270  
FXUS65 KRIW 171711  
AFDRIW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE RIVERTON WY  
1111 AM MDT FRI APR 17 2026  
   
KEY MESSAGES
 
 
- STEADY SNOW ENDS THIS MORNING. OTHERWISE, RATHER COOL TODAY  
WITH A SCATTERING OF SNOW SHOWERS, ESPECIALLY IN THE  
AFTERNOON.  
 
- QUITE COLD TONIGHT WITH A HARD FREEZE FOR MOST LOCATIONS EAST  
OF THE DIVIDE.  
 
- DRY AND TRANQUIL WEATHER EXPECTED FROM SATURDAY THROUGH EARLY  
NEXT WEEK, WITH ABOVE NORMAL TEMPERATURES RETURNING SUNDAY AND  
ESPECIALLY FROM MONDAY THROUGH WEDNESDAY.  
 

 
   
DISCUSSION
 
 
ISSUED AT 135 AM MDT FRI APR 17 2026  
 
SCORE ONE FOR THE GFS YESTERDAY. IT HAD THE AREA OF SNOW FROM THE  
FREMONT / NATRONA COUNTY LINE TO CASPER NAILED DOWN FAIRLY WELL.  
SOME SNOW IS CONTINUING THIS MORNING AS I WRITE THIS AROUND 1 AM AND  
WILL CONTINUE IN EASTERN PORTIONS OF THE AREA THROUGH THE NIGHT BUT  
IT APPEARS THE HEAVIEST SNOW HAS COME TO AN END. WE WILL LIKELY  
EXPIRE MOST OF THE ADVISORIES AT 6 AM AND LIKELY CANCEL THE WIND  
RIVER RANGE AS MOST GUIDANCE SHOWS THE HEAVY SNOW JUST ABOUT OVER.  
WE WILL LEAVE NATRONA COUNTY UP FOR NOW, GIVEN IT HAS BEEN THE  
CENTER OF THE HEAVIEST SNOW AND ROADS SHOULD REMAIN SLICK UNTIL THE  
STRONG MID APRIL SUN CAN MELT THEM OFF THROUGH THE MORNING.  
 
THE MAIN STORY TODAY WILL BE THE MUCH COLDER TEMPERATURES WHEN  
COMPARED THE PREVIOUS SEVERAL DAYS. WITH AREAS THAT SAW SNOW, LIKE  
CASPER, STRUGGLING TO GET OUT OF THE 30S. AND, WITH MOIST NORTHWEST  
FLOW REMAINING AS WELL AS CYCLONIC CURVATURE OVER THE AREA, THERE  
WILL BE SOME CONVECTIVE SNOW SHOWERS AROUND THE AREA AND POSSIBLY A  
FEW SNOW BANDS. THESE ARE ALMOST IMPOSSIBLE TO PINPOINT BUT MOST  
AREAS WILL HAVE AT LEAST A 1 IN 5 CHANCE OF ONE. ACCUMULATIONS  
SHOULD REMAIN LIGHT, WITH A LESS THAN 1 IN 10 CHANCE OF 3 INCHES OR  
MORE EVEN IN THE MOUNTAINS, WITH MOST LOCATIONS RECEIVING LESS THAN  
AN INCH. AT THIS TIME, TRAVEL CONCERNS FROM THEM SHOULD BE MINIMAL,  
AS THE STRONG SUN ANGLE SHOULD KEEP ROADS MAINLY WET UNLESS THE SNOW  
PERSISTS.  
 
THESE SNOW SHOWERS SHOULD DECREASE AS WE LOSE THE HEATING OF THE  
DAY, WITH MOST ENDING BY MIDNIGHT. THE CONCERN THEN TURNS TO THE  
COLD TEMPERATURES. WE STILL LOOK TO HAVE A WIDESPREAD FREEZE ACROSS  
MANY LOCATIONS EAST OF THE DIVIDE. WE WILL CONTINUE THE FREEZE  
WARNINGS IN THE ZONES THAT ALREADY HAVE THEM. WE WILL LIKELY NEED  
THEM IN OTHER ZONES BUT WILL LET THE DAY SHIFT DO THAT AFTER THE  
WINTER WEATHER ADVISORIES ARE OVER. EXPECTED LOW TEMPERATURES HAVE  
COME UP A BIT IN THE AREA WITH LITTLE SNOW, BUT MOST LOCATIONS STILL  
HAVE A GREATER THAN 4 OUT OF 5 CHANCE OF LOW TEMPERATURES BELOW 25  
DEGREES. EXACTLY HOW COLD IT DOES GET WILL HAVE TO DO WITH HOW  
QUICKLY THE SKY CAN CLEAR, AND THERE IS STILL SOME UNCERTAINTY WITH  
THIS.  
 
MORE TRANQUIL WEATHER SHOULD THEN BE THE RULE FOR AT LEAST THE NEXT  
4 DAYS AS RIDGING BUILDS ACROSS THE NORTHERN ROCKIES. TEMPERATURES  
WILL BEGIN TO REBOUND. SATURDAY LOOKS NEAR TO BELOW NORMAL, BUT THEN  
MUCH WARMER TEMPERATURES MOVE IN FOR SUNDAY AND THROUGH AT LEAST  
WEDNESDAY. MONDAY AND TUESDAY LOOK ESPECIALLY WARM, WITH SOME OF THE  
WARMER SPOTS MAKING A RUN AT 80 DEGREE HIGH TEMPERATURES. THE ONLY  
CONCERN WOULD BE POSSIBLE ELEVATED FIRE WEATHER, ESPECIALLY IN AREAS  
FAVORED TO SOUTHWESTERLY BREEZES, LIKE CASPER. SATURDAY LIKELY WON'T  
BE A PROBLEM WITH THE SNOW BRINGING SOME NEEDED MOISTURE, BUT  
POSSIBLE SUNDAY AND EARLY INTO NEXT WEEK, ESPECIALLY WEDNESDAY. THE  
NEXT POTENTIAL WEATHER MAKER IS AN UPPER LEVEL LOW THAT WILL MOVE  
INTO THE PACIFIC NORTHWEST ON TUESDAY AND MOVE TOWARD THE AREA FOR  
THE MIDDLE OF THE WEEK. THERE HAS BEEN POOR MODEL CONSISTENCY IN  
REGARDING THE LOW, SO DETAILS ARE IMPOSSIBLE TO PREDICT AT THIS  
TIME. HOWEVER, THIS LOOKS TO BE OUR NEXT CHANCE OF PRECIPITATION FOR  
THE MIDDLE OR END OF NEXT WEEK.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
 
 
ISSUED AT 1100 AM MDT FRI APR 17 2026  
 
VFR CONDITIONS EXPECTED AS ANY LINGERING SNOW HAS PUSHED EAST OF  
CPR. IMPROVING SKIES IN THE AFTERNOON WITH BREEZY WINDS AT  
BPI/COD/LND/PNA/RKS UP TO 18-25KTS THROUGH SUNSET, DIMINISHING  
AFTER 01-03Z. POSSIBLE FOG AT CPR SATURDAY MORNING DUE TO THE  
RECENT SNOWFALL WITH LOW STRATUS EXPECTED AT JAC OFF THE NEARBY  
LAKES AND COLDER TEMPERATURES. OTHERWISE, MAINLY CLEAR SATURDAY  
WITH INCREASING WINDS BY 16Z FOR COD/CPR/RIW/RKS HEADING INTO  
THE NEXT TAF CYCLE.  
 
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 WARNING UNTIL 9 AM MDT SATURDAY FOR WYZ003>006-017-018.  
 

 
 

 
 
DISCUSSION...HATTINGS  
AVIATION...LOWE  
 
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