211
FXUS63 KMQT 211812
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
112 PM EST THU NOV 21 2024
KEY MESSAGES
- WET SNOW FALLING OVER PORTIONS SOUTHERN AND CENTRAL UPPER MI
CHANGES TO RAIN EARLY THIS MORNING. A RAINY DAY FOLLOWS,
ESPECIALLY FOR CENTRAL UPPER MI.
- A WINDY DAY TODAY WITH GUSTS 30 TO 45 MPH (STRONGEST KEWEENAW
AND NEAR THE LAKE BARAGA/MARQUETTE COUNTIES TO WESTERN ALGER
COUNTY). ON LAKE SUPERIOR, NORTH TO NORTHEAST GALES TO 40
KNOTS WITH A FEW GUSTS TO 45 KNOTS POSSIBLE.
SHORT TERM /THROUGH THIS AFTERNOON/
ISSUED AT 326 AM EST THU NOV 21 2024
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A BROAD MID-LEVEL LOW
CENTERED OVER LOWER MI. SHORTWAVE THAT HAS BEEN ROUNDING THE
CIRCULATION IS WRAPPING BACK TO THE W ACROSS NORTHERN LWR MI. AT THE
SFC, THIS WAVE IS SUPPORTING DEEPENING LOW PRES NOW OVER FAR EASTERN
UPPER MI, JUST S OF WHITEFISH BAY. A GOOD PUSH OF WAA/ISENTROPIC
ASCENT WRAPPING WESTWARD THRU ONTARIO INTO UPPER MI TO THE N OF THE
LOW HAS SUPPORTED A SURGE OF PCPN ACROSS MUCH OF UPPER MI DURING THE
NIGHT. COLUMN HAS BEEN COLD ENOUGH TO SUPPORT SNOW ACROSS MUCH
SOUTHERN UPPER MI INTO N CENTRAL UPPER MI. A NUMBER OF MDOT WEBCAMS
SHOW A COATING OF SNOW ON THE GROUND WITH SOME ROADS SNOW/SLUSH
COVERED. TEMPS ARE MOSTLY IN THE 30S (32-34F WHERE SNOW IS FALLING),
BUT ARE WARMING INTO THE LOW/MID 40S NEAR LAKE SUPERIOR.
WAA FROM THE NE WILL RESULT IN SNOW CHANGING TO RAIN/SNOW MIX THEN
RAIN THRU THE EARLY MORNING HRS. THIS IS SHOWN NICELY IN THE MODEL
FORECASTS OF RISING WETBULB ZERO HEIGHTS FROM NE TO SW. BY 12Z, LAST
OF THE SUB 700AGL WETBULB ZERO HEIGHTS (SUGGESTING ALL SNOW) WILL BE
SLIPPING ACROSS THE MI/WI STATELINE. SO, WHERE IT IS CURRENTLY
SNOWING, EXPECT A TRANSITION TO RAIN/SNOW, THEN RAIN FROM NE TO SW
THRU THE EARLY MORNING. LAST OF THE RAIN/SNOW MIX OVER THE WESTERN
FCST AREA ALONG THE MI/WI STATELINE WILL CHANGE TO ALL RAIN BEFORE
15Z. OVERALL, WHERE IT HAS BEEN SNOWING, ACCUMULATIONS WILL RANGE
FROM JUST A LITTLE SLOPPY SNOW ACCUMULATION UP TO 1 TO 2 INCHES.
LOCALLY UP TO 2-3 INCHES SEEMS ON TRACK IN FAR WESTERN MARQUETTE
COUNTY/EASTERN BARAGA COUNTY INTO IRON COUNTY. THERE WILL BE
SLIPPERY TRAVEL CONDITIONS FOR THE NEXT FEW HRS IN SOME AREAS. MDOT
WEBCAMS SHOW ROADS IN SOME AREAS BECOMING SLUSH/SNOW, ESPECIALLY
AROUND COOKS AND MICHIGAMME. AFTER THE CHANGEOVER TO RAIN EARLY THIS
MORNING, RAIN WILL BE THE RULE THRU THE AFTN, STEADIEST FROM
MARQUETTE/BARAGA COUNTIES TO POINTS SW AS RAIN WILL BE LAKE ENHANCED
UNDER NE LOW-LEVEL FLOW. THIS AREA WILL ALSO BE UNDER A LONG
MOISTURE FEED/PRECIPITABLE WATER RIDGE WRAPPING FROM OFF OF THE MID-
ATLANTIC COAST TO ONTARIO THEN SW ACROSS LAKE SUPERIOR AND INTO
UPPER MI. LAKE ENHANCEMENT/NE UPSLOPING WINDS SHOULD PUSH
PRECIPITATION TOTALS IN THE HIGH TERRAIN FROM EASTERN BARAGA COUNTY
ACROSS MARQUETTE COUNTY TO NEAR 2 INCHES FOR THE 00Z TO 24Z TODAY
TIME PERIOD.
AS FOR WINDS, AS LOW PRES WRAPS FROM EASTERN UPPER MI TO NORTHERN
LAKE MI EARLY THIS MORNING, NW WINDS WILL SHIFT TO N TO NE AND
INCREASE. THE INCREASE IN WINDS WILL BE FURTHER AIDED BY AN
ISALLOBARIC COMPONENT TOWARD A 5-6MB/3HR PRES RISE OCCURRING JUST
AHEAD OF THE LOW TRACK. THIS RESULTS IN AN ISALLOBARIC WIND
COMPONENT SIMILAR IN DIRECTION TO THE GRADIENT WIND. EXPECT WIND
GUSTS TO 30-40MPH TO BECOME FAIRLY COMMON ACROSS MUCH OF THE FCST
AREA, ESPECIALLY KEWEENAW TO CENTRAL UPPER MI. WINDS WILL BE LIGHTER
OVER THE EASTERN FCST AREA. GUSTS COULD BE STRONGER, BUT LOW LEVELS
AREN'T WELL MIXED. NEAR LAKE SUPERIOR AND ACROSS THE KEWEENAW,
EXPECT GUSTS UP TO 45MPH. OPTED TO HOLD OFF ON WIND ADVY HEADLINE
FOR NOW GIVEN LOW COVERAGE OF HIGHEST GUSTS WHICH WILL ONLY BE
AROUND THE ADVY THRESHOLD AND WILL BE LIMITED LARGELY TO SHORELINE
AND EXPOSED HIGH TERRAIN OF THE KEWEENAW.
EXPECT HIGH TEMPS TODAY TO BE A FEW DEGREES EITHER SIDE OF 40F.
LONG TERM /TONIGHT THROUGH WEDNESDAY/
ISSUED AT 257 AM EST THU NOV 21 2024
UPPER AIR PATTERN CONSISTS OF A 500 MB CLOSED LOW OVER WESTERN PA
00Z FRI WITH RIDGING IN THE ROCKIES. ANOTHER CLOSED LOW MOVES INTO
MANITOBA 00Z SAT AND INTO WESTERN ONTARIO BY 12Z SAT. THIS LOW HEADS
SOUTHEAST INTO QUEBEC SAT NIGHT. SLOW MODIFICATION OF THE COLD
AIRMASS WILL CONTINUE THIS PERIOD WITH MOST OF THE PCPN CONTINUING
TO BE RAIN, BUT SOME SNOW IS POSSIBLE FRI NIGHT ACROSS THE HIGHER
TERRAIN OF THE WEST. SNOW IS POSSIBLE SAT AND SAT NIGHT IN THE EAST.
LITTLE ACCUMULATION IS EXPECTED THOUGH. DID LOOKS AT 850 MB
TEMPERATURES AND THEY STAY JUST BELOW BORDERLINE LAKE EFFECT FOR
THIS PERIOD, EVEN LAKE ENHANCEMENT. PCPN WILL MOSTLY COME FROM
SYSTEM SNOW OR WRAPAROUND FROM THE UPPER LEVEL LOW AND TROUGH NEAR
THE AREA.
IN THE EXTENDED, THE GFS AND ECMWF SHOW A 500 MB TROUGH OFF THE WEST
COAST, A TROUGH IN THE NORTHERN PLAINS AND ZONAL FLOW ACROSS THE
SOUTHERN U.S. 12Z SUN. TROUGHING MOVES INTO THE UPPER GREAT LAKES
12Z MON AND INTO THE LOWER GREAT LAKES 12Z TUE. TROUGHING MOVES INTO
THE ROCKIES 12Z WED AND INTO THE PLAINS 12Z THU. TEMPERATURES COOL
FROM ABOVE NORMAL TO SLIGHTLY BELOW NORMAL TUE THROUGH THU. WILL
CONTINUE TO BE WET FOR THIS FORECAST PERIOD WITH INCREASINGLY COLDER
AIR MOVING IN AND CAUSING LAKE EFFECT SHOWERS OF RAIN AND SNOW.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 112 PM EST THU NOV 21 2024
WHILE THE SFC LOW OVER LAKE MI CONTINUES SOUTH, WEAKENING INTO THIS
EVENING, UPPER MI CONTINUES TO BE IMPACTED FROM THE LARGER
CIRCULATION ALOFT AND NORTHERLY UPSLOPE FLOW OFF LAKE SUPERIOR. AS A
RESULT, IFR CONDITIONS WILL DOMINATE THE 18Z TAF PERIOD. RAIN IS
EXPECTED TO PERSIST AT SAW INTO TONIGHT WITH ON AND OFF SHOWERS AT
IWD AND CMX THIS AFTERNOON AND EVENING. FOR TONIGHT, THERE IS ~30%
CHANCE FOR SHOWERS STREAMING OFF LAKE SUPERIOR, BUT BEST CONFIDENCE
IN SHOWERS IS AT SAW. OTHERWISE, NORTHERLY WINDS REMAIN GUSTY THIS
AFTERNOON, MAINLY BETWEEN 20-25 KT. THAT SAID, CMX COULD STILL SEE
SOME GUSTS UP TO 30 KT. WINDS DIMINISH THROUGH THIS EVENING,
BECOMING MAINLY 10-20 KT FOR TONIGHT.
MARINE
ISSUED AT 257 AM EST THU NOV 21 2024
A SURFACE LOW PRESSURE OVER THE EASTERN U.P. WILL DESCEND DOWN THE
AXIS OF LAKE MICHIGAN TODAY AND WEAKEN AS IT MOVES FURTHER SOUTH AND
BRING MARINE HAZARDS TO LAKE SUPERIOR THROUGH THIS EVENING. NORTH
GALES OF 35 TO 40 KNOTS WILL CONTINUE INTO EARLY THIS AFTERNOON
BEFORE THE WIND STARTS TO DECREASE TO 20 TO 30 KNOTS LATE IN THE
AFTERNOON. NORTH WINDS CONTINUE AT 20 TO 30 KNOTS UNTIL LATER
TONIGHT WHEN THEY FALL TO 15 TO 25 KNOTS WHERE THEY REMAIN INTO
SATURDAY WHILE BACKING SLOWLY TO THE NORTHWEST. WINDS REMAIN BELOW
20 KNOTS SATURDAY NIGHT INTO MONDAY BEFORE BECOMING 15 TO 25 KNOTS
LATER ON MONDAY.
MQT WATCHES/WARNINGS/ADVISORIES
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
STORM WARNING UNTIL 5 PM EST /4 PM CST/ THIS AFTERNOON FOR
LSZ162.
GALE WARNING UNTIL 2 PM EST /1 PM CST/ THIS AFTERNOON FOR
LSZ240>247-264.
GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR LSZ263.
LAKE MICHIGAN...
NONE.
SHORT TERM...ROLFSON
LONG TERM...07
AVIATION...JABLONSKI
MARINE...07
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