983
FXUS63 KLOT 070818
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE, IL
318 AM CDT THU JUL 7 2022
SHORT TERM
ISSUED AT 317 AM CDT THU JUL 7 2022
THROUGH FRIDAY...
THE SEEMINGLY ENDLESS PARADE OF MCSS AND ASSOCIATED MCVS CONTINUES
TO RIDE THE PERIPHERY OF THE UPPER RIDGE ACROSS THE CENTRAL AND
EASTERN U.S. TUESDAY NIGHT'S MCS DID SHOVE THE EFFECTIVE BOUNDARY
AND PATH OF THE MCS TRAIN SOUTH OF OUR CWA, PROVIDING THE SHORT
RESPITE FROM THE ACTIVE WEATHER THAT OUR CWA IS CURRENTLY
EXPERIENCING.
OVER THE NEXT 24 TO 36 HOURS THE EFFECTIVE BOUNDARY WILL BE
CREEPING SLOWLY NORTHWARD ALLOWING FOR WET WEATHER TO RETURN.
LOOKING UPSTREAM, MCS WITH WELL DEFINED MCV IS PASSING JUST NORTH
OF KANSAS CITY AND HEADING IN OUR GENERAL DIRECTION. THE
ORIENTATION OF THE DOWNSTREAM INSTABILITY/MOIST AXIS AND MID-UPPER
LEVEL FLOW BOTH FAVOR THIS COMPLEX TURNING EAST AND EAST-SOUTHEAST
TODAY AS IT APPROACHES AND THEN CROSSES THE MISSISSIPPI RIVER. WE
WILL SEE MID-HIGH CLOUDINESS INCREASE IN ADVANCE OF THIS FEATURE
WITH SOME THREAT FOR SOME SHOWERS AND PERHAPS A THUNDERSTORM
AFFECTING OUR FAR SOUTHWESTERN CWA THIS AFTERNOON.
WATER VAPOR IMAGERY EARLY THIS MORNING SHOWS A WELL DEFINED, MORE
AMPLIFIED SHORTWAVE TROUGH OVER EASTERN MT AND FAR WESTERN ND
CRESTING THE UPPER RIDGE AT THIS TIME. THIS FEATURE WILL SHOULD
PROVIDE THE FOCUS FOR THE NEXT MCS TO DEVELOP TONIGHT OVER THE
LOWER MISSOURI RIVER VALLEY EAST INTO THE CORN BELT. WILL BE
INTERESTING TO SEE THE EVOLUTION OF THIS SHORTWAVE AND HOW LIKELY
TO DEVELOP MCV INTERACTS WITH THE APPROACHING SHORTWAVE TROUGH.
SOME MODELS ARE DEPICTING A SIGNIFICANTLY WOUND UP VORT WITH A
MORE WELL DEVELOPED SURFACE REFLECTION (IE FV3 AND ESPECIALLY THE
NAM). WHILE THAT TYPE OF SOLUTION CAN'T BE RULED OUT, SUSPECT THE
LIKELY SCENARIO WILL BE A MORE MUTED SURFACE WAVE LIKE DEPICTED BY
THE ECMWF AND GFS.
EITHER WAY, DOES APPEAR FAIRLY WIDESPREAD AND POTENTIALLY SOAK
RAIN COULD AFFECT A LARGE PORTION OF OUR CWA LATE TONIGHT INTO
MAINLY THE FIRST HALF OF FRIDAY. THE SOUTHERN HALF OF THE CWA
SHOULD SEE THE HEAVIER RAINFALL TOTALS AND ALSO STANDS A BETTER
CHANCE AS SEEING SOME EMBEDDED CONVECTION OWING TO THEIR CLOSER
PROXIMITY TO THE INSTABILITY. THE MORE ROBUST SFC BASED
INSTABILITY AND MEANINGFUL SEVERE THUNDERSTORM THREAT FRIDAY
SHOULD STAY SOUTH AND SOUTHEAST OF OUR CWA.
IF THE MORE AMPED UP NAM-LIKE SOLUTION WERE TO PAN OUT, THEN
HEAVIER RAINFALL TOTALS COULD SPREAD FARTHER NORTH INTO THE CWA
AND AFFECT EVEN THE CHICAGO METRO AREA WITH MORE PRONOUNCED
DEFORMATION LIKE BAND WITH THE SHORTWAVE. REGARDLESS OF THE
SOLUTION, FRIDAY LOOKS TO START WET WITH RAIN CHANCES WINDING DOWN
FROM WEST TO EAST LATE MORNING INTO THE EARLY AFTERNOON.
INITIALLY RAIN, THEN CLOUD COVER AND STRENGTHENING NORTH TO
NORTHEAST WINDS DURING PEAK HEATING SHOULD RESULT IN MUCH BELOW
AVERAGE TEMPS FRIDAY. AREAS NEAR THE LAKE MAY HOLD IN THE UPPER
60S IN THE AFTERNOON WITH LOW/MID 70S NORTH OF I-80 SHOULD BE
FAIRLY COMMON FOR HIGH TEMPS.
- IZZI
LONG TERM
ISSUED AT 316 AM CDT THU JUL 7 2022
FRIDAY NIGHT THROUGH WEDNESDAY...
THE REMNANTS OF SHOWERS ASSOCIATED WITH A WEAK SURFACE FRONT/UPPER
WAVE WILL BE MOVING EAST-SOUTHEAST OUT OF OUR FORECAST AREA FRIDAY
NIGHT, WITH NORTHEASTERLY WINDS AS HIGH PRESSURE MOVES IN. COOLER,
DRIER AIR WILL MOVE IN OVER THE WEEKEND, WITH BELOW SEASONAL
TEMPERATURES, ESPECIALLY ON SATURDAY WHEN MOST HIGH TEMPERATURES
WILL BE AT OR BELOW 80. THIS WILL BE ESPECIALLY TRUE ALONG THE LAKE
MICHIGAN SHORE, WHERE TEMPERATURES WILL STAY IN THE LOWER 70S. THE
SURFACE RIDGE AXIS WILL MOVE SOUTH OF OUR REGION SUNDAY AFTERNOON,
SHIFTING WINDS TO THE SOUTHEAST, WHICH WILL TEND TO KEEP ONLY THE
ILLINOIS SHORE COOLER IN THE MID 70S VS. LOWER 80S INLAND. A WEAK
FRONT MOVES THROUGH THE REGION ON MONDAY, WITH A CHANCE OF SHOWERS
AND POSSIBLE STORMS MONDAY INTO MONDAY NIGHT. AHEAD OF THIS FRONT
DEWPOINTS WILL CLIMB INTO THE UPPER 60S TO LOWER 70S, SO MONDAY MAY
FEEL A LITTLE MUGGY. NORTHWESTERLY WINDS BEHIND THE FRONT SHOULD
BRING IN SLIGHTLY DRIER (LOWER 60S DEWPOINTS) AND COOLER AIR (HIGHS
IN THE MID TO LOW 80S) BEHIND THE FRONT. AN UPPER WAVE OR TWO MAY
MOVE OVERHEAD TOWARDS THE MIDDLE OF THE WEEK, BRINGING CHANCES FOR
SHOWERS, BUT THIS FAR OUT CONFIDENCE IN THE EXACT TRACK OF THESE
WAVES IS LOW.
BKL
AVIATION
FOR THE 06Z TAFS...
AVIATION WEATHER CONCERNS FOR 06Z TAFS:
* MVFR TO IFR CEILINGS ARE OVER OR IN THE VICINITY OF THE TERMINALS,
AND COULD DROP CEILINGS, OR VISIBILITIES IN EASTERN SITES, BELOW
VFR.
* CHANCE FOR SHOWERS, POSSIBLE STORMS, LATE THURSDAY INTO FRIDAY
MORNING.
HIGH PRESSURE REMAINS OVER OUR AREA WITH NORTHEASTERLY FLOW.
OCCASIONAL MVFR TO IFR CEILINGS MAY MOVE OVER THE TERMINALS FROM OFF
OF LAKE MICHIGAN, BUT THESE LOWER CIGS ARE SHORT-LIVED, WITH THE
EXCEPTION OF GARY (GYY), WHICH HAS BEEN IFR FOR THE PAST FEW HOURS.
IN ADDITION TO LOW CIGS, GYY'S VISIBILITIES HAVE BEEN DOWN TO 3
MILES THIS EVENING. GYY WILL CONTINUE TO SEE THESE LOWER CIGS AND
VIS UNTIL LATER THIS MORNING. THE THREAT OF LOWER CIGS SHOULD END
SHORTLY AFTER SUNRISE THIS MORNING. AFTERWARDS VFR CONDITIONS WILL
PREVAIL TODAY AT LEAST UNTIL THE MID-AFTERNOON. A WAVE WILL APPROACH
FROM THE WEST THIS AFTERNOON, BRINGING A CHANCE FOR SHOWERS IN THE
LATE AFTERNOON FOR ROCKFORD, AND IN THE EARLY EVENING FOR THE OTHER
SITES. CONFIDENCE ON THIS OCCURRING AND TIMING OF SHOWERS IS LOW,
WITH BETTER CHANCES FOR PRECIPITATION FURTHER SOUTH, SO I'VE KEPT
THE PROB30 INDICATING THIS POSSIBILITY. THERE IS NO MENTION OF
THUNDERSTORMS AT THIS TIME, BUT THEY CANNOT BE RULED OUT, ALTHOUGH
THE TIMING AND DYNAMICS FOR STORM ACTIVITY IS NOT GREAT. THEREFORE
THERE IS NO MENTION IN PRESENT TAFS.
BKL
LOT WATCHES/WARNINGS/ADVISORIES
IL...NONE.
IN...NONE.
LM...NONE.
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