Severe Thunderstorm Warning 94, NWS Denver/Boulder, CO

Area Forecast Discussion
National Weather Service Denver/Boulder CO
338 PM MDT Fri Jul 3 2020

.SHORT TERM...(This evening through Saturday)
Issued at 338 PM MDT Fri Jul 3 2020

A single severe thunderstorm has developed over Douglas County and
appears to be weakening as it moves northeastward. Additional weak
shower activity has also been brewing over the southern Front
Range foothills. Outflow boundaries from these showers may kick
off additional thunderstorm activity over the I-25 corridor to the
north of Denver in the next few hours. HRRR model runs show the
evening convection consolidating as a line over Weld, Morgan,
Adams and Lincoln Counties after 6 PM this evening. Southeasterly
winds on the plains with dew points in the lower to mid 50s will
provide decent inflow to keep showers developing as the progress
eastward. The forecast will have scattered thunderstorms on the
plains through the late evening. A few cells may produce moderate
to large hail at times.

Another day with morning sun and afternoon thunderstorms seems to
be in store for Saturday. The weak southwesterly flow aloft will
continue while moist air and weak low pressure also remains in
place. CAPE values from the NAM show lower values tomorrow,
compared with this afternoon. So the threat of severe storms
should be lower, but scattered afternoon coverage will still be
possible. Temperatures should also reach the lower 90s on the
plains again.

.LONG TERM...(Saturday night through Friday)
Issued at 338 PM MDT Fri Jul 3 2020

The ridge of high pressure aloft will remain over Colorado and
persist through next week. Afternoon and evening showers and
storms are expected to continue over the weekend, but warmer
temperatures and drier air aloft will decrease the chances of
convection through next week. There will be considerably less
precipitation across the area after Monday. Models show 700 hPa
temperatures frequently warmer than 60 F over the plains with
generally decreasing humidity. Surface high temperatures
will be in the 90s most of the week on the plains. There will
still be some summer storms, but much decreased in coverage and
intensity. Upper level flow will turn slightly more westerly over
the weekend, as an upper trough over the Pacific Northwest
advances eastward. Flow will turn back to southwesterly from
Monday night the rest of the week.

Fire concerns on the plains will be increasing through next week
due to the warming temperatures and decreasing precipitation,
though strong winds are not expected. Heat may also become a
concern as temperatures continue to rise, especially for the heat
islands of the urban corridor.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 338 PM MDT Fri Jul 3 2020

Afternoon thunderstorms are moving out of Douglas County and
appear to be far enough east that impact on Denver area airports
will be minimal. Additional showers are still possible for the
next few hours as storms are still brewing over the foothills of
Park, Jefferson, Clear Creek and Pitkin Counties. Outflow
boundaries from the Douglas County are presently moving over KAPA
and should move over KDEN between 4 PM and 5 PM. Gusts of 35 to 40
knots will be possible. After the next couple hours of shower
activity, the rest of tonight should be benign with winds
returning to southerlies. Another round of thunderstorms are
expected for Saturday afternoon.

&&

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

SHORT TERM...Dankers
LONG TERM...DiRenzo
AVIATION...Dankers

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1053 AM MDT Fri Jul 3 2020

COZ030>051-041700-
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-
1053 AM MDT Fri Jul 3 2020

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

.DAY ONE...Today and Tonight

Scattered thunderstorms are expected over the Front Range
foothills by early this afternoon which will then move across the
plains through the late afternoon and early evening hours.
Isolated severe thunderstorms may develop as the storms move east
of a Fort Morgan to Limon line. Wind gusts up to 60 mph and hail
up to an inch in diameter will be the main threat. In addition,
heavy rainfall may cause some minor flooding over portions of the
plains as well.

The shower and thunderstorm activity will gradually end over the
plains during the evening hours.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Storm coverage will increase further on Saturday as moisture
remains high. While coverage will be slightly less Sunday, this
weekend's storms will be quite wet and may produce heavy rain for
localized flooding issues. Further east, more instability will
allow for a better chance of hail and gusty outflow winds. Putting
lightning on top off all the hazards mentioned above, all people
planning on spending the holiday weekend outside need to make sure
they have a way of receiving weather alerts.

Monday through Wednesday will bring a warmer and drier weather
pattern due to westerly flow aloft increasing. Tuesday and
Wednesday may be within a few degrees of the record high
temperatures for those dates.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today or tonight. However, any
reports of severe weather would be appreciated.

Special Weather Statement
National Weather Service Denver CO
434 PM MDT Fri Jul 3 2020

COZ044-032315-
Morgan County CO-
434 PM MDT Fri Jul 3 2020

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL MORGAN COUNTY UNTIL 515
PM MDT...

At 434 PM MDT, Doppler radar was tracking a strong thunderstorm near
Fort Morgan, moving north at 10 mph.

Nickel size hail, heavy rain and winds in excess of 40 mph will be
possible with this storm.

Locations impacted include...
Fort Morgan, Brush and Log Lane Village.

LAT...LON 4012 10359 4012 10384 4034 10393 4034 10360
TIME...MOT...LOC 2234Z 171DEG 10KT 4021 10376

ENTREKIN

Special Weather Statement
National Weather Service Denver CO
514 PM MDT Fri Jul 3 2020

COZ044-032345-
Morgan County CO-
514 PM MDT Fri Jul 3 2020

...Brief Landspout Tornado Sighted...

At 509 PM MDT, trained weather spotters reported several weak
landspout tornadoes just south of a line from Wiggins to Fort
Morgan.  Conditions continue to favor the potential for landspouts
as storms develop; however at this time it is unknown which if any
storm would produce a landspout. Any landspouts which develop are
expected to pose a limited threat.

Locations impacted include...
Fort Morgan, Brush, Wiggins, Log Lane Village, Weldona, Twelve-Mile
Corner, Jackson Reservoir, Adena School and Goodrich.

Landspout tornadoes can form with a developing thunderstorm before
rain, hail, and even thunder is observed. Landspout tornadoes are not
usually associated with a wall cloud and are often difficult to
detect with weather radar.

&&

LAT...LON 4044 10409 4027 10350 4001 10367 4013 10415

ENTREKIN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
538 PM MDT FRI JUL 3 2020

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

0538 PM     HAIL             3 N ADENA SCHOOL        40.17N 103.79W
07/03/2020  E0.88 INCH       MORGAN             CO   TRAINED SPOTTER

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
600 PM MDT FRI JUL 3 2020

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

0557 PM     HAIL             2 SSW WOODROW           39.95N 103.59W
07/03/2020  E1.00 INCH       WASHINGTON         CO   PUBLIC

            HAIL COVERING THE HIGHWAY.

&&

JLS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
608 PM MDT FRI JUL 3 2020

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

0604 PM     HAIL             1 NNW LINDON            39.74N 103.41W
07/03/2020  E0.88 INCH       WASHINGTON         CO   STORM CHASER

&&

JLS

Special Weather Statement
National Weather Service Denver CO
626 PM MDT Fri Jul 3 2020

COZ038-042-040115-
Northeast Weld County CO-
Larimer County Below 6000 Feet/Northwest Weld County CO-
626 PM MDT Fri Jul 3 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN WELD COUNTY UNTIL
715 PM MDT...

At 625 PM MDT, Doppler radar was tracking a strong thunderstorm 6
miles north of Pawnee Buttes, or 27 miles southwest of Kimball,
moving northeast at 15 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Grover, New Raymer, Keota, Stoneham, Hereford, Briggsdale and Pawnee
Buttes.

LAT...LON 4099 10358 4055 10358 4063 10446 4100 10435
      4100 10403
TIME...MOT...LOC 0025Z 212DEG 44KT 4091 10396

ENTREKIN