040
FXUS65 KBOU 132028
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
228 PM MDT SAT SEP 13 2025
KEY MESSAGES
- SCATTERED/NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING, WITH AN ISOLATED THREAT OF SEVERE STORMS ACROSS THE
NORTHEAST PLAINS.
- SCATTERED SHOWERS AND A SLIGHT CHANCE FOR THUNDERSTORMS, MAINLY
NORTH SUNDAY MORNING.
- UNSETTLED, UNCERTAIN PATTERN FOR MOST OF NEXT WEEK.
DISCUSSION /THROUGH SATURDAY/
ISSUED AT 228 PM MDT SAT SEP 13 2025
WATER VAPOR SATELLITE IMAGERY SHOWING A STRONG SHORTWAVE TROUGH
OVER UTAH WITH SCATTERED/NUMEROUS SHOWERS AND THUNDERSTORMS AHEAD
OF IT OVER WESTERN COLORADO. OVER NORTHEAST COLORADO, SBCAPE HAS
REACHED 300-800 J/KG (MORE THAN YESTERDAY). LIFT FROM THE TROUGH
COMBINED WITH THE INSTABILITY IN PLACE IS EXPECTED TO BRING
SCATTERED/NUMEROUS SHOWERS AND THUNDERSTORMS TO NORTHEAST COLORADO
LATER THIS AFTERNOON AND EVENING. CAN'T RULE OUT AN ISOLATED
SEVERE THUNDERSTORM OR TWO, BUT MOST/ALL STORMS ARE EXPECTED TO BE
SUB- SEVERE. BEST CHANCE FOR A SEVERE STORM WILL BE OVER THE
NORTHEAST PLAINS. THE TROUGH LIFTS NORTH OF COLORADO TONIGHT AND
WILL BE OVER WESTERN NEBRASKA SUNDAY MORNING. WILL KEEP A CHANCE
FOR SHOWERS IN THE FORECAST THROUGH THE NIGHT AS THE TROUGH TRACKS
ACROSS COLORADO. THE BEST CHANCE FOR ADDITIONAL SHOWERS WILL BE
WRAP AROUND SHOWERS ON THE BACKSIDE OF THE LOW TOWARDS SUNRISE
SUNDAY MORNING. SHOWERS SLOWLY COME TO AN END FROM WEST TO EAST
SUNDAY MORNING AND MAY LINGER INTO THE AFTERNOON OVER THE
NORTHEAST CORNER. HIGHS SUNDAY ARE EXPECTED TO REACH THE LOWER TO
MID 70S ACROSS NORTHEAST COLORADO.
THE UPPER LEVEL TROUGH TO OUR NORTHEAST LIFTS NORTHWARD AND
MERGES WITH THE LONGWAVE TROUGH OVER WESTERN CANADA AND THE
NORTHERN ROCKIES. COLORADO WILL SEE A SOMEWHAT DRY WESTERLY FLOW
MONDAY AROUND THE BASE OF THE TROUGH. THIS WILL BRING WARMER
TEMPERATURES WITH HIGHS IN THE LOWER TO MID 80S ACROSS NORTHEAST
COLORADO. A SHORTWAVE TROUGH EMBEDDED IN THE LONGWAVE TROUGH TO
THE NORTH PUSHES SOUTHWARD BRINGING A COLD FRONT AND CHANCE FOR
SHOWERS TUESDAY. TROUGHINESS REMAINS OVER THE AREA INTO WEDNESDAY
WITH COOLER TEMPERATURES AND CONTINUED CHANCE FOR SHOWERS.
FOR THURSDAY THROUGH SATURDAY, MODELS ARE STARTING TO CONVERGE ON
A SOLUTION. THEY ARE SHOWING RIDGING DEVELOPING WEST OF THE
REGION THURSDAY. THE RIDGE INTENSIFIES INTO FRIDAY AND SATURDAY
OVER THE CENTRAL ROCKIES. THIS IS EXPECTED TO PRODUCE DRY
CONDITIONS WITH TEMPERATURE AT OR ABOVE NORMAL. CHANCES FOR
PRECIPITATION ARE LOW, BUT WE COULD SEE A FEW
SHOWERS/THUNDERSTORMS IF ENOUGH MOISTURE FILTERS IN UNDER THE
RIDGE.
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
ISSUED AT 1144 AM MDT SAT SEP 13 2025
NORTHEAST WINDS ARE EXPECTED TO PERSIST THROUGH 21Z AHEAD OF THE
SHOWERS AND THUNDERSTORMS. OUTFLOW FROM THE SHOWERS/STORMS SHOULD
BRING A WESTERLY WIND SHIFT AT FIRST. ADDITIONAL WIND SHIFTS WILL
BE POSSIBLE AS SHOWERS AND THUNDERSTORMS DEVELOP. MOST FAVORABLE
TIME FRAME FOR THUNDERSTORMS IS 21-24Z. AIRMASS THEN STABILIZES
AND MOSTLY SHOWERS ARE EXPECTED AFTER 00Z.
THE CHANCES FOR SHOWERS DECREASES OVERNIGHT, BUT THEN INCREASES
INTO SUNDAY MORNING AS WRAP AROUND SHOWERS MOVE SOUTHWARD.
CEILINGS ARE EXPECTED TO FALL LATE TONIGHT/SUNDAY MORNING TO
5000-8000 FEET, AND POSSIBLY LOWER TO 3000 UNDER/NEAR THE SHOWERS.
AS FAR AS WINDS GO, NORMAL SOUTHWEST DRAINAGE WINDS WILL BE
BATTLING THE PREVAILING NORTHWEST FLOW. EXPECT A SHORT PERIOD OF
SOUTHWEST DRAINAGE AROUND 12Z SUNDAY, THEN A QUICKER THAN USUAL
TURN TO THE NORTHWEST BY 13- 14Z SUNDAY. BY 18Z SUNDAY, THE
SHOWERS ARE EXPECTED TO BE WELL NORTHEAST OF THE DENVER AREA WITH
LIGHTER SOUTHEAST WINDS FOR SUNDAY AFTERNOON.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...MEIER
AVIATION...MEIER
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