729
FXUS63 KDVN 211135
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
535 AM CST TUE JAN 21 2025
KEY MESSAGES
- DANGEROUS COLD CONTINUES THROUGH THE MORNING HOURS TODAY, WITH
AN EXTREME COLD WARNING NOW IN EFFECT ACROSS THE ENTIRE
FORECAST AREA
- LIGHT ACCUMULATING SNOW IS EXPECTED LATE TONIGHT THROUGH WEDNESDAY
NIGHT, WITH SOME ISOLATED ACCUMULATIONS OVER AN INCH POSSIBLE
- TEMPERATURES BECOME SEASONAL BY WEDNESDAY, WITH A LARGELY DRY
STRETCH EXPECTED THROUGH THE UPCOMING WEEKEND
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 310 AM CST TUE JAN 21 2025
OUR COLDEST MORNING OF THIS ENTIRE STRETCH OF BITTERLY COLD
CONDITIONS IS UPON US! AS OF 09Z/3 AM THIS MORNING, WIDESPREAD WIND
CHILLS WERE REPORTED BETWEEN -25 TO AS LOW AS -34 DEGREES AT THE
INDEPENDENCE, IA MUNICIPAL AIRPORT (HAD A MINIMUM WIND CHILL OF -37
DEGREES THERE AS OF 1 AM!). THE TREND HAS BEEN FOR COLDER
TEMPERATURES, WHICH IS QUITE IMPRESSIVE GIVEN NORTHWEST WINDS
BETWEEN 10 TO 15 MPH, WITH GUSTS AS HIGH AS 20 TO 25 MPH. GIVEN THIS
TREND TOWARDS EVEN COLDER AND PERSISTENT WINDS WITHIN THE COLD AIR
ADVECTION REGIME, NEW FORECAST WIND CHILL VALUES SUPPORT AN
EXPANSION OF THE ONGOING EXTREME WIND WARNING ACROSS THE REMAINDER
OF THE NWS QUAD CITIES FORECAST AREA, REMAINING IN EFFECT THROUGH
NOON TODAY. REMEMBER, FROSTBITE IN THESE FRIGID CONDITIONS COULD
OCCUR IN AS LITTLE AS 10 MINUTES, SO MAKE SURE TO TAKE THIS EXTREME
COLD VERY SERIOUSLY! MAKE SURE TO DRESS IN LAYERS, INCLUDING HAT,
FACE MASK, AND GLOVES IF YOU MUST GO OUTSIDE. DON'T FORGET THE FUR
BABIES - KEEP YOUR PETS INDOORS AS MUCH AS POSSIBLE!
ONE THING TO KEEP AN EYE ON LATER THIS MORNING IS THE POTENTIAL FOR
A AN IMPRESSIVELY COLD 850 MB LEVEL TEMPERATURE PER THE SPC SOUNDING
CLIMATOLOGY AS BOTH THE GEFS AND EPS ENSEMBLE MEAN 850 MB
TEMPERATURES CONTINUE TO BE THEIR COLDEST RIGHT AROUND 12Z/6 AM THIS
MORNING, WITH VALUES HOVERING AROUND 30 TO 32 DEGREES BELOW ZERO
ACROSS THE AREA! TO PUT THIS INTO CLIMATOLOGICAL PERSPECTIVE, IF
THESE 850 MB TEMPERATURES ACTUALLY OCCUR AT THAT TIME, THESE VALUES
WOULD BE NEAR THE COLDEST 850 MB TEMPERATURE IN THE ENTIRE SPC
SOUNDING CLIMATOLOGY FOR DVN, WHICH DATES BACK TO 1995 (THE COLDEST
VALUE IN THE WHOLE CLIMATOLOGY IS -29.5 DEGREES C FROM THE 00Z
12/24/2022 RAOB)!
THESE CONDITIONS ARE EXPECTED TO QUICKLY IMPROVE FROM SOUTH TO NORTH
AFTER 15Z/9 AM AS TEMPERATURES INCREASE. A SURFACE HIGH PRESSURE
RIDGE AXIS IS EXPECTED TO SWEEP THROUGH THE AREA LATE THIS MORNING
INTO THE EARLY AFTERNOON, RESULTING IN WINDS TURNING MORE
SOUTHWESTERLY IN ITS WAKE. THE RESULTING WARM AIR ADVECTION WILL
HELP USHER IN SOME RELATIVELY WARMER TEMPERATURES FOR TONIGHT. WHILE
DAYTIME HIGHS TODAY WILL STILL BE IN THE SINGLE DIGITS ABOVE ZERO,
TONIGHT'S LOWS WILL ALSO REMAIN IN THE SINGLE DIGITS TO NEAR ZERO,
SO NO MAJOR FALL IN TONIGHT'S TEMPERATURES. WHILE IT WILL REMAIN
VERY COLD, IT DOESN'T APPEAR TO WARRANT ANY ADDITIONAL COLD WEATHER
HEADLINES AT THIS TIME. THERE IS LIGHT AT THE END OF THIS LONG,
FRIGID TUNNEL!
LONG TERM /WEDNESDAY THROUGH MONDAY/
ISSUED AT 310 AM CST TUE JAN 21 2025
WEDNESDAY WILL BE A DAY OF TRANSITION TO MORE SEASONAL CONDITIONS AS
THE SOUTHERN RETURN FLOW/WARM AIR ADVECTION INCREASES FURTHER.
FARTHER WEST, AN APPROACHING MID-LEVEL SHORTWAVE IS PROGGED TO SWEEP
THROUGH THE AREA FROM WEST TO EAST, LEADING TO INCREASING CHANCES
(40 TO 60%) OF LIGHT SNOW ACROSS THE AREA. HREF ENSEMBLE SOUNDINGS
INDICATE INCREASING SATURATION WITHIN THE DENDRITIC GROWTH ZONE
ALOFT, WHICH SHOULD EFFICIENTLY GENERATE ICE CRYSTALS. THERE DOES
APPEAR TO BE SOME DRY AIR IN THE LOWER LEVELS, SO IF THIS DRY AIR
HANGS ON LONGER THAN EXPECTED, THIS COULD LIMIT SNOW TOTALS. AT THIS
TIME, IT APPEARS THAT THE DRY AIR WILL ERODE, LEADING TO SOME LIGHT
SNOWFALL MAINLY DURING THE WEDNESDAY PM HOURS, ALTHOUGH THERE COULD
BE SOME LIGHT SNOW FALLING ACROSS OUR NORTHERN AREAS WEDNESDAY
MORNING. LREF ENSEMBLE GUIDANCE CONTINUES TO SUGGEST VERY HIGH (70
TO 90%) EXCEEDANCE PROBABILITIES OF MEASURABLE SNOW (0.1" OR MORE).
DIVING INTO THE ENSEMBLES PER THE WSE PLUME VIEWER, MOST OF THE
MEMBERS OF THE GEFS, EPS, AND GEPS ENSEMBLES SUGGEST TOTAL SNOWFALL
LESS THAN AN INCH, WITH SOME MEMBERS SUGGESTING TOTALS BETWEEN 1-2
INCHES NEAR DUBUQUE AND POINTS EAST OF THERE IN NORTHWEST ILLINOIS.
THUS, CONFIDENCE REMAINS QUITE HIGH FOR AN OVERALL MINOR SNOWFALL
EVENT, BUT IT COULD BE ENOUGH TO GENERATE SLIPPERY SPOTS, ESPECIALLY
ON UNTREATED ROADWAYS. DESPITE THE SNOWFALL, TEMPERATURES SHOULD
WARM INTO THE MIDDLE 20S NORTHEAST TO THE LOWER 30S SOUTHWEST,
ESSENTIALLY NEAR AVERAGE FOR THIS TIME OF THE YEAR.
FOR THURSDAY THROUGH THE UPCOMING WEEKEND, WE WILL SEE SOME
FLUCTUATIONS IN TEMPERATURES, WITH SOME COOLER THAN AVERAGE DAYS
THURSDAY AND FRIDAY BEFORE A SIGNIFICANT WARM-UP FOR SATURDAY (HIGHS
ABOVE FREEZING FOR MOST?). OVERNIGHT TEMPERATURES WILL, OF COURSE,
BE ON THE COLD SIDE, ESPECIALLY THURSDAY NIGHT/FRIDAY MORNING, WITH
LOWS IN THE SINGLE DIGITS ABOVE ZERO. WINDS SHOULD REMAIN LIGHT AND
VARIABLE THOUGH, SO FRIGID WIND CHILLS AREN'T EXPECTED TO BE WORTHY
OF A COLD WEATHER HEADLINE. ADDITIONALLY, THERE AREN'T ANY NOTABLE
SIGNS OF PRECIPITATION, EVEN WITH A FEW MID-LEVEL IMPULSES MOVING
THROUGH AT TIMES. OVERALL, NOT MUCH ELSE OF NOTE IN THE
EXTENDED.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 535 AM CST TUE JAN 21 2025
VFR CONDITIONS ARE EXPECTED THROUGHOUT THE TAF PERIOD. WEST-
NORTHWEST WINDS AROUND 5 TO 10 KNOTS EARLY THIS MORNING WILL
GRADUALLY TURN MORE FROM THE SOUTHWEST THIS AFTERNOON AND REMAIN
FROM THE SOUTH THIS EVENING INTO EARLY WEDNESDAY MORNING. THESE
SOUTHERLY WINDS WILL STRENGTHEN TONIGHT, GUSTING BETWEEN 20 TO
30 KNOTS. LOW-LEVEL WIND SHEAR SHOULD ALSO DEVELOP BY MID- TO
LATE-EVENING TONIGHT AS A 40 TO 50 KNOT SOUTHWESTERLY LOW-LEVEL
JET DEVELOPS.
DVN WATCHES/WARNINGS/ADVISORIES
IA...EXTREME COLD WARNING UNTIL NOON CST TODAY FOR IAZ040>042-
051>054-063>068-076>078-087>089-098-099.
IL...EXTREME COLD WARNING UNTIL NOON CST TODAY FOR ILZ001-002-007-
009-015>018-024>026-034-035.
MO...EXTREME COLD WARNING UNTIL NOON CST TODAY FOR MOZ009-010.
SHORT TERM...SCHULTZ
LONG TERM...SCHULTZ
AVIATION...SCHULTZ
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page