Tornado Warning 28, NWS Denver/Boulder, CO

261 
WWUS55 KBOU 112255
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
455 PM MDT Sun Aug 11 2019

COC075-112315-
/O.CON.KBOU.TO.W.0028.000000T0000Z-190811T2315Z/
Logan CO-
455 PM MDT Sun Aug 11 2019

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 515 PM MDT FOR
NORTHWESTERN LOGAN COUNTY...
    
At 455 PM MDT, a severe thunderstorm capable of producing a tornado
was located 4 miles west of North Sterling Reservoir, or 13 miles
northwest of Sterling, moving north at 25 mph.

HAZARD...Tornado and tennis ball size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
North Sterling Reservoir.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4063 10323 4064 10346 4090 10345 4090 10323
TIME...MOT...LOC 2255Z 181DEG 20KT 4079 10336 

TORNADO...RADAR INDICATED
HAIL...2.50IN

$$

RPK

Area Forecast Discussion
National Weather Service Denver/Boulder CO
340 PM MDT Sun Aug 11 2019

.SHORT TERM...(This evening through Monday)
Issued at 252 PM MDT Sun Aug 11 2019

Strong to severe thunderstorms are ongoing across the eastern
plains this afternoon. The best threat for severe storms will be
along and north of a boundary that is currently across southern
Washington to eastern Arapahoe Counties due to better instability
and shear there. Dew points are in the upper 60s to low 70s across
Logan, Sedgwick and Phillips Counties and precipitable water
values are near 1.5 inches so heavy rain and flooding are
possible there. The storms will move east of our CWA by around
midnight tonight with near normal low temperatures.

NVA behind a departing trough along with a low level high
pressure center moving over the area tomorrow will dry things out.
The only chance for showers and storms will be over the high
country mainly south of I-70 and the Palmer Divide. Northwesterly
winds will increase during the late morning with sustained winds
between 10-20 mph, highest across the Cheyenne Ridge. With
minimum relative humidities reaching as low as 15 percent over
Weld and Larimer Counties, there will be elevated fire weather
conditions. However, a red flag warning will not be needed due to
the moisture in the ground from recent storms. Otherwise, highs
will generally be near or slightly below normal.

.LONG TERM...(Monday night through Sunday)
Issued at 335 PM MDT Sun Aug 11 2019

Models have a flat upper ridge Monday night building back up a
bit west of out CWA late Tuesday through Wednesday night. The flow
aloft will be southwesterly Monday night, then westerly on
Tuesday into Tuesday evening, then northwesterly later Tuesday
night through Wednesday night. There is weak downward synoptic
scale energy progged for the CWA on the QG Omega fields Monday
night through Wednesday evening. The boundary layer winds should
adhere to normal diurnal trends all five periods. For moisture,
precipitable water values generally range from 0.50 over the
western plains to about 1.0 over the far east. So it dries
somewhat compared to of late. There is some CAPE around through
the periods. Values are fairly significant over the far northeast
corner late day Tuesday and late day Wednesday. The basic trend
for the forecast will be drier conditions, less pops and
temperatures right around normals. For temperatures. highs on
Tuesday will be similar to Monday's. Wednesday's readings warm up
1-2 C from Tuesday's highs. For the later days, Thursday through
Sunday, models have the upper ridge over Colorado flattening on
Thursday. A fairly decent upper trough/closed low moves into the
northwestern United State Thursday night into Saturday. A flat
upper ridge is still around for the CWA through Sunday, with the
flow aloft to be west-southwesterly. Moisture is not great all
four days. Temperatures may be a tad above seasonal normals Friday
through Sunday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 252 PM MDT Sun Aug 11 2019

A westerly push from the outflow of showers over the foothills
has moved across the airport this afternoon. Additional storms and
outflow boundaries will develop this afternoon with strong wind
gusts being the main concern the airports. Storms may lower
ceilings and visibilities to IFR temporarily as well. Winds will
turn southerly this evening and before trending toward drainage
tonight.

Northerly winds will increase during the late morning tomorrow as
conditions should remain dry at the airports.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&

SHORT TERM...Danielson
LONG TERM....RJK
AVIATION.....Danielson

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1052 AM MDT Sun Aug 11 2019

COZ030>051-121700-
Jackson County Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
South and East Jackson/Larimer/North and Northeast Grand/
Northwest Boulder Counties Above 9000 Feet-
South and Southeast Grand/West Central and Southwest Boulder/
Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet-
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Central and Southeast Park County-
Larimer County Below 6000 Feet/Northwest Weld County-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County-
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
Central and East Adams and Arapahoe Counties-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
Logan County-Washington County-Sedgwick County-Phillips County-
1052 AM MDT Sun Aug 11 2019

This hazardous weather outlook is for northeast and north central
Colorado.

.DAY ONE...Today and Tonight

Scattered thunderstorms will develop over the mountains by noon
and spread across the northeast plains during the afternoon and
evening hours. Storms may become severe on the plains, especially
east a line from Greeley to Denver International Airport. Impacts
will be large hail up to 2 inches in diameter, damaging winds to
60 mph, and even a brief tornado. Very heavy rain may also be a
factor with rainfall rates up to 2 inches in less than one hour.
This may lead to localized flooding. Storms will end from west to
east this evening.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Mainly, a slight chance of late day showers and thunderstorms can
be expected through the period. The high country will see a
better chance than the plains will. The storms will produce light
rain showers and gusty outflow winds. Temperatures will be at or a
tad above seasonal normals most of the time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed across the northeast
plains of Colorado after 2 pm this afternoon.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
345 PM MDT SUN AUG 11 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0326 PM     TORNADO          4 NW OTIS               40.19N 103.02W
08/11/2019                   WASHINGTON         CO   TRAINED SPOTTER

            MULTIPLE REPORTS OF A TORNADO NORTHWEST OF OTIS.

&&

RDANIELS

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DENVER CO
346 PM MDT SUN AUG 11 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0142 PM     HAIL             2 ESE PONDEROSA PARK    39.39N 104.60W
08/11/2019  M1.00 INCH       ELBERT             CO   TRAINED SPOTTER

0255 PM     HAIL             6 NW AKRON              40.22N 103.29W
08/11/2019  M1.00 INCH       WASHINGTON         CO   TRAINED SPOTTER

0307 PM     TORNADO          3 NE AKRON              40.20N 103.17W
08/11/2019                   WASHINGTON         CO   STORM CHASER

0317 PM     HAIL             1 N AKRON               40.18N 103.21W
08/11/2019  M1.50 INCH       WASHINGTON         CO   TRAINED SPOTTER

            AT THE AKRON AIRPORT

0326 PM     TORNADO          4 NW OTIS               40.19N 103.02W
08/11/2019                   WASHINGTON         CO   TRAINED SPOTTER

            MULTIPLE REPORTS OF A TORNADO NORTHWEST OF OTIS.

&&

RDANIELS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
353 PM MDT SUN AUG 11 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0351 PM     HAIL             3 W OTIS                40.15N 103.02W
08/11/2019  M2.50 INCH       WASHINGTON         CO   TRAINED SPOTTER

&&

RDANIELS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
406 PM MDT SUN AUG 11 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0359 PM     TORNADO          3 E OTIS                40.15N 102.91W
08/11/2019                   WASHINGTON         CO   TRAINED SPOTTER

&&

RDANIELS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
409 PM MDT SUN AUG 11 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0355 PM     HAIL             OTIS                    40.15N 102.96W
08/11/2019  M4.00 INCH       WASHINGTON         CO   TRAINED SPOTTER

&&

RDANIELS

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DENVER CO
410 PM MDT SUN AUG 11 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0142 PM     HAIL             2 ESE PONDEROSA PARK    39.39N 104.60W
08/11/2019  M1.00 INCH       ELBERT             CO   TRAINED SPOTTER

0255 PM     HAIL             6 NW AKRON              40.22N 103.29W
08/11/2019  M1.00 INCH       WASHINGTON         CO   TRAINED SPOTTER

0307 PM     TORNADO          3 NE AKRON              40.20N 103.17W
08/11/2019                   WASHINGTON         CO   STORM CHASER

0317 PM     HAIL             1 N AKRON               40.18N 103.21W
08/11/2019  M1.50 INCH       WASHINGTON         CO   TRAINED SPOTTER

            AT THE AKRON AIRPORT

0326 PM     TORNADO          4 NW OTIS               40.19N 103.02W
08/11/2019                   WASHINGTON         CO   TRAINED SPOTTER

            MULTIPLE REPORTS OF A TORNADO NORTHWEST OF OTIS.

0351 PM     HAIL             3 W OTIS                40.15N 103.02W
08/11/2019  M2.50 INCH       WASHINGTON         CO   TRAINED SPOTTER

0355 PM     HAIL             OTIS                    40.15N 102.96W
08/11/2019  M4.00 INCH       WASHINGTON         CO   TRAINED SPOTTER

0359 PM     TORNADO          3 E OTIS                40.15N 102.91W
08/11/2019                   WASHINGTON         CO   TRAINED SPOTTER

&&

RDANIELS