342 AM CDT
MAIN CONCERNS/ISSUES ARE WITH THE NEXT CHANCES FOR PRECIP ON
SUNDAY AND SUNDAY NIGHT...WITH A SLIGHT WARMING TREND INTO THE
START OF NEXT WEEK.
LATEST SATELLITE IMAGERY SHOWING LONGWAVE TROUGH AND ASSOCIATED
TROUGH OF LOW PRESSURE SLOWLY PUSHING THROUGH THE CENTRAL GREAT
LAKES REGION EARLY THIS MORNING. OUT AHEAD OF THESE
FEATURES...PRECIP CONTINUES TO SHIFT EAST OVER THE LAKE AND ACROSS
PORTIONS OF NORTHWEST INDIANA. LATEST RUC ANALYSIS STILL
INDICATING VERY STEEP MID LEVEL LAPSE RATES OVERHEAD THIS
MORNING...WITH VERY STEEP LOW LEVEL LAPSE RATES SITUATED OVER THE
LAKE. THIS HAS RESULTED WITH SOME ISOLATED THUNDER EMBEDDED WITHIN
THESE SHOWERS ACROSS THE SOUTHERN HALF OF THE LAKE. WITH THE
SYSTEMS EASTERLY PROGRESSION...EXPECT ANY LINGERING MOISTURE TO
CONTINUE TO EXIT OVER THE NEXT SEVERAL HOURS. ON THE BACKSIDE OF
THIS SYSTEM...CLEARING HAS BEEN OBSERVED WITHIN THE LAST COUPLE OF
HOURS WITH ALL OF NORTHERN ILLINOIS CURRENTLY CLEAR. THESE
CLEARING SKIES AND LIGHT SOUTH/SOUTHWEST WINDS HAS RESULTED IN
SOME GOOD TEMPERATURES DROPS WITH MANY AREAS IN THE NORTHWEST CWA
FALLING TO THE LOW TO MID 30S. EXPECT TEMPS IN THIS LOCATION TO
CONTINUE TO FALL OVER THE NEXT COUPLE OF HOURS WITH THE REMAINING
CWA TO FOLLOW. AS TEMPS FALL INTO THE LOWER 30S...CURRENT FREEZE
WARNING WILL CONTINUE TO BE VALID THIS MORNING. WITH THE UPPER
LEVEL TROUGH SHIFTING EAST...HIGH PRESSURE AND DRIER AIR WILL
BUILD ACROSS THE REGION PROVIDING MOSTLY SUNNY SKIES TODAY. WITH
THIS SUNSHINE IN PLACE...MOST LOCATIONS SHOULD OBSERVE HIGH
TEMPERATURES IN THE MID 50S WITH EVEN SOME UPPER 50S FORECAST
ACROSS THE SOUTHERN HALF OF THE CWA.
ALTHOUGH AS QUICKLY AS THIS LAST SYSTEM EXITS...THE NEXT SYSTEM
WILL APPROACH FROM THE NORTHWEST LATE TONIGHT INTO EARLY SUNDAY
MORNING. WITH A BRIEF PERIOD OF RIDGING ACROSS PORTIONS OF THE
MIDWEST TODAY AND TONIGHT...HEIGHTS WILL FALL ON SUNDAY AS AN
UPPER LEVEL TROUGH DIGS SOUTH FROM THE NORTHERN PLAINS. THIS UPPER
LEVEL TROUGH AND SHORT WAVE TROUGH WILL ALLOW A SURFACE TROUGH OF
LOW PRESSURE TO DEVELOP AND MOVE EAST THROUGH THE UPPER
MISSISSIPPI VALLEY. ALTHOUGH...FORECAST MODELS CONTINUE TO SHOW
SOME SLIGHT DIFFERENCES IN THE EXACT EVOLUTION/TRACK OF THIS
TROUGH AND ASSOCIATED SURFACE FEATURE. NONETHELESS...IT WOULD
APPEAR AT THIS TIME THAT THE BEST CHANCES FOR SHOWERS WILL BE
ACROSS THE NORTHERN PORTION OF THE CWA COME SUNDAY AFTERNOON. SO
DESPITE THE DIFFERENCES AMONGST THE MODELS...THE LIKELIHOOD OF
OBSERVING PRECIP WITHIN THIS AREA IS INCREASING AND HAVE ADJUSTED
POPS DURING THIS TIME TO REFLECT THIS. ALTHOUGH A WARMER AIR MASS
WILL ADVECT OUT AHEAD OF THIS SYSTEM ON SUNDAY...DONT THINK TEMPS
WILL REFLECT THIS AS A GOOD AMOUNT OF CLOUD COVER/PRECIP WILL BE
OVERHEAD HELPING TO LIMIT ANY WARMING.
FORECAST MODELS CONTINUE TO INDICATE THAT THIS UPPER LEVEL TROUGH
WILL REMAIN FAIRLY PROGRESSIVE IN NATURE...WITH IT AND THE
SURFACE TROUGH EXITING BY MONDAY MORNING. SKIES WILL BE CLEARING
WITH UPPER LEVEL RIDGING ONGOING ACROSS THE REGION ON MONDAY. THIS
WILL RESULT IN SOUTHERLY FLOW SETTING UP AND WAA TO OCCUR OVER THE
CENTER CONUS WITH 850 TEMPS ON THE RISE. A DRY AND WARMING PERIOD
IS FORECAST MONDAY INTO TUESDAY WITH HIGH TEMPS OF AROUND 60 AND
EVEN THE LOWER 60S POSSIBLE BY TUESDAY. ALTHOUGH THE NEXT UPPER
LEVEL SYSTEM WILL BE APPROACHING ONCE AGAIN COME WEDNESDAY WITH
PRECIP CHANCES ON THE INCREASE AND COOLER TEMPS FORECAST BY THE
MIDDLE PART OF THE WEEK.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 21Z...
* NO CONCERNS THROUGH 06Z SUN.
* STEADY INCREASE IN WINDS AFT 06Z SUN FROM THE SOUTHWEST. GUSTY
CONDITIONS SUNDAY MORNING THROUGH AFTERNOON UP TO 25KT.
* PRECIP CHANCES INCREASE AFT 18Z SUN.
BEACHLER
//DISCUSSION...UPDATED 18Z...
SFC RIDGE PROVIDING ABUNDANT SUNSHINE TO NORTHERN IL/NORTHWEST IN.
AN AREA OF CLOUDS WAS NOTED BY THE VISIBLE SATELLITE IMAGERY OVER
NORTHCENTRAL INDIANA STRETCHING NORTH THROUGH LOWER
MICHIGAN...SLIDING EAST. WINDS HAVE REMAINED FROM THE
WEST/NORTHWEST TODAY...AND AS HIGH PRESSURE SLIDES ACROSS THE
REGION WINDS WILL REMAIN AROUND 10KT. AFT 00Z WINDS WILL QUICKLY
DECOUPLE TO AROUND 3 TO 5 KT AND TURN SOUTHERLY. THEN WINDS
STEADILY RAMP UP AS A TIGHTENING PRESSURE GRADIENT AHEAD OF A LOW
PRESSURE SYSTEM PROVIDES BREEZY CONDITIONS FOR SUN MORNING. IT
APPEARS THE MIXED LAYER WILL FILTER TO THE SFC A CORE OF WINDS IN
EXCESS OF 25KT. EXPECT MOST AIRFIELDS WILL SEE GUSTS BETWEEN 23
AND 27 KT SUN. BETTER MOISTURE DOES NOT APPEAR TO ARRIVE OVER
NORTHERN IL/NORTHWEST IN UNTIL MIDDAY. SO HAVE HELD OFF ON MENTION
OF PRECIP UNTIL AFT 18Z. GUIDANCE CONTINUES TO SUGGEST THAT PRECIP
MAY NOT ARRIVE UNTIL CLOSER TO 21Z SUN.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 21Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST THRU 12Z SUN.
* HIGH CONFIDENCE IN VFR CONDS THRU DAYBREAK SUN.
* MEDIUM/HIGH CONFIDENCE IN AIRFIELDS REMAINING DRY THRU 18Z SUN.
* MEDIUM CONFIDENCE IN WIND SPEED FORECAST SUN AFT 12Z.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHC EVENING SHRA WITH MVFR CIGS.
MONDAY...VFR.
TUESDAY...VFR.
WEDNESDAY...CHC SHRA. MAINLY VFR.
THURSDAY...CHC SHRA. MVFR CIGS POSSIBLE.
FRIDAY...VFR.
RATZER
&&
.MARINE...
245 PM CDT
RIDGE OF HIGH PRESSURE REMAINS OVERHEAD THIS EVENING...HOWEVER
THIS WILL STEADILY DRIFT EAST. A TROUGH OF LOW PRESSURE CONTINUES
TO DEVELOP ACROSS THE UPPER MISSISSIPPI VALLEY AND IS EXPECTED TO
SLIDE SOUTHEAST AND APPROACH THE WESTERN GREAT LAKES REGION
SUNDAY. PRIOR TO THIS THE WINDS ARE EXPECTED TO TURN SOUTHWESTERLY
TO SOUTHERLY AND INCREASE. THE PRESSURE GRADIENT FOR SEVERAL MODEL
RUNS HAS CONTINUED TO INDICATE GALE CRITERIA IS LIKELY FOR THE
OPEN WATERS...WITH GALES TO 35 KT. A FEW SOLUTIONS INDICATED THAT
WINDS MAY PUSH TO 40KT...HOWEVER FEEL THAT THE MAJORITY OF WINDS
WILL BE IN THE 35KT RANGE FROM THE SOUTH. FOR THE NEARSHORE WATERS
WINDS WILL ALSO BECOME ELEVATED...AND GUIDANCE CONTINUES TO
INDICATE WINDS BETWEEN 15 AND 25 KT TO AT TIMES APPROACHING 30KT
OR JUST UNDER GALE CRITERIA. FOR NOW HAVE GONE WITH A SMALL CRAFT
ADVISORY FOR THE ENTIRE NEARSHORE WATERS OF ILLINOIS/NORTHWEST
INDIANA THROUGH SUNDAY EARLY EVENING.
PRESSURE GRADIENT BEGINS TO RELAX LATE SUNDAY AFTERNOON AND WILL
EVENTUALLY ALLOW WINDS TO GO BELOW GALE CRITERIA. NONETHELESS
WAVES WILL REMAIN ELEVATED FROM THE DURATION OF SOUTHERLY WINDS
THROUGH SUNDAY EVENING...AND POSSIBLY INTO MONDAY MORNING. THEN
WINDS AND WAVES RELAX THROUGH MIDWEEK.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 AM
SUNDAY TO 9 PM SUNDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...7 AM SUNDAY TO 10 PM SUNDAY.
&&
$$
