Alert archive / Arizona / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 59, NWS Flagstaff, AZ

August 8, 2015Navajo County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 8, 2015, 2:04 PM MDT for Navajo County, Arizona. It was in force for 26 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 8, 2015, 2:04 PM MDT (20:04 UTC)
Expired
Aug 8, 2015, 2:30 PM MDT
In force
26 min
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 122 km from the middle of the area, began a volume at 20:06 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Flagstaff, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 8, 10:23 AM MDT, 3 hours 41 minutes earlier.

Area forecast discussion, Aug 8, 10:23 AM MDT, 3 hours 41 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
923 AM MST SAT AUG 8 2015

.SYNOPSIS...FAIR CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
CONTINUE TODAY ACROSS CENTRAL AND EASTERN ARIZONA. A GRADUAL WEST
TO EAST DRYING TREND WILL DEVELOP ON SUNDAY AND MONDAY. DEEPER
MOISTURE WILL RETURN AGAIN NEXT WEEK...RAMPING UP STORM ACTIVITY
FROM TUESDAY ONWARD.

&&

.DISCUSSION...THE GREAT BASIN LOW HAS MOVED NORTH INTO SOUTHERN
IDAHO THIS MORNING WITH A DRYING SOUTHWEST FLOW OVER ARIZONA.
DRIER AIR CAN BE SEEN ON SATELLITE IMAGERY THIS MORNING PUSHING
INTO NORTHWESTERN ARIZONA AND THIS WILL LEAD TO A DECREASE IN
ACTIVITY ACROSS WESTERN ARIZONA AS COMPARED TO YESTERDAY. A MOIST
BOUNDARY LAYER EXISTS ALONG AND NORTH OF THE RIM FROM YESTERDAY'S
RAINFALL AND THIS WILL LEAD TO SOME INSTABILITY THIS AFTERNOON.
OVERALL...WE STILL EXPECT SCATTERED SHOWERS AND STORMS THIS
AFTERNOON WITH THE BEST CHANCES ACROSS EASTERN ARIZONA...AND ONLY
ISOLATED ACTIVITY ACROSS WESTERN COCONINO/YAVAPAI COUNTIES. A
STRONG STORM CANNOT BE RULED OUT...AND WOULD BE MOST LIKELY ACROSS
FAR NORTHERN ARIZONA WHERE VERTICAL WIND SHEAR REMAINS ELEVATED.

&&

.PREV DISCUSSION /426 AM MST/...A LOW PRESSURE SYSTEM WILL MOVE
NORTHEASTWARD AWAY FROM ARIZONA TODAY AS ANOTHER PACIFIC LOW MOVES
DOWN THE WEST COAST. THE DEEP TROPICAL MOISTURE PLUME WILL SHIFT
EASTWARD KEEPING THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS
OVER CENTRAL AND EASTERN ARIZONA TODAY. OVER FAR WESTERN ARIZONA A
FEW STORMS REMAIN IN THE FORECAST AS DRIER AIR STABILIZES THE AIR
MASS LIMITING CONVECTIVE SHOWERS.

SUNDAY AND MONDAY...EXPECT A LOW GRADE MONSOON PATTERN AS DRIER
AIR MOVES INTO ARIZONA FROM THE SOUTHWEST. ON MONDAY...A RIDGE
AXIS MOVING INTO ARIZONA FROM THE SOUTH WILL HELP TO STABILIZE THE
UPPER ATMOSPHERE.

TUESDAY THROUGH FRIDAY...A SEASONABLY STRONG PACIFIC LOW WILL FORM
JUST WEST OF THE CALIFORNIA COAST AND THE SUBTROPICAL RIDGE EAST
OF ARIZONA WILL BUILD NORTH. THE INTERACTION BETWEEN THE LOW AND
THE HIGH OVER NEW MEXICO AND TEXAS WILL BRING A STRONG SOUTHERLY
FLOW AND ADVECT DEEPER MOISTURE BACK INTO ARIZONA. EXPECT
INCREASING MOISTURE...CLOUDS AND A RETURN TO THUNDERSTORM ACTIVITY
FROM TUESDAY ONWARD.

&&

.AVIATION...FOR THE 18Z PACKAGE...EXPECT MOSTLY SCATTERED SHRA/TSRA
TO DEVELOP FROM KFLG EASTWARD AFT 18Z-19Z SAT. MOST CEILINGS WILL BE
4-6KFT AGL IN SHOWERS...WITH BRIEF PERIODS OF IFR CONDITIONS
POSSIBLE UNDER THE STRONGEST STORMS. STORM ACTIVITY WILL DECREASE
BETWEEN 02-04Z WITH MAINLY ISOLATED SHRA/TSRA OVER APACHE COUNTY
OVERNIGHT. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

PUBLIC...MCS/MCS
AVIATION...RR

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF

In the hours before

Special weather statement, Aug 8, 12:48 PM MDT, 1 hour 16 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1148 AM MST SAT AUG 8 2015

AZZ012-040-081915-
LITTLE COLORADO RIVER VALLEY IN COCONINO COUNTY-
NORTHEAST PLATEAUS AND MESAS SOUTH OF HWY 264-
1148 AM MST SAT AUG 8 2015

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL COCONINO COUNTY
UNTIL 1215 PM MST...

AT 1147 AM MST...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 8
MILES EAST OF WUPATKI NATIONAL MONUMENT...OR 29 MILES NORTHEAST OF
FLAGSTAFF. THIS STORM WAS NEARLY STATIONARY.

HALF INCH HAIL AND WIND GUSTS OF 50 TO 55 MPH WILL BE POSSIBLE WITH
THIS STORM.

THIS STORM WILL REMAIN OVER MAINLY RURAL AREAS OF EAST CENTRAL
COCONINO COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 3535 11129 3548 11138 3569 11107 3548 11092
TIME...MOT...LOC 1847Z 242DEG 4KT 3548 11123

MCS
Special weather statement, Aug 8, 1:20 PM MDT, 44 minutes before
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Special weather statement, Aug 8, 1:32 PM MDT, 32 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1232 PM MST SAT AUG 8 2015

AZZ012-013-082000-
LITTLE COLORADO RIVER VALLEY IN COCONINO COUNTY-LITTLE COLORADO RIVER
VALLEY IN NAVAJO COUNTY-
1232 PM MST SAT AUG 8 2015

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL NAVAJO COUNTY UNTIL
100 PM MST...

AT 1228 PM MST...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
NEAR WINSLOW...MOVING NORTHEAST AT 20 MPH.

WIND GUSTS OF 50 TO 55 MPH WILL BE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
WINSLOW AND HOMOLOVI STATE PARK CAMPGROUND.
I-40 BETWEEN MP253 AND MP267

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 3489 11071 3499 11080 3516 11056 3500 11040
TIME...MOT...LOC 1928Z 235DEG 17KT 3500 11061

MOTTICE
Special weather statement, Aug 8, 1:54 PM MDT, 10 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1254 PM MST SAT AUG 8 2015

AZZ012-015-082045-
LITTLE COLORADO RIVER VALLEY IN COCONINO COUNTY-WESTERN MOGOLLON RIM-
1254 PM MST SAT AUG 8 2015

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL COCONINO COUNTY
UNTIL 145 PM MST...

AT 1253 PM MST...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 9
MILES NORTHWEST OF WUPATKI NATIONAL MONUMENT...OR 28 MILES NORTH OF
FLAGSTAFF...MOVING EAST AT 10 MPH.

HALF INCH HAIL AND WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
WUPATKI NATIONAL MONUMENT AND WUPATKI VISITORS CENTER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

LAT...LON 3549 11158 3565 11163 3580 11129 3553 11120
TIME...MOT...LOC 1953Z 251DEG 10KT 3560 11151

MCS

The office that day

Everything else NWS Flagstaff, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 7, 7:07 PM MDTSevere Thunderstorm WarningFGZCoconino23 min
Aug 7, 7:25 PM MDTSevere Thunderstorm WarningFGZCoconino35 min
Aug 7, 11:40 PM MDTAreal Flood AdvisoryFGZCoconino110 min
Aug 8, 12:48 PM MDTSpecial Weather StatementFGZ27 min
Aug 8, 1:20 PM MDTSpecial Weather StatementFGZCoconino25 min
Aug 8, 1:32 PM MDTAreal Flood AdvisoryFGZCoconino, Navajo118 min
Aug 8, 1:32 PM MDTSpecial Weather StatementFGZNavajo28 min
Aug 8, 1:54 PM MDTSpecial Weather StatementFGZCoconino51 min
Aug 8, 2:17 PM MDTSevere Thunderstorm WarningFGZCoconino28 min
Aug 8, 3:22 PM MDTSpecial Weather StatementFGZCoconino23 min
Aug 8, 3:45 PM MDTSevere Thunderstorm WarningFGZCoconino, Navajo30 min
Aug 8, 4:29 PM MDTSpecial Weather StatementFGZNavajo46 min
Aug 8, 5:17 PM MDTSpecial Weather StatementFGZ43 min
Aug 8, 5:49 PM MDTSpecial Weather StatementFGZ41 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2015Every severe thunderstorm warning in 2015

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.