637
FXUS65 KGJT 211710
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1010 AM MST SAT DEC 21 2024
KEY MESSAGES
- UNSEASONABLY WARM AND DRY CONDITIONS CONTINUE INTO THE
WEEKEND WITH HIGH PRESSURE OVERHEAD.
- A MUCH MORE ACTIVE WEATHER PATTERN ARRIVES NEXT WEEK
PROVIDING PERIODIC SNOWFALL CHANCES.
- SNOWFALL COULD IMPACT TRAVEL IN THE MOUNTAINS LATE SUNDAY
NIGHT INTO MONDAY AND AGAIN ON WEDNESDAY.
SHORT TERM /THROUGH SUNDAY/
ISSUED AT 305 AM MST SAT DEC 21 2024
HIGH PRESSURE REMAINS OVERHEAD TODAY THROUGH TOMORROW AFTERNOON
LEADING TO SEASONABLY WARM AND DRY CONDITIONS. TEMPERATURES WILL
CONTINUE TO RUN 10 TO 15 DEGREES ABOVE NORMAL WITH THE
EXCEPTION OF THE INVERTED, SNOW-COVERED HIGH VALLEYS.
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/
ISSUED AT 305 AM MST SAT DEC 21 2024
A MUCH MORE ACTIVE WEATHER PATTERN SETS UP NEXT WEEK AS A TRAIN OF
SHORTWAVE TROUGHS AND AN UPTICK IN MOISTURE COMBINE TO PROVIDE
PERIODIC PRECIPITATION CHANCES. WITH PWATS 200% OF NORMAL MOVING
INTO THE INTERMOUNTAIN WEST SUNDAY PM, FLURRIES/LIGHT SNOW
CANNOT BE RULED OUT NORTH OF I-70 MAINLY DUE TO OROGRAPHIC LIFT.
LITTLE, IF ANY, ACCUMULATION IS ANTICIPATED DUE TO A LACK OF
UPPER-LEVEL SUPPORT.
THE UPPER-LEVEL DYNAMICS GET MORE INTERESTING ON MONDAY WITH A
WEAK SHORTWAVE TROUGH SET TO PROPAGATE ACROSS THE FORECAST AREA.
TRENDS OVER THE LAST 24 HOURS HAVE INDICATED THAT THE TROUGH
MAY PASS FURTHER SOUTH THAN PREVIOUSLY THOUGHT LEADING TO
INCREASING PRECIPITATION CHANCES IN THE MOUNTAINS SOUTH OF I-70.
MODELS HAVE ALSO COME INTO BETTER AGREEMENT WITH THE TIMING OF
THIS SYSTEM WITH THE THROUGH PASSING THROUGH MONDAY AFTERNOON
AND EVENING, ALTHOUGH LIGHT SNOW WILL LIKELY GET STARTED EARLY
MONDAY MORNING. WHILE WE ARE STILL WAITING ON HI-RES GUIDANCE,
THE GLOBAL ENSEMBLES SUPPORT UP TO 4-6" IN THE NORTHERN
MOUNTAINS WITH LIGHT MOUNTAIN SNOW UP TO A FEW INCHES ELSEWHERE.
SLIPPERY STRETCHES WILL DEVELOP ON SNOW-COVERED ROADS,
ESPECIALLY OVER MOUNTAIN PASSES. DRIER AIR MOVES IN BEHIND THE
TROUGH LEADING TO A LULL IN PRECIPITATION LATE MONDAY NIGHT AND
TUESDAY.
A MORE ORGANIZED TROUGH ARRIVES EARLY WEDNESDAY. GUIDANCE
CONTINUES TO INDICATE THAT THIS SYSTEM WILL PROVIDE WIDESPREAD
PRECIPITATION CHANCES. HOWEVER, PWATS 150-175% OF NORMAL WILL
MAKE IT HARD TO PRODUCE HIGHER SNOWFALL AMOUNTS. IN GENERAL,
LIGHT MOUNTAIN SNOW AND PERIODS OF VALLEY RAIN AND LIGHT SNOW
ARE POSSIBLE WEDNESDAY AND COULD LEAD TO SLIPPERY HOLIDAY
TRAVEL.
THE ACTIVE PATTERN CONTINUES WITH THE PASSAGE OF YET ANOTHER
TROUGH ON FRIDAY, ALMOST A RINSE AND REPEAT OF THE MID-WEEK
SYSTEM. CONTINUE TO STAY WEATHER AWARE HEADING INTO THE NEW WEEK
AS THE DETAILS OF THESE DISTURBANCES MAY EVOLVE OVER TIME.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1009 AM MST SAT DEC 21 2024
LIGHT, TERRAIN-DRIVEN WINDS AMIDST REGION-WIDE VFR CONDITIONS
ARE EXPECTED ONCE AGAIN THROUGHOUT THE TAF PERIOD.
GJT WATCHES/WARNINGS/ADVISORIES
CO...NONE.
UT...NONE.
SHORT TERM...KAA
LONG TERM...KAA
AVIATION...TGJT
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