Alert archive / Arizona / Severe Thunderstorm Warnings in 2019
Severe Thunderstorm Warning 50, NWS Flagstaff, AZ
NWS Flagstaff, AZ issued this severe thunderstorm warning at Sep 16, 2019, 12:35 PM MST for Apache County, Navajo County, Arizona. It was in force for 40 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
- Sep 16, 2019, 12:35 PM MST (19:35 UTC)
- Expired
- Sep 16, 2019, 1:15 PM MST
- In force
- 40 min
- Issued by
- NWS Flagstaff, AZ
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Apache County, AZ, Navajo County, AZ
The radar
The Flagstaff radar (KFSX), 149 km from the middle of the area, began a volume at 19:35 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
Phoenix, AZ (KPSR), launched 12:00Z, 7.6 hours before the alert went out and 289 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.
- Mixed-layer CAPE
- 436 J/kg
- Mixed-layer CIN
- -185 J/kg
- Mixed-layer LCL
- 2091 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 56 m²/s²
- 0-3 km storm-relative helicity
- 98 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
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 Sep 16, 9:39 AM MST, 2 hours 56 minutes earlier.
Area forecast discussion, Sep 16, 9:39 AM MST, 2 hours 56 minutes before
Area Forecast Discussion National Weather Service Flagstaff AZ 939 AM MST Mon Sep 16 2019 .SYNOPSIS...Moisture will remain in place across northern Arizona today as a low pressure system moves into the Great Basin. The result will be a chance for showers and thunderstorms through this evening, along with strengthening southwest winds. Drier and breezier conditions are forecast for Tuesday and Wednesday. && .UPDATE...The trough moving onto the west coast this morning continues to pull low-level moisture northward into central and northern Arizona. Some isolated shower and thunderstorm activity is already developing from around Prescott up to near Williams and Bellemont. Still expecting storm coverage to increase into the afternoon and early evening, with the highest coverage along/east of a Prescott to Flagstaff to four corners line. Best instability is forecast over Gila and southern Yavapai counties where a few stronger storms with hail and gusty winds could develop. Winds at the surface and aloft have increased this morning, and storms will be moving toward the northeast at around 20 mph. && .PREV DISCUSSION /352 AM MST/...Satellite indicates mid-level clouds from about I-17/US 89 westward, with an area of lower clouds near the New Mexico state line. Surface observations and ADOT web cameras are indicating just lower clouds with no appreciable fog, but patchy fog has been added to a few spots in eastern Arizona through 8 am MST just in case it develops as the low clouds dissipate. For today...SPC mesoanalysis indicates an area of instability across much of Yavapai County at present. Hi-res models indicate the possibility of a few storms over this area through the morning. Coverage of showers and storms is expected to increase to the north and east after about noon, with some training storms possible given the increase in southwesterly winds. Tuesday and Wednesday...HREF mean QPF is much less on Tuesday than on Monday, with a few storms possible in the afternoon but fairly weak in nature given the expected drying. Southwest wind gusts to around 35 mph are forecast along the Mogollon Rim and Coconino Plateau on both Tuesday and Wednesday as another low pressure system drops from the Pacific Northwest into the Great Basin. Temperatures will be near to slightly above normal. From Thursday onward...the strongest winds of the week are forecast for Thursday with gusts in excess of 40 mph expected, along with a chance for precipitation especially in eastern Arizona. Cooler temperatures are expected Thursday as the trough gets closer. Friday through Sunday, a general westerly flow is expected with some weak disturbances perhaps moving through. Frost and even some local freezing temperatures will be possible at high elevations through this period. Low rain chances appear again toward the early part of next week. && .AVIATION...For the 18Z package...Isolated to scattered SHRA/TSRA are expected through this evening with the higher coverage along/east of a KPRC-KFLG-KOV7 line. Gusty winds to 35 kt and decreased visibility near the strongest storms. Otherwise, VFR conditions are forecast through 18z Tuesday. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Moisture will remain over northern Arizona today with a chance for showers and thunderstorms during the afternoon and evening. Southwest winds will increase from today into Tuesday which will promote drying. Much lower storm coverage is expected on Tuesday. Wednesday through Friday...Near critical fire weather conditions will be possible across portions of northwestern Arizona Wednesday and Thursday due to gusty southwest winds and low relative humidity. A chance of precipitation returns Thursday to mainly eastern Arizona. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...JJ/AT AVIATION...JJ FIRE WEATHER...JJ For Northern Arizona weather information visit weather.gov/flagstaff
In the hours before
Special weather statement, Sep 16, 11:14 AM MST, 1 hour 21 minutes before
Special Weather Statement National Weather Service Flagstaff AZ 1114 AM MST Mon Sep 16 2019 AZZ015-037-038-161845- Yavapai County Valleys and Basins-Western Mogollon Rim-Oak Creek and Sycamore Canyons- 1114 AM MST Mon Sep 16 2019 ...SIGNIFICANT WEATHER ADVISORY FOR SEDONA IN YAVAPAI COUNTY AND PORTIONS OF COCONINO COUNTIES UNTIL 1145 AM MST... At 1112 AM MST, Doppler radar was tracking a strong thunderstorm near Page Springs, or near Sedona, moving northeast at 25 mph. Penny size hail and wind gusts up to 50 mph will be possible with this storm. Locations impacted include... Sedona, Junipine Resort, Garland's Oak Creek Lodge, Slide Rock State Park, Red Rock State Park, Manzanita Campground and West Fork Of Oak Creek. LAT...LON 3477 11194 3487 11201 3501 11177 3484 11164 TIME...MOT...LOC 1812Z 240DEG 22KT 3483 11188 ET
Special weather statement, Sep 16, 12:00 PM MST, 35 minutes before
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</html>The office that day
Everything else NWS Flagstaff, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 16, 11:14 AM MST | Special Weather Statement | FGZ | 31 min | |
| Sep 16, 12:00 PM MST | Special Weather Statement | FGZ | 30 min | |
| Sep 16, 1:58 PM MST | Special Weather Statement | FGZ | Apache | 32 min |
| Sep 16, 2:07 PM MST | Severe Thunderstorm Warning | FGZ | Apache | 23 min |
| Sep 16, 4:33 PM MST | Special Weather Statement | FGZ | Yavapai | 27 min |
Nearby
Severe Thunderstorm Warnings in Arizona, 2019Every severe thunderstorm warning in 2019
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.