDING AROUND 2-4SM AND
EVEN SOME BRIEF PERIODS OF VIS AROUND 1-3SM. THIS IS MOST LIKELY
DUE IN PART TO SOME AREAS WHICH RECEIVED SOME SHOWERS/MOISTURE
YESTERDAY EVENING. DONT EXPECT TOO MUCH EXPANSION OF THIS
FOG...MAINLY REMAINING ISOLATED. ALTHOUGH...WITHIN THESE
AREAS...LOWER VISIBILITY COULD BE OBSERVED.
LATEST SATELLITE IMAGERY SHOWING THE NEXT WAVE TO BRING OUR AREA
SOME SHOWERS UP ACROSS THE NORTHERN PLAINS...WITH ASSOCIATED CLOUD
COVER AND LIGHT SHOWERS ALSO PRESENT. THIS MID LEVEL WAVE AND
SURFACE TROUGH AXIS WILL DIG SOUTH THROUGH THE MIDWEST TODAY AND
REACH THE CWA LATER THIS AFTERNOON. NOT ONLY WILL FORCING BE ON
THE INCREASE...BUT MUCH COLDER AIR ALOFT WILL SHIFT SOUTHWARD.
THIS WILL RESULT IN STEEP LOW AND MID LEVEL LAPSE RATES. THESE TWO
FEATURES COINCIDING WITH ONE ANOTHER WILL ENABLE SHOWERS TO
DEVELOP WITH THE WESTERN PORTION OF THE CWA OBSERVING THE BETTER
CHANCES THIS AFTERNOON. THEN THIS TROUGH AXIS WILL SHIFT EAST WITH
FORCING EXPANDING EAST ACROSS THE REMAINDER OF THE CWA WITH THE
OVERALL BEST CHANCES FOR THE CWA TO OBSERVE SHOWERS COMING IN THE
LATE AFTERNOON AND EARLY EVENING. THERMAL PROFILES OVER THE LAKE
DURING THIS TIME FRAME WILL NOT ONLY BE FAVORABLE FOR SHOWERS BUT
EVEN THE POSSIBILITY FOR THUNDER AS VERY LOW AND MID LEVEL LAPSE
RATES WILL BE IN PLACE AS THE COLDEST AIR ALOFT MOVES OVERHEAD.
THEN WITH THIS UPPER LEVEL TROUGH SHIFTING EAST...THIS
PRECIP/CLOUD COVER WILL ALSO SLOWLY SHIFT EAST. AS CLEAR SKIES
SLOWLY WORK BACK IN FROM THE WEST...TEMPS COULD FALL ONCE AGAIN
WITH SIMILAR CONDITIONS/TEMPS POSSIBLE TONIGHT. A BRIEF PERIOD OF
RIDGING ON SATURDAY WILL RESULT IN FAIR CONDITIONS BUT THIS WILL
BE ONGOING AS THE NEXT SYSTEM APPROACHES FROM THE WEST. ANOTHER
TROUGH WILL DIG SOUTHEAST OUT OF THE NORTHERN PLAINS SATURDAY
NIGHT INTO SUNDAY WITH SURFACE REFLECTION PUSHING THROUGH DURING
THE DAY SUNDAY. SHOWERS WILL DEVELOP OUT AHEAD OF THIS
SYSTEM...WITH MODELS IN FAIR AGREEMENT OF THE EVOLUTION OF THIS
SYSTEM. WITH THE BEST CHANCES ACROSS THE NORTHERN CWA...HAVE
RAISED POPS ON SUNDAY. THEN CLEARING ON MONDAY WITH A WARMING
TREND EXPECTED THAT DAY INTO TUESDAY WITH MAX TEMPS POSSIBLY
REACHING THE LOWER 60S.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* OCCASIONAL GUST FROM THE SW UP TO 16KT THRU 23Z.
* UPPER LEVEL DISTURBANCE SWINGS EAST AND MAY PRODUCE ISO SHRA
POSSIBLY TS AND GRAUPEL.
* POST FRONT WINDS TURN WEST/NORTHWEST.
BEACHLER
//DISCUSSION...UPDATED 18Z...
VISIBLE IMAGERY EARLY THIS AFTERNOON INDICATES CONSIDERABLE CLEAR
SKIES ACROSS THE GREAT LAKES REGION...WITH A FEW POCKETS OF CLOUDS
DEVELOPING ACROSS CENTRAL INDIANA STRETCHING NORTH THROUGH
MICHIGAN. ALONG THE LEE SIDE OF THE UPPER LEVEL DISTURBANCE OVER
WESTERN WISCONSIN/NORTHEAST IOWA SOME MID/HIGH LEVEL MOISTURE WAS
BEGINNING TO SHOW UP. A FEW GUIDANCE MEMBERS CONTINUE TO INDICATE
THAT ISOLATED SHOWERS MAY DEVELOP THROUGH THE NEXT FEW HOURS IN
THIS REGION...THEN PROGRESS EAST. ONE MAJOR INHIBITING FACTOR WILL
BE THE LACK OF LOW LEVEL MOISTURE. DEW POINT/TEMPERATURE
DEPRESSIONS CONTINUE TO HOVER IN THE 20 TO 30 DEG RANGE. THIS WILL
MAKE IT EXTREMELY DIFFICULT FOR PRECIP TO DEVELOP...AND THE OTHER
ITEM IS THAT GUIDANCE HAS CONTINUED TO OVER FORECAST THE MIXED
LAYER. THE BEST CHANCE FOR PRECIP ACROSS NORTHERN IL/NORTHWEST IN
WILL BE SOMETIME AFT 00Z...HOWEVER CONFIDENCE IN THIS REMAINS VERY
LOW. FOR NOW HAVE MAINTAINED THE PROB30 GROUP...BUT COULD EASILY
SEE THIS WITH FUTURE TAF ISSUANCES BEING REMOVED.
FRONT SWEEPS THROUGH THE AREA FROM WEST TO EAST LATER THIS EVENING
WITH WINDS VEERING NORTHWEST AND LINGERING THROUGH MUCH OF EARLY
SATURDAY MORNING. THEN HIGH PRESSURE BUILDS BACK IN AND PROVIDES
MINIMAL CLOUD COVER. THE ONE CAVEAT COULD BE POTENTIAL FOR
LINGERING CLOUDS ACROSS NORTWHEST IN.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED.
* MEDIUM CONFIDENCE AIRFIELDS REMAIN DRY THIS EVENING/OVERNIGHT.
* LOW CONFIDENCE ON PRECISE TIMING/COVERAGE OF PRECIP.
* MEDIUM/HIGH CONFIDENCE CIGS REMAIN VFR.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...VFR.
SUNDAY...CHANCE OF SHOWERS. LOCAL MVFR CIGS POSSIBLE.
MONDAY...MVFR POSSIBLE EARLY...THEN VFR.
TUESDAY...VFR.
WEDNESDAY...CHC SHRA. MVFR POSSIBLE.
THURSDAY...VFR.
RATZER
&&
.MARINE...
155 AM CDT
SEVERAL UPPER LEVEL DISTURBANCES/CLIPPER SYSTEMS SHOULD AFFECT THE
WEATHER OVER LAKE MICHIGAN FOR THE NEXT FEW DAYS. EACH DISTURBANCE
LOOKS TO PROVIDE AN INCREASE IN THE WINDS AND GOOD CHANCES FOR LAKE
EFFECT/LAKE ENHANCED SHOWERS AND EVEN SOME THUNDERSTORMS.
THE FIRST CLIPPER SYSTEM WILL RACE SOUTHEASTWARD ACROSS THE LAKE
LATER TODAY AND TONIGHT. THE ASSOCIATED SURFACE TROUGH OF LOW
PRESSURE SHOULD INDUCE AN INCREASE IN THE SOUTH TO SOUTHWESTERLY
WINDS LATER THIS AFTERNOON AND DURING THE EVENING. THIS SHOULD
PROVIDE A WINDOW OF 15 TO 25 KT WINDS INTO THIS EVENING BEFORE THE
WINDS ABATE. THE OTHER CONCERN WITH THIS SYSTEM WILL BE THE THREAT OF
SOME THUNDERSTORMS AND WATERSPOUTS TONIGHT. VERY COLD TEMPERATURES
ALOFT ASSOCIATED WITH THE UPPER LEVEL DISTURBANCE SHOULD PROVIDE A
FAVORABLE THERMODYNAMIC SETUP FOR THUNDERSTORMS AND WATERSPOUTS. THE
WATERSPOUT THREAT WILL LIKELY BE THE HIGHEST DURING THE LATER
EVENING AND OVERNIGHT HOURS AS THE SURFACE TROUGH PROVIDES A GOOD
SURFACE CONVERGENCE ZONE. THIS THREAT WILL DIMINISH ON SATURDAY
MORNING.
THERE WILL BE A BRIEF QUIET PERIOD DURING THE DAY ON SATURDAY AS A
SURFACE RIDGE OF HIGH PRESSURE BUILDS IN ACROSS THE LAKE.
HOWEVER...ANOTHER CLIPPER SYSTEM LOOKS TO AFFECT LAKE MICHIGAN ON
SUNDAY AND SUNDAY NIGHT. THIS SYSTEM APPEARS TO BE THE STRONGEST OF
THE TWO...AND THEREFORE THE SOUTHERLY WINDS THAT IT INDUCES ON
SUNDAY COULD APPROACH LOW END GALE FORCE. WILL STAY CONSERVATIVE AND
CAP THE WINDS AT 32 KT AT THIS TIME. AT THE LEAST...THIS LOOKS TO
PRODUCE A GOOD CHANCE OF SMALL CRAFT CONDITIONS FOR THE NEAR SHORE
WATERS ON SUNDAY.
NEXT WEEK IT APPEARS THAT THE WEATHER PATTERN WILL REMAIN ACTIVE
ACROSS THE CENTRAL CONUS. HOWEVER...AT THIS TIME THE STRENGTH OF THE
STORM SYSTEMS REMAIN IN QUESTION.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZE WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039...2 AM SATURDAY TO 9 AM SATURDAY.
IN...FREEZE WARNING...INZ001-INZ002-INZ010-INZ011-INZ019...2 AM
SATURDAY TO 9 AM SATURDAY.
LM...NONE.
&&
$$
