402 AM CDT
VERY PLEASANT MORNING AHEAD FOR MUCH OF THE CWA AS HIGH PRESSURE
REMAINS IN CONTROL. HOWEVER CHANGE IS UPON US. A WEAK SHORT WAVE
TROUGH WILL PASS THROUGH CENTRAL ILLINOIS EARLY THIS
MORNING...CREATING LIGHT SHOWERS OVER
LIVINGSTON...FORD...IROQUOIS...AND BENTON COUNTIES. THE SHOWERS
WILL DISSIPATE BEFORE NOON. THE REMAINDER OF THE CWA WILL BE DRY
FOR THE VAST MAJORITY OF TODAY...WITH HIGH TEMPERATURES IN THE MID
TO UPPER 60S.
A COLD FRONT APPROACHES FROM THE NORTHWEST LATE THIS AFTERNOON.
MODEL GUIDANCE VARIES ON THE TIMING OF THE FROPA...BUT DECIDED TO
SIDE WITH THE ECMWF/UKMET/GEM SOLUTIONS AS THEY HAVE BEEN VERY
CONSISTENT OVER THE PAST FEW MODEL RUNS. SHOWERS WILL ENVELOP THE
CWA FROM WEST TO EAST BEGINNING LATE THIS AFTERNOON AS THE COLD
FRONT SWEEPS THROUGH. THE FRONT WILL HAVE LITTLE MOISTURE TO WORK
WITH AND WEAK FORCING...THEREFORE EXPECTING LIGHT TO MODERATE
SHOWERS. INCLUDED A CHANCE OF ISOLATED TS AFTER 7PM FOR LAND AND
THE SOUTHERN HALF OF LAKE MICHIGAN AS MODEL SOUNDINGS INDICATE
WEAK INSTABILITY WILL DEVELOP THIS EVENING INTO THE EARLY
OVERNIGHT HOURS.
BY MONDAY MORNING ALL OF THE RAIN WILL HAVE MOVED OUT OF THE
CWA...AND SKIES WILL BE CLEAR DURING THE DAY ON MONDAY. THE NEXT
STRONGER LOW PRESSURE SYSTEM ARRIVES ON TUESDAY. STRONG SOUTHERLY
FLOW BEHIND THE WARM FRONT WILL SEND HIGH TEMPERATURES ON TUESDAY
INTO THE LOW TO MID 70S. A COLD FRONT WILL PASS THROUGH LATE
TUESDAY AFTERNOON INTO TUESDAY EVENING...BRINGING ANOTHER ROUND OF
SHOWERS. NOT ANTICIPATING WIDESPREAD TS DEVELOPMENT ALONG THE COLD
FRONT ATTM...AS MODEL SOUNDINGS INDICATE INSTABILITY WILL BE
LIMITED. MODEL SOUNDINGS ALSO SHOW A SIGNIFICANT CAP
FORMING...WHICH WOULD CERTAINLY DIMINISH CONVECTIVE DEVELOPMENT.
HIGH TEMPERATURES ON WEDNESDAY WILL BE DRASTICALLY LOWER THAN ON
TUESDAY...WITH HIGHS IN THE 50S. HAVE A CHANCE OF SHOWERS
WEDNESDAY NIGHT INTO THURSDAY MORNING AS UPPER LEVEL VORTICITY
MAXIMA PASS OVER THE GREAT LAKES REGION. WITH COLD AIR OVER THE
LAKE AND STRONG NORTHERLY FLOW...THE NORTHERN INDIANA COUNTIES
WILL SEE LAKE EFFECT SHOWERS THURSDAY NIGHT INTO FRIDAY MORNING.
OTHERWISE...HIGH PRESSURE WILL RESIDE OVER THE EASTERN HALF OF THE
US THROUGH THE WEEKEND...RESULTING IN A SUNNY BUT CHILLY END OF
THE WEEK. HIGH TEMPERATURES ON WILL BE IN THE LOW 50S EACH DAY AND
LOW TEMPERATURES WILL BE IN THE 30S EACH NIGHT FROM THURSDAY NIGHT
THROUGH SATURDAY NIGHT.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
SHOWERS AND SOME THUNDERSTORMS LATE AFTERNOON AND THROUGH THIS
EVENING.
WIND VEERING FROM SW TO W AND NW WITH CFP LATE THIS EVE AND
OVERNIGHT.
TRS
//DISCUSSION...UPDATED 18Z...
A SHORT WAVE TROUGH EXTENDS SOUTHWARD ACROSS THE EASTERN PORTIONS
OF MN...IA AND MO WITH A STRONG VORT MAX OVER CENTRAL MN. BY 06Z
THE SHORT WAVE TROUGH AXIS IS PROGGED TO BE OVER CENTRAL LAKE
SUPERIOR...EASTERN U.P. OF MI...FAR SE WI AND BACK TO W CENTRAL
IL...WITH THE VORT MAX TRACKING E ACROSS CENTRAL WI.
WITH STRONGER DYNAMICS N OF THE LOCAL TERMINALS MORE WISE-SPREAD
RAIN AND SHOWERS EXPECTED THERE. HOWEVER...AS MID LEVEL WINDS OVER
THE LOCAL AREA BACK FROM WNW TO WSW THIS LEVEL TO MOISTEN BY LATE
AFTERNOON/THIS EVENING. WITH THIS MID LEVEL MOISTURE...STEEP MID
LEVEL LAPSE RATES...APPROACH OF THE MID LEVEL TROUGH AND
SIGNIFICANT UPPER DIFLUENCE EXTENDING SW ACROSS THE LOCAL AREA AT
THE LEFT EXIT REGION OF THE STRONG 130KT JET MAX DROPPING OVER
EASTERN ND SE ACROSS THE UPPER MIDWEST AT 00Z-06Z EXPECT SOME
HIGHER BASED SHOWERS AND THUNDERSTORMS. LOW LEVEL MOISTURE
CONVERGENCE AHEAD/ALONG THE COLD FRONT WILL ALSO AID CONVECTIVE
DEVELOPMENT AS UPPER 40S-LOWER 50S DEW POINTS ADVECT NORTHEASTWARD
THE REST OF THIS AFTERNOON AND THIS EVENING.
ONCE THE SHORT WAVE TROUGH PASSES OFF TO THE E OF THE LOCAL AREA
OVERNIGHT STRONG SUBSIDENCE MOVES IN ALONG WITH STRONG LOW AND
MID LEVEL DRYING SPREADING NE-SE ACROSS THE AREA.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
HIGH CONFIDENCE EXCEPT MODERATE CONFIDENCE IN EXACT TIMING OF
PRECIPITATION AND NUMBER OF THUNDERSTORM CELLS.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR
TUESDAY...STRONG SSW WINDS WITH SCT TSRA IN EVENING.
WEDNESDAY...IFR/LOW END MVFR CIGS POSSIBLE...MAINLY EARLY.
THURSDAY...MVFR CIGS POSSIBLE WITH A CHC OF -SHRA.
FRIDAY AND SATURDAY...VFR.
IZZI
&&
.MARINE...
245 AM CDT
WINDS WILL BECOMING SOUTH AND INCREASE SOME THIS AFTERNOON AND
EVENING AS A LOW TRACKS NORTH OF LAKE SUPERIOR. RELATIVELY WARM
AIR RUNNING INTO THE CHILLY MARINE LAYER SHOULD PREVENT FULL
FORCE OF WINDS FROM BEING FELT...ESPECIALLY OVER SOUTHERN PORTIONS
OF THE LAKE THIS AFTERNOON. FRONT SWEEPS ACROSS THE LAKE TONIGHT
AND COULD SEE A BRIEF PERIOD OF 30KT WINDS FOR A COUPLE/FEW HOURS
BEHIND THE FRONT BEFORE WINDS BEGIN TO SUBSIDE AGAIN LATE
TONIGHT.
NEXT LOW DEVELOPS OVER THE PLAINS AND TRACKS EAST INTO WISCONSIN
TUESDAY AFTERNOON. WHILE THERE ARE STILL SOME DIFFERENCES IN MODEL
SOLUTIONS FOR THIS LOW...THEY ARE SMALLER THAN THE LAST FEW DAYS.
WINDS SHOULD INCREASE TUESDAY AS THIS LOW TRACKS QUICKLY MOVES
EAST TOWARD THE REGION...THOUGH AGAIN WARM AIR WITH THE SOUTHERLY
FLOW OVER THE SOUTHERN PORTIONS OF THE LAKE SHOULD KEEP WINDS FROM
GETTING TOO OUT OF HAND. IN THE WAKE OF THE LOW STILL THINK WINDS
WILL RAMP UP QUICKLY OUT OF THE NORTH/NORTHWEST WITH A POTENTIAL
FOR AT LEAST A PERIOD OF GALES BEHIND THE LOW. ENOUGH DIFFERENCES
REMAIN TO HOLD OFF ON GOING ABOVE 30KT IN THE FORECAST JUST
YET...BUT GALES STILL LOOK POSSIBLE FOR A TIME LATE TUESDAY NIGHT
INTO WEDNESDAY AND MAY NEED TO BE ADDED AS MODELS COME AROUND TO
A MORE UNIFIED SOLUTION WITH THIS NEXT SYSTEM.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
