340 AM CDT
THE END IS UPON US...AND THAT END IS THE ENDLESS SUMMER-LIKE
CONDITIONS THAT HAD BECOME THE NORM FOR THE LAST FEW WEEKS. THE
CHANGES WILL INCLUDE THE SHOWERS TODAY...CHANCES AGAIN TOMORROW
AND AGAIN ON SUNDAY...COUPLED WITH CHILLIER TEMPERATURES THROUGH
THE WEEKEND AND INTO THE WORK WEEK.
THIS MORNING...WATER VAPOR IMAGERY AND PROFILER ANALYSIS SHOW A
LARGE TROUGH TRAVERSING THE PLAINS. DIVING SOUTHEAST ALONG THE
WESTERN FLANK OF THE TROUGH AND THROUGH EASTERN NEBRASKA IS A FAIRLY
POTENT SHORTWAVE...BUT THAT WILL HAVE MORE OF A TRIGGER ON WEATHER
SOUTH ACROSS THE LOWER MISSISSIPPI VALLEY TODAY. ACROSS OUR NECK OF
THE WOODS...A WEAK SURFACE LOW IS NOTED ALONG THE ILLINOIS/IOWA AND
WISCONSIN BORDERS. EXTENDING SOUTH OF THIS LOW IS A COLD FRONT THAT
DRAPES SOUTH TO EASTERN TEXAS. BOTH OF THESE FEATURES WILL CONTINUE
TO SLOWLY PUSH EAST AND ACROSS THE CWA THROUGH THE DAY. FULLY EXPECT
THE JUMBLED MESS OF SHOWERS TO CONTINUE THROUGH THE MORNING HOURS
AND INCREASE BEFORE SLOWLY COMING TO AN END FROM WEST TO EAST
THROUGH THE AFTERNOON. ENDED UP PULLING OUT THE MENTION OF THUNDER
FROM THE GOING FORECAST THIS MORNING AS FORECAST SOUNDINGS ARE
SHOWING NARY A GASP OF INSTABILITY TO WORK WITH. SPC MESOSCALE
ANALYSIS SHOWS THE BETTER AXIS OF INSTABILITY TO THE SOUTH AND
ACROSS CENTRAL ILLINOIS...WITH MAYBE 100 J/KG OF MUCAPE NOSING
INTO THE SOUTHERN THIRD OF THE CWA. AS THE AFOREMENTIONED TROUGH
SHIFTS TO THE EAST...WITH SURFACE LOW AND FRONT MOVING TO THE EAST
AS WELL...COULD ARGUE THAT IF THERE WAS ANY CHANCE FOR THUNDER
TODAY IT WOULD BE GENERALLY EAST OF I-57 AND SOUTH OF
I-80...HELPING TO ADVECT IN HIGHER DEWPOINT AIR. BUT GIVEN THE
LIMITED INGREDIENTS TO WORK WITH...WILL KEEP ANY WORDING OUT.
UPPER LEVEL TROUGH WILL MOVE EAST THROUGH THE DAY TODAY AND
LINGERING CLOUDS PRECIP AND CLOUDS WILL KEEP TEMPERATURES
DOWN...WITH MOST LOCATIONS ONLY SEEING SOME INCREASE OVER THE
MORNING READINGS. STRONGER NORTHWEST WINDS WILL THEN BE ON THE
INCREASE OVERNIGHT BRINGING IN A COOLER AIRMASS BY FRIDAY WITH
CYCLONIC FLOW REMAINING IN PLACE THROUGH THE WEEKEND. MAINTAINED THE
MENTION OF LIGHT SHOWERS AGAIN TOMORROW AS ANOTHER WAVE RIPPLES
THROUGH THE FLOW. LAPSE RATES TO REMAIN STEEP /ON THE ORDER OF
6.5C/KM OR GREATER FROM THE SURFACE THROUGH THE MID LEVELS/.
MOISTURE AVAILABILITY AND FORCING IS NOT THAT STRONG AND ANYTHING
THAT DOES MANAGE TO FORM AND FALL...SHOULD BE LIGHT AND BRIEF.
WITH THE STEEP LAPSE RATES AND EFFICIENT MIXING...EXPECT WINDS TO
BE THE BIGGEST FEATURE/NUANCE TOMORROW...WITH MOST AREAS SEEING
GUST INTO THE 20 TO 30 MPH RANGE BY THE AFTERNOON.
THE OPENING OF THE WEEKEND SHOULD DRY AND A FEW DEGREES WARMER THAN
FRIDAY AS RIDGING BUILDS IN FROM THE WEST. BY SUNDAY A MID LEVEL
BAROCLINIC ZONE WILL TIGHTEN ACROSS WISCONSIN AND SLOWLY SHIFT
SOUTHEAST...COINCIDENT WITH A WEAKENING SURFACE LOW THAT WILL
SLIDE ACROSS THE UPPER MISSISSIPPI VALLEY. CHANCES FOR LIGHT
SHOWERS WILL AGAIN LOOM IN THAT TIMEFRAME BEFORE CLEARING OUT BY
THE EVENING HOURS.
SHEA
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* RAIN SHOWERS CONTINUING INTO THE AFTERNOON WITH MOST WIDESPREAD
COVERAGE THROUGH THE MORNING...VISIBILITY GENERALLY 3-5 SM IN
THE RAIN THOUGH 2SM POSSIBLE AT TIMES.
* WIND DIRECTION THROUGH EARLY AFTERNOON...WITH LOW PASSING VERY
CLOSE DIRECTION WILL BE TRICKY...SOUTHEAST THIS MORNING THEN
BECOMING VARIABLE EARLY THIS AFTERNOON. WINDS THEN TURN
NORTHWEST AND INCREASE MID/LATE AFTERNOON AS A COLD FRONT
PASSES.
* EXPECT MAINLY IFR CIGS INTO EARLY AFTERNOON WITH LOWEST CIGS
LIKELY 600-800 FT...IMPROVEMENT TO MVFR POSSIBLE AT TIMES LATE
THIS MORNING...WITH STEADY IMPROVEMENT TO MVFR EARLY AFTERNOON.
* LOW CHANCE FOR EMBEDDED THUNDERSTORMS.
MDB
//DISCUSSION...UPDATED 12Z...
LOW PRESSURE STILL TO THE WEST OF THE TERMINALS AND TRYING TO
BECOME BETTER ORGANIZED. BANDS OF RAIN CONTINUE AHEAD OF THE LOW
WITH A DRY SLOT CENTERED ALONG THE MISSISSIPPI RIVER AND SLOWLY
SHIFTING EAST. THIS WILL SLOWLY MOVE INTO RFD OVER THE NEXT FEW
HOURS. TO THE EAST...BANDS OF RAIN WILL CONTINUE ACROSS THE CHI
AREA AND NW INDIANA TERMINALS THROUGH MID/LATE MORNING BEFORE
COVERAGE BECOMES MORE SCATTERED. CIGS HAVE BEEN RATHER VARIABLE
BETWEEN IFR/MVFR BUT EXPECT STEADY IFR 600-800 FT ACROSS THE CHI
TERMINALS OVER TOWARDS GYY INTO MID MORNING BEFORE MVFR BREAKS
START TO OCCUR. RFD WILL LIKELY BE A MIX OF IFR/MVFR...WITH IFR
MAINLY THROUGH MID MORNING.
WINDS WILL BE A CHALLENGE TODAY. LOW PRESSURE SHOULD BECOME BETTER
ORGANIZED BUT RIGHT NOW THERE ARE TWO SEPARATE CENTERS INDICATED
BY LATEST OBS. AXIS OF THE CURRENT BROAD LOW WILL PASS RFD THIS
MORNING ALLOWING A SHIFT TO A WESTERLY DIRECTION. THE CHI/NW INDY
TERMINALS EXPECTED TO SEE MORE VARIABILITY WITH SOUTHEAST TO START
THEN PROBABLY A PERIOD OF VARIABLE LATE MORNING/EARLY AFTERNOON
WITH THE LOW OVERHEAD OR POSSIBLY JUST TO THE SOUTH. A SLIGHT
SOUTHWARD SHIFT OF THE EXPECTED TRACK COULD RESULT IN AN EASTERLY
DIRECTION BY MIDDAY BUT THE GRADIENT MIGHT BE TOO WEAK TO SUPPORT
ANYTHING OTHER THAN VARIABLE. SPEEDS DURING THIS PERIOD SHOULD
REMAIN BELOW 10 KT. AS THE LOW PASSES A COLD FRONT WILL PASS WITH
IT SHIFTING WINDS TO WEST-NORTHWEST MID/LATE AFTERNOON WITH SPEEDS
INCREASING TO 10-15 KT WITH SOME GUSTS TO AROUND 20 KT POSSIBLE.
MVFR CIGS SHOULD LINGER BEHIND THE FRONT INTO EARLY EVENING BEFORE
SCATTERING LEAVING LITTLE IN THE WAY OF CLOUD COVER OVERNIGHT.
WINDS WILL STAY ELEVATED AROUND 10 KT AND SOME GUSTS COULD PERSIST
AS THE LOW DEEPENS OFF TO THE NORTHEAST. GUSTS WILL INCREASE
FRIDAY MORNING TO AROUND 25 KT WITH 30 KT GUSTS POSSIBLE BY FRIDAY
AFTERNOON. LOW END VFR STRATOCU IS ALSO EXPECTED TO DEVELOP DURING
THE MORNING AS WELL. AN UPPER WAVE WILL PASS WHICH MAY RESULT IN
SOME ISOLATED SHOWER ACTIVITY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE THAT BULK OF THE RAIN WILL BE THIS MORNING WITH
LESS WIDESPREAD RAIN THIS AFTERNOON.
* MEDIUM CONFIDENCE IN WIND DIRECTION...STILL SOME CHANCE THAT
WINDS COULD TURN EASTERLY LATE THIS MORNING IF LOW MOVES
SLIGHTLY SOUTH.
* MEDIUM-HIGH CONFIDENCE THAT MAINLY IFR CIGS WILL CONTINUE
THROUGH MID MORNING...MEDIUM CONFIDENCE IN MVFR BREAKS LATE
MORNING. MEDIUM-HIGH CONFIDENCE IN MVFR THIS AFTERNOON.
* LOW CONFIDENCE THAT THUNDERSTORMS WILL OCCUR AND WHEN THEY MIGHT
EXACTLY...COULD BE ANYTIME FROM DAYBREAK INTO MID AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...LINGERING SHOWER POSSIBLE DURING THE EVENING...BREEZY...VFR.
SATURDAY...VFR.
SUNDAY THROUGH TUESDAY...VFR WITH PERIODIC RAIN CHANCES...SOME
MVFR POSSIBLE.
WEDNESDAY...VFR.
MDB
&&
.MARINE...
320 AM CDT
POTENT AREA OF LOW PRESSURE WILL STEADILY DEEPEN TODAY ACROSS
NORTHEAST ILLINOIS LIFTING NORTHEAST ACROSS SOUTHERN LAKE
MICHIGAN...THEN CONTINUING TO LIFT NORTH/NORTHEAST ACROSS LOWER
MICHIGAN. THE PRESSURE GRADIENT IS EXPECTED TO RAPIDLY TIGHTEN ON
THE BACK SIDE OF THIS LOW PRESSURE LATE TONIGHT...ALLOWING WINDS
TO STEADILY INCREASE FROM 10 TO 20 KT...TO NEAR GALE CRITERIA BY
EARLY FRIDAY MORNING. GUIDANCE CONTINUES TO LEAN TOWARDS GALES TO
40KT PRIMARILY FOR THE OPEN WATERS PORTION OF LAKE MICHIGAN. ALONG
THE NEARSHORE WATERS OF ILLINOIS AND NORTHWEST INDIANA IT APPEARS
WINDS WILL HOVER BETWEEN 25 AND 30 KT. THUS HAVE HOISTED A SMALL
CRAFT ADVISORY FOR THOSE NEARSHORE WATERS. IT IS POSSIBLE THAT A
FEW GUSTS TO GALE CRITERIA MAY BE OBSERVED IN THE NEARSHORE
WATERS...HOWEVER CONFIDENCE IS NOT HIGH ENOUGH AT THIS POINT TO
HOIST A GALE WATCH FOR THE NEARSHORE WATERS. LATER SHIFTS MAY NEED
TO MAKE AN ADJUSTMENT IF NEW GUIDANCE INDICATES FURTHER
STRENGTHENING OF THE LOW PRESSURE.
ELEVATED WINDS/WAVES ARE EXPECTED TO PERSIST THROUGH FRIDAY NIGHT
AND INTO EARLY SATURDAY...BEFORE THE PRESSURE GRADIENT BEGINS TO
SLACKEN SATURDAY AFTERNOON. WITH THE PERSISTING NORTHWEST WINDS
AND MUCH COOLER AIR TRAVELING OVER THE LAKE...WAVES WILL REMAIN
ELEVATED DESPITE THE DIMINISHING WINDS. THUS HAVE HELD ONTO THE
SMALL CRAFT ADVISORY FOR THE NEARSHORE WATERS THROUGH SATURDAY
AFTERNOON FOR THE ILLINOIS NEARSHORE. SLIGHTLY LATER FOR THE
INDIANA NEARSHORE.
ANOTHER POTENT LOW PRESSURE SYSTEM IS POISED TO TRAVERSE THE GREAT
LAKES REGION EARLY NEXT WEEK. GUIDANCE CONTINUES TO BE FOCUSED ON
A LATE MON THROUGH TUE TIMEFRAME.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ744-LMZ745...1 AM FRIDAY TO 10 PM
SATURDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...10 AM
FRIDAY TO 4 PM SATURDAY.
GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...9 AM FRIDAY TO NOON
SATURDAY.
&&
$$
