844
FXUS65 KRIW 120007
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
607 PM MDT SAT JUL 11 2026
KEY MESSAGES
- THE HEAT WAVE HAS BEGUN. OVERNIGHT LOWS WILL BE ABOUT 10 TO 15
DEGREES ABOVE NORMAL AND HUMIDITY RECOVERY WILL BE VERY POOR
FOR MOST LOCATIONS. HEAT WILL CONTINUE THROUGH AT LEAST
TUESDAY.
- SUNDAY WILL BE THE HOTTEST DAY WITH SOME ALL-TIME STATION
RECORD HIGHS LIKELY PUSHING 110 DEGREES.
- ELEVATED TO NEAR CRITICAL FIRE WEATHER IS LIKELY THE NEXT FOUR
DAYS. CRITICAL FIRE WEATHER IS LIKELY SUNDAY AFTERNOON AND
ONCE AGAIN ON TUESDAY AFTERNOON.
UPDATE
ISSUED AT 1200 PM MDT SAT JUL 11 2026
NO CHANGES WITH THE FORECAST. IR SHOWS CLEAR SKIES OVER MUCH OF
THE STATE WITH DRY CONDITIONS EXPECTED FOR THE WEEKEND.
WIDESPREAD TRIPLE DIGITS EXPECTED THIS AFTERNOON AND EVEN A BIT
HOTTER FOR SUNDAY. SIMILAR TEMPERATURES FOR MONDAY AND TUESDAY
AS SATURDAY A COUPLE DEGREES BUT A FEW DEGREES LESS HEADING INTO
THE REST OF THE WORK WEEK AS STORM CHANCES INCREASE AS WELL.
DISCUSSION
ISSUED AT 219 AM MDT SAT JUL 11 2026
I DO NOT HAVE THE TRADITIONAL PATH FOR A METEOROLOGIST: 4 YEARS
OF COLLEGE RIGHT OUT OF HIGH SCHOOL. LET US SAY IT HAS BEEN A
BIT OF A WAVY ROUTE FOR THIS CAREER. I DROPPED OUT OF COLLEGE
FOR A WHILE TO WORK SOME BLUE COLLAR JOBS. AND WITH THE WEATHER
COMING UP THE NEXT FEW DAYS, IT REMINDS ME OF A COUPLE OF THEM.
ONE IS ROOFING, WHICH I DID NORTH CAROLINA DURING A COUPLE OF
SUMMERS, INCLUDING USING TORCHES. ANOTHER WAS WORKING IN A
LIQUID PACKAGING PLANT, IN THE EXTRUDER DEPARTMENT, WHERE WE HAD
4 OF THEM RUNNING AT 500 DEGREES TO PUT COATING ON CARTONS. AS
YOU WOULD EXPECT, THESE JOBS WERE HOT. AND THE TEMPERATURES THE
NEXT FEW DAYS WILL LET ME FLASHBACK TO THESE JOBS I WORKED
ALMOST 30 YEARS AGO (YES, I'M OLD). WE HAVE TWO MAIN HAZARDS,
HEAT AND FIRE WEATHER, AND WE WILL COVER EACH OF THESE
SEPARATELY.
HEAT...THIS WILL BE MOST WIDESPREAD HAZARD. WE HAVE CONTINUED THE
EXCESSIVE HEAT WARNING AS IS FOR NOW. I COULD SEE EXTENDING IT
ANOTHER DAY THROUGH TUESDAY, BUT WE WILL HOLD OFF FOR NOW.
REASONING REMAINS THE SAME, WITH A RIDGE OF HIGH PRESSURE OVER
THE DESERT SOUTHWEST BUILDING NORTHWARD THROUGH THE WEEKEND,
ENDING UP CENTERED OVER THE NORTHERN ROCKIES FOR THE WEEKEND,
WITH 500 MILLIBAR HEIGHTS AS HIGH AS 6000 METERS ON SOME RUNS OF
THE ENSEMBLES. THE 700 MILLIBAR TEMPERATURES CLIMB AS HIGH AS
21 CELSIUS TODAY, AND THIS TRANSLATES TO JUST ABOUT ALL
LOCATIONS BEING ABOVE 90 DEGREES FOR HIGH TEMPERATURES TODAY.
LOCATIONS BELOW 5200 FEET HAVE AT LEAST A 1 IN 2 CHANCE OF HIGH
TEMPERATURES OVER 100 TODAY, WITH AN ALMOST 100 PERCENT CHANCE
IN THE WARMEST SPOT, THE STRETCH FROM THERMOPOLIS TO LOVELL. THE
STRETCH FROM WORLAND TO GREYBULL HAS A 1 IN 2 CHANCE OF HIGH
TEMPERATURES OVER 105.
THE PEAK OF THE HEAT WILL LIKELY BE SUNDAY. THE 700 MILLIBAR
TEMPERATURES CLIMB ABOUT 2 TO 3 DEGREES CELSIUS, BRINGING
TEMPERATURES ABOUT 3 TO 5 DEGREES WARMER. THERE WILL ALSO BE A
BIT MORE WIND IN NORTHERN WYOMING, BRINGING BETTER MIXING. THE
CHANCE OF HIGH TEMPERATURES OVER 100 IS AROUND 4 OUT OF 5 BELOW
6000 FEET ON THIS DAY, AND INCLUDES LOCATIONS WHERE THIS IS RARE
INCLUDING GREEN RIVER AND CODY. EVEN DOWNTOWN JACKSON HAS
AROUND A 1 IN 2 CHANCE. THE MOST IMPRESSIVE IS THE AREA OF
GREATER THAN 4 OUT OF 5 CHANCE OF 105 DEGREES OR GREATER, WHICH
STRETCHES FROM THERMOPOLIS ALMOST TO THE MONTANA BORDER THROUGH
THE BIGHORN BASIN, AS WELL AS MUCH OF EASTERN JOHNSON COUNTY.
AND WE CONTINUE TO HAVE AT LEAST A 1 IN 2 CHANCE OF HIGH
TEMPERATURES OVER 110 DEGREES FROM WORLAND TO GREYBULL. IF THAT
OCCURRED, THESE WOULD BE ALL-TIME STATION RECORD HIGH
TEMPERATURES. THESE ARE POSSIBLE AT A LOT OF LOWER ELEVATION
LOCATIONS THOUGH.
WITH SLIGHTLY LOWER TEMPERATURES ALOFT AND SOMEWHAT LESS WIND,
MONDAY WILL BE A FEW DEGREES COOLER. HOWEVER, THE CHANCE OF HIGH
TEMPERATURES OVER 100 WILL STILL BE 4 OUT OF 5 OR GREATER BELOW
5500 FEET ON THIS DAY. AND NOW, EVEN TUESDAY LOOKS JUST AS HOT,
WITH SIMILAR CONDITIONS AS THE RIDGE HOLDS. WE MAY NEED TO
EXTEND THE EXCESSIVE HEAT WARNING ANOTHER DAY, BUT WE WILL HOLD
OFF FOR NOW. THE EXTREME HEAT LOOKS TO END WEDNESDAY AS THE
RIDGE WEAKENS SOMEWHAT, BUT ABOVE NORMAL TEMPERATURES SHOULD
CONTINUE INTO NEXT WEEKEND.
FIRE WEATHER...ELEVATED FIRE WEATHER REMAINS LIKELY TODAY WITH THE
HOT TEMPERATURES AND HUMIDITY FALLING INTO THE SINGLE DIGITS ACROSS
MUCH OF THE AREA. HOWEVER, WITH WIND EXPECTED TO REMAIN LIGHT TO
MODERATE, CRITICAL FIRE WEATHER IS NOT EXPECTED THIS AFTERNOON. THIS
WILL LIKELY CHANGE SUNDAY AS WIND INCREASES, WITH GUSTS TO 30 MPH
POSSIBLE ACROSS WYOMING. WITH THE RECORD HEAT AND VERY LOW HUMIDITY
(AS LOW AS 5 PERCENT), THE NORTHERN ZONES LOOK MOST LIKELY TO
REACH RED FLAG CRITERIA. FURTHER SOUTH, ESPECIALLY IN FREMONT
COUNTY, IT IS A BIT MORE QUESTIONABLE. FOR NOW, IN COORDINATION
WITH OUR NEIGHBORS TO THE NORTH, WE WILL MAINTAIN THE WATCH AND
LET THE DAY SHIFT MAKE THE FINAL CALL. ON MONDAY, WIND SHOULD
DECREASE ENOUGH FOR CONDITIONS TO NOT BE CRITICAL. THERE COULD
BE ANOTHER PERIOD OF CRITICAL FIRE WEATHER ON TUESDAY AFTERNOON.
HOWEVER, INCREASING MOISTURE AND SOMEWHAT HIGHER HUMIDITY WILL
BE A FACTOR. PLENTY OF TIME TO DECIDE ON THIS THOUGH.
OTHERWISE, THINGS LOOK DRY THROUGH THE WEEKEND. STRONG RIDGING AND
WARM AIR ALOFT SHOULD CAP THE ATMOSPHERE AND PREVENT CONVECTION AND
EVEN MUCH IN THE WAY OF CLOUD COVER. I CAN'T COMPLETELY RULE OUT
A VIRGA SHOWER OVER THE MOUNTAINS LATE THIS AFTERNOON, BUT THE
CHANCE IS LESS THAN 1 OUT OF 10 SO WE LEFT THE FORECAST DRY.
STARTING ON MONDAY, SOME MIDLEVEL MOISTURE MAY WRAP AROUND THE
BACKSIDE OF THE RIDGE AND COULD BRING AN ISOLATED THUNDERSTORM
TO THE WESTERN MOUNTAINS. WITH THE CHANCE LESS THAN 1 OUT OF 10
THOUGH, WE AGAIN LEFT THE FORECAST DRY FOR NOW. BY TUESDAY AND
ESPECIALLY ON WEDNESDAY, MOISTURE SHOULD BE DEEP ENOUGH FOR A
CHANCE OF DIURNAL CONVECTION EACH DAY THROUGH FRIDAY. IT IS
DIFFICULT TO PINPOINT A MORE ACTIVE DAY AT THIS TIME THOUGH. SO,
TO SUM IT UP, PREPARE FOR A STRETCH OF HEAT OVER THE NEXT FOUR
DAYS WE HAVE NOT SEEN IN A WHILE.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 353 PM MDT SAT JUL 11 2026
VFR CONDITIONS THROUGH THE PERIOD, WITH NO PRECIPITATION EXPECTED.
LIGHT WINDS TONIGHT WITH A CLEAR SKY. SOUTH TO SOUTHEAST WINDS
INCREASE INTO SUNDAY MORNING, WITH GUSTY AFTERNOON WINDS 15 TO 30
KNOTS. SUNDAY WILL ALSO BE VERY HOT, WITH SURFACE HIGH TEMPERATURES
GENERALLY 95 TO 105 DEGREES.
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZDV AND ZLC FOR
THE LATEST INFORMATION ON SMOKE, ICING AND TURBULENCE
FORECASTS.
FIRE WEATHER
ISSUED AT 1200 PM MDT SAT JUL 11 2026
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS THIS
AFTERNOON AND EVENING DUE TO VERY HOT TEMPERATURES AND MINIMUM
RELATIVE HUMIDITY VALUES DROPPING TO BELOW 10 PERCENT. WINDS
WILL REMAIN RELATIVELY LIGHT. GUSTY SOUTHEAST WINDS UP TO 25 TO
35 MPH WILL COMBINE WITH RECORD HIGH TEMPERATURES AND MINIMUM
RELATIVE HUMIDITY AS LOW AS 5 PERCENT TO BRING NEAR-CRITICAL TO
CRITICAL FIRE WEATHER TO MUCH OF NORTHERN AND CENTRAL WYOMING.
POOR RELATIVE HUMIDITY RECOVERY OVERNIGHT DROPPING ONCE AGAIN
FOR MONDAY AFTERNOON. WIND, HOWEVER, WILL BECOME RELATIVELY
LIGHT ONCE AGAIN WITH SIMILAR FIRE WEATHER CONDITIONS AS
SATURDAY AFTERNOON AND EVENING.
RIW WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WARNING UNTIL 9 PM MDT MONDAY FOR WYZ003>006-010-
011-013-016>020-023-025>030.
RED FLAG WARNING FROM 11 AM TO 10 PM MDT SUNDAY FOR WYZ275-276-
280>283.
UPDATE...LOWE
DISCUSSION...HATTINGS
AVIATION...WITTMANN
FIRE WEATHER...LOWE
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