121
FXUS63 KDMX 150540
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1140 PM CST TUE JAN 14 2025
...UPDATED FOR THE 06Z AVIATION DISCUSSION...
KEY MESSAGES
- COLD CONTINUES TONIGHT INTO TOMORROW MORNING, THEN WARMER
TOMORROW. CHANCE FOR A FEW FLURRIES NORTHEAST TOMORROW
AFTERNOON AND EVENING.
- NEAR TO ABOVE NORMAL TEMPERATURES THURSDAY AND FRIDAY
- FRIGID COLD SETS BACK IN SATURDAY THROUGH MONDAY, WITH
OVERNIGHT & MORNING WIND CHILLS IN THE TWENTIES TO TEENS
BELOW ZERO THROUGH THAT PERIOD.
DISCUSSION
ISSUED AT 231 PM CST TUE JAN 14 2025
THE LIGHT SNOW THAT PASSED THROUGH THE AREA LAST NIGHT BROUGHT
MOSTLY A DUSTING OF SNOW TO THE AREA, BUT DID MANAGE TO DROP A
CORRIDOR OF HIGHER AMOUNTS IN THE 1 TO 2 INCH RANGE OVER NORTH
CENTRAL IOWA. THAT BEING SAID, ANY REMNANTS OF THIS WAVE HAVE
LEFT THE STATE, LEAVING CLEAR SKIES AND COLD TEMPERATURES IN
IT’S WAKE. TEMPERATURES REMAIN IN THE SINGLE DIGITS OVER MUCH OF
CENTRAL IOWA BY MID-DAY TODAY WITH WIND CHILLS IN THE TEENS TO
SINGLE DIGITS BELOW ZERO. A FEW MORE DEGREES OF WARMING ARE
EXPECTED OVER THE NEXT FEW HOURS, BUT OTHERWISE TEMPERATURES
REMAIN COLD INTO TONIGHT. SURFACE HIGH PRESSURE WILL ALLOW WINDS
TO CALM OVERNIGHT, WHICH WILL HELP MITIGATE EXTREME WIND CHILL
VALUES. HOWEVER, LIGHT WINDS WILL ALSO BE MORE CONDUCIVE FOR
RADIATIONAL COOLING, ESPECIALLY WITH APPROACHING CLOUD COVER
LOOKING TO HOLD OFF UNTIL EARLY TOMORROW MORNING. FOR THIS
REASON, HAVE KNOCKED TONIGHT’S LOWS A FEW DEGREES LOWER THAN NBM
AND MODEL CONSENSUS, ESPECIALLY OVER NORTHERN IOWA.
WHILE TEMPERATURES WILL BE FRIGID AGAIN TONIGHT, THE HIGH
PRESSURE CONTINUES TO DRIFT THROUGH, SWITCHING WINDS TO A MORE
SOUTHERLY COMPONENT AND INTRODUCING MORE WARM AIR ADVECTION BY
TOMORROW. THIS WILL HELP TO BOOST TEMPERATURES UP A BIT THROUGH
THE DAY TOMORROW, TAKING HIGHS INTO THE 20S TO NEAR 30 IN THE
WEST. OUR CHANGE IN PATTERN COMES AS A WEAK UPPER TROUGH PASSES
THROUGH THE GREAT LAKES REGION, PULLING SURFACE LOW PRESSURE TO
THE NORTH AND EAST OF THE STATE. PRESSURE GRADIENTS TIGHTEN AS
THIS LOW PASSES NEARBY, WHICH WILL ALSO RESULT IN BREEZY
CONDITIONS TOMORROW, ESPECIALLY IN NORTHERN IOWA. WE’LL ALSO SEE
A WEAK BOUNDARY PASSAGE MOVE THROUGH IN THE AFTERNOON AND
EVENING. THIS WILL SWITCH WINDS TO A MORE NORTHWESTERLY
COMPONENT TOMORROW NIGHT, AS WELL AS BRING THE POTENTIAL FOR A
FEW FLURRIES TO NORTHEAST IOWA. MODEL SOUNDINGS AREN’T OVERLY
FAVORABLE FOR SNOWFALL, WITH WEAK LIFT AND PLENTY OF DRY AIR IN
THE COLUMN. THAT SAID, THERE DOES LOOK TO BE A BRIEF PERIOD
WHERE THE COLUMN ATTEMPTS TO SATURATE JUST ABOVE THE SURFACE
INVERSION, WHICH COULD SQUEEZE OUT A FEW FLAKES TOMORROW
EVENING. HOWEVER, WITH DRY AIR STILL IN PLACE AT THE SURFACE,
MEASURABLE ACCUMULATIONS ARE NOT EXPECTED.
AFTER THIS FRONTAL PASSAGE, LOW PRESSURE DEPARTS THE AREA WITH
A BRIEF PERIOD OF SURFACE RIDGING THURSDAY. HOWEVER, ANOTHER
TROUGH APPROACHES THE AREA THURSDAY NIGHT INTO FRIDAY AND FLIPS
FLOW BACK SOUTHERLY. THIS PROGRESSION WILL BRING UNSEASONABLY
WARM TEMPERATURES ON THURSDAY AND ESPECIALLY FRIDAY, AS HIGHS
CLIMB INTO THE UPPER 30S ON THURSDAY AND LOW TO MID 40S ON
FRIDAY. PRECIPITATION CHANCES FOR FRIDAY NIGHT INTO SATURDAY
CONTINUE TO TREND FURTHER SOUTH AND EAST, WITH MOST MODELS NOW
KEEPING ALL OF THE RAIN OUTSIDE OF THE STATE. THEREFORE, WILL
CONTINUE TO MONITOR PRECIPITATION CHANCES IN OUR SOUTHEAST BUT
THE CURRENT FORECAST REMAINS DRY.
DON’T GET TOO ATTACHED TO THE ABOVE NORMAL TEMPERATURES TO END
THE WORK WEEK, BECAUSE TEMPERATURES WILL PLUMMET AGAIN THIS
WEEKEND AND INTO EARLY NEXT WEEK. A BROAD UPPER TROUGH BEGINS TO
BUILD OVER THE US, BRINGING A SIGNIFICANT PUSH OF COLD AIR INTO
MUCH OF THE CONUS. LOCALLY, THIS WILL COME ON THE BACKSIDE OF A
BOUNDARY PASSING THROUGH LATE IN THE DAY ON FRIDAY BRINGING A
STEADY STREAM OF NORTHWESTERLY FLOW AND COLD AIR ADVECTION THAT
PERSISTS THROUGHOUT THE WEEKEND. SATURDAY WILL BE THE
“TRANSITION” DAY WHERE HIGHS ONLY REACH THE TEENS, FOLLOWED BY
THE “COLD” DAYS ON SUNDAY AND MONDAY WHERE HIGHS ONLY REACH THE
SINGLE DIGITS ACROSS THE AREA. OVERNIGHT LOWS WILL BE EVEN
COLDER, WITH TEMPERATURES FALLING INTO THE SINGLE DIGITS BELOW
ZERO MULTIPLE NIGHTS IN A ROW, WITH THE COLDEST NIGHT BEING
SUNDAY NIGHT INTO MONDAY MORNING. IN ADDITION TO THE COLD
TEMPERATURES, CAA AND TIGHTENED PRESSURE GRADIENTS WILL RESULT
IN BREEZY CONDITIONS THROUGH THE WEEKEND, DROPPING WIND CHILLS
DOWN EVEN MORE. AGAIN, THIS WILL BE MOST SIGNIFICANT IN THE
OVERNIGHTS, WITH WIND CHILLS IN THE TWENTIES BELOW ZERO
POSSIBLE OVER THE NORTHERN HALF OF THE STATE AND TEENS BELOW
ZERO FURTHER SOUTH, MAKING FOR SOME BITTERLY COLD MORNINGS
SUNDAY, MONDAY AND TUESDAY. FORTUNATELY, SOME MODERATION IN
TEMPERATURES IS EXPECTED AS WE GET INTO THE MIDDLE OF NEXT WEEK.
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 1140 PM CST TUE JAN 14 2025
VFR CONDITIONS ARE STILL FORECAST TO BE WIDESPREAD FOR THE
DURATION OF THE PERIOD. UNRESTRICTED VISIBILITIES ARE EXPECTED
WITH VFR CEILINGS OVERHEAD AS MID LEVEL CLOUDS PASS OVER THE
STATE. SURFACE WINDS START LIGHT AND VARIABLE WITH SURFACE
RIDGING OVERHEAD TONIGHT. WINDS INCREASE QUICKLY ON WEDNESDAY
FROM THE SOUTHWEST AND BECOME GUSTY BY AFTERNOON.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...DODSON
AVIATION...COGIL
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