763
FXUS63 KIWX 210918
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
418 AM EST THU NOV 21 2024
KEY MESSAGES
- SNOWSHOWERS WILL BECOME MORE WIDESPREAD THROUGH THE DAY,
MIXING WITH RAIN IN SOME AREAS THIS AFTERNOON. HIGHEST SNOW
ACCUMULATIONS WEST OF INDIANA 15.
- SOME LAKE EFFECT RAIN SHOWERS ARE POSSIBLE FRIDAY, BUT OVERALL
A QUIET WEEKEND APPEARS TO BE IN STORE.
- RAIN CHANCES RETURN EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 417 AM EST THU NOV 21 2024
GENERALLY LIGHT SNOWSHOWERS ARE IMPACTING MANY AREAS AS THE
POCKET OF COLDER AIR, COMBINED WITH A DISTURBANCE CLIPPING SW
AREAS, AID IN INCREASED LIFT. THUS FAR NO IMPACTS HAVE BEEN
REPORTED WITH SOME SPOTS LIKELY SEEING A DUSTING OR MAYBE TENTH
OF SNOW. THE EXCEPTION MAY BE CLOSER TO LK MI WHERE SOMEWHAT
HEAVIER SHOWERS EXISTED AS LAKE ENHANCEMENT WAS HELPING. QPF
AMOUNTS FROM KBEH HAVE NOT BEEN OVERLY IMPRESSIVE SO FAR, WITH
MDOT PLOW AND STATIONARY CAMERAS SHOWING MAYBE A FEW TENTHS TO
LOCALLY AN INCH.
THE UPPER LEVEL LOW IS SLOWLY WORKING ACROSS CENTRAL LOWER MI
WITH THE SFC LOW MOVING ACROSS THE EASTERN UP OF MI. MODELS HAVE
BEEN PRETTY PRONOUNCED ON COVERAGE, INTENSITY AND QPF POTENTIAL
AS THE LOW DROPS SOUTH DOWN THE HEART OF LAKE MI TODAY, REACHING
NW AREAS LATER THIS MORNING (16Z OR SO) AND THEN EXISTING THE
SOUTH NEAR 00Z FRI. CONCERNED THAT QPF MAY BE WAY OVERDONE GIVEN
A CLOSE LOOK AT OBSERVATIONS IN THE UP WHERE THE HEAVIEST
PRECIP IS SUPPOSED TO EXIST PER THE MODELS. THE SFC LOW WILL BE
SLOWLY WEAKENING AS IT DROPS SOUTH, BUT STILL HAVE A FAIR AMOUNT
OF ENERGY AND MOISTURE ACCOMPANYING IT. THE BIGGEST CHANGES FOR
NOW WAS TO LIMIT THE EASTERN EDGE OF THE HIGHEST POPS AS THE
BULK OF THE PRECIP LOOKS TO REMAIN ALONG/WEST OF INDIANA 15. QPF
AMOUNTS WERE LOWERED SOME, BUT NOT SUBSTANTIALLY FOR NOW,
YIELDING SLIGHTLY LOWER ACCUMULATIONS WEST (STILL IN THE 1 TO
MAYBE 2 INCH RANGE). MODEL TRENDS HAVE ALSO SHOWED SOMEWHAT
HIGHER AFTERNOON TEMPS WITH EVEN A DEGREE OR 2 WARMER IMPACTING
THE OVERALL ACCUMULATION. AS THE AREA OF PRECIP COMES THROUGH,
EXPECT REDUCED VISIBILITY AND IN AREAS THAT SEE SNOWFALL,
ACCUMULATIONS WOULD OCCUR ON GRASSY AND ELEVATED AREAS. ROAD
TEMPERATURE FORECASTS SUGGEST READINGS IN THE 40S DURING THE
PEAK OF THE EVENT, MEANING ROADS SHOULD BE WET. WHILE IT WILL BE
BREEZY TODAY THE SFC LOW TRACK WILL PUSH THE STRONGEST PRESSURE
GRADIENT WEST OF THE AREA (WHERE WIND ADVISORIES HAVE BEEN
ISSUED ACROSS IL). STRONGEST WINDS FOR OUR AREA WILL BE BOTH
AHEAD OF AND BEHIND THE LOW, WITH GUSTS OF 35 TO MAYBE 40 MPH IN
THE WEST.
SIGNIFICANT CHANGES MADE FOR TONIGHT TO TREND MUCH DRIER AND
ALSO COLDER AS SUBSIDENCE ARRIVES IN THE WAKE OF THE LOW AND
MAYBE EVEN SOME BREAKS OR THINNING OF THE CLOUDS. LOWS WILL BE
IN THE UPPER 20S NE TO NEAR FREEZING WEST, SO ANY WET ROADS
COULD FREEZE IN SPOTS (ALTHOUGH SUSPECT MINIMAL IF ANY IMPACTS).
LAKE EFFECT SHOWERS WILL BE POSSIBLE ON FRIDAY AS ANOTHER
DISTURBANCE DROPS SOUTH. THERMAL PROFILES SUPPORT ALL RAIN WITH
OVERALL INTENSITY LIKELY NOT VERY HIGH AS DELTA TS ARE CLOSER TO
12 TO 14 C (ENOUGH FOR LAKE EFFECT, BUT NOT IDEAL FOR HEAVIER
PRECIP). IN ADDITION, INVERSION HEIGHTS WILL BE LOWER (7 TO
8KFT).
WITH FOCUS ON THE NEXT 24 TO 36 HOURS, LITTLE WAS MODIFIED IN
THE EXTENDED PERIOD (SAT-THU) WITH THE WEEKEND LIKELY DRY AND
WARMER (ABOVE NORMAL), FOLLOWED BY A NORTHERN STREAM WAVE THAT
MAY BRING SOME RAIN OR SNOW CHANCES MID TO LATE WEEK.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1250 AM EST THU NOV 21 2024
UPPER LOW ALMOST DIRECTLY OVERHEAD WILL CONTINUE TO SUPPORT SCT
SNOW SHOWERS AND MVFR CEILINGS THROUGH THE MORNING. A GRADUAL
LOWERING OF CEILINGS IS EXPECTED THROUGH THE MORNING AS COLDER
AIR SETTLES INTO THE AREA. STILL EXPECT THE HEAVIEST SNOW TO
OCCUR ROUGHLY 17-23Z THIS AFTERNOON AS PRIMARY VORT MAX AND
SURFACE LOW DIVE THROUGH THE AREA. FAR BETTER CHANCES FOR
ACCUMULATING SNOW AND VISIBILITIES DROPPING TO AROUND 1/2SM WILL
BE AT KSBN BUT DO STILL EXPECT SOME BRIEF, LIGHTER SNOW AT
KFWA. CONDITIONS IMPROVE AT KFWA THURSDAY NIGHT BUT LAKE EFFECT
RAIN BANDS AND LOW MVFR CEILINGS WILL LIKELY PERSIST AT KSBN
WELL INTO FRIDAY.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR LMZ043-
046.
GALE WARNING FROM 7 AM THIS MORNING TO 1 AM EST FRIDAY FOR
LMZ043-046.
DISCUSSION...FISHER
AVIATION...AGD
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