878
FXUS65 KPUB 182035
AFDPUB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PUEBLO CO
235 PM MDT FRI SEP 18 2026
KEY MESSAGES
- SCATTERED SHOWERS AND STORMS POSSIBLE THIS EVENING BEFORE
ACTIVITY DIMINISHES OVERNIGHT.
- THUNDERSTORM CHANCES INCREASE OVER THE PLAINS THIS WEEKEND
WHILE THE MOUNTAINS DRY OUT. STRONG TO SEVERE STORMS POSSIBLE
BOTH DAYS EAST OF I-25.
- WETTER CONDITIONS RETURN TO MUCH OF THE AREA NEXT WEEK, THOUGH
STILL SOME UNCERTAINTY ABOUT WHEN AND WHERE THE GREATEST
CHANCE FOR RAINFALL WILL BE.
SHORT TERM /THROUGH SATURDAY/
ISSUED AT 141 PM MDT FRI SEP 18 2026
CURRENTLY, SCATTERED STORMS FIRING AGAIN AS OF 130 PM OVER THE
MOUNTAINS/PALMER DIVIDE AND I-25 CORRIDOR, WITH ACTIVITY IN EL
PASO HELPED ALONG BY WEAK LOW LEVEL CIRCULATION (EVIDENT IN
KPUX REFLECTIVITY) DRIFTING NORTHWARD THROUGH THE ERN HALF OF
THE COUNTY. FOR THE REMAINDER OF THE AFTERNOON INTO THE
EVENING, SCATTERED SHOWERS/STORMS WILL CONTINUE, BEST COVERAGE
ALONG THE CONTINENTAL DIVIDE AND NEAR THE PALMER DIVIDE, VERY
LOW CHANCE OF STORMS ON THE PLAINS WHERE INSTABILITY IS MINIMAL.
BRIEF HEAVY RAIN/GUSTY WINDS THE MAIN STORM HAZARDS TODAY. COLD
FRONT ON THE PLAINS TONIGHT MAY PRODUCE SOME BRIEFLY GUSTY
NORTH WINDS FROM LATE EVENING TOWARD MIDNIGHT, ESPECIALLY ALONG
AND NORTH OF THE ARKANSAS RIVER.
ON SATURDAY, WESTERN U.S. UPPER LOW MOVES INTO THE CENTRAL
ROCKIES, WITH DEEPENING SWLY FLOW ACROSS CO. MOISTURE OVER THE
HIGHER TERRAIN CONTINUES TO THIN OUT THROUGH THE DAY, WITH ONLY
ISOLATED CONVECTION EXPECTED MOST LOCATIONS, BEST CHANCE FOR A
STORM WILL BE OVER THE CENTRAL MOUNTAINS WHERE UPPER FORCING IS
STRONGER. OVER THE PLAINS/I-25 CORRIDOR, POST-FRONTAL EASTERLY
FLOW IS RATHER WEAK, KEEPING DEEPEST MOISTURE/INSTABILITY
GENERALLY EAST OF I-25. CAPE (1000-200 J/KG) AND SHEAR (0-6KM
35-45 KTS) LOOK SUFFICIENT FOR STRONG/SEVERE STORMS, ESPECIALLY
LATE IN THE DAY AS LOW LEVEL EASTERLY FLOW PICKS UP A BIT. MAIN
QUESTION IS TIMING OF STRONGER STORMS, AS A FEW CAMS (I.E. 18Z
HRRR) DEVELOP STORMS EARLY AFTERNOON NEAR I-25, WITH A BROKEN
LINE OF CONVECTION MOVING EAST ACROSS THE PLAINS FROM MID-
AFTERNOON INTO EARLY EVENING. OTHER MODELS INITIATE STORMS MUCH
LATER, WITH BULK OF THE ACTIVITY IN THE EVENING AND OVERNIGHT.
ADJUSTED NBM POPS TO AT LEAST ACKNOWLEDGE EARLIER CONVECTION
POSSIBLE ALONG I-25 AND THE PLAINS, KEPT HIGHEST POPS IN THE
EVENING HRS, THEN ENDED MOST STORMS AFTER MIDNIGHT EXCEPT ALONG
THE KS BORDER. FAIRLY STRONG EASTERLY WINDS BEHIND DEPARTING
CONVECTION SHOULD SHOVE DEEPER LOW LEVEL MOISTURE WESTWARD
TOWARD THE MOUNTAINS, SETTING UP POTENTIAL CONVECTION ON THE
PLAINS FOR SUNDAY.
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
ISSUED AT 141 PM MDT FRI SEP 18 2026
POTENTIAL DAY-2 SEVERE SET-UP ON THE PLAINS SUNDAY, AS POST
FRONTAL UPSLOPE DEEPENS UNDER BRISK W-SW FLOW ALOFT, WHILE
STRONG UPPER TROUGH LIFTS OUT OF WY INTO THE HIGH PLAINS. CAPE
1K-2K J/KG AND 0-6KM SHEAR OVER 30 KTS (LOCALIZED 40-50 KTS
BETWEEN KCOS AND KLIC) LOOK FAVORABLE FOR STRONG/SEVERE STORMS,
ESPECIALLY WITH DYNAMIC LIFT FROM THE UPPER TROUGH PASSING OVER
THE REGION. STORMS LIKELY INITIATE ALONG THE PALMER DIVIDE
MID/LATE AFTERNOON, SPREADING SOUTHEAST ONTO THE PLAINS THROUGH
THE EVENING. NBM POPS LOOKED OK FOR THE MOST PART, BUT DID TRIM
BACK NUMBERS SOME, ESPECIALLY ALONG THE WETS/SRN I-25 CORRIDOR,
WHERE FORCING LOOKS WEAKER. MODELS SUGGEST WEAKENING ACTIVITY
COULD EVEN PERSIST INTO MON MORNING, THOUGH QPF BY THEN WILL BE
RATHER LIGHT.
FOR NEXT WEEK, TREND WOULD APPEAR TO BE TOWARD WETTER
CONDITIONS ONCE AGAIN, WITH UPPER HIGH OVER TX AND GENERAL
TROUGHING ALONG THE WEST COAST. STILL A GOOD DEAL OF
VARIANCE AMONG THE MODELS/ENSEMBLES REGARDING TIMING/STRENGTH ON
S/W TROUGHS AND ASSOCIATED MOISTURE SURGES, SO FORECAST
CONFIDENCE IS MODERATE AT THIS POINT. CURRENTLY THINKING IS MON
MAY END UP THE DRIEST DAY, AT LEAST OVER MOUNTAINS, WITH
SCATTERED STORMS STILL POSSIBLE ON THE PLAINS. WETTEST DAYS
COULD BE TUE AND AGAIN THU, WITH SRN MOUNTAINS (ERN SAN
JUANS/SRN SANGRES) MOST FAVORED FOR RAINFALL. TEMPS WILL LIKELY
STAY WITHIN A FEW DEGF OF SEASONAL AVERAGES THROUGH THE PERIOD.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1137 AM MDT FRI SEP 18 2026
AT KPUB AND KCOS, VFR THE NEXT 24 HRS, WITH A PROB30 FOR -TSRA
AT BOTH SITES (BEST CHANCE AT KCOS) FROM MID-AFTERNOON INTO
EARLY EVENING. MAIN STORM THREAT WILL BE GUSTY WINDS AND BRIEF
HEAVY RAINFALL. WEAK COLD FRONT WILL PASS THROUGH THE AREA
MID/LATE EVENING, WITH BRIEFLY GUSTY NORTH WINDS BEHIND THE
BOUNDARY UNTIL AROUND 06Z.
AT KALS, VFR THIS AFTERNOON AND EVENING, WITH A PROB30 FOR -TSRA
FROM MID-AFTERNOON INTO EARLY EVENING. STORM THREAT THEN ENDS
TOWARD SUNSET WITH MID/HIGH LEVEL CLOUD DECK OVERNIGHT. DID
INCLUDE A TEMPO FOR FOG/STRATUS 10Z-14Z AS WINDS BECOME LIGHT
AND LOW LEVELS SATURATE.
PUB WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...PETERSEN
LONG TERM...PETERSEN
AVIATION...PETERSEN
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