054
FXUS63 KOAX 251703
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1103 AM CST SAT JAN 25 2025
KEY MESSAGES
- COOLER TEMPERATURES THROUGH THE WEEKEND, WITH POSSIBLY A FEW
FLURRIES THIS MORNING AND GUSTY NORTHWEST WINDS THIS AFTERNOON
- WARMER TEMPERATURES MONDAY THROUGH WEDNESDAY
- A MORE ACTIVE PATTERN WITH THE POTENTIAL, 15 TO 30% THURSDAY
INCREASING TO 30-50% FRIDAY, FOR WINTRY PRECIPITATION, WITH
THE 50-60% CHANCE OF ACCUMULATING SNOW.
DISCUSSION
ISSUED AT 357 AM CST SAT JAN 25 2025
ZONAL FLOW IN PLACE ACROSS THE FORECAST AREA THIS MORNING, WITH
UPPER AIR AND MODEL DATA INDICATING A 110-120 KT JET MOVING
ACROSS THE REGION. RADAR DETECTING LIGHT PRECIPITATION FROM
CENTRAL NEBRASKA TO NEAR THE MISSOURI RIVER, COINCIDENT WITH THE
RIGHT-REAR QUADRANT OF THE UPPER LEVEL JET. THUS FAR, SURFACE
OBSERVATIONS HAVE NOT CAPTURED ANY PRECIPITATION REACHING THE
GROUND, AND GIVEN THE DRY SUB-CLOUD LAYER IT'S LIKELY THAT
PRECIPITATION WILL SUBLIMATE BEFORE REACHING THE GROUND. DID
CARRY VERY LOW POP (10-12%) ACROSS SOUTHEAST NEBRASKA WITH
ISOLATED FLURRIES, BUT CONFIDENCE ANYTHING WILL MATERIALIZE IS
VERY LOW.
TODAY AND SUNDAY:
WILL DETERMINE WHETHER TO CARRY ANY FLURRIES IN FORECAST FOR
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA INTO THE LATE MORNING
HOURS. MAIN JET CORE WILL HAVE MOVED INTO THE MIDWEST BY 12PM,
AND LOW LEVEL DRY AND COLD ADVECTION MAY FURTHER UNDERCUT
PRECIPITATION. CONFIDENCE REMAINS VERY LOW (15%) ANYTHING WILL
REACH THE GROUND. AFTERNOON TEMPERATURES WILL BE ABOUT 10
DEGREES COOLER THAN THOSE SEEN ON FRIDAY. GIVEN NORTHWEST
COMPONENT OF THE WIND, DOWNSLOPE WARMING LESS LIKELY. HREF MEAN
EQUIVALENT TO THE 25 PERCENTILE OF NBM, WITH LEFT SKEW OF
INDIVIDUAL MEMBERS. THERE MAY BE SOME BIAS WITH NBM GIVEN
TEMPERATURES ON FRIDAY EXCEEDED 90 PERCENTILE, SO WILL TREND
TOWARD NBM MODE VERSUS MEDIAN WHICH REALIZES TO THE LOW 30S IN
NORTHEAST NEBRASKA TO THE UPPER 30S SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA. AS MENTIONED IN PREVIOUS FORECAST, EXPECT WINDS
TO BE RATHER GUSTY THIS AFTERNOON DUE TO KATABATIC EFFECT FROM
LOW- LEVEL COLD ADVECTION. GUSTS OF 30-35 MPH APPEAR LIKELY.
EXPECT TEMPERATURES TONIGHT TO FALL INTO THE SINGLE DIGITS
ACROSS NORTHEAST NEBRASKA AND NORTHWEST IOWA DUE TO A
COMBINATION OF H8 THERMAL TROUGH, PERSISTENT LOW LEVEL COLD
ADVECTION WITH LESS/THINNER CLOUD COVER. MORE CLOUDINESS IS
EXPECTED ACROSS SOUTHEAST NEBRASKA AND SOUTHWEST IOWA, THAT AND
WINDS BACK TO A MORE WESTERLY DIRECTION BY SUNRISE, SO THAT
MIGHT MITIGATE MAXIMUM COOLING. GENERALLY ACCEPTED NBM MEAN
VALUES IN THE LOWER TEENS IN THESE AREAS.
CLOUDS WILL THIN AS THE DAY PROGRESSES ON SUNDAY WITH WEAK
WESTERLY FLOW. H8 THERMAL TROUGH REMAINS ACROSS EXTREME EASTERN
NEBRASKA AND WESTERN IOWA. TEMPERATURES IN THESE LOCATIONS WILL
BE NEAR OR EVEN SLIGHTLY COOLER THAN THOSE ON SATURDAY,
GENERALLY THE LOW TO MIDDLE 30S. FURTHER WEST, A SLIGHT
INCREASE IN TEMPERATURES IS EXPECTED AS H8 RIDGING INCREASES,
WHERE TEMPERATURES NEAR 40 WILL BE POSSIBLE.
LESS CLOUD COVER IS EXPECTED SUNDAY NIGHT, BUT AS SURFACE HIGH
SINKS INTO SOUTHERN PLAINS, WINDS WILL BE COME MORE
SOUTHWESTERLY. THIS SHOULD KEEP OVERNIGHT TEMPERATURES FROM
PLUMMETING TOO LOW, WITH TEMPERATURES IN THE UPPER TEENS TO
LOWER 20S ANTICIPATED.
MONDAY AND TUESDAY:
TEMPERATURES WILL BE QUITE A BIT WARMER COMPARATIVELY THAN
THEY'VE BEEN OF LATE,WITH TEMPERATURES RISING INTO THE UPPER 40S
TO LOWER 50S. SOME MIXED SIGNALS ON HOW WARM IT WILL BECOME AS
A SHORTWAVE MOVING ACROSS THE GREAT LAKES REDUCES H8 HEIGHTS
ACROSS THE REGION WHILE H5 HEIGHTS INCREASE. OF THE TWO DAYS,
TUESDAY LOOKS TO BE THE WARMER. LOW TEMPERATURES WILL BE IN THE
20S.
WEDNESDAY THROUGH FRIDAY:
ANOTHER SHORTWAVE DIVES ACROSS THE NORTHERN PLAINS INTO THE
UPPER MIDWEST ON WEDNESDAY, WITH ANOTHER SURGE OF LOW LEVEL COLD
ADVECTION EXPECTED. TEMPERATURES WILL BE 5-10 DEGREES COOLER ON
WEDNESDAY AS A RESULT. THERE IS A WEAK SIGNAL THAT AS A SERIES
OF UPPER LEVEL JET STREAKS DIVE ALONG THE PERIPHERY OF THE UPPER
TROUGH, A NARROW BAND OF MOIST MID-LEVEL FRONTOGENESIS COULD
DEVELOP AND SQUEEZE OUT SPRINKLES OR LIGHT RAIN. THE DRY LOW
LEVELS MAY MITIGATE ANY PRECIPITATION REACHING THE GROUND.
THURSDAY WILL BE A TRANSITION DAY AS THE EASTERN U.S. TROUGH
MOVES EAST AND ALLOWS FOR CUT-OFF SHORTWAVE TROUGH IN THE DESERT
SOUTHWEST TO BEGIN LIFTING INTO THE SOUTHERN PLAINS.
TEMPERATURES WILL BE A FEW DEGREES COOLER, BUT STILL IN THE 40S
FOR HIGHS.
PRECIPITATION CHANCES INCREASE LATE THURSDAY INTO EARLY
SATURDAY. TIMING DIFFERENCES REMAIN BETWEEN THE OPERATIONAL
GFS, CMC AND EC, WITH ALL MOVING A CLOSED UPPER LOW ACROSS THE
SOUTHERN PLAINS, THOUGH THE GFS NOW IS TAKING A MORE NORTHWEST
TRACK. CLUSTERS CONTINUE TO FAVOR EC TRACK, BUT SLOWER THAN THE
OPERATIONAL EC. THE TRACK OF THE UPPER LOW WILL DETERMINE THE
PRECIPITATION TYPE DURING ONSET PERIOD. A MORE NORTHWEST TRACK
WILL LEAD TO INITIAL MIXED PHASED PRECIPITATION, WITH CONVECTIVE
ELEMENTS. A SOUTHERN TRACK, THE MORE FAVORED BY ENSEMBLE
CLUSTERING, WOULD KEEP FORECAST AREA ON THE COLD SIDE OF ANY
UPPER AND SURFACE LOW TRACK. THUS, PRECIPITATION TYPE LIKELY
WOULD BE ALL SNOW. CURRENTLY THE 25-75 PERCENT SNOWFALL RANGE IN
THE 1 TO 3 INCH RANGE, WITH THE 75 TO 95 PERCENTILE AMOUNTS IN
THE 4 TO 6 INCH RANGE.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1049 AM CST SAT JAN 25 2025
GUSTY NORTHWEST WINDS OF 22 TO 34 KTS ARE LIKELY THROUGH 00Z,
WITH STRONGEST WINDS AT OFK. EXPECT SCT/BKN BETWEEN 028 AND 035
FEET AT OFK, AND POSSIBLY AT OMA THIS AFTERNOON, BUT SHOULD
REMAIN MAINLY VFR. WINDS WEAKEN AFTER 00Z, AND BECOME LIGHT OUT
OF THE WEST AROUND SUNRISE WITH VFR CONDITIONS LIKELY.
OAX WATCHES/WARNINGS/ADVISORIES
NE...NONE.
IA...NONE.
DISCUSSION...FORTIN
AVIATION...BARJENBRUCH
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