323 AM CDT
WARMER TEMPERATURES ARE THE NEAR TERM FOCUS AS BROAD UPPER RIDGE
SHIFTS EAST ACROSS THE GREAT LAKES TODAY...WHILE NORTHERN STREAM
SHORT WAVE TRAVERSES ONTARIO. SURFACE LOW ASSOCIATED WITH THIS WAVE
TRAILS A SLOW MOVING COLD FRONT FROM NORTHERN WISCONSIN INTO CENTRAL
IOWA BY THIS EVENING...WITH WFO LOT FORECAST AREA IN BREEZY WARM
SECTOR DURING THE DAY. OTHER THAN A LITTLE PATCHY THIN
CIRRUS...SHOULD BE RELATIVELY CLOUD-FREE...WITH TEMPS SURGING INTO
THE 60S. COMPARING LOW LEVEL MODEL THERMAL PROGS AND UPSTREAM TEMPS
ACROSS THE MID-MISSOURI VALLEY YESTERDAY...HAVE GONE A COUPLE
DEGREES ABOVE GUIDANCE FOR HIGHS AS FORECAST SOUNDINGS AND 00Z
UPSTREAM RAOBS INDICATE FAIRLY SHALLOW MIXED LAYER TO AROUND 950 MB
TODAY. SOUTH WINDS AT 15-20 KTS AT 950 MB SHOULD PREVENT LAKE
BREEZE...SO 6-9 DEGREE ABOVE NORMAL WARMTH WILL BE EXPERIENCED RIGHT
UP TO THE LAKE SHORE.
FORECAST CONCERNS THEN SHIFT TO RAIN POTENTIAL WEDNESDAY AND
THURSDAY. COLD FRONT MOVES SOUTHEAST INTO FAR NORTHERN ILLINOIS
WEDNESDAY MORNING...WITH THERMAL GRADIENT TIGHTENING ACROSS THE AREA
DURING THE AFTERNOON IN RESPONSE TO SURFACE LOW DEVELOPMENT OVER THE
LOWER MISSOURI VALLEY AS SOUTHERN STREAM SHORT WAVE CLOSES OFF OVER
SOUTHERN PORTION OF TROUGH. RESULTING LOW LEVEL FRONTOGENESIS OVER
THE NORTHWEST HALF OF THE CWA AND INCREASING LARGE SCALE ASCENT WITH
APPROACHING TROUGH WILL INCREASE RAIN POTENTIAL ALONG/BEHIND FRONT.
AS SYSTEM CONTINUES TO CLOSE OFF OVER MISSOURI AND SOUTHERN ILLINOIS
WEDNESDAY NIGHT INTO THURSDAY AND FRONTAL ZONE SHIFTS SOUTHEAST
ACROSS THE FORECAST AREA...RAIN CHANCES WILL INCREASE ACROSS THE
REMAINDER OF THE CWA. HIGHEST POPS WILL BE WEDNESDAY NIGHT AND EARLY
THURSDAY...BEFORE UPPER/SFC LOWS DRIFT EAST THROUGH THE OHIO VALLEY
AS FLOW OTHERWISE REMAINS PROGRESSIVE. EARLIER DIFFERENCES WITH
POSITION OF THE SFC LOW BY THURSDAY MORNING APPEAR TO BE DIMINISHING
WITH 00Z RUNS...WITH 00Z GFS/ECMWF AND GEFS ENSEMBLE CLUSTERING
SUGGESTING LOW NEAR KSTL BY 12Z. OF CURIOUS NOTE...THE NAM REALLY
COOLS THE COLUMN ACROSS THE FAR NORTHWEST CWA LATE WEDNESDAY NIGHT
WHICH WOULD SUGGEST POTENTIAL FOR WET SNOW TO MIX IN WITH RAIN AS
FAR SOUTHEAST AS KRFD...BUT MAINLY NORTH AND WEST OF THE CWA. GIVEN
STRONGER FORCING TO THE SOUTH WITH THE MAIN VORT AND UPPER LOW...
PREFER WARMER LOOK OF GFS/ECMWF/GEM SOLUTIONS AT THIS POINT AND WILL
NOT MENTION THE S-WORD IN THE FORECAST. RAIN SHOULD DIMINISH FROM
NORTHWEST TO SOUTHEAST THURSDAY AFTERNOON AND EVENING...AS LOW
SCOOTS OFF TO THE EAST. WHILE NOT EXCESSIVE...TOTAL RAIN AMOUNTS MAY
RANGE BETWEEN A HALF INCH AND AN INCH OR SO.
TEMPS WILL BE A LITTLE TRICKY WEDNESDAY WITH FRONT PUSHING INTO THE
NORTHWEST PORTION OF THE CWA. HAVE LEANED FROM A BLEND OF MAV/MET
GUIDANCE NORTHWEST WHERE MORE CLOUDS AND HIGH PRECIP POTENTIAL WILL
BE TO A WARMER MET SOLUTION FAR SOUTHEAST. SIDED WITH A BLENDED
GUIDANCE WHICH UNDERCUTS MAV/MEX MOS BY A DEGREE OR TWO THURSDAY
GIVEN RAIN AND CLOUD COVER.
QUIET WEATHER RETURNS BY FRIDAY AS SURFACE HIGH PRESSURE SPREADS
ACROSS THE GREAT LAKES IN THE WAKE OF THE LOW...AND IN RESPONSE TO
RIDGING ALOFT IN WHAT REMAINS A HIGHLY AMPLIFIED JET PATTERN. LONGER
RANGE GUIDANCE REMAINS IN VERY GOOD AGREEMENT IN DIGGING SHORT WAVE
TROUGH BECOMING NEGATIVELY TILTED AND LIFTING OUT ACROSS THE UPPER
MIDWEST SATURDAY. OVERALL TREND IN GUIDANCE HAS BEEN TO SLOW THE
PROGRESSION OF THIS SYSTEM SOMEWHAT...WITH NEW 00Z ECMWF SLOWER
STILL THAN THE GFS. SYSTEM LOOKS FAIRLY DRY FOR OUR AREA...WITH MAIN
LOW-PROBABILITY PRECIP CHANCE COMING WITH THE PASSAGE OF THE
OCCLUDED COLD FRONT SATURDAY NIGHT INTO SUNDAY. WHILE WARM SECTOR
BECOMES PINCHED OFF...TEMPS NEAR 60 NOT TOO SHABBY A WEEK INTO
NOVEMBER. ONLY MODESTLY COOLER PACIFIC AIR BEHIND SYSTEM INTO MONDAY
WITH NEXT CHANCE OF RAIN LOOKING TO ARRIVE MONDAY NIGHT.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* NO CONCERNS IN THE NEAR TERM.
* SOUTHERLY WINDS PICKING UP BY MID MORNING WITH GUSTS UP TO 20KT
POSSIBLE THROUGH THE AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
WITH HIGH PRESSURE STRETCHED ACROSS THE REGION...QUIET WEATHER
ONGOING ACROSS THE TERMINALS. OUTSIDE OF SOME SCATTERED HIGH
LEVEL CIRRUS TODAY...NO REAL CLOUD COVER EXPECTED. THEN A
DEVELOPING SYSTEM TO THE WEST WILL SLOWLY SHIFT EAST WITH TIME
CLOSER TO THE END OF THE FORECAST PERIOD...WITH AN INCREASE IN
HIGH LEVEL CIRRUS AND MID LEVEL MOISTURE BUT WITH ANY PRECIP
STAYING WELL WEST OF THE TERMINALS.
LIGHT SOUTHERLY WINDS WILL GRADUALLY PICK UP BY MID MORNING WITH
GUSTS UP TO 20KT POSSIBLE THROUGH THE AFTERNOON...BEFORE
DIMINISHING BY THE EVENING. ALTHOUGH AS THE SYSTEM TO THE WEST
SLOWLY SHIFTS EAST...WINDS ALOFT WILL REMAIN ON THE INCREASE. THIS
COULD KEEP SOUTH/SOUTHWEST WINDS AROUND THE 10KT RANGE TOWARDS
THE END OF THE FORECAST PERIOD.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* HIGH CONFIDENCE IN VFR CONDITIONS.
* HIGH CONFIDENCE IN WIND SPEED AND DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...COLD FRONT/WIND SHIFT TO THE NORTH LATE AFTERNOON/EARLY
EVENING. SHOWERS DEVELOPING LATE AFTERNOON/EARLY EVENING. MVFR CIGS
DEVELOPING IN THE EVENING.
THURSDAY...MVFR CIGS/SHOWERS IN THE MORNING...VFR IN THE AFTERNOON.
FRIDAY...VFR.
SATURDAY AND SUNDAY...SLIGHT CHANCE OF SHOWERS.
&&
.MARINE...
259 AM CDT
A COLD FRONT THAT SPANS THE NORTHERN PLAINS WILL SLOWLY PUSH EAST
ACROSS THE NORTHERN MISSISSIPPI VALLEY TODAY...WHILE RIDGING
OVER THE EASTERN CONUS MOVES EAST. THE PRESSURE GRADIENT WILL
TIGHTEN THROUGH THE DAY AND WINDS WILL INCREASE CONSIDERABLY. NOT
EXPECTING WINDS TO REACH GALE LEVELS FOR THE OPEN WATERS...BUT
REMAIN AT OR AROUND 30 KT LATER THIS AFTERNOON AND INTO THE
EVENING HOURS. DID HOIST A SMALL CRAFT ADVISORY FOR LATER THIS
MORNING THAT WILL BE IN EFFECT INTO THE EVENING. CONDITIONS WILL
BE MARGINAL FOR MOST LOCATIONS...THOUGH CANT COMPLETELY RULE OUT
THE OCCASIONAL GUST AOA CRITERIA. WINDS WILL THEN FLIP TO THE
NORTH AS THE FRONT SLIDES BY AND THE STRONGER CASE FOR AN ADVISORY
WILL CREEP UP OVERNIGHT WEDNESDAY AS WAVES WILL INCREASE ABOVE
CRITERIA. WINDS WILL ALSO PICK UP OUT OF THE NORTH AND REACH 30 KT
FROM THE OPEN WATERS TO ALL COASTAL LOCATIONS. HIGH PRESSURE WILL
THEN WORK ACROSS THE LAKES BY THE END OF THE WEEK ALLOWING THE
STRONG NORTHERLY WINDS TO ABATE FOR A SHORT TIME. ANOTHER CENTRAL
PLAINS STORM SYSTEM WILL MOVE ACROSS LAKE SUPERIOR AND INTO CANADA
THIS WEEKEND...BRINGING WINDY SOUTHERLY CONDITIONS ACROSS THE
ENTIRE SPAN OF THE LAKE.
SHEA
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...10 AM TUESDAY TO 10 PM TUESDAY.
&&
$$
