583  
FXUS65 KBOU 122054  
AFDBOU  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DENVER/BOULDER CO  
254 PM MDT SUN APR 12 2026  
   
KEY MESSAGES  
 
 
- CRITICAL FIRE WEATHER CONDITIONS EXPECTED TODAY AND MONDAY OVER  
THE SOUTHERN PORTIONS OF THE FORECAST AREA AND THE PLAINS NEAR  
THE WYOMING BORDER.  
 
- CONTINUED ABOVE NORMAL WARMTH SUNDAY AND MONDAY WITH A FEW,  
MAINLY ALPINE LATE DAY SHOWERS.  
 
- THE NEXT SYSTEM WILL BRING COOLER TEMPERATURES AND A DECENT  
CHANCE OF PRECIPITATION TO THE FORECAST AREA TUESDAY AND TUESDAY  
EVENING. SOME MINOR TRAVEL IMPACTS POSSIBLE MOUNTAIN PASSES.  
 
- ANOTHER SYSTEM CAPABLE OF WIDESPREAD PRECIPITATION LOOKING  
POSSIBLE BY THE WEEK'S END.  
   
DISCUSSION /THROUGH SUNDAY/  
 
ISSUED AT 242 PM MDT SUN APR 12 2026  
 
WATER VAPOR IMAGERY SHOWS OUR NEXT EXPECTED WEATHER SYSTEM  
CURRENTLY SPINNING OFF THE COAST OF NORTHERN CALIFORNIA. ANOTHER  
LESS DEFINED DISTURBANCE IS VISIBLE JUST ON ITS HEELS, WITH  
GUIDANCE SHOWING THESE FEATURES MERGING AS THEY PROGRESS EASTWARD  
ACROSS THE GREAT BASIN AND INTO THE CENTRAL ROCKIES OVER THE NEXT  
FEW DAYS. THE EXTENDED FORECAST PERIOD LOOKS TO REMAIN FAIRLY  
ACTIVE THIS WEEK, WITH ELEVATED TO CRITICAL FIRE WEATHER  
CONDITIONS MIXED IN WITH MULTIPLE CHANCES FOR MOUNTAIN SNOW AND  
LOW ELEVATION PRECIPITATION.  
 
IT'S A RATHER NICE DAY ACROSS THE FORECAST AREA TODAY, ALBEIT A  
LITTLE BREEZY ACROSS THE SOUTHERN FOOTHILLS, MOUNTAIN VALLEYS, AND  
ALONG THE PALMER DIVIDE AND ADJACENT PLAINS. TEMPERATURES ARE  
ALREADY IN THE 70S ACROSS THE PLAINS AND 50S IN THE FOOTHILLS AND  
MOUNTAIN VALLEYS. WITH THE BREEZY AND DRY CONDITIONS IN PLACE, THE  
MAIN CONCERN FOR TODAY IS WITH ELEVATED TO CRITICAL FIRE WEATHER  
CONDITIONS. TODAY'S RED FLAG WARNING REMAINS IN PLACE UNTIL 8 PM FOR  
THE SOUTHERN PORTION OF THE FORECAST AREA AS WELL AS EASTERN LARIMER  
AND NORTHWESTERN WELD COUNTIES. RELATIVE HUMIDITIES ARE ALREADY IN  
THE TEENS ACROSS THE MAJORITY OF OUR LOWER ELEVATIONS AND EVEN ALONG  
THE I-70 MOUNTAIN CORRIDOR , SO EVEN WHERE WINDS ARE EXPECTED TO  
REMAIN BELOW CRITICAL THRESHOLDS, ELEVATED FIRE WEATHER CONDITIONS  
ARE FAIRLY WIDESPREAD ACROSS THE FORECAST AREA.  
 
FOR TONIGHT, SOUTHWESTERLY FLOW ALOFT STARTS TO INCREASE AHEAD OF  
OUR NEXT APPROACHING UPPER-LEVEL TROUGH. THERE WILL BE ENOUGH MID-  
LEVEL MOISTURE TO BRING SOME VERY LIGHT SNOW SHOWER CHANCES TO THE  
NORTHERN MOUNTAINS. COOLER TEMPERATURES ALOFT WILL START TO FILTER  
IN ON MONDAY AS THE TROUGH MOVES MUCH COOLER TEMPERATURES OUR WAY.  
GUSTY SOUTHWESTERLY WINDS ARE EXPECTED TO INCREASE BY LATE MORNING  
WHILE RELATIVE HUMIDITY VALUES DROP AS LOW AS 10% ACROSS PORTIONS OF  
THE PLAINS. DUE TO ANOTHER DAY OF BREEZY WINDS AND LOW RH, HAVE GONE  
AHEAD AND UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG WARNING FOR  
ALL FIRE ZONES EXCEPT FOR WASHINGTON COUNTY WHERE WINDS WILL BE MORE  
MARGINAL. LIKE TODAY, WITH LOW RH VALUES EXPECTED TO BE BELOW  
CRITICAL THRESHOLDS FOR ALL OF THE PLAINS, THERE WILL BE WIDESPREAD  
ELEVATED CRITICAL FIRE WEATHER CONDITIONS IN PLACE, WITH SOME BRIEF  
PATCHY CRITICAL CONDITIONS POSSIBLE TO DEVELOP OUTSIDE THE RFW  
AREAS, SO EVERYONE SHOULD CONTINUE PRACTICING GOOD FIRE SAFETY.  
 
ENSEMBLE TRENDS HAVE SHOWN A BIT OF A TURNAROUND OVER THE PAST FEW  
MODEL RUNS, SHOWING AN INCREASE IN QPF FOR TUESDAY'S EXPECTED TROUGH  
PASSAGE, LEADING TO HIGHER CONFIDENCE IN SOME ADVISORY LEVEL  
SNOWFALL TOTALS FOR OUR MOUNTAINS. MOISTURE WILL START TO RAMP UP  
LATE MONDAY NIGHT ACROSS THE HIGHER ELEVATIONS, WITH DEEPER MOISTURE  
NOT EXPECTED TO MAKE IT OVER THE LOWER ELEVATIONS UNTIL LATE TUESDAY  
MORNING, WITH THE BEST QG FORCINGS AND COLD FRONT EXPECTED TUESDAY  
AFTERNOON AND EVENING. EXPECT INCREASING CHANCES FOR MOUNTAIN SNOW  
THROUGH THE DAY ON TUESDAY, SHIFTING TO THE PLAINS BY THE AFTERNOON  
IN THE FORM OF RAIN SHOWERS WITH SOME SCATTERED THUNDERSTORMS  
POSSIBLE. THE CURRENT FORECAST WOULD INDICATE THE NEED FOR A WINTER  
WEATHER ADVISORY FOR ACCUMULATIONS OF 4 TO 9 INCHES POSSIBLE FOR  
ELEVATIONS ABOVE 10,000 FEET WITH THIS SYSTEM, THOUGH WILL HOLD OFF  
TO SEE WHAT THE HI-RES MODELS SHOW AND MONITOR THE UPWARDS TREND FOR  
ONE MORE MODEL RUN BEFORE MAKING AND DECISIONS. FOR NOW, IT'S SAFE  
TO SAY THOSE TRAVELING INTO THE HIGH COUNTRY ON TUESDAY SHOULD  
EXPECT WINTER DRIVING CONDITIONS.  
 
WARMER AND DRIER CONDITIONS ARE EXPECTED BEHIND TUESDAY'S WEATHER  
MAKER, AS A BRIEF PERIOD OF UPPER-LEVEL RIDGING LOOKS TO DEVELOP ON  
WEDNESDAY. CROSS SECTIONS SHOW LITTLE MOISTURE REMAINING OVER THE  
LOWER ELEVATIONS BY WEDNESDAY MORNING, AND WITH GUSTY WINDS POSSIBLE  
OVER THE EASTERN PLAINS AS A LEE TROUGH SHIFTS EASTWARD, THERE COULD  
BE SOME ELEVATED FIRE WEATHER CONCERNS FOR THE AFTERNOON.  
 
BY THURSDAY, SOUTHWESTERLY FLOW ALOFT STARTS TO RAMP UP AGAIN AHEAD  
OF ANOTHER UPPER-LEVEL TROUGH DROPPING OUT OF THE PACIFIC NORTHWEST.  
AT THE SURFACE, ANOTHER LEE TROUGH IS EXPECTED TO DEVELOP OVER  
EASTERN COLORADO. CRITICAL FIRE WEATHER CONCERNS WILL BE ON THE MENU  
ONCE AGAIN AS RH DROPS INTO THE SINGLE DIGITS OVER PORTIONS OF THE  
PLAINS, AND WINDS INCREASE OVER THE HIGHER TERRAIN.  
 
FOR FRIDAY AND ONWARD, THIS NEXT UPPER-LEVEL TROUGH LOOKS TO BRING  
GREATER CHANCES FOR A DECENT SPRING SYSTEM, BUT MUCH IS STILL  
UNCERTAIN THIS FAR OUT.  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z MONDAY/  
 
ISSUED AT 1142 AM MDT SUN APR 12 2026  
 
VFR CONDITIONS ARE EXPECTED THROUGHOUT THE TAF PERIOD. WE ARE  
CURRENTLY TRANSITIONING OUT OF DRAINAGE FLOW AS THE INVERSION HAS  
MIXED OUT ACCORDING TO ACARS SOUNDINGS. THERE IS SOME UNCERTAINTY  
ON THE WINDS FOR THIS AFTERNOON. WE HAVE KEPT IN WSW/W WINDS WITH  
GUSTS AROUND 20-25 KTS AT ALL THREE SITES STARTING BETWEEN 19Z  
AND 22Z THIS AFTERNOON. KAPA IS EXPECTED TO SEE THE STRONGEST  
GUSTS. THERE IS A SMALL POSSIBILITY (20-30%) THAT THE STRONGER  
WINDS DO NOT MATERIALIZE THIS AFTERNOON.  
 
WINDS WILL LIGHTEN UP THIS EVENING AND TURN TO DRAINAGE. THEY  
ARE EXPECTED TO STAY AT 10 KTS OR LESS THROUGH TOMORROW AROUND  
18Z TO 21Z. WE EXPECT ANOTHER TRANSITION FROM DRAINAGE TO A WSW/W  
WIND TOMORROW AFTERNOON. WIND GUSTS WILL ONCE AGAIN BE AROUND  
20-25 KTS AT ALL THREE SITES STARTING AROUND 19Z TO 21Z. THE ONSET  
OF THESE STRONGER GUSTS COULD BE AN HOUR OR TWO EARLIER AT KAPA  
AND SLIGHTLY STRONGER THAN AT KBJC AND KAPA.  
 
 
   
FIRE WEATHER  
 
ISSUED AT 242 PM MDT SUN APR 12 2026  
 
TODAY'S RED FLAG WARNING REMAINS IN PLACE UNTIL 8 PM FOR  
THE SOUTHERN PORTION OF THE FORECAST AREA AS WELL AS EASTERN LARIMER  
AND NORTHWESTERN WELD COUNTIES. RELATIVE HUMIDITIES ARE ALREADY IN  
THE TEENS ACROSS THE MAJORITY OF OUR LOWER ELEVATIONS AND EVEN ALONG  
THE I-70 MOUNTAIN CORRIDOR, SO EVEN WHERE WINDS ARE EXPECTED TO  
REMAIN BELOW CRITICAL THRESHOLDS, ELEVATED FIRE WEATHER CONDITIONS  
ARE FAIRLY WIDESPREAD ACROSS THE FORECAST AREA. DUE TO ANOTHER  
DAY OF BREEZY WINDS AND LOW RH EXPECTED ON MONDAY, HAVE GONE  
AHEAD AND UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG WARNING  
FOR ALL FIRE ZONES EXCEPT FOR WASHINGTON COUNTY WHERE WINDS WILL  
BE MORE MARGINAL. LIKE TODAY, WITH LOW RH VALUES EXPECTED TO BE  
BELOW CRITICAL THRESHOLDS FOR ALL OF THE PLAINS, THERE WILL BE  
WIDESPREAD ELEVATED CRITICAL FIRE WEATHER CONDITIONS IN PLACE,  
WITH SOME BRIEF PATCHY CRITICAL CONDITIONS POSSIBLE TO DEVELOP  
OUTSIDE THE RFW AREAS, SO EVERYONE SHOULD CONTINUE PRACTICING GOOD  
FIRE SAFETY. A WEATHER SYSTEM IS EXPECTED TO BRING MOUNTAIN SNOW  
AND WIDESPREAD PRECIPITATION TO THE LOWER ELEVATIONS ON TUESDAY.  
DESPITE THE INCREASED MOISTURE, WE MAY STILL SEE SOME CRITICAL  
FIRE WEATHER CONDITIONS DEVELOP OVER SOUTHERN LINCOLN COUNTY ON  
TUESDAY BEFORE THE BETTER MOISTURE ARRIVES, WHERE WIND GUSTS  
BETWEEN 30-35 MPH WILL BE POSSIBLE COINCIDING WITH RH AT OR JUST  
BELOW CRITICAL THRESHOLDS.  
 
 
   
BOU WATCHES/WARNINGS/ADVISORIES  
 
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ214-216-238-  
241-246-247-249.  
 
RED FLAG WARNING FROM 11 AM TO 8 PM MDT MONDAY FOR COZ214-216-  
238-241-242-246-247.  
 
 
 
 
 
DISCUSSION...9  
AVIATION...MV  
FIRE WEATHER...9  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab CO Page
Main Text Page