878
FXUS65 KPUB 120901
AFDPUB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
301 AM MDT FRI SEP 12 2025
KEY MESSAGES
- ROUNDS OF SHOWERS AND STORMS TO CONTINUE THROUGH SATURDAY, WITH
THE BEST COVERAGE OVER AND NEAR THE HIGHER TERRAIN.
- A FEW STRONGER STORMS OVER THE HIGHER TERRAIN, WITH POTENTIAL
FOR SEVERE STORMS ACROSS THE SOUTHEAST PLAINS ON SATURDAY.
- LOCALLY HEAVY RAINFALL AND THE POTENTIAL FOR LOCALIZED FLASH
FLOODING, MAINLY ALONG AND WEST OF THE CONTDVD FRIDAY, WITH
SOME LIGHT SNOW ACCUMULATIONS ON THE HIGHEST PEAKS SATURDAY.
- PATCHY FROST MAY BE POSSIBLE ACROSS PORTIONS OF THE SAN LUIS
VALLEY ON SUNDAY AND MONDAY MORNING
SHORT TERM /THROUGH SATURDAY/
ISSUED AT 300 AM MDT FRI SEP 12 2025
CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS IS INDICATING
MODERATE SOUTH TO SOUTHWEST FLOW ALOFT ACROSS THE REGION, AS AN
UPPER LOW AND BROAD UPPER TROUGH ELONGATES ACROSS THE WEST COAST.
WATER VAPOR IMAGERY IS ALSO INDICATING EMBEDDED SHORT WAVES WITHIN
SOUTHERLY FLOW, WITH ONE SAID WAVE TRANSLATING ACROSS DESERT SOUTHWEST
AT THIS TIME. GOES BLENDED TOTAL WATER VAPOR IMAGERY CONTINUES TO
INDICATE PWATS RUNNING 100-150 PERCENT OF NORMAL ACROSS THE DESERT
SOUTHWEST AND GREAT BASIN REGION INTO THE ROCKIES AT THIS TIME.
AS OF 1 AM, REGIONAL RADARS ARE INDICATING SCATTERED SHOWERS AND A
FEW EMBEDDED THUNDERSTORMS ONGOING ACROSS THE HIGHER TERRAIN WITH
TEMPERATURES IN 60S ACROSS THE PLAINS, AND MAINLY IN THE 40S AND
50S ACROSS THE HIGHER TERRAIN.
TODAY AND TONIGHT...LATEST MODELS AGREE ON INCREASING SOUTHERLY FLOW
ALOFT ACROSS THE ROCKIES INTO TONIGHT, AS THE BROAD UPPER TROUGH
STARTS TO TRANSLATE INTO THE GREAT BASIN WITH JET ENERGY ROUNDING
THE BASE OF THE TROUGH ACROSS THE DESERT SOUTHWEST. THIS WILL BRING
ANOTHER ROUND OF SHOWERS AND STORMS TO SOUTH CENTRAL COLORADO THROUGH
THE DAY TODAY, WITH A FEW SHOWERS AND STORMS SPREADING ACROSS THE
EASTERN MTNS AND OUT ACROSS THE I-25 CORRIDOR THROUGH THE LATE
AFTERNOON AND EVENING HOURS. DESPITE GOOD UNIDIRECTIONAL SHEAR, MODELS
CONTINUE TO SUGGEST LIMITED INSTABILITY WITH LATEST HREF INDICATING
MEAN CAPE LESS THAN 1000 J/KG AREAWIDE. WITH SOME DCAPE PROGGED AS
WELL, STRONGER STORMS COULD STILL PRODUCE GUSTY OUTFLOW WINDS UP TO
50 MPH, AS WELL AS SOME SMALL HAIL AND LOCALLY HEAVY RAIN. STORMS
WILL BE MOVING WHICH WILL LIMIT THE FLASH FLOODING THREAT, HOWEVER,
WILL STILL NEED TO WATCH FOR STORM TRAINING, ESPECIALLY ALONG THE
CONTINENTAL DIVIDE, FOR POSSIBLE LOCALIZED FLASH FLOODING. FURTHER
EAST, SOME DRIER AIR MIXES DOWN ACROSS THE PLAINS, WITH SOUNDINGS
INDICATED CAPPING THROUGH THE DAY, WITH THE POTENTIAL FOR A FEW
STORMS THROUGH THE EVENING INTO FRIDAY NIGHT, AS THE UPPER TROUGH
CONTINUES INTO THE GREAT BASIN. AS FOR TEMPERATURES, THERE IS SOME
SLIGHT COOLING ALOFT, ESPECIALLY ACROSS WESTERN COLORADO, BUT STAYED
ON THE WARMER SIDE OF GUIDANCE WITH THE EXPECTED SOUTHERLY FLOW ALOFT,
WITH HIGHS IN THE 80S TO LOWER 90S ACROSS THE PLAINS, AND IN THE 50S
TO 70S ACROSS THE HIGHER TERRAIN WITH FRIDAY NIGHT WITH OVERNIGHT LOWS
IN THE 50S TO LOWER 60S ACROSS THE PLAINS AND IN THE 30S AND 40S ACROSS
THE HIGHER TERRAIN.
FOR SATURDAY...LATEST MODELS CONTINUE TO INDICATE MODERATE SOUTHWEST
FLOW ALOFT ACROSS THE REGION, AS THE GREAT BASIN SYSTEM LIFTS OUT ACROSS
THE ROCKIES. OROGRAPHIC FLOW WILL KEEP SHOWERS ONGOING ACROSS THE HIGHER
TERRAIN, ESPECIALLY ALONG THE CONTINENTAL DIVIDE, WITH SOME LIGHT SNOW
ACCUMULATIONS EXPECTED ACROSS THE HIGHEST PEAKS, GENERALLY ABOVE 12K
FEET, THROUGH THE DAY. FURTHER EAST, THE SOUTHWEST FLOW ALOFT WILL HELP
DEVELOP LEE TROUGHING AND SHARPEN A DRY LINE ACROSS THE SOUTHEAST PLAINS
THROUGH THE AFTERNOON, WHERE THE LATEST SPC DAY 2 OUTLOOK HAS A MARGINAL
RISK FOR SEVERE STORMS. LARGE HAIL AND STRONG OUTFLOW WINDS WILL BE THE
MAIN RISKS WITH THESE STORMS ON SATURDAY. COOLING ALOFT CONTINUES WITH
HIGHS EXPECTED TO BE AT TO SLIGHTLY BELOW SEASONAL LEVELS IN THE 70S TO
LOWER 80S ACROSS THE PLAINS, AND MAINLY 50S AND 60S ACROSS THE HIGHER
TERRAIN, SAVE FOR 30S AT THE PEAKS.
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
ISSUED AT 300 AM MDT FRI SEP 12 2025
SATURDAY NIGHT THROUGH MONDAY..
MODELS DRAG THE TROUGH AXIS OVERHEAD SATURDAY EVENING, ALLOWING FOR
CONTINUED CONVECTION ON OUR PLAINS THROUGH THE EVENING AND INTO THE
EARLY OVERNIGHT HOURS. AT THE SAME TIME, NORTHWEST FLOW ALOFT AND
CLEARING CONDITIONS OVER THE HIGH COUNTRY WILL LIKELY LEAD TO VERY
EFFICIENT COOLING AS WE HEAD INTO SUNDAY MORNING. OUR FIRST FROST
CHANCES OF THE SEASON ARE LOOKING MORE AND MORE POSSIBLE (AROUND 50-
70% CHANCE) FOR BOTH SUNDAY MORNING AND MONDAY MORNING ACROSS
PORTIONS OF THE SAN LUIS VALLEY. AT THIS TIME, LOWS LOOK TO REMAIN
NEAR AND JUST ABOVE FREEZING ACROSS THE VALLEY, WITH 40S OVER
PORTIONS OF OUR MOUNTAIN ADJACENT PLAINS, AND 50S OVER OUR FAR
EASTERN PLAINS. OUR FLOW ALOFT TRANSITIONS FROM NORTHWESTERLY SUNDAY
MORNING TO DUE WESTERLY/ZONAL BY SUNDAY EVENING, AND SOUTHWESTERLY
BY MONDAY AS OUR NEXT LOW FORMS UP OVER THE NORTHERN ROCKIES. NEAR
NORMAL TEMPERATURES AND DRY CONDITIONS ARE EXPECTED FOR SUNDAY, WITH
ONLY VERY ISOLATED CONVECTION EXPECTED OVER THE PIKES PEAK REGION
AND AREA GENERALLY NORTH OF HIGHWAY 50. OUR TEMPERATURES WARM A FEW
DEGREES ON MONDAY, WITH HIGHS CLIMBING JUST A FEW DEGREES WARMER
THAN NORMAL. MONDAY LOOKS TO BE THE DRIEST DAY OF THE PERIOD, WITH
LITTLE TO NO CHANCES FOR SHOWERS AND THUNDERSTORMS AT ANY LOCATION
ACROSS THE REGION. THOUGH WE WILL BE WARMER AND DRIER, WINDS WILL BE
TOO WEAK TO WARRANT ANY FIRE WEATHER CONCERNS, AND RH VALUES LOOK TO
REMAIN ABOVE CRITICAL LEVELS AS WELL.
TUESDAY ONWARDS..
THERE IS STILL SOME MEASURE OF DISAGREEMENT IN REGARDS TO THE
NORTHERN ROCKIES LOW THAT MODELS BRING IN AROUND MID-WEEK. EPS
ENSEMBLE MEMBERS ARE SLIGHTLY MORE AMPLIFIED AND GFS ENSEMBLE
MEMBERS ARE SLIGHTLY MORE PROGRESSIVE. EITHER WAY, IT SEEMS THAT THE
SYSTEM WILL MAINLY PASS TO OUR NORTH, AND THIS WILL OCCUR SOMEWHERE
AROUND THE LATE TUESDAY INTO EARLY WEDNESDAY TIMEFRAME. THIS WILL
ALLOW FOR RENEWED SHOWER AND THUNDERSTORM CHANCES FOR AT LEAST
TUESDAY THROUGH THURSDAY, ALONG WITH A BIT OF A COOL DOWN FOR
WEDNESDAY AND THURSDAY AS WELL. AFTER THIS SYSTEM'S PASSAGE, MODELS
HINT AT RIDGING BUILDING IN FROM FRIDAY INTO NEXT WEEKEND.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1126 PM MDT THU SEP 11 2025
PATCHY VFR CIGS AND ISOLATED -SHRA AT 06Z WILL DISSIPATE OVERNIGHT,
WITH VFR CONDITIONS FROM FRIDAY MORNING INTO THE AFTERNOON. ANOTHER
ROUND OF CONVECTION WILL DEVELOP OVER THE MOUNTAINS AFTER 18Z FRI,
WITH PROB30 FOR -TSRA AT KALS AFTER 20Z, THEN STARTING AT KCOS AND
KPUB AFTER 22Z. GUSTS TO 35 PLUS KTS THE MAIN STORM THREATS, PERHAPS
SOME BRIEF HEAVIER RAINFALL AND LOWER CIGS/VIS AT KALS, WHERE MOISTURE
AND LIFT WILL BE SLIGHTLY BETTER. STORMS BEGIN TO WEAKEN/DISSIPATE
02Z-03Z FRI EVENING, WITH LINGERING VFR CIGS AND ISOLATED -SHRA
UNTIL 06Z.
PUB WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...MW
LONG TERM...EHR
AVIATION...PETERSEN
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