077
FXUS65 KBOU 040632
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1232 AM MDT SAT JUL 4 2026
KEY MESSAGES
- LAST DAY OF CRITICAL FIRE WEATHER CONDITIONS AS WINDS GRADUALLY
RELAX. HOWEVER, STILL PLENTY OF HOT, DRY WEATHER AHEAD.
- ANOTHER ROUND OF NOCTURNAL (AND POTENTIALLY SEVERE) CONVECTION
POSSIBLE TONIGHT.
- SCATTERED STRONG TO SEVERE STORMS EXPECTED FOR THE AFTERNOON AND
EARLY EVENING OF THE 4TH.
- A FEW STORMS EXPECTED EACH DAY OF THE COMING WEEK, WITH THE
HIGHEST PROBABILITIES SHAPING UP FOR TUESDAY AND WEDNESDAY FROM
THE FRONT RANGE EASTWARD.
DISCUSSION /THROUGH FRIDAY/
ISSUED AT 233 PM MDT FRI JUL 3 2026
ANOTHER DAY (AND NIGHT) OF UNCERTAINTY WITH REGARD TO CONVECTIVE
DEVELOPMENT. CAMS HAVE NOT BEEN DOING A GREAT JOB OF ASSESSING
POTENTIAL AND DURATION OF NOCTURNAL CONVECTION, AND AMOUNT OF LOW
LEVEL MOISTURE SURGING WESTWARD FROM MCSS IN THE CENTRAL/HIGH
PLAINS THE LAST COUPLE OF NIGHTS.
AS OF EARLY THIS AFTERNOON, WEAK CONVECTION HAS BEEN DEVELOPING
OVER THE NORTHERN MOUNTAINS AND FOOTHILLS. AS THAT MOVES EAST ONTO
THE PLAINS, A COUPLE STORMS ARE EXPECTED TO TAP INTO THE HIGHER
MLCAPE NEAR 1500-2000 J/KG AND BECOME SEVERE LATE THIS AFTERNOON
INTO EARLY EVENING. WHERE MORE UNCERTAINTY ENTERS THE FORECAST IS
OVERNIGHT, AND THAT'S WHEN A COUPLE PIECES OF THE PUZZLE ATTEMPT
TO COME TOGETHER AND PRODUCE ANOTHER ROUND OF STRONG TO
POTENTIALLY SEVERE STORMS. THAT POTENTIAL WOULD EXTEND FARTHER
WEST TOWARD THE I-25 CORRIDOR. THAT WOULD BE FUELED BY OUTFLOW
FROM THE INITIAL ROUND OF STORMS OVER THE NORTHERN TIER OF
COLORADO, AND POTENTIALLY ANOTHER OUTFLOW FROM A MORE ORGANIZED
STORM COMPLEX (MCS) OVER NEBRASKA. THAT SECOND SURGE WOULD LIKELY
ARRIVE LATER IN THE EVENING, AND THAT COULD SPARK STORMS THAT
LINGER WELL PAST MIDNIGHT. AT THE SAME TIME, WE'LL ALSO HAVE SOME
UPPER LEVEL SUPPORT FROM THE LEFT EXIT REGION OF AN UPPER LEVEL
SPEED MAX. WHILE WEAKLY CAPPED, THE LIFT FROM ANY UPSLOPE WOULD
LIKELY BE ENOUGH TO BREAK THROUGH AND INITIATE MORE STORMS. MLCAPE
BY THAT TIME WOULD BE A LITTLE LOWER (800-1600 J/KG), BUT STILL
ENOUGH FOR A COUPLE STRONG TO SEVERE STORMS THAT LINGER WELL PAST
MIDNIGHT.
SATURDAY, THE 4TH OF JULY, IS STILL SHAPING UP TO SERVE UP SOME
OF NATURE'S FIREWORKS. IT WILL LIKELY BE A MORE ACTIVE
THUNDERSTORM DAY WITH HIGHER MLCAPE ACROSS THE FRONT RANGE AND
ADJACENT PLAINS. SOME PATCHY MORNING STRATUS IS POSSIBLE, BUT NOT
ENOUGH TO SIGNIFICANTLY IMPACT WARMING AND CAP EROSION BY EARLY
TO MID AFTERNOON. MLCAPE IS FORECAST TO INCREASE TO 1500-2000 J/KG
ALONG/EAST OF THE I-25 CORRIDOR, BUT AT THE SAME TIME THERE IS
PLENTY OF UNCERTAINTY WITH EXACTLY HOW FAR WEST THE GREATEST
MOISTURE AND INSTABILITY CAN HOLD (HIGHLY DEPENDENT ON STRENGTH OF
SURGES TONIGHT). MOST LIKELY, DEEPER INSTABILITY HOLDS ROUGHLY
EAST OF I-25, WITH LESSER CERTAINTY WEST OF I-25. WE THINK STORM
INITIATION WILL BE IN/VERY CLOSE TO THE FRONT RANGE MOUNTAINS AND
FOOTHILLS BY EARLY AFTERNOON, WITH EASTWARD PROPAGATION ACROSS
THE PLAINS FROM MID AFTERNOON THROUGH EARLY EVENING. 0-6KM BULK
SHEAR IS FORECAST TO INCREASE TO 30-35 KTS, ENOUGH FOR SUPERCELL
DEVELOPMENT. INITIAL ISOLATED SEVERE STORMS ARE EXPECTED TO HAVE A
LARGE HAIL THREAT, AND THOSE STORMS MAY THEN ATTEMPT TO ORGANIZE
INTO A LINEAR STRUCTURE ONTO THE PLAINS WITH A GREATER HIGH WIND
THREAT (IN ADDITION TO THE HAIL). A FAILURE MODE WOULD BE IF THE
AIRMASS REMAINS TOO CAPPED DUE TO WEAK SYNOPTIC SUBSIDENCE SEEN
ARRIVING IN THE AFTERNOON. ANYONE PLANNING OUTDOOR CELEBRATIONS OR
ACTIVITIES TOMORROW SHOULD REMAIN WEATHER AWARE AND BE PREPARED
TO TAKE SHELTER OR MOVE OFF OPEN WATERS BEFORE STORMS ARRIVE.
FINALLY, WITH THE ABOVE MENTIONED ARRIVAL OF SUBSIDENCE, WE DO
THINK THE VAST MAJORITY OF STORMS SHOULD CLEAR THE FORECAST AREA
BEFORE DARK AND ANY FIREWORKS SHOWS.
BY SUNDAY AND MONDAY, UPPER LEVEL RIDGING BUILDS ACROSS COLORADO.
WHILE THIS WILL TEND TO STABILIZE THINGS A BIT, IT WILL STILL BE
HOT AND RESIDUAL MOISTURE MEANS A CONTINUED CHANCE OF STORMS EACH
AFTERNOON AND EVENING. TYPICALLY THIS PATTERN HAS THE MOST
CONVECTION OCCURRING OVER PARK COUNTY AND THE FRONT RANGE
MOUNTAINS INTO THE PALMER DIVIDE AREA, WITH LOWER PROBABILITIES TO
THE NORTH AND EAST. HIGH TEMPERATURES WILL LIKELY REACH THE 90-95
DEGREE RANGE OVER THE PLAINS, AFTER JUST SLIGHT COOLING (NEAR
NORMAL TEMPS) FOR SATURDAY.
FOR TUESDAY AND WEDNESDAY, THE UPPER LEVEL RIDGE IS FORECAST TO
FLATTEN WITH WEAK ZONAL FLOW DEVELOPING ACROSS THE FORECAST AREA.
AS LOW LEVEL MOISTURE REMAINS LOCKED IN EAST OF THE ROCKIES,
INSTABILITY BUILDS SLIGHTLY AND SHEAR IMPROVES SO SCATTERED
THUNDERSTORMS ARE EXPECTED BOTH DAYS WITH POTENTIAL FOR A COUPLE
SEVERE STORMS. TEMPERATURES WILL REMAIN A FEW DEGREES ABOVE
NORMAL.
DRYING IS EXPECTED FOR THE LATTER PORTION OF THE WEAK AS THERE IS
GROWING CONFIDENCE WE REMAIN UNDER ZONAL FLOW ALOFT. SOME LEE
TROUGHING IS ALSO FORECAST, WHICH MEANS THE GREATEST CHANCE OF
STORMS WILL LIKELY SHIFT TO THE EASTERN PLAINS WHILE DRIER AIR AND
A RETURN OF ELEVATED FIRE WEATHER CONDITIONS (WITH INCREASING
BREEZES) IS EXPECTED OVER THE HIGH COUNTRY.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
ISSUED AT 1203 AM MDT SAT JUL 4 2026
CONVECTION HAS MOVED EASTWARD AND AWAY FROM THE TAF SITES AT THIS
TIME. WITH THE EXITING CONVECTION, WINDS ARE EXPECTED TO TURN TO
A MORE EASTERLY COMPONENT FOR THE NEXT HOUR OR TWO BEFORE SETTLING
INTO DRAINAGE FOR THE OVERNIGHT HOURS, THOUGH WITH STORMS EXPECTED
TO PERSIST OVER EASTERN COLORADO AND PUSH INTO KS/NE THROUGH THE
EARLY MORNING, THERE IS SOME UNCERTAINTY ON WHETHER WINDS MAINTAIN
AN EASTERLY COMPONENT A TAD LONGER THAN IN THE CURRENT TAF. THERE
IS A CHANCE WE SEE SOME LOWER CLOUDS MOVE IN WITH THE EASTERLY
FLOW AS WELL. AS SUCH, HAVE ADDED A FEW005 TO SHOW THIS
POTENTIAL, WITH THE MOST LIKELY TIME BEING BETWEEN ~8Z-11Z THIS
MORNING.
WITH SLIGHTLY HIGHER CONFIDENCE IN DRAINAGE WINDS WINNING OUT,
EXPECTING SOUTHERLY WINDS TO INCREASE BETWEEN 12Z-14Z BEFORE
TURNING TO THE SOUTHEAST BY EARLY AFTERNOON.
PROB30S REMAIN IN PLACE FOR THE POTENTIAL FOR CONVECTION TO BEGIN
BETWEEN 20Z-22Z ACROSS THE TAF SITES, WITH VARIABLE AND GUSTY
WINDS BETWEEN 30-40 KTS POSSIBLE WITH ANY PASSING STORMS. A FEW OF
THESE STORMS MAY BECOME SEVERE (15% CHANCE).
WITH WILDFIRES STILL BURNING ACROSS THE REGION, SMOKE WILL
CONTINUE TO BE A NUISANCE TO SLANT RANGE VIS CONCERNS, ESPECIALLY
NEAR SUNRISE AND SUNSET.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...20
AVIATION...9
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