285
FXUS65 KRIW 040500
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1100 PM MDT SUN MAY 3 2026
KEY MESSAGES
- VIRGA SHOWERS, MOVING TO THE SOUTHEAST, WILL END THROUGH THE
EVENING. A BRIEF GUST UP TO 40 MPH WILL REMAIN POSSIBLE FROM
THESE PASSING SHOWERS.
- THE NEXT WEATHER SYSTEM MOVES ACROSS THE STATE MONDAY AND
TUESDAY, BRINGING A BETTER OPPORTUNITY FOR RAIN AND SNOW.
CONFIDENCE REMAINS LOW IN RAINFALL AND SNOWFALL AMOUNTS.
- FREEZE WATCHES NOW IN EFFECT FOR LOWER ELEVATIONS EAST OF THE
CONTINENTAL DIVIDE TUESDAY NIGHT INTO WEDNESDAY MORNING.
DISCUSSION
ISSUED AT 211 AM MDT SUN MAY 3 2026
THE MORE PROGRESSIVE PATTERN CONTINUES ACROSS THE NORTHERN
ROCKIES DURING THE NEXT WEEK. TODAY WILL START WITH SOME HIGH
CLOUDS AND WARM TEMPERATURES REACHING THE 60S AND 70S. THE
APPROACH OF THE NEXT WEATHER SYSTEM WILL BRING ENOUGH
INSTABILITY TODAY FOR SOME SHOWER ACTIVITY ALONG THE HIGHER
REACHES OF THE ABSAROKAS AND BIGHORNS. WHILE MOISTURE HAS
STARTED TO INCREASE ACROSS NORTHERN WY IN THE PAST 24 HOURS,
THERE STILL ISN'T A WHOLE LOT TO PRODUCE MUCH ACCUMULATION WITH
SHOWERS TODAY.
THE MAIN SYSTEM ITSELF WILL BEGIN TO IMPACT WYOMING MONDAY
MORNING, AS A FRONT SWEEPS IN FROM THE NORTH. THE FIRST PUSH
SHOULD REACH THE NORTHERN WY/MT BORDER RIGHT AROUND SUNRISE
MONDAY, AND REACHES AROUND THE CONTINENTAL DIVIDE BY 18Z, BEFORE
SPREADING SOUTHWEST LATE IN THE AFTERNOON. THE FRONT WILL BRING
ALONG VALLEY RAIN AND MOUNTAIN SNOW BEHIND IT, SPREADING
SOUTHWARD THROUGH THE DAY. MOST AREAS SHOULD RECEIVE A GOOD
WETTING RAIN, BUT SOME SHADOWING ACROSS THE BIGHORN BASIN MAY
KEEP AMOUNTS THERE TO A MINIMUM. WITH THE FRONT STRETCHED ALONG
THE SOUTHERN WY BORDER DURING THE EVENING, BEST OPPORTUNITY FOR
RAINFALL WOULD BE FOCUSED FROM THE WINDS EAST ALONG THE GREENS
AND CASPER MOUNTAIN. RAIN DECREASES LATE MONDAY NIGHT INTO
TUESDAY, BUT A BRIEF SECONDARY NORTH WIND PUSH WILL KEEP VERY
LIGHT RAIN/SNOW GOING FOR ALL EXCEPT FOR THE BIGHORN BASIN AND
THE NW PARKS DURING THE DAY TUESDAY. CURRENT ACCUMULATION
NUMBERS HAVE REMAINED STEADY FOR A COUPLE TENTHS FOR THE
SOUTHERN 2/3 OF THE STATE, WITH THE HIGHEST BAND NEAR A HALF
INCH FOR THE WINDS EAST TO CASPER MOUNTAIN. MODELS HAVE NUDGED
AMOUNTS DOWNWARD SLIGHTLY SINCE YESTERDAY, AND WITH THE LAST
COUPLE EVENTS THE MODELS HAVE OVERESTIMATED FINAL TOTALS, SO
CURRENT TOTALS MAY BE A BIT HIGH.
ONCE THIS SYSTEM SWEEPS SOUTHEAST EARLY WEDNESDAY, UPPER LEVEL
PATTERN REMAINS FROM THE NORTHWEST, SO WHILE TEMPERATURES WILL
RETURN TO THE 60S AND 70S, WEAK EMBEDDED IMPULSES MAY BRING
LIGHT HEATING-OF-THE-DAY SHOWERS TO THE NORTHERN MOUNTAINS
THROUGH THE REST OF THE WEEK.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1100 PM MDT SUN MAY 3 2026
VFR CONDITIONS TO START THE PERIOD ACROSS ALL TERMINALS. HOWEVER, A
NEARING COLD FRONT WILL START TO BRING IMPACTS TO TERMINALS STARTING
AS EARLY AS 12-15Z MONDAY. NORTHERLY TERMINALS SUCH AS KCOD AND KWRL
SEE WINDS INCREASE AROUND THIS TIME ALONG WITH LOWERING CEILINGS TO
NEAR MVFR. GUSTY NORTHERLY WINDS OF 20-30 KNOTS WILL GRADUALLY PUSH
SOUTH THROUGH THE DAY MAKING IT TO CENTRAL TERMINALS BY AROUND 18Z.
DEVELOPMENT OF SHOWERS WILL OCCUR AHEAD OF THE FRONT IN THE
AFTERNOON WITH NEARLY ALL TERMINALS HAVING A CHANCE AROUND A 20-40%
FOR A BRIEF SHOWER FROM 18Z MONDAY THROUGH 00Z TUESDAY. AN ISOLATED
THUNDERSTORM OR TWO CANNOT BE RULED OUT WITH TERMINALS WEST OF THE
DIVIDE HAVING THE BEST CHANCES. THE MAIN CONCERNS AS A RESULT OF ANY
SHOWERS WILL BE GUSTY OUTFLOW WINDS OF 25-35 KNOTS. A SECOND ROUND
OF PRECIPITATION LOOKS POSSIBLE AFTER 00Z TUESDAY IN ASSOCIATION
WITH THE COLD FRONT PASSAGE. PROB30 GROUPS HAVE BEEN ADDED TO
NUMEROUS TERMINALS WITH SOME SEEING SHOWERS WHILE OTHERS MAY SEE A
PERIOD OF PREVAILING PRECIPITATION TO END THE TAF PERIOD.
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZDV AND
ZLC FOR THE LATEST INFORMATION ON ICING AND TURBULENCE
FORECASTS.
RIW WATCHES/WARNINGS/ADVISORIES
FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
FOR WYZ003>006-010-011-017-018-020.
DISCUSSION...STRAUB
AVIATION...DZIEWALTOWSKI
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