350
FXUS65 KFGZ 142150
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
250 PM MST THU AUG 14 2025
SYNOPSIS
INCREASING MONSOONAL MOISTURE AND COOLER TEMPERATURES
CONTINUE, WITH THE BEST CHANCES FOR THUNDERSTORMS THROUGH FRIDAY.
DRIER AND WARMER CONDITIONS LOOK TO GRADUALLY RETURN BY THE START OF
NEXT WEEK.
DISCUSSION
ARIZONA IS CURRENTLY UNDER A SYNOPTIC PATTERN WITH HIGH
PRESSURE TO OUR EAST, AND A TROUGH BEGINNING TO ESTABLISH OVER
CALIFORNIA. THE FLOW ALOFT IS SOUTHERLY, ALLOWING SUBTROPICAL
MOISTURE TO SURGE INTO OUR AREA AND BRING SCATTERED THUNDERSTORM
ACTIVITY FOR THE NEXT FEW DAYS. THIS MOISTURE SURGE IS NOT OVERLY
IMPRESSIVE, WITH PW PEAKING AT AROUND 0.75-1 INCHES ACROSS NORTHERN
AZ. OVERNIGHT SHOWERS ON WEDNESDAY NIGHT LED A THICK LAYER OF DEBRIS
CLOUDS OVER MUCH OF NORTHERN AZ THIS MORNING. MUCH OF THIS CLOUD
LAYER HAS FINALLY DISSIPATED, AND WE ARE SEEING ISOLATED TO
SCATTERED THUNDERSTORMS INITIATE ACROSS MUCH OF NORTHERN AZ.
HI-RES GUIDANCE HAS BEEN IN STRONG AGREEMENT THAT AN MCV WILL
MOVE ACROSS NORTHERN AZ LATE TONIGHT AND EARLY TOMORROW MORNING.
THIS WILL LIKELY BRING ANOTHER LAYER OF MID-LEVEL CLOUDS AND LIGHT
SHOWERS TOMORROW MORNING THAT WILL INHIBIT CONVECTIVE ACTIVITY
FOR FAR EASTERN AZ. HOWEVER, THINGS MAY BE MORE INTERESTING FOR
NORTH-CENTRAL AZ.
THE TROUGH OVER CALIFORNIA BEGINS TO INDUCE A MORE SOUTHWESTERLY
FLOW TOMORROW. THIS WILL BRING DRY AIR ALOFT THAT PUSHES AGAINST THE
CLOUD COVER ALONG THE WESTERN EDGE OF THE MCV. THIS WILL DECREASE
THE TOTAL PW, HOWEVER IT WILL LIKELY REMAIN LARGE ENOUGH ALONG THE
MCV EDGE WITH AMPLE SURFACE MOISTURE. THE TROUGH ALSO WILL BRING
COOL AIR ALOFT. THE RESULT IS A NARROW REGION WITH HIGH
INSTABILITY THAT DEVELOPS. HI-RES GUIDANCE IS PLACING THIS REGION
FLAGSTAFF AND NORTHWARD, AND IS PICKING UP ON THE POTENTIAL FOR
SOME TRAINING STORMS WITH HEAVY RAINFALL RATES. THERE IS STILL A
LOT OF UNCERTAINTY IN THE PLACEMENT OF THESE FEATURES, BUT GIVEN
THE LARGE SENSITIVE BURN SCARS IN THE KAIBAB PLATEAU AND LOW
THRESHOLDS FOR FLASH FLOODING, A FLASH FLOOD WATCH HAS BEEN ISSUED
THIS REGION AND SURROUNDING DRAINAGES.
INTO THE WEEKEND, THE DRY SOUTHWESTERLY FLOW BECOMES MORE
ESTABLISHED AND STARTS TO SWEEP OUT MUCH OF THE AVAILABLE MOISTURE.
A SIGNIFICANT DECREASE IN SHOWER COVERAGE IS EXPECTED SATURDAY.
BY SUNDAY, IT LOOKS AS IF WE WILL RETURN TO JUST ISOLATED COVERAGE
OF SHOWERS CONFINED TO THE WHITE MOUNTAINS. THIS PATTERN WILL
LIKELY CONTINUE THROUGH THE MIDDLE OF NEXT WEEK.
AVIATION...THURSDAY 14/18Z THROUGH FRIDAY 15/18Z
MAINLY VFR
CONDITIONS. SCATTERED -SHRA/-TSRA THROUGH 03Z THEN MAINLY
ISOLATED -SHRA. BRIEF MVFR CONDITIONS AND GUSTY, ERRATIC WINDS
POSSIBLE IN AND AROUND THUNDERSTORMS. OUTSIDE OF STORMS, SOUTHWEST
WINDS 10-15 KTS WITH GUSTS 20-25 KTS THROUGH 02Z. EXPECT LIGHT
AND VARIABLE WINDS OVERNIGHT AROUND 5-10 KTS.
OUTLOOK...FRIDAY 15/18Z THROUGH SUNDAY 17/18Z...MAINLY VFR
CONDITIONS. NUMEROUS SHRA/TSRA ON FRIDAY BECOMING ISOLATED ON
SATURDAY, MAINLY OVER THE HIGHER TERRAIN. BRIEF MVFR CONDITIONS
AND GUSTY, ERRATIC WINDS POSSIBLE IN AND AROUND THUNDERSTORMS.
OUTSIDE OF STORMS, SOUTHWEST WINDS 5-15 KTS EACH DAY WITH LIGHT
AND VARIABLE WINDS OVERNIGHT.
FIRE WEATHER...TODAY AND FRIDAY
COOLER TEMPERATURES WITH
INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS EACH DAY WITH
WETTING RAINS POSSIBLE. GUSTY AND ERRATIC OUTFLOW WINDS OF 35-45 MPH
IN AND AROUND STORMS WITH BRIEF PERIODS OF HEAVY RAINFALL. OUTSIDE
OF OUTFLOW WINDS, DAYTIME WINDS WEST-SOUTHWEST 10-20 MPH WITH
TERRAIN DRIVEN WINDS EACH NIGHT.
SATURDAY THROUGH MONDAY...SCATTERED SHOWERS AND THUNDERSTORMS ON
SATURDAY WITH DECREASING CHANCES THROUGH MONDAY. TEMPERATURES WILL
WARM EACH DAY WITH MINIMUM AFTERNOON RH VALUES DROPPING TO 10-30% BY
MONDAY. DAYTIME WINDS WEST-SOUTHWEST 10 TO 20 MPH EACH AFTERNOON
WITH TERRAIN DRIVEN WINDS EACH NIGHT. GUSTY AND ERRATIC OUTFLOW
WINDS POSSIBLE IN AND AROUND THUNDERSTORMS.
FGZ WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
AZZ004>006.
EXTREME HEAT WARNING UNTIL 8 PM MST THIS EVENING FOR AZZ006.
PUBLIC...LEWANDOWSKI
AVIATION...MCCOLLUM
FIRE WEATHER...MCCOLLUM
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
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