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 12Z...
* NONE IN NEAR TERM.
RATZER
//DISCUSSION...UPDATED 12Z...
WEAK COOL FRONT HAS MOVED THROUGH THE TERMINALS OVERNIGHT. SKIES
HAVE CLEARED...AND WINDS HAVE SHIFTED TO THE WEST-NORTHWEST. WINDS
SHOULD REMAIN IN THE 280-310 DEGREE RANGE INTO THIS AFTERNOON...
WITH SPEEDS AROUND 10 KNOTS AND A FEW GUSTS A COUPLE KNOTS HIGHER
POSSIBLE DURING THE LATE MORNING AND EARLY AFTERNOON. SURFACE HIGH
PRESSURE RIDGE MOVES IN FROM THE WEST BY EVENING...ALLOWING WINDS
TO DIMINISH AND BACK TO THE SOUTH AFTER SUNSET.
ANOTHER AREA OF LOW PRESSURE WILL MOVE SOUTHEAST OUT OF CANADA
INTO THE UPPER MIDWEST LATE TONIGHT AND EARLY SUNDAY. SOUTH WINDS
WILL INCREASE TOWARD MORNING...WITH AN INCREASE IN VFR MID/HIGH
CLOUDS IN ADVANCE OF THE LOW. BEYOND 12Z SUNDAY...WINDS MAY GUST
ABOVE 20 KNOTS.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN ALL ELEMENTS.
RATZER
//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...
323 AM CDT
THE MAIN MARINE FORECAST CONCERN THIS MORNING IS WITH SOUTH GALES
DEVELOPING ON THE SOUTH HALF OF LAKE MICHIGAN SUNDAY MORNING AS
LOW PRESSURE DROPS SOUTHEAST ACROSS THE UPPER MIDWEST. MODELS ARE
IN GOOD AGREEMENT IN SOUTH WINDS STRENGTHENING RAPIDLY AS THE
GRADIENT TIGHTENS AHEAD OF THE LOW...WITH FORECAST SOUNDINGS
DEPICTING WINDS INCREASING ABOVE 30 KTS WITHIN THE MIXED LAYER BY
MID MORNING. THE LOW WILL THEN BEGIN TO FILL BY EVENING AS IT
DRIFTS EAST...WITH GALES DROPPING OFF FAIRLY QUICKLY LATE IN THE
DAY. BASED ON THIS HAVE HOISTED A GALE WARNING FOR THE OPEN WATERS
OF SOUTHERN LAKE MICHIGAN FOR SUNDAY.
FOR THE ILLINOIS AND INDIANA NEARSHORE WATERS...WINDS WILL LIKELY
GUST TO 30 KTS FOR A TIME SUNDAY. WILL HAVE A SMALL CRAFT ADVISORY
FROM EARLY SUNDAY MORNING THROUGH EARLY SUNDAY EVENING.
THE LOW WILL CONTINUE TO FILL AS IT DRIFTS EAST ACROSS THE LAKE
LATER SUNDAY NIGHT AND MONDAY. DEEPER LOW PRESSURE WILL MOVE
ACROSS CENTRAL CANADA EARLY NEXT WEEK...SETTING UP A PERIOD OF
SOUTHWEST FLOW ACROSS THE WESTERN LAKES REGION.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZE WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 9 AM SATURDAY.
IN...FREEZE WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 9 AM
SATURDAY.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 AM
SUNDAY TO 7 PM SUNDAY.
&&
$$
