530
FXUS63 KOAX 061007
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
407 AM CST THU MAR 6 2025
KEY MESSAGES
- WINTER STORM SYSTEM EXPECTED TO IMPACT THE FORECAST AREA LATER
TODAY INTO TONIGHT AND FRIDAY MORNING. SOME RAIN IS POSSIBLE
(20-30% CHANCE) LATE THIS MORNING INTO THE EARLY AFTERNOON
HOURS ACROSS THE FORECAST AREA.
- POPS PEAK AT 60-90% ACROSS OUR NORTHERN TIER OF COUNTIES IN
THE LATE AFTERNOON AND EVENING HOURS. PRECIP WILL START OUT AS
RAIN BEFORE A GRADUAL TRANSITION TO SNOW. A 50-60% CHANCE OF
GREATER THAN 4 INCHES OF SNOW EXISTS ACROSS THE FAR NORTH,
WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
- A WINTER WEATHER ADVISORY IS IN EFFECT FROM 9PM TONIGHT TO 6
PM FRIDAY FOR THE RESULTING SNOWFALL AND AREAS OF BLOWING
SNOW.
- A WARM UP TAKES SHAPE FOR THIS WEEKEND INTO NEXT WEEK, WITH
MINIMAL CHANCES FOR POPS ON WEDNESDAY.
DISCUSSION
ISSUED AT 402 AM CST THU MAR 6 2025
SHORT TERM
/TODAY THROUGH FRIDAY NIGHT/
GOES-16 NIGHTTIME MICROPHYSICS SHOWS GENERALLY CLEAR SKIES ACROSS A
LARGE CHUNK OF OUR FORECAST AREA EARLY THIS MORNING, ASIDE FROM SOME
LONE STRATUS ACROSS OUR FAR NORTHEAST. THIS IS QUITE THE CHANGE
COMPARED TO YESTERDAY AS THE POWERFUL STORM SYSTEM THAT BROUGHT SNOW
AND STRONG WINDS HAS MOVED AWAY TOWARD THE EASTERN CONUS/GREAT LAKES
AREA. MOST AREAS YESTERDAY SAW SOME SUNSHINE AS WELL WHICH HAS
HELPED MELT THE SNOWFALL/REFREEZE FROM THE AFOREMENTIONED STORM
SYSTEM.
OUR ATTENTION NOW TURNS TO ANOTHER DISTURBANCE APPROACHING FROM THE
COLORADO/ROCKIES AREA DURING THE DAY TODAY INTO FRIDAY. A SHORTWAVE
TROF ACROSS THE COLORADO/ROCKIES AREA, WHICH IS EMBEDDED WITHIN A
LONGWAVE TROF WHOSE BASE IS ACROSS THE CALIFORNIA/SW US AREA, WILL
CONTINUE TO AMPLIFY DURING THE DAY TODAY. LEE CYCLOGENESIS WILL
OCCUR IN CONJUNCTION WITH THIS AMPLIFYING SHORTWAVE AND WILL LEAD TO
OUR NEXT ROUND OF PRECIPITATION LATER TODAY. 700-500 MB QG FORCING
WILL BE ON THE INCREASE THIS MORNING INTO THE AFTERNOON HOURS, ALONG
WITH A SURGE OF THETA E ADVECTION ACROSS THE CENTRAL PLAINS REGION.
THE INITIAL SURGE OF MOISTURE LOOKS TO BE AROUND THE 700-500 MB
LEVELS AND ORIGINATES FROM THE SW US/PACIFIC AREA. THIS WILL PROVIDE
THE SOURCE OF MOISTURE FOR OUR POP CHANCES LATER THIS MORNING INTO
THE AFTERNOON HOURS. TEMPERATURES SEEN FROM FORECAST SOUNDINGS WILL
BE WARM ENOUGH TO SUPPORT RAINFALL WITH THIS INITIAL ACTIVITY.
DRY AIR IN THE LOW LEVELS MAY HAMPER RAINFALL, HOWEVER, AS
BUFKIT SOUNDINGS AND RAP CROSS-SECTIONS SHOW A DRY LAYER FROM
AROUND 900 MB TO JUST ABOVE 800 MB FESTERING FOR A LARGE PORTION
OF THE DAYTIME. THUS, HAVE OPTED TO KEEP POP CHANCES AT 20%-30%
FOR THIS INITIAL MORNING WAVE. ANY PRECIP BAND THAT FORMS WILL
MOVE NORTHEASTWARD DURING THE MORNING INTO THE AFTERNOON HOURS.
BY THE LATE AFTERNOON AND EVENING HOURS, WE START TO SEE A 50-
60 KT 850 MB LLJ PUMP IN GULF MOISTURE AS THE LOW ACROSS EASTERN CO
BEGINS TO DEEPEN IN STRENGTH AND MOVE EASTWARD. THIS INCREASE IN
MOISTURE COUPLED WITH SPEED CONVERGENCE SEEN AT THE NOSE OF THIS LLJ
AND THE QG LIFT WILL PROVIDE SOME EXTRA FUEL FOR THE NORTHEASTWARD
MOVING PRECIP BAND AND HELP IT EXPAND IN COVERAGE. THIS RESULTS IN
POP CHANCES INCREASING TO 60 TO 90%, PRIMARILY ACROSS THE NORTHERN
HALF OF OUR FORECAST AREA. THIS EXTRA SOURCE OF MOISTURE SHOULD HELP
OUT IN ELIMINATING THE DRY LAYER ACROSS THE NORTH. AGAIN, FOR THE
AFTERNOON HOURS, EXPECT TO SEE RAIN, WITH AMOUNTS BEING LIGHT AT
AROUND A FEW HUNDREDTHS OF AN INCH. TEMPERATURES WILL BEGIN COOLING
IN THE EVENING, SO EXPECT TO SEE A TRANSITION FROM RAIN TO SNOW.
FORECAST SOUNDINGS FROM BUFKIT ACROSS NORFOLK, O'NEIL, AND WAYNE
SHOW MODERATE TO STRONG LIFT (BETWEEN -10 TO -15 UBARS OF OMEGA)
WITHIN AN ALREADY SATURATED DGZ. THIS WILL LEAD TO EFFICIENT
SNOWFALL PRODUCTION, AND WHEN LOOKING AT SOME OF THE HREF GUIDANCE,
SOME MEMBERS HINT AT 1 INCH PER HOUR RATES ACROSS OUR FAR NORTH,
MAINLY ALONG OUR SERVICE AREA BORDER WITH NORTH PLATTE AND SIOUX
FALLS. GIVEN THE POTENTIAL FOR EFFICIENT SNOWFALL POTENTIAL, HAVE
CONTINUED THE SLIGHTLY UPWARD ADJUSTMENT OF SLRS FROM NBM GUIDANCE
TO RESEMBLE MORE OF WHAT THE COBB OUTPUT WAS SHOWING IN COORDINATION
WITH OUR NEIGHBORING WFOS.
REGARDING SNOWFALL AMOUNTS, A GENERAL SWATH OF 4-6 INCHES EXISTS
GENERALLY ALONG AND NORTH OF A LINE FROM BOONE TO BURT COUNTY TOWARD
THE SOUTH DAKOTA BORDER. WITHIN THIS ZONE, LOCALLY HIGHER AMOUNTS UP
TO 7 OR 8 INCHES ARE CERTAINLY NOT OUT OF THE QUESTION. MANY OF THE
HREF ENSEMBLE MEMBERS HINT AT SOME LOCATIONS ACROSS OUR FAR NORTH
HITTING OR EVEN SLIGHTLY EXCEEDING THIS CRITERIA, WITH 25TH TO 75TH
PERCENTILES SHOWING ANYWHERE FROM 5 TO 9 INCHES OF NEW SNOW
ACCUMULATION. SOME CAM GUIDANCE ALSO SHOWS A NARROW BAND OF HIGHER
SNOWFALL ACCUMULATIONS. THESE SCENARIOS ARE CERTAINLY PLAUSIBLE,
GIVEN MODEL CROSS SECTIONS TRY TO DEVELOP A NARROW BAND OF FGEN
WITHIN THE DEFORMATION ZONE OF THE SFC LOW. THIS BAND OF FGEN FORMS
SOMEWHERE ACROSS OUR FAR NORTHERN TIERS OF COUNTIES BORDERING THE
PREVIOUSLY MENTIONED WFOS. GIVEN THE UNCERTAINTY WITH HIGHER
SNOWFALL TOTALS ACROSS THESE AREAS, HAVE OPTED TO ISSUE A WINTER
WEATHER ADVISORY ACROSS PORTIONS OF NORTHEAST NEBRASKA INTO WEST
CENTRAL IOWA FROM 9 PM TONIGHT TO 6 PM FRIDAY EVENING FOR THIS
FORECAST PACKAGE. HOWEVER, GIVEN THE UNCERTAINTY IN WHERE THE NARROW
BAND OF HIGHER SNOWFALL TOTALS COULD FALL OVER OUR FAR NORTHERN TIER
OF COUNTIES, IT IS POSSIBLE THAT AN UPGRADE TO A WINTER STORM
WARNING MAY OCCUR FOR THE AFTERNOON FORECAST PACKAGE IF TRENDS
CONTINUE TO INDICATE HIGHER SNOWFALL TOTALS IN THE
AFOREMENTIONED AREA. WHILE WINDS WILL NOT BE AS STRONG/GUSTY
COMPARED TO OUR MOST RECENT WINTER STORM EVENT, NORTHWEST WINDS
OF 15-20 MPH WITH GUSTS UP TO 25 MPH MAY LEAD TO AREAS OF
BLOWING AND DRIFTING SNOW. THE FRIDAY MORNING COMMUTE WILL BE
IMPACTED BY THIS SYSTEM, SO THOSE TRAVELING IN THE AFFECTED
AREAS SHOULD TRAVEL SLOW AND CONTINUE TO MONITOR OUR FORECASTS
FOR THE LATEST INFORMATION. SNOWFALL WILL GRADUALLY COME TO AN
END FRIDAY EVENING FROM NORTH TO SOUTH AS THE SFC LOW DEPARTS
THE AREA.
LONG TERM
/SATURDAY THROUGH WEDNESDAY/
AFTER OUR SPELL OF RECENT WINTER WEATHER SYSTEMS, THE AREA WILL SEE
A BIT OF A BREAK AS 500 MB RIDGING BEGINS TO TAKE SHAPE ACROSS THE
WESTERN CONUS. THE ASSOCIATED 1000-500 MB THERMAL RIDGE WILL BEGIN
TO AMPLIFY AND STRENGTHEN THIS WEEKEND INTO THE START OF THE
UPCOMING WORK WEEK. THIS WILL LEAD TO TEMPERATURES WARMING INTO THE
40S AND 50S FOR SATURDAY, 50S TO 60S BY SUNDAY, AND A VERY WARM
MONDAY WITH HIGHS REACHING THE MID 60S NORTH TO UP TO EVEN 75F
ACROSS OUR VERY FAR SOUTHWEST! PRECIPITATION CHANCES LOOK MINIMAL AS
DOES CLOUD COVER DURING THIS PERIOD. BY TUESDAY INTO WEDNESDAY, THE
THERMAL RIDGE PATTERN STARTS TO BREAK DOWN DESPITE TEMPERATURES
REMAINING RATHER WARM IN THE 50S AND 60S. WHILE STILL SEVERAL DAYS
OUT, AN UPPER LEVEL LOW TRIES TO DEVELOP SOMETIME WEDNESDAY, WHICH
MAY LEAD TO OUR NEXT ROUND OF PRECIP, BUT NBM CURRENTLY HAS LESS
THAN 15% POPS FOR THE AREA AT THIS TIME.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1056 PM CST WED MAR 5 2025
CALMER WINDS TONIGHT GRADUALLY SHIFTING MORE WEST THEN
SOUTHERLY WITH TIME THROUGH THE OVERNIGHT HOURS. KOFK WILL BE
THE EXCEPTION AS WINDS THERE AND ACROSS NORTHEAST NEBRASKA
BECOME MORE NORTHWESTERLY. WE'LL SEE INCREASING HIGH CLOUDS
TOWARD DAYBREAK. WE SEE A MORE DISTINCT FRONTAL BOUNDARY SET UP
WEST TO EAST BETWEEN KOMA-KLNK AND KOFK AS WINDS FLIP TO
EASTERLY BY THURSDAY AFTERNOON WHILE WINDS TURN SOUTHEASTERLY AT
KOMA AND KLNK. CLOUDS WILL GRADUALLY LOWER AS A BAND OF RAIN
APPROACHES KOFK AND KOMA. KOMA WILL BE ON THE SOUTHERN FRINGE OF
THE PRECIPITATION BAND, WITH A BETTER CHANCE KLNK STAYS DRY
(40% CHANCE OF PRECIP). THIS RAIN WILL START TO TRANSITION OVER
TO SNOW AT KOFK NEAR THE END OF THE TAF PERIOD, WITH A
TRANSITION TO SNOW EXPECTED AT KOMA BEYOND THE END OF THIS TAF
PERIOD.
OAX WATCHES/WARNINGS/ADVISORIES
NE...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
FRIDAY FOR NEZ011-012-015>018-030>034-042>045.
IA...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST
FRIDAY FOR IAZ043-055-056.
DISCUSSION...CASTILLO/MEAD
AVIATION...MCCOY
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