132
FXUS63 KDTX 180856
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
356 AM EST TUE FEB 18 2025
KEY MESSAGES
- COLD WEATHER ADVISORY IN EFFECT UNTIL 9AM THIS MORNING FOR MOST OF
SOUTHEAST MICHIGAN. WIND CHILLS RANGE BETWEEN 10 DEGREES BELOW
ZERO AND 20 DEGREES BELOW ZERO.
- LIGHT SNOWFALL CHANCES WEDNESDAY NIGHT INTO THURSDAY MORNING.
- TEMPERATURES BELOW NORMAL HOLD THROUGH THE REMAINDER OF THE WORK
WEEK.
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.
PREV DISCUSSION
ISSUED AT 1140 PM EST MON FEB 17 2025
AVIATION...
ONGOING VEERING OF THE LOW LEVEL WIND FIELDS TO THE NORTH-NORTHWEST
OVER LAKE MICHIGAN HAS FORCED MOST OF THE LAKE CLOUDS SOUTH OF THE
TERMINALS, LEAVING MAINLY CLEAR SKIES ACROSS THE TERMINAL. WHILE
THERE WILL BE SOME NIGHTTIME DECOUPLING IN THE BOUNDARY LAYER, THE
GRADIENT WINDS WILL MAINTAIN AT LEAST A 6 TO 10 KNOT WIND AT THE
SURFACE TONIGHT. MODEL SOUNDINGS INDICATE DIURNAL MIXING WITH THE
PRESENCE OF SHALLOW LAKE MOISTURE WILL SUPPORT A SCATTERED TO BROKEN
LOW END VFR CU FIELD TUES AFTERNOON.
DTW THRESHOLD PROBABILITIES...
* LOW IN CEILINGS AOB 5000 FEET TUESDAY.
DTX WATCHES/WARNINGS/ADVISORIES
MI...COLD WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MIZ047>049-
053>055-060>063-068>070-075-076.
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.
DISCUSSION...AA
MARINE.......SF
AVIATION.....SC
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