029
FXUS65 KRIW 110827
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
227 AM MDT SAT JUL 11 2026
KEY MESSAGES
- THE HEAT WAVE BEGINS TODAY WITH HIGHS IN THE 90S AND 100S FOR
THE LOWER ELEVATIONS, WITH HOTTEST TEMPERATURES IN THE BIG
HORN BASIN WHERE SOME HIGHS WILL APPROACH 105. HEAT WILL
CONTINUE THROUGH AT LEAST TUESDAY.
- SUNDAY STILL LOOKS LIKE THE HOTTEST DAY. WITH SOME ALL TIME
STATION RECORD HIGHS POSSIBLE. SOME OF THE HOTTEST LOCATIONS
MAY REACH 110 DEGREES.
- ELEVATED TO NEAR CRITICAL FIRE WEATHER IS LIKELY THE NEXT FOUR
DAYS. CRITICAL FIRE WEATHER IS LIKELY SUNDAY AFTERNOON AND
POSSIBLY ONCE AGAIN ON TUESDAY AFTERNOON.
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 IF 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 REMAINS 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 FLASH BACK TO THESE JOBS I WORKED
ALMOST 30 YEARS AGO (YES, I'M OLD). WE HAVE TWO MAIN HAZARDS,
HEAT AND FIRE WEATHER, AND WE 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 BIG
HORN 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 HERE, 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 FINALLY 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 MID LEVEL 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 HAVE 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 /06Z TAFS THROUGH 06Z SUNDAY/
ISSUED AT 947 PM MDT FRI JUL 10 2026
HIGH PRESSURE STRENGTHENS OVER THE NEXT 24 HOURS, WHICH WILL INHIBIT
CONVECTION SATURDAY AFTERNOON. THE RESULT WILL BE PREVAILING VFR AND
SKC CONDITIONS THROUGH THE TAF PERIOD. THERE IS A VERY SLIGHT CHANCE
(10%) OF A VIRGA SHOWER OR TWO NEAR KLND LATE SATURDAY AFTERNOON
BETWEEN 23Z AND 03Z. WIND WILL INCREASE TO AROUND 10 KNOTS FOR MOST
TERMINALS SATURDAY AFTERNOON, WITH SOME GUSTS UP TO 20 KNOTS AT KCOD
AND KCPR. OTHERWISE, WIND WILL BE LIGHT FOR THE NEXT 24 HOURS.
PLEASE SEE THE AVIATION WEATHER CENTER AND/OR CWSU ZDV AND ZLC FOR
THE LATEST INFORMATION ON ICING AND TURBULENCE FORECASTS.
FIRE WEATHER
ISSUED AT 219 AM MDT SAT JUL 11 2026
ELEVATED FIRE WEATHER IS LIKELY TODAY WITH A COMBINATION OF VERY
HOT TEMPERATURES AND HUMIDITY FALLING INTO THE SINGLE DIGITS.
WIND SHOULD REMAIN LIGHT TO MODERATE THOUGH. ON SUNDAY, A GUSTY
SOUTHEASTERLY BREEZE WILL COMBINE WITH RECORD HIGH TEMPERATURES
AND HUMIDITY AS LOW AS 5 PERCENT TO BRING NEAR CRITICAL TO
CRITICAL FIRE WEATHER TO MUCH OF NORTHERN AND CENTRAL WYOMING.
CONDITIONS SHOULD IMPROVE SOMEWHAT ON MONDAY AS LIGHTER WIND IS
EXPECTED, ALTHOUGH IT WILL REMAIN VERY HOT WITH CONTINUED LOW
HUMIDITY.
RIW WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WARNING FROM NOON TODAY TO 9 PM MDT MONDAY FOR
WYZ003>006-010-011-013-016>020-023-025>030.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR WYZ275-276-280>283.
DISCUSSION...HATTINGS
AVIATION...ROWE
FIRE WEATHER...HATTINGS
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