301 AM CDT
LITTLE CHANGE TO THE GOING FORECAST WITH THE MAIN FORECAST ISSUES
BEING THE COOLING TREND FOR THE NEXT FEW DAYS AND PCPN CHANCES.
FOR THE REMAINDER OF THE NIGHT AND TOMORROW CONDITIONS WILL BE
QUIET. CONTINUED COLD ADVECTION ACROSS THE AREA WITH NWLY FLOW ALOFT
AROUND THE SWRN PERIPHERY OF THE DEEP LOW OVER JAMES BAY WILL KEEP
TEMPERATURES ON A COOLING TREND. FOR TODAY...ANTICIPATE HIGHS ONLY
IN THE UPPER 50S TO AROUND 60F. A WEAK SHORTWAVE MOVING THROUGH THE
CNTRL PLAINS/MIDDLE MISSISSIPPI VALLEY WILL BRING INCREASING CLOUD
COVER TO THE SRN PORTIONS OF THE CWA...WHILE NRN LOCATIONS REMAIN
REMAIN MOSTLY SUNNY.
BY LATE THIS EVENING AND OVERNIGHT TONIGHT...THE SHORTWAVE WILL
BRING INCREASING PCPN CHANCES TO THE FAR SRN PORTIONS OF THE CWA. A
DIGGING LONGWAVE TROUGH MOVING SLOWLY ACROSS THE MISSISSIPPI VALLEY
AND INTO THE MIDWEST WILL KEEP TEMPERATURES ACROSS THE REGION
SLIGHTLY BELOW NORMAL FOR THE NEXT FEW DAYS. THROUGH
THURSDAY...HIGHS WILL ONLY BE IN THE LOWER 50S. OVERNIGHT LOWS WILL
BE SIMILARLY CHILLY...RANGING FROM THE UPPER 30S OVER THE ROCKFORD
AREA AND WEST OF THE I-39 CORRIDOR TO THE LOWER 40S TO THE EAST.
THE NEXT CHANCE FOR MORE WIDESPREAD RAIN WILL COME BY TUESDAY NIGHT
AS THE LONGWAVE TROUGH CROSSES THE MISSISSIPPI VALLEY AND A
REINFORCING SHOT OF COOLER AIR ASSOCIATED WITH A NRN STREAM
SHORTWAVE DROPS OUT OF CANADA AND INTO THE UPPER MISSISSIPPI
VALLEY. AT THE SURFACE...HIGH PRESSURE WILL BUILD ACROSS THE
CENTRAL PLAINS AS A DEEPENING LOW MOVES OUT OF THE GULF OF MEXICO
AND INTO THE MID ATLANTIC REGION. THIS WILL SET UP GENERALLY
NORTHERLY FLOW ACROSS THE AREA. IN PARTICULAR...COOL NORTHERLY FLOW
OVER LAKE MICHIGAN WILL SET UP A PERIOD OF LAKE EFFECT RAIN
SHOWERS. WHILE THE GREATEST CHANCE FOR PCPN WILL BE IN THE LEE OF
THE LAKE OVER NWRN INDIANA...LOW LEVEL TRAJECTORIES MAY BE JUST EAST
OF NORTHERLY ENOUGH TO PUSH MORE WIDESPREAD SHOWERS OVER FAR NERN IL
AT TIMES. SO...WHILE THE GOING FORECAST WILL CONFINE THE LIKELY
POPS TO LAKE AND PORTER COUNTIES...WITH SLIGHT CHANCE TO CHANCE POPS
OVER THE REMAINDER OF THE CWA...ANTICIPATE THAT THERE SHOULD BE
TIMES WHEN LIKELY POPS MAY BE JUSTIFIED OVER FAR NERN
IL...PARTICULARLY WEDNESDAY AND WEDNESDAY NIGHT.
FOR THE LONGER TERM FORECAST PERIOD...THURSDAY THROUGH SUNDAY...THE
UPPER TROUGH WILL BEGIN TO LIFT OUT TO THE NORTHEAST WHILE UPPER
RIDGING BUILDS ACROSS THE NRN PLAINS AND UPPER MISSISSIPPI VALLEY.
GRADUALLY RISING HEIGHTS THROUGH THE EXTENDED PERIOD WILL LEAD TO A
SLOW WARMING TREND FOR THE LATTER PORTIONS OF THE WEEK AND INTO THE
WEEKEND. ALSO...THROUGH THE EXTENDED PERIOD...SFC HIGH PRESSURE
WILL BUILD ACROSS THE REGION KEEPING THE CWA DRY FOR THURSDAY NIGHT
THROUGH SATURDAY. BY SUNDAY...SOME OF THE LONGER RANGE GUIDANCE IS
INDICATING AN INCREASING CHANCE FOR SOME MORE RAIN AS NRN STREAM
SHORTWAVE TRACKS ACROSS THE AREA.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY WEST WINDS TODAY.
KJB
//DISCUSSION...UPDATED 18Z...
LOW PRESSURE ACROSS NORTHEASTERN ONTARIO CONTINUES TO PRODUCE GUSTY
WESTERLY WINDS ACROSS THE TERMINALS THIS AFTERNOON. THESE WIND GUSTS
SHOULD QUICKLY ABATE AROUND SUNSET. A COLD FRONT WILL PUSH ACROSS
THE AREA EARLY TUESDAY MORNING. THIS WILL BRING A WIND SHIFT OUT OF
THE NORTH NORTHWEST FOR THE DAY ON TUESDAY.
VFR FLYING CONDITIONS ARE EXPECTED THROUGH THE PERIOD. HOWEVER...
SOME MID AND HIGH LEVEL CLOUDS...ASSOCIATED WITH A MID LEVEL
DISTURBANCE ACROSS THE MID MISSOURI RIVER VALLEY...WILL LEAD TO
BKN-OVC CONDITIONS AT 15-20,000 FT AGL THIS AFTERNOON. ANY
PRECIPITATION ASSOCIATED WITH THIS SYSTEM SHOULD REMAIN SOUTH AND
WEST OF THE TERMINALS. SOME LOWER BKN-OVC CIGS ARE EXPECTED TO
DEVELOP TUESDAY AFTERNOON IN THE WAKE OF THE FRONTAL PASSAGE.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE ALL ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT AND WEDNESDAY...CHANCE OF SHOWERS THOUGH SHOWERS
LIKELY CLOSER TO LAKE MI AND ACROSS NW IN. N WINDS GUSTING 25-30KT
DURING THE DAY WED.
THURSDAY THROUGH SUNDAY...VFR. WX NIL TIL CHANCE OF SHOWERS SUN.
TRS
&&
.MARINE...
301 AM CDT
300 AM...ACTIVE WEEK EXPECTED WITH WEST GALES DIMINISHING THIS
AFTERNOON AND THE POTENTIAL FOR NORTH GALES WEDNESDAY INTO THURSDAY.
DEEP LOW PRESSURE WILL SLOWLY WEAKEN TODAY AS IT WOBBLES AROUND
JAMES BAY. IT FINALLY SHIFTS EAST INTO QUEBEC TONIGHT AS IT MERGES
WITH ANOTHER LOW FURTHER TO THE NORTHEAST. THE GRADIENT WILL SLOWLY
WEAKEN AS WELL AND EXPECT GALES TO RELAX TO 30 KTS THIS AFTERNOON
WITH SPEEDS CONTINUING TO DIMINISH OVERNIGHT INTO TUESDAY MORNING.
FOCUS THEN SHIFTS TO A BROAD AREA OF DEVELOPING LOW PRESSURE OVER
THE SOUTHEAST U.S. TUESDAY. LATEST MODEL GUIDANCE SUGGESTS THERE MAY
BE A TROUGH OF LOW PRESSURE WITH TWO SEPARATE LOWS BY WEDNESDAY...
ONE OVER THE MID ATLANTIC AND THE SECOND AS FAR NORTHWEST AS LAKE
ERIE. THE MAIN LOW THEN MOVES NORTH/NORTHEAST ACROSS THE EASTERN
LAKES REGION WEDNESDAY NIGHT INTO THURSDAY. AT THE SAME TIME...A
LARGE RIDGE OF HIGH PRESSURE IS BUILDING EAST ACROSS THE PLAINS AND
SOUTHERN CANADA. SHOULD THIS VERIFY...THE GRADIENT WILL LIKELY
BECOME TIGHT ENOUGH FOR A PERIOD OF NORTH GALES WEDNESDAY NIGHT INTO
THURSDAY MORNING. GIVEN THE UNCERTAINTY OF WHERE THE MAIN LOW TRACKS
HAVE OPTED TO MAINTAIN 30 KTS DURING THIS PERIOD FOR NOW...BUT
POTENTIAL FOR GALES WILL NEED TO BE MONITORED WITH LATER FORECASTS.
CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM TUESDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 7 PM
MONDAY.
&&
$$
