750
FXUS63 KDTX 181734
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1234 PM EST TUE FEB 18 2025
KEY MESSAGES
- WIND CHILLS AROUND 0 DEGREES CONTINUE THIS AFTERNOON.
- LIGHT SNOWFALL CHANCES WEDNESDAY NIGHT INTO THURSDAY MORNING.
- TEMPERATURES OF 5 TO 10 DEGREES BELOW NORMAL WILL HOLD THROUGH THE
REMAINDER OF THE WEEK.
AVIATION
HIGH PRESSURE HOLDS STEADY OVER THE PLAINS MAINTAINING WEST
NORTHWEST FLOW ACROSS THE AIRSPACE THROUGH TONIGHT. THESE WINDS
ACTIVATE LAKE MICHIGAN MOISTURE WHICH WILL GENERATE SCATTERED TO
BROKEN COVERAGE OF STRATOCUMULUS CLOUDS THIS AFTERNOON. CLOUD BASES
ARE EXPECTED TO BE BETWEEN 3.0 AND 5.0 KFT AGL WITH THE SHALLOW
MOIST LAYER POTENTIALLY SQUEEZING OUT A FEW FLURRIES AS WELL. THE
LOW CLOUDS DISSIPATES TONIGHT WHILE CIRRUS BEGINS STREAM IN AHEAD OF
THE NEXT UPPER LEVEL SYSTEM. CLOUDS CONTINUE TO THICKEN AND LOWER ON
THURSDAY AS ANOTHER SCATTERED TO BROKEN STRATOCUMULUS DECK DEVELOPS
MIDDAY.
DTW THRESHOLD PROBABILITIES
* LOW IN CEILINGS AOB 5000 FEET THIS AFTERNOON (17Z TO 22Z).
PREV DISCUSSION
ISSUED AT 356 AM EST TUE FEB 18 2025
DISCUSSION...
AN ARCTIC AIRMASS COMBINED WITH CLEARING SKIES AND ELEVATED WINDS OF
5-10 KNOTS THIS MORNING IS PRODUCING DANGEROUSLY COLD WIND CHILLS TO
NEGATIVE 15 DEGREES F AND BELOW. SUFFICIENT CLEARING OF THE SKIES
ACROSS MUCH OF THE SOUTHERN HALF OF THE CWA AND THE SURFACE
OBSERVATIONS EARLY THIS MORNING WERE REASON ENOUGH TO EXPAND THE
COLD WEATHER ADVISORY. JUST ENOUGH LINGERING CLOUDS ACROSS LENAWEE
AND MONROE SHOULD KEEP THEM JUST ABOVE CRITERIA WITH WIND CHILLS
AROUND NEGATIVE 10 DEGREES.
MICHIGAN WILL BE IN A ZONAL FLOW PATTERN UNDER THE LEFT ENTRANCE
REGION OF THE UPPER JET TODAY AS SURFACE HEIGHT RISES CREEP IN FROM
THE WEST. PLENTY OF DRY AIR ALONG AND STABLE CONDITIONS WILL MAKE FOR
QUIET WEATHER. JUST ENOUGH SHALLOW LAKE MOISTURE IN THE BOUNDARY
LAYER SHOULD BE ENOUGH TO GENERATE SOME DAYTIME CUMULUS AS DIURNAL
MIXING ENSUES. THERE IS AN OVERALL LACK OF FORCING, BUT FORECAST
SOUNDINGS SHOWING GOOD SATURATION WITH RESPECT TO ICE WITHIN THE
CLOUD LAYER THAT RESIDES IN A PORTION OF THE DGZ. IT IS POSSIBLE A
FEW FLAKES MAY FALL OUT OF ANY CLOUDS THAT DEVELOP THIS AFTERNOON,
BUT IT IS NOT REALLY WORTH THE MENTION IN THE GRIDS GIVEN THE VERY
ISOLATED NATURE IF THEY DO. EXPECT DAYTIME HIGHS TODAY TOPPING OUT IN
THE TEENS WITH ANOTHER COLD NIGHT TONIGHT AS LOWS FALL TO AROUND
ZERO. AT THIS TIME, WIND CHILLS LOOK TO FALL TO AROUND NEGATIVE 10
DEGREES AND HOLD JUST ABOVE ANY COLD HEADLINES.
A SHORTWAVE WILL DROP OUT OF NORTHERN PLAINS AND BECOME A RELATIVELY
WEAK CLOSED MID/UPPER LOW WITH THE CENTER PASSING OVER LOWER
MICHIGAN AND THE OHIO VALLEY DURING THE DAY THURSDAY. THIS SYSTEM IS
EXPECTED TO DRAW IN JUST ENOUGH MOISTURE FROM THE NORTH TO RESULT IN
LIGHT SNOWFALL ACROSS SOUTHEAST MICHIGAN WEDNESDAY NIGHT INTO
THURSDAY MORNING. FORCING WITH THIS SYSTEM WILL BE WEAK AND OVERALL
MOISTURE IS LACKING, SO ANY ACCUMULATIONS WILL LIKELY BE LESS THAN
AN INCH.
SURFACE HIGH PRESSURE DRIFTING EAST OUT OF THE CENTRAL PLAINS AND
LOW/MID LEVEL RIDGE GAIN GREATER INFLUENCE OVER MICHIGAN LATE
THURSDAY INTO FRIDAY BRINGING DRY WEATHER DURING THE LATE WEEK.
TEMPERATURES ARE EXPECTED TO MODERATE LATE IN THE WEEK, BUT STILL
REMAIN BELOW THE AVERAGE WITH DAYTIME HIGHS THURSDAY AND FRIDAY IN
THE 20S. A WEDGE OF WARMER AIR MAY ARRIVE SUNDAY BRINGING THE
OPPORTUNITY FOR DAYTIME HIGHS TO CLIMB JUST ABOVE FREEZING. LOW
CHANCE POPS EXIST SUNDAY INTO EARLY NEXT WEEK AS A SERIES OF SEVERAL
WEAK SHORTWAVES PASS THROUGH THE GREAT LAKES.
MARINE...
FRIGID AIRMASS IN PLACE OVER THE GREAT LAKES REGION TODAY, WITH A
TIGHT PRESSURE GRADIENT IN PLACE STILL SUPPORTING NORTHWEST WIND
GUSTS OF 25 TO 30 KNOTS OVER LAKE HURON. THE HEAVY FREEZING SPRAY
WARNING CONTINUES THROUGH THE AFTERNOON. WINDS FINALLY LOOK TO
DECREASE IN SPEED TUESDAY EVENING/NIGHT WITH MODEST MODIFICATION OF
THE AIRMASS INTO WEDNESDAY. DESPITE THE MODERATE NORTHERLY WINDS ON
THURSDAY, FURTHER WARMING WILL OCCUR INTO FRIDAY. MODERATE SOUTHWEST
WINDS FOR THE FIRST HALF OF THE WEEKEND, AHEAD OF A MOSTLY DRY COLD
FRONT DROPPING SOUTH FROM THE NORTHERN GREAT LAKES REGION.
DTX WATCHES/WARNINGS/ADVISORIES
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
LHZ361>363-462-463.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
AVIATION.....RBP
DISCUSSION...AA
MARINE.......SF
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