Alert archive / Utah / Special Weather Statements in 2021
Special Weather Statement, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this special weather statement at Jul 22, 2021, 4:48 PM MDT for Washington County, Utah. 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 as issued.
The facts
- Issued
- Jul 22, 2021, 4:48 PM MDT (22:48 UTC)
- Expired
- Jul 22, 2021, 5:15 PM MDT
- In force
- 27 min
- Issued by
- NWS Salt Lake City, UT
County Washington County, UT
The radar
The Cedar City radar (KICX), 72 km from the middle of the area, began a volume at 22:47 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
Las Vegas, NV (KVEF), launched 12:00Z, 10.8 hours before the alert went out and 212 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
- 112 J/kg
- Mixed-layer CIN
- -243 J/kg
- Mixed-layer LCL
- 2637 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 8 m²/s²
- 0-3 km storm-relative helicity
- -4 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
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</html>What forecasters said that day
The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Salt Lake City, UT wrote its last area forecast discussion before this special weather statement went out at Jul 22, 4:13 PM MDT, 35 minutes earlier.
Area forecast discussion, Jul 22, 4:13 PM MDT, 35 minutes before
Area Forecast Discussion
National Weather Service Salt Lake City UT
413 PM MDT Thu Jul 22 2021
.SYNOPSIS...
High pressure near the Four Corners will get suppressed southward
as a trough moves eastward along the Canadian border into Friday.
Drier westerly flow will move into northern Utah for the weekend,
while deep moisture will linger across the south leading to daily
showers and thunderstorms with localized heavy rainfall.
&&
.SHORT TERM (Through 12Z Sunday)...A shortwave trough will
continue to move along the Canadian border tonight and into Friday
which will switch winds aloft to westerly. The weak boundary
associated with the trough will move across Northwest Utah this
afternoon into this evening. A broken line of showers and
thunderstorms have developed over extreme NW Utah already and the
high resolution models have been indicating that this line will
move east Southeast into the Wasatch Front from Ogden to Prove
this evening. high increased the PoPs accordingly. Gusty winds in
excess of 45 mph are expected over the west desert but most
likely will be somewhat less than this by the time the storms
reach the Wasatch Front.
The westerly winds behind this boundary will bring in drier air
as well as smoke from the western fires. The smoke may be thick enough
to shave a couple of degrees off the max temperatures over
northwest Utah Friday and and most of the northern third of Utah
Saturday. However, temperatures will remain slightly above normal
both days.
Farther, south, deep moisture with PWs in excess of 1.25 and cape
over 1000 will prevail into this evening. A Flash Flood Watch
remains in effect until midnight across most of the area south of
I-70, excluding the St. George portion of Washington Co. A mix of
severe thunderstorms and flash flooding has been occurring in this
region this afternoon, including some areas just north into
Richfield. The storm motion has been mainly NE to E this
afternoon, but a switch to more E to possibly SE over eastern
portions of the area is expected by this evening. This will place
the drainages of the Escalante Staircase under a more vulnerable
flow for flash flooding into this evening. Most of the storm
activity will die off by midnight.
The 4 Corners' ridge will shift south and west by Friday and
this combined with an easterly wave moving into Arizona will
result in northerly flow aloft to develop over southern Utah. Once
again this will place the flash flood prone areas of the southern
tier counties to be under the gun for thunderstorms producing heavy
rain to move down drainage. The high resolution models are not all
in agreement with producing widespread thunderstorms, so have
held off on any highlights at this point, but would not be
surprised if another Flash Flood Watch gets issued tonight for
this region. Because the flow becomes more NE by late afternoon
and evening, St George will likely be in the cross-hairs for
thunderstorms Friday evening.
The drier air from the north will press a little farther south
into central Utah by Saturday, but the deep moisture will remain
pinned along the southern third of the state for another day of
potential flash flooding. Temperatures across the south will be
near normal, except have lower temps a little over the mountains
for Friday and Saturday where thunderstorms and cloud cover will
have a cooling influence of the max temps during the midday hours.
.LONG TERM (After 12Z Sunday)...As an inverted trough moves west
across Arizona on Sunday, monsoonal moisture will increase across
southern Utah. Widespread cloud cover early in the day could
initially limit convection, but the synoptic-scale lift should
overcome the limited thermally-driven instability. Storms may be
more broad and showery in nature initially, with ample moisture
allowing strong convection and heavy rainfall where the environment
is favorable. The relatively weak mid-level northeast flow will
allow storms to potentially track slowly down-drainage, greatly
enhancing the flash flood risk. As the low exits to the west,
precipitable water values will begin to climb above 1" first across
southern Utah by Monday, with the warm and moist airmass pushing
into northern Utah on Tuesday and into Wednesday. The return to
typical southerly monsoonal flow and primed environment keeps flash
flooding as the primary concern for the first half of next week.
By Wednesday, models suggest a shift to drier, northwesterly flow at
the lower levels across the northern half of the forecast area.
Ample amounts of moisture remain and diurnal convection can be
expected across much of the forecast area. Most of the convection
will likely initiate along higher terrain and orographic convergence
zones during the afternoon and evening on Wednesday. Where low level
dry air is undercutting the mid-level moisture, strong outflow winds
can be expected. Temperatures through the extended forecast period
will maximize on Saturday and Sunday with the St. George area and
Salt Lake Valley approaching or exceeding 100F before cooling by a
few degrees and sitting near normal for the upcoming work week.
&&
.AVIATION...KSLC...Northerly winds are expected to persist until
04-05z, when a round of showers and/or thunderstorms will likely
bring periods of gusty and erratic winds embedded in a primarily
south flow. Winds should diminish to normal diurnal magnitude by
07z. VFR conditions are expected throughout the TAF period.
Rest of Utah and southwest Wyoming...Showers and thunderstorms are
expected to diminish by sundown in southern and central Utah. Gusty
and erratic winds will likely persist in shower vicinity. VFR
conditions are expected outside of thunderstorms areas.
&&
.FIRE WEATHER...A shortwave trough moving along the Canadian border
tonight into Friday will turn the flow aloft over northern Utah
westerly as it suppresses the 4 Corner's ridge into Arizona. This
westerly flow will bring drier air into the northwest portion of
Utah Friday and most of the remaining northern half of the state
by Saturday. The westerly flow will bring in smoke as well from
Western fires.
Farther south, deep moisture will remain in place through the
period with locally heavy rain. RH values will remain elevated
through out the weekend with a slight chance of some drying next
week.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Flood Watch until midnight MDT tonight for UTZ124-125.
Flood Watch until midnight MDT tonight for UTZ128-129.
WY...None.
&&
SHORT TERM...Struthwolf
LONG TERM...Wessler
AVIATION...Verzella
FIRE WEATHER...Struthwolf
For more information from NOAA's National Weather Service visit...
http://weather.gov/saltlakecity
For frequently asked questions about the Area Forecast Discussion
visit...
http://weather.gov/saltlakecity/general/afd_faqs.phpHazardous weather outlook, Jul 22, 4:06 AM MDT, 12 hours 42 minutes before
Hazardous Weather Outlook National Weather Service Salt Lake City UT 406 AM MDT Thu Jul 22 2021 UTZ101>131-WYZ021-231200- Great Salt Lake Desert and Mountains-Tooele and Rush Valleys- Eastern Box Elder County-Northern Wasatch Front-Salt Lake Valley- Utah Valley-Cache Valley/Utah Portion-Wasatch Back- Bear Lake and Bear River Valley-Wasatch Mountains I-80 North- Wasatch Mountains South of I-80-Western Uinta Mountains- Wasatch Plateau/Book Cliffs-Western Uinta Basin- Western Millard and Juab Counties-Eastern Juab/Millard Counties- Central Mountains-Sanpete Valley-Sevier Valley-Castle Country- San Rafael Swell-Southwest Utah-Lower Washington County- Zion National Park-Southern Mountains-Upper Sevier River Valleys- Bryce Canyon Country-South Central Utah- Capitol Reef National Park and Vicinity-Western Canyonlands- Glen Canyon Recreation Area/Lake Powell-Southwest Wyoming- 406 AM MDT Thu Jul 22 2021 This Hazardous Weather Outlook is for portions of central Utah... northern Utah...southern Utah...southwest Utah and southwest Wyoming. .DAY ONE...Today and Tonight Daily showers and thunderstorms will be capable of heavy rain, gusty winds and small hail each afternoon and evening. Those planning outdoor activities especially across particularly flood prone areas of southern Utah should continue to monitor future forecasts. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Daily showers and thunderstorms will be capable of heavy rain, gusty winds and small hail each afternoon and evening. Those planning outdoor activities especially across particularly flood prone areas of southern Utah should continue to monitor future forecasts. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. For more information from NOAA/s National Weather Service visit... http://weather.gov/saltlakecity For information on potential road travel impacts visit... http://www.udottraffic.utah.gov/roadweatherforecast.aspx
In the hours before
Local storm report, Jul 22, 3:12 PM MDT, 1 hour 36 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
312 PM MDT THU JUL 22 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0225 PM FLASH FLOOD TROPIC 37.62N 112.09W
07/22/2021 GARFIELD UT TRAINED SPOTTER
TRAINED SPOTTER REPORTED WATER RUNNING DOWN STREETS IN
TROPIC.
&&
ALEX.DESMETLocal storm report, Jul 22, 3:14 PM MDT, 1 hour 34 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
314 PM MDT THU JUL 22 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0312 PM FLASH FLOOD MILFORD 38.40N 113.02W
07/22/2021 BEAVER UT EMERGENCY MNGR
EMERGENCY MANAGEMENT REPORTED FLOODWATER 3 FEET DEEP IN
DOWNTOWN MILFORD.
&&
ALEX.DESMETSpecial weather statement, Jul 22, 3:14 PM MDT, 1 hour 34 minutes before
Special Weather Statement National Weather Service Salt Lake City UT 314 PM MDT Thu Jul 22 2021 UTZ123-125-222200- Southern Mountains UT-Lower Washington County UT- 314 PM MDT Thu Jul 22 2021 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL WASHINGTON COUNTY UNTIL 400 PM MDT... At 314 PM MDT, National Weather Service Doppler radar indicated a strong thunderstorm near Dameron Valley, or 25 miles southeast of Beaver Dam. Penny to nickel size hail will be possible. Locations impacted include... Dameron Valley and Veyo. This includes Utah Route 18 between mile markers 16 and 27. PRECAUTIONARY/PREPAREDNESS ACTIONS... If threatening weather approaches, take shelter in a sturdy building. Heavy rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3727 11368 3737 11375 3743 11361 3732 11354 TIME...MOT...LOC 2114Z 250DEG 6KT 3734 11364 ND
Local storm report, Jul 22, 3:57 PM MDT, 51 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
357 PM MDT THU JUL 22 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0353 PM HEAVY RAIN RICHFIELD 38.77N 112.08W
07/22/2021 E1.00 INCH SEVIER UT PUBLIC
WIDESPREAD STANDING WATER AND URBAN FLOODING. MULTIPLE
PUBLIC VIDEOS SHARED ON SOCIAL MEDIA. RADAR ESTIMATES
1-1.25 INCH OVER BRIEF PERIOD.
&&
MICHAEL.WESSLERSpecial weather statement, Jul 22, 4:15 PM MDT, 33 minutes before
Special Weather Statement National Weather Service Salt Lake City UT 415 PM MDT Thu Jul 22 2021 UTZ101-103-222245- Eastern Box Elder County UT-Great Salt Lake Desert and Mountains UT- 415 PM MDT Thu Jul 22 2021 ...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL BOX ELDER COUNTY UNTIL 445 PM MDT... At 415 PM MDT, National Weather Service Doppler radar indicated a strong thunderstorm near Juniper, or 18 miles west of Snowville... moving east at 20 mph. Half inch hail and wind gusts up to 50 mph will be possible. Locations impacted include... Snowville and Curlew Junction. This includes the following highways... Interstate 84 between mile markers 1 and 8. Utah Route 30 between mile markers 60 and 90. PRECAUTIONARY/PREPAREDNESS ACTIONS... If threatening weather approaches, take shelter in a sturdy building. && LAT...LON 4173 11278 4175 11327 4200 11319 4199 11267 TIME...MOT...LOC 2215Z 269DEG 19KT 4196 11307 ND
Special weather statement, Jul 22, 4:48 PM MDT, 0 minutes before
Special Weather Statement National Weather Service Salt Lake City UT 448 PM MDT Thu Jul 22 2021 UTZ122-125-222315- Southwest Utah UT-Southern Mountains UT- 448 PM MDT Thu Jul 22 2021 ...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL WASHINGTON AND SOUTHWESTERN IRON COUNTIES UNTIL 515 PM MDT... At 448 PM MDT, National Weather Service Doppler radar indicated a strong thunderstorm 19 miles north of Dameron Valley, or 20 miles east of Beaver Dam. Nickel size hail will be possible. Locations impacted include... Enterprise. This includes Utah Route 18 between mile markers 32 and 49. PRECAUTIONARY/PREPAREDNESS ACTIONS... If threatening weather approaches, take shelter in a sturdy building. Heavy rainfall is also occurring with this storm, and may lead to localized flooding. Do not drive your vehicle through flooded roadways. Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && LAT...LON 3747 11364 3756 11384 3772 11373 3762 11352 TIME...MOT...LOC 2248Z 210DEG 16KT 3758 11370 ND
The office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 21, 8:41 PM MDT | Flash Flood Warning | SLC | Kane | 6 hr |
| Jul 22, 2:43 AM MDT | Flash Flood Watch | SLC | Emery, Garfield, Kane, Sevier, Washington, Wayne | 20 hr |
| Jul 22, 11:16 AM MDT | Special Weather Statement | SLC | Piute | 29 min |
| Jul 22, 11:41 AM MDT | Special Weather Statement | SLC | 49 min | |
| Jul 22, 11:54 AM MDT | Flood Watch | SLC | Beaver, Garfield, Iron, Kane, Piute, Washington and 1 more | 11 hr |
| Jul 22, 1:02 PM MDT | Special Weather Statement | SLC | Iron | 43 min |
| Jul 22, 1:13 PM MDT | Special Weather Statement | SLC | Garfield | 32 min |
| Jul 22, 1:18 PM MDT | Areal Flood Advisory | SLC | Iron | 117 min |
| Jul 22, 1:20 PM MDT | Severe Thunderstorm Warning | SLC | Garfield | 25 min |
| Jul 22, 1:45 PM MDT | Special Weather Statement | SLC | Kane | 45 min |
| Jul 22, 2:00 PM MDT | Special Weather Statement | SLC | Beaver | 30 min |
| Jul 22, 2:13 PM MDT | Flash Flood Warning | SLC | Garfield, Kane | 3 hr |
| Jul 22, 2:13 PM MDT | Severe Thunderstorm Warning | SLC | Beaver | 32 min |
| Jul 22, 2:34 PM MDT | Flash Flood Warning | SLC | Kane, Washington | 3 hr |
| Jul 22, 2:42 PM MDT | Areal Flood Advisory | SLC | Beaver | 2 hr |
| Jul 22, 2:58 PM MDT | Severe Thunderstorm Warning | SLC | Washington | 32 min |
| Jul 22, 3:08 PM MDT | Flash Flood Warning | SLC | Garfield, Wayne | 3 hr |
| Jul 22, 3:14 PM MDT | Flash Flood Warning | SLC | Garfield, Kane | 5 hr |
| Jul 22, 3:14 PM MDT | Special Weather Statement | SLC | Washington | 46 min |
| Jul 22, 3:30 PM MDT | Severe Thunderstorm Warning | SLC | Garfield | |
| Jul 22, 3:46 PM MDT | Flash Flood Warning | SLC | Garfield, Kane | 7 hr |
| Jul 22, 4:02 PM MDT | Severe Thunderstorm Warning | SLC | Iron | 28 min |
| Jul 22, 4:15 PM MDT | Special Weather Statement | SLC | Box Elder | 30 min |
| Jul 22, 4:28 PM MDT | Severe Thunderstorm Warning | SLC | Iron | 32 min |
| Jul 22, 5:51 PM MDT | Special Weather Statement | SLC | 39 min | |
| Jul 22, 5:58 PM MDT | Flash Flood Warning | SLC | Utah | 3 hr |
Nearby
Special Weather Statements in Utah, 2021Every special weather statement in 2021
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.