Alert archive / Arizona / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 129, NWS Flagstaff, AZ

October 19, 2015Yavapai County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Oct 19, 2015, 10:26 PM MST for Yavapai County, Arizona. It was in force for 49 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: Oct 19, 2015, 10:26 PM MST (05:26 UTC)
Expired: Oct 19, 2015, 11:15 PM MST
In force: 49 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon

County Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 124 km from the middle of the area, began a volume at 05:28 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 nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 5.4 hours before the alert went out and 98 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: 6 J/kg
Mixed-layer CIN: -66 J/kg
Mixed-layer LCL: 1311 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 164 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

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 Oct 19, 8:16 PM MST, 2 hours 10 minutes earlier.

Area forecast discussion, Oct 19, 8:16 PM MST, 2 hours 10 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
816 PM MST MON OCT 19 2015

.SYNOPSIS...PERSISTENT LOW PRESSURE SYSTEMS WILL LEAD TO CHANCES
FOR SHOWERS AND THUNDERSTORMS AND COOL CONDITIONS OVER NORTHERN
ARIZONA THROUGH THURSDAY. A DRYING TREND AND A RETURN TO NEAR
NORMAL TEMPERATURES ARE FORECAST FRIDAY THROUGH THE WEEKEND.

&&

.DISCUSSION...THOUGH THUNDERSTORM COVERAGE HAS BEEN RATHER
UNIMPRESSIVE THIS EVENING...WE HAVE SEEN ISOLATED SEVERE STORM
ACTIVITY IN YAVAPAI COUNTY. WE CAN SEE TWO DISTINCT SHORTWAVES ON
WATER VAPOR SATELLITE IMAGERY THIS EVENING (ONE JUST OFF THE
CA/BAJA COAST AND 2ND ALONG THE SAN FRANCISCO COASTLINE) WHICH
ARE BOTH ACTING TO DEEPEN THE WEST COAST TROUGH AS IT DROPS SOUTH
INTO THE SOUTHWESTERN UNITED STATES. THE PERIOD OF CONCERN FOR
SEVERE WEATHER WILL CONTINUE TO BE OVER THE NEXT 18 HRS AS THE LOW
DEEPENS AND FORMS A CLOSED LOW OVER THE LOWER COLORADO RIVER BY
NOON TUESDAY. THE OVERALL THINKING REMAINS UNCHANGED WITH THE BEST
POTENTIAL BETWEEN NOW AND TUESDAY MORNING FOR COCONINO AND YAVAPAI
COUNTIES...SHIFTING EAST INTO GILA/NAVAJO/APACHE COUNTIES FROM
TUESDAY MORNING THROUGH EARLY AFTERNOON.

&&

.PREV DISCUSSION /322 PM MST/ BY LATE TONIGHT THROUGH TUESDAY
MORNING, AN INCREASE IN STORM COVERAGE IS POSSIBLE AS A WEST COAST
TROUGH APPROACHES AND RESULTS IN COOLING ALOFT A WEAK LARGE SCALE
LIFT. THIS COULD BE ENOUGH TO TRIGGER OVERNIGHT CONVECTION, AND IN
THE PRESENCE OF STRONG DEEP-LAYER SHEAR, A FEW OF THESE STORMS
COULD BECOME SEVERE. THIS THREAT PERSISTS THROUGH THE MORNING
HOURS TUESDAY FOR MUCH OF NORTHERN ARIZONA, THEN SHIFTS TO MAINLY
EASTERN ARIZONA BY LATE MORNING AND AFTERNOON AS WIND SHEAR
DECREASES CLOSER TO THE CENTER OF THE LOW PRESSURE SYSTEM.

THE LOW PRESSURE SYSTEM IS FORECAST TO BE NEARLY STATIONARY
TUESDAY EVENING THROUGH WEDNESDAY WITH A GOOD CHANCE OF SHOWERS
AND THUNDERSTORMS CONTINUING OVER MOST OF NORTHERN ARIZONA. WIND
SHEAR VALUES DECREASE SO THE THREAT OF SEVERE THUNDERSTORMS IS
MUCH LOWER. A CHANCE OF SHOWERS AND A FEW STORMS CONTINUES
THURSDAY WITH ONLY A SLIGHT CHANCE BY FRIDAY. MODELS ARE IN GOOD
AGREEMENT THAT IMPROVING WEATHER FINALLY ARRIVES FOR THE WEEKEND.

&&

.AVIATION...FOR THE 06Z PACKAGE...EXPECT SCT SHRA/TSRA ALONG AND
WEST OF A KPGA-KFLG-KPAN LINE THROUGH 12Z TUESDAY WITH ISOLATED
MVFR/IFR IN +TSRA. THERE IS A MARGINAL THREAT OF ISOLATED SEVERE
STORMS PRODUCING HAIL AND STRONG WINDS. COVERAGE OF SHRA/TSRA IS
EXPECTED TO INCREASE TUESDAY AS LOW PRESSURE MOVES ACROSS THE
REGION. STRONGER STORMS WILL PRODUCE MVFR/IFR CONDITIONS...HAIL
AND GUSTY WINDS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

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

&&

PUBLIC...MCS/JJ
AVIATION...MCS

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF

Hazardous weather outlook, Oct 19, 1:50 PM MST, 8 hours 36 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 19, 6:27 PM MST	Areal Flood Advisory	FGZ	Coconino	12 hr
Oct 19, 6:38 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	23 min
Oct 19, 9:36 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	24 min
Oct 19, 9:52 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	23 min
Oct 19, 10:03 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	42 min
Oct 19, 10:11 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	49 min
Oct 19, 10:56 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	34 min
Oct 20, 1:21 AM MST	Special Weather Statement	FGZ		24 min
Oct 20, 1:56 AM MST	Severe Thunderstorm Warning	FGZ	Coconino, Gila	24 min
Oct 20, 2:09 AM MST	Special Weather Statement	FGZ		36 min
Oct 20, 3:08 AM MST	Severe Thunderstorm Warning	FGZ	Apache, Navajo	37 min
Oct 20, 3:58 AM MST	Special Weather Statement	FGZ		32 min
Oct 20, 4:25 AM MST	Severe Thunderstorm Warning	FGZ	Navajo	20 min
Oct 20, 5:09 AM MST	Severe Thunderstorm Warning	FGZ	Yavapai	41 min
Oct 20, 5:20 AM MST	Special Weather Statement	FGZ		25 min
Oct 20, 5:27 AM MST	Severe Thunderstorm Warning	FGZ	Yavapai	33 min
Oct 20, 6:24 AM MST	Areal Flood Advisory	FGZ	Coconino	6 hr
Oct 20, 7:35 AM MST	Special Weather Statement	FGZ		25 min
Oct 20, 8:57 AM MST	Special Weather Statement	FGZ		33 min
Oct 20, 9:13 AM MST	Severe Thunderstorm Warning	FGZ	Navajo	21 min
Oct 20, 9:37 AM MST	Severe Thunderstorm Warning	FGZ	Coconino, Navajo	23 min
Oct 20, 9:56 AM MST	Areal Flood Advisory	FGZ	Yavapai	3 hr
Oct 20, 9:59 AM MST	Severe Thunderstorm Warning	FGZ	Coconino, Navajo	15 min
Oct 20, 10:22 AM MST	Flash Flood Warning	FGZ	Yavapai	3 hr
Oct 20, 10:24 AM MST	Severe Thunderstorm Warning	FGZ	Coconino, Navajo	36 min
Oct 20, 10:29 AM MST	Special Weather Statement	FGZ	Navajo	31 min
Oct 20, 10:41 AM MST	Tornado Warning	FGZ	Navajo	34 min
Oct 20, 10:46 AM MST	Severe Thunderstorm Warning	FGZ	Gila	29 min
Oct 20, 11:03 AM MST	Severe Thunderstorm Warning	FGZ	Apache	27 min
Oct 20, 11:06 AM MST	Tornado Warning	FGZ	Navajo	24 min
Oct 20, 11:28 AM MST	Severe Thunderstorm Warning	FGZ	Coconino, Gila, Navajo	32 min
Oct 20, 11:34 AM MST	Areal Flood Advisory	FGZ	Navajo	3 hr
Oct 20, 11:40 AM MST	Special Weather Statement	FGZ		50 min
Oct 20, 11:48 AM MST	Special Weather Statement	FGZ		42 min
Oct 20, 12:09 PM MST	Severe Thunderstorm Warning	FGZ	Apache	36 min
Oct 20, 12:53 PM MST	Special Weather Statement	FGZ		37 min
Oct 20, 1:21 PM MST	Areal Flood Advisory	FGZ	Apache, Navajo	3 hr
Oct 20, 1:39 PM MST	Severe Thunderstorm Warning	FGZ	Apache	21 min
Oct 20, 1:46 PM MST	Special Weather Statement	FGZ		29 min
Oct 20, 1:57 PM MST	Special Weather Statement	FGZ		33 min
Oct 20, 3:07 PM MST	Special Weather Statement	FGZ		23 min
Oct 20, 4:06 PM MST	Special Weather Statement	FGZ		24 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2015 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.