185
FXUS63 KMQT 191935
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
235 PM EST TUE NOV 19 2024
KEY MESSAGES
- A SLOW MOVING SYSTEM WILL USHER IN A WET PATTERN INTO THE
WEEKEND. PRECIP WILL MAINLY BE RAIN, BUT SOME SNOW WILL BE
POSSIBLE WEDNESDAY NIGHT INTO THURSDAY MORNING ACROSS THE WEST
HALF.
- NORTHERLY GALES TO 35 KNOTS WILL BE POSSIBLE THURSDAY
SHORT TERM /THROUGH THIS AFTERNOON/
ISSUED AT 507 AM EST TUE NOV 19 2024
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A 984 MB LOW CENTERED OVER
CENTRAL MINNESOTA WITH ASSOCIATED FRONTAL BOUNDARY DRAPED
SOUTHEASTWARD ACROSS WISCONSIN. THIS HAS KEPT THE MQT RADAR ACTIVE
ALL NIGHT WITH WIDESPREAD RAIN SHOWERS. AND, WITH ONSET OF DRY
SLOTTING NOT EXPECTED UNTIL LATER TODAY, WIDESPREAD 0.25-0.50 INCH
RAINFALL AMOUNTS CAN BE EXPECTED. THE MAIN FOCUS TODAY, THOUGH,
WILL BE THE STRONG SOUTHEASTERLY WINDS AS THE PRESSURE GRADIENT
TIGHTENS. MOST IMPACTED WILL BE THE KEWEENAW/NORTHERN HOUGHTON
AND I-28 CORRIDOR WHERE WIND ADVISORIES ARE IN EFFECT FOR GUSTS
UP TO 50 MPH. UNSECURED OBJECTS WILL BE BLOWN AROUND AND POWER
OUTAGES ARE LIKELY. HIGHER TERRAIN ACROSS THE WESTERN COUNTIES
WILL ALSO APPROACH CRITERIA LEVELS WITH WIDESPREAD GUSTS UP TO
35 MPH EXPECTED OVER THE REMAINDER OF THE UP. THE STRONG WINDS
WILL CREATE LARGE WAVES ALSO MAKING THE SOUTHERN/EASTERN
LAKESHORES OF KEWEENAW AND DELTA COUNTIES SUSCEPTIBLE TO MINOR
BEACH EROSION AND LAKESHORE FLOODING. THEREFORE, LAKESHORE FLOOD
ADVISORIES ARE ALSO IN EFFECT FOR THOSE COUNTIES. AS THE
ASSOCIATED OCCLUDED FRONT LIFTS NORTHWARD LATER TODAY/THIS
EVENING, WINDS WILL VEER TO THE SOUTHWEST AND FINALLY WEAKEN.
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED AT 234 PM EST TUE NOV 19 2024
THERE CONTINUES TO BE VERY GOOD AGREEMENT AMONG THE DETERMINISTIC
MODELS AND THEIR RESPECTIVE ENSEMBLE PACKAGES THIS MORNING,
SUGGESTING THE MAIN ITEM OF INTEREST WILL BE THE EVOLUTION OF A
CLOSED MID-LEVEL LOW AND MULTIPLE SURFACE LOWS THROUGH THE GREAT
LAKES INTO THE WEEKEND. CURRENT WATER VAPOR IMAGERY FROM GOES 16,
MSAS ANALYSIS, AND RAP HEIGHT ANALYSIS SHOW THE INITIAL CLOSED
CIRCULATION OVER MINNESOTA, WITH AN OCCLUDED FRONT EXTENDING
SOUTHEAST FROM THE SURFACE FEATURE ACROSS NORTHERN WISCONSIN.
TONIGHT, THE MID-LEVEL LOW WILL PROGRESS SOUTHEAST WHILE THE DRY
SLOT OF THIS SYSTEM MOVES OVERHEAD BEHIND THE NORTHWARD LIFTING
FRONT AND THE SURFACE FRONT FIZZLES. AS THE MID-LEVEL FEATURE
MIGRATES EAST, IT WILL AGAIN AMPLIFY, RESULTING IN A SECOND SURFACE
LOW DEVELOPING NEAR MICHIGAN'S THUMB BY WEDNESDAY AFTERNOON. THE LOW
WILL LIFT NORTH TO THE NORTHERN SHORES OF LAKE HURON IN THE EVENING,
BEFORE RETROGRADING WESTWARD, AND THEN BACK SOUTH DOWN LAKE MICHIGAN
OR WESTERN LOWER MICHIGAN. THIS SURFACE REFLECTION WILL WEAKEN LATE
THURSDAY WHILE A THIRD SURFACE LOW DEVELOPS OFF THE MID-ATLANTIC
COAST IN RESPONSE TO THE MID-LEVEL LOW AGAIN, AMPLIFYING AS IT
SHIFTS EASTWARD. THE SYSTEM WILL OCCLUDE FRIDAY THEN SLOWLY EXIT
THROUGH NEW ENGLAND ON SATURDAY, PERHAPS DEEPENING AGAIN SATURDAY
EVENING AS IT LIFTS INTO THE CANADIAN MARITIMES. THIS WILL SUPPORT A
PROLONGED WET PERIOD ACROSS THE FORECAST AREA WITH SYNOPTIC PRECIP
SHIFTING OVER TO LAKE ENHANCED AND EVENTUALLY LAKE EFFECT THROUGH AT
LEAST SATURDAY. THE MAIN FORECASTING CHALLENGES IN THIS PERIOD
CONTINUE TO REVOLVE AROUND THE EXACT WESTWARD EDGE THE SECOND
SURFACE LOW'S POSITION WHILE IT WOBBLES AROUND THE GREAT LAKES AND
THE SUBSEQUENT POSITION OF THE LOW'S DEFORMATION AXIS/INVERTED
TROUGH WHILE COOLING OCCURS WEDNESDAY NIGHT.
FOLLOWING THE EROSION OF THE DRY SLOT WEDNESDAY MORNING, INCREASING
MID-LEVEL CONVERGENCE WILL SUPPORT AND PRECIP SPREADING INTO EASTERN
UPPER MICHIGAN WHILE THE SECOND SURFACE LOW DEVELOPS. THE CONSENSUS
AMONG THE GEPS, GEFS, AND EPS SURFACE LOW CLUSTERING IS THAT THE LOW
WILL DRIFT NORTH THEN RETROGRADE WEST, BEFORE MIGRATING SOUTH.
CURRENT TIMING OF THIS EVOLUTION WILL BE OVERNIGHT WEDNESDAY INTO
THURSDAY WHEN SURFACE TEMPERATURES DIP NEAR OR BELOW FREEZING AND
WETBULB ZERO HEIGHTS FALL LESS THAN 600FEET, WHICH WILL SUPPORT A
RAIN TO WET SNOW TRANSITION OVER WESTERN UPPER MICHIGAN. THERE'S
ENOUGH SPREAD AMONG THESE SYSTEMS ON THE NORTHWARD AND WESTWARD
POSITION TO QUESTION HOW FAR WEST HIGHER QPF AXIS WILL BE, WHICH
IMPACTS SNOWFALL AMOUNTS. MIDDLE OF THE ROAD OPTION CONFORMS TO MOST
DETERMINISTIC SOLUTIONS, WHILE THE MOST NOTABLE OUTLIER IS THE
EASTWARD NAMNEST. THIS FORECAST REPRESENTS THE CONSENSUS OPTION
WHERE CONFIDENCE IS HIGHEST. ENSEMBLES SUGGEST A 50% CHANCE OR
HIGHER OF A MAJORITY OF THE FORECAST AREA GETTING ANOTHER 0.5" OF
QPF AND THE EPS SUGGESTS A 20-60% CHANCE OF EXCEEDING 1.0" IN THE
HIGHER TERRAIN REGIONS OF BARAGA AND MARQUETTE COUNTIES. WITH
ANTICIPATED SNOW RATIOS APPROXIMATELY 10:1 OR LESS, THIS WOULD YIELD
A COUPLE INCHES OF WET SNOW. SNOW AMOUNTS AMONG THE VARIOUS ENSEMBLE
AND DETERMINISTIC ARE MIXED AND LARGELY DEPEND ON THE RATE OF
COOLING, THE POSITION OF THE LOW, AND THE QPF SPREAD. CURRENT
FORECAST REFLECTS ~1 INCH ACROSS MOST OF WESTERN UPPER MICHIGAN AWAY
FROM THE LAKESHORES AND A SWATH OF 2 TO 4 INCHES FROM THE HURON
MOUNTAINS SOUTHWESTWARD TOWARD SIDNAW/WATTON. TIMING CURRENTLY LOOKS
LIKE IN THE OVERNIGHT PERIOD AFTER MIDNIGHT FOR THE BULK OF THE
POTENTIAL.
EVENTUALLY, THE MID-LEVEL LOW EXITS EAST, LEAVING BEHIND CONTINUED
CYCLONIC FLOW WITH 850MB TEMPS OF -4 TO -1C. THIS SHOULD KEEP LAKE
EFFECT RAIN/SNOW SHOWERS DOWNWIND OF LAKE SUPERIOR INTO SATURDAY
WHEN ITS POSSIBLE A COOLER AIRMASS MAY BUILD IN. MID-LEVEL RIDGING
WILL EVENTUALLY FILTER IN FROM WEST TO EAST LATE SATURDAY/SUNDAY,
WITH A MORE UNCERTAIN PATTERN DEVELOPING AFTERWARDS. A BRIEF, PSEUDO-
ZONAL FLOW PATTERN LOOKS TO DEVELOP ACROSS CONUS AFTERWARDS BUT THIS
LOOKS SHORT LIVED AS AN EASTWARD MIGRATING SHORTWAVE INTERRUPTS THIS
FOR OUR FORECAST AREA SUNDAY NIGHT INTO EARLY NEXT WEEK. THERE
CONTINUES TO BE PLENTY OF UNCERTAINTY WITH THIS WAVE, BUT GUIDANCE
CONTINUES TO SUGGEST THE AIRMASS BEHIND IT OF 850MB TEMPS IN THE -10
TO -5C FOR THE START OF NEXT WEEK.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 108 PM EST TUE NOV 19 2024
A LOW PRESSURE SYSTEM LIFTING NORTH THROUGH NORTHERN MN THIS
AFTERNOON CONTINUES SCT RAIN SHOWERS ACROSS THE UP INTO THIS EVENING
AND FLIGHT RESTRICTIONS AT ALL SITES THROUGH THE DURATION OF THE 18Z
TAF PERIOD. SHOWERS BRING PERIODS OF IFR TO LIFR INTO THIS EVENING
BEFORE A PERIOD OF MVFR TO LOW VFR CIGS SETS UP TONIGHT THROUGH MUCH
OF THE DAY WEDNESDAY. CHANCES FOR VFR CIGS ARE HIGHEST AT IWD/CMX
LATE. SOUTHWEST WINDS AHEAD OF THE FRONTAL BOUNDARY LOCATED OVER
NORTHERN WI ARE STILL GUSTING UP TO 30 KT AT SAW/CMX. A LULL IN THE
WINDS, ALREADY BEING OBSERVED AT IWD, IS EXPECTED TO CONTINUE
LIFTING NORTH THROUGH THIS EVENING AHEAD OF THE FRONTAL BOUNDARY.
THIS DIMINISHES WIND GUSTS AS WINDS VEER SOUTHWEST. A LOW LEVEL JET
OVER THE WEST LOOKS TO INCREASE SOUTHWEST WINDS AGAIN AT IWD AND CMX
THIS EVENING WITH GUSTS BACK INTO THE 20-30 KT RANGE BEFORE WINDS
DIMINISH AT ALL SITES TONIGHT INTO WEDNESDAY.
MARINE
ISSUED AT 234 PM EST TUE NOV 19 2024
STRONG GALES WITH SOME STORM FORCE GUSTS WILL SETTLE DOWN THIS
AFTERNOON AND EVENING FROM SOUTH TO NORTH WITH THE PASSAGE OF AN
OCCLUDED FRONT. EXPECT THE SOUTHEAST WINDS TO SHIFT TO SOUTHWEST
IMMEDIATELY AFTER THE FRONT AND CONTINUE TO BLOW GALES OF 35KTS OVER
THE WEST HALF INTO THE EVENING HOURS. WINDS WILL SETTLE FURTHER
OVERNIGHT, FALLING TO NEAR 20KTS BY MORNING LAKE-WIDE. ATTENTION
THEN TURNS TO A DEVELOPING SURFACE LOW OVER LAKE HURON THAT WILL
LIFT NORTH WEDNESDAY NIGHT THEN SHIFT WEST AND SOUTH OVER LOWER
MICHIGAN INTO THURSDAY. THERE CONTINUES TO BE DIFFERENCES IN THE
DETERMINISTIC AND ENSEMBLE GUIDANCE PACKAGES OF WHERE EXACTLY THE LOW
WILL WOBBLE AND HOW DEEP IT WILL BE, AND THUS THE IMPACT OF THE
INCREASING PRESSURE GRADIENT FORCES. HOWEVER, CONFIDENCE CONTINUES
TO GROW THAT A WIDESPREAD GALE EVENT TO AT LEAST 35KNOTS WILL BE
POSSIBLE THURSDAY. INTERNAL PROBABILISTIC GUIDANCE SUGGESTS 30-50%
CHANCE OF AT LEAST 34KTS WHICH IS REINFORCED BY EPS PROBABILITIES
SUGGESTING >50% ACROSS LAKE SUPERIOR. ITS POSSIBLE THAT A GALE WATCH
MAY BE ISSUED LATER THIS EVENING OR BY WEDNESDAY MORNING.
WINDS SHOULD LIGHTEN LATE THURSDAY BUT REMAIN GENERALLY NORTH AT 20-
30KTS INTO THE WEEKEND. CURRENT THINKING IS FOR WINDS TO FALL BELOW
20KTS FROM WEST TO EAST SATURDAY INTO THE EVENING HOURS. LIGHT WINDS
LOOK TO REMAIN INTO EARLY NEXT WEEK, BUT A SYSTEM MOVING THROUGH THE
REGION LATE SUNDAY/MONDAY WITH TRAILING COLD AIR MAY RESULT IN
INCREASING WINDS AGAIN MONDAY/TUESDAY.
MQT WATCHES/WARNINGS/ADVISORIES
UPPER MICHIGAN...
WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ001-003.
LAKESHORE FLOOD ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ001.
WIND ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MIZ006.
LAKESHORE FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MIZ013.
LAKE SUPERIOR...
GALE WARNING UNTIL 11 PM EST /10 PM CST/ THIS EVENING FOR
LSZ162-263.
GALE WARNING UNTIL 6 PM EST /5 PM CST/ THIS EVENING FOR
LSZ241>244.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ245-251-
264>267.
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LSZ246>250.
LAKE MICHIGAN...
NONE.
SHORT TERM...TDUD
LONG TERM...JTP
AVIATION...JABLONSKI
MARINE...JTP
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