289
FXUS65 KFGZ 190937
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
237 AM MST SAT JUL 19 2025
SYNOPSIS
FOR TODAY, THE BEST CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL BE EAST OF INTERSTATE 17 AND SOUTH OF
INTERSTATE 40, WITH MORE ISOLATED STORM ACTIVITY FORECAST
ELSEWHERE. LOW GRADE MONSOON CONDITIONS ARE FORECAST TO PERSIST
INTO NEXT WEEK, WITH THE GREATEST STORM CHANCES OVER THE HIGHER
TERRAIN FROM FLAGSTAFF EASTWARD.
DISCUSSION
NORTHERN ARIZONA REMAINS SANDWICHED BETWEEN A 500 MB
LOW CENTERED OVER SOUTHERN CALIFORNIA AND A BROAD 500 MB HIGH
CENTERED OVER TEXAS. SOUTHERLY FLOW BETWEEN THESE FEATURES
CONTINUES TO ADVECT TROPICAL MOISTURE INTO THE STATE, BUT WITH A
NOTICEABLE MOIST-EAST TO DRY-WEST ORIENTED GRADIENT THAT WILL
LARGELY DICTATE THE CHANCES FOR SHOWERS AND THUNDERSTORMS THIS
AFTERNOON.
FOR TODAY, THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE
EAST OF INTERSTATE 17 AND SOUTH OF INTERSTATE 40, WITH MORE
ISOLATED STORM ACTIVITY FORECAST ELSEWHERE. WHERE THE GREATEST
MOISTURE EXISTS, MARGINAL CAPE BETWEEN 100-500 J/KG IS FORECAST.
ESPECIALLY IN THIS AREA, STORMS WILL BE SLOW MOVING, SO FLASH
FLOODING WILL BE THE PRIMARY THREAT. HOWEVER, BETWEEN 25-35 KTS OF
DEEP LAYER SHEAR IS ALSO FORECAST. THIS IMBALANCE WILL MAKE IT
DIFFICULT FOR BUILDING STORMS TO REMAIN INTACT, BUT FOR THOSE THAT
DO SURVIVE, A FEW MORE POWERFUL ROTATING STORMS ARE POSSIBLE
TODAY AS WELL. SO, ISOLATED, SEVERE STORMS CANNOT BE COMPLETELY
RULED OUT.
ACTIVE, BUT LOW GRADE MONSOON CONDITIONS ARE FORECAST TO CONTINUE
INTO EARLY NEXT WEEK, WITH THE GREATEST STORM CHANCES OVER THE
HIGHER TERRAIN FROM FLAGSTAFF EASTWARD. AROUND THE MIDDLE OF NEXT
WEEK, THE GENERAL MODEL CONSENSUS SHOWS THAT A DEEP LOW WILL
BECOME ESTABLISHED OFF THE WEST COAST, FORCING THE SUBTROPICAL
HIGH AND TROPICAL MOISTURE PLUME EASTWARD, LEADING TO A DOWNTREND
IN STORM ACTIVITY. THAT SAID, CONSIDERABLE SPREAD EXISTS, AND SOME
MODEL SOLUTIONS KEEP THE STATE ENTRENCHED IN ENOUGH MOISTURE FOR
A CONTINUATION OF LOW GRADE MONSOON ACTIVITY THROUGH THE WEEK.
AVIATION...SATURDAY 19/06Z THROUGH SUNDAY 20/06Z
VFR
CONDITIONS, ISOLATED THUNDERSTORMS POSSIBLE BETWEEN 18Z AND 03Z.
WINDS LIGHT AND VARIABLE OR TERRAIN DRIVEN OVERNIGHT, SW 5-15KTS,
GUSTS TO 20KTS DURING THE AFTERNOON. BRIEF MVFR AND GUSTY WINDS
POSSIBLE NEAR THUNDERSTORMS.
OUTLOOK...SUNDAY 20/06Z THROUGH TUESDAY 22/06Z...VFR CONDITIONS,
ISOLATED TO SCATTERED THUNDERSTORMS POSSIBLE EACH DAY BETWEEN 18Z
AND 03Z. WINDS SW-W 5-15KTS, GUSTS TO 20KTS DURING THE DAY, LIGHT
AND VARIABLE OR TERRAIN DRIVEN OVERNIGHT. BRIEF MVFR AND GUSTY
WINDS POSSIBLE NEAR THUNDERSTORMS.
FIRE WEATHER...SATURDAY AND SUNDAY
ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS ARE EXPECTED EACH AFTERNOON AND EVENING, MOST
NUMEROUS OVER THE EASTERN MOGOLLON RIM AND WHITE MOUNTAINS.
LOCALIZED WETTING RAINS AND GUSTY/ERRATIC OUTFLOW WINDS ARE LIKELY
IN THE VICINITY OF STORMS. AWAY FROM STORMS, DAYTIME WINDS
WEST/SOUTHWEST AT 5-10 MPH WITH GUSTS TO 10-20 MPH. EXPECT
SEASONABLY COOL TEMPERATURES AND DAILY MINIMUM RH 15-30%.
MONDAY THROUGH WEDNESDAY...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS EACH AFTERNOON/EVENING, WITH THE BEST CHANCES OVER THE
EASTERN MOGOLLON RIM AND WHITE MOUNTAINS. DAYTIME WINDS
WEST/SOUTHWEST AT 5-10 MPH WITH GUSTS TO 10-20 MPH. OTHERWISE,
THE FORECAST CALL FOR SEASONABLY COOL TEMPERATURES AND DAILY
MINIMUM RH 15-30%.
FGZ WATCHES/WARNINGS/ADVISORIES
NONE.
PUBLIC...RR
AVIATION...BERNHART
FIRE WEATHER...RR
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page