Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 18, NWS Flagstaff, AZ

July 4, 2001Coconino County, Yavapai County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 4, 2001, 9:18 PM MST for Coconino County, Yavapai County, Arizona. It was in force for 27 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: Jul 4, 2001, 9:18 PM MST (04:18 UTC)
Expired: Jul 4, 2001, 9:45 PM MST
In force: 27 min
Issued by: NWS Flagstaff, AZ
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Coconino County, AZ, Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 134 km from the middle of the area, began a volume at 04:20 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 4, 3:30 PM MST	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 4.3 hours before the alert went out and 58 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1020 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 2258 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: -12 m²/s²
0-3 km storm-relative helicity: 64 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS55 KFGZ 050422
SVRFLG

AZC005-025-050445-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
918 PM MST WED JUL 4 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN COCONINO COUNTY IN ARIZONA
  NORTH CENTRAL YAVAPAI COUNTY IN ARIZONA

* UNTIL 945 PM MST

* AT 918 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 7 MILES EAST OF ASH FORK...OR ABOUT 32 MILES
  NORTH OF CHINO VALLEY...MOVING WEST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL AFFECT ASH FORK AT 930 PM 
MST...INTERSTATE 40 FROM DEVIL DOG HILL WESTWARD TO MILE MARKER 
135...AND STATE ROUTE 89 FROM MILE MARKER 355 NORTHWARD TO ASH FORK.

LARGE HAIL AND VERY STRONG WINDS ARE LIKELY WITH THIS SEVERE 
THUNDERSTORM. IF YOU ARE IN THE PATH OF THE STORM...PUT YOUR CAR IN 
A GARAGE AND MOVE TO A SUBSTANTIAL SHELTER.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY 
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST 
OFFICE.

LAT...LON 3517 11263 3514 11239 3525 11227 3526 11234
          3526 11239 3525 11258

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 Jul 4, 2:30 PM MST, 6 hours 48 minutes earlier.

Area forecast discussion, Jul 4, 2:30 PM MST, 6 hours 48 minutes before

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST WED JUL 04 2001

SYNOPSIS...HIGH PRESSURE ALOFT WILL SHIFT EASTWARD OVER THE NEXT FEW
DAYS WITH SOME INCREASE IN MOISTURE OVER NORTHERN ARIZONA AS SOUTHERLY
FLOW DEVELOPS. AS A RESULT...LOOK FOR THE CHANCE OF MAINLY AFTERNOON
AND EVENING THUNDERSTORMS TO CONTINUE INTO EARLY NEXT WEEK.

DISCUSSION...STRONG UPPER RIDGE CENTERED OVER THE UTAH/COLORADO
BORDER THIS AFTERNOON. MODELS IN GENERAL AGREEMENT IN MOVING THE
RIDGE EASTWARD OVER THE NEXT TWO DAYS. DEEP SOUTHEASTERLY FLOW WILL
CONTINUE ON THURSDAY BUT BECOME MORE SOUTHERLY ON FRIDAY AS A TROUGH
ON THE WESTERN EDGE OF THE RIDGE MOVES NORTHWARD ACROSS ARIZONA.
EXPECT A GENERAL UPTICK IN MOISTURE AND THUNDERSTORM COVERAGE
THURSDAY AND FRIDAY AS FLOW TURNS TO A MORE MOIST SOUTHERLY
TRAJECTORY. TEMPERATURES WILL REMAIN ABOVE NORMAL WITH LIGHT AND
VARIABLE WINDS ON THURSDAY. WITH UPPER TROUGH APPROACHING ON FRIDAY
WILL GO WITH A GENERAL PARTLY TO MOSTLY CLOUDY FORECAST WITH NO
SIGNIFICANT DIURNAL TRENDS IN CLOUDINESS OR THUNDERSTORM ACTIVITY.
DAYTIME HIGHS WILL LOWER SOME ON FRIDAY WITH INCREASED MOISTURE AND
CLOUDINESS. FRIDAY COULD GET INTERESTING NEAR THE MOGOLLON RIM WITH
DEEP MOISTURE POISED TO MOVE INTO CENTRAL ARIZONA..STRONG SOUTHERLY
FLOW AND VERTICAL SHEAR. A GOOD SETUP FOR HEAVY RAIN PRODUCING
STORMS WITH A TRAINING BEHAVIOR. HOWEVER...IF A MIDLEVEL CLOUD DECK
FORMS IN ADVANCE OF THE TROUGH AXIS ON FRIDAY WONT SEE MUCH MORE
THAN SCATTERED STORMS.

IN THE EXTENDED...INVERTED TROUGH OVER BAJA CALIFORNIA WILL PHASE
WITH WEAK SHORT-WAVE TROUGH IN THE WESTERLY FLOW OFF THE CALIFORNIA
COAST. THIS WILL CAUSE A RELATIVELY STRONG TROUGH TO MOVE ACROSS
ARIZONA ON FRIDAY. THE LATEST AVN MODEL DATA IS SUGGESTING THIS
SYSTEM WILL DEVELOP STRONG SOUTHWEST TRAJECTORIES WITH A DRIER AIR
MASS PUNCHING INTO ARIZONA OVER THE WEEKEND. HOWEVER...WOULD LIKE TO
SEE A COUPLE MODEL RUNS BEFORE CHANGING THE CURRENT TRENDS IN THE
EXTENDED. WILL CONTINUE WITH THE GENERAL PARTLY CLOUDY WITH A CHANCE
OF THUNDERSTORMS IN THE EXTENDED.

MCCOLLUM

.FGZ...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 4, 8:34 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	41 min
Jul 5, 11:50 AM MST	Severe Thunderstorm Warning	FGZ	Coconino	35 min
Jul 5, 12:52 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	43 min
Jul 5, 1:34 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	41 min
Jul 5, 1:58 PM MST	Flash Flood Warning	FGZ	Yavapai	2 hr
Jul 5, 2:13 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	47 min
Jul 5, 3:08 PM MST	Severe Thunderstorm Warning	FGZ	Gila	52 min
Jul 5, 4:06 PM MST	Severe Thunderstorm Warning	FGZ	Gila	39 min
Jul 5, 4:32 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	43 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2001 Every severe thunderstorm warning in 2001

Sources

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