Severe Thunderstorm Warning 12, NWS Denver/Boulder, CO

014 
WWUS55 KBOU 040455
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
1055 PM MDT Sun May 3 2020

COC075-040530-
/O.CON.KBOU.SV.W.0012.000000T0000Z-200504T0530Z/
Logan CO-
1055 PM MDT Sun May 3 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1130 PM MDT
FOR SOUTHWESTERN LOGAN COUNTY...

At 1054 PM MDT, a severe thunderstorm was located near Sterling,
moving east at 35 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees. Hail damage to 
         vehicles is expected.

Locations impacted include...
Sterling, Merino, Iliff, Padroni, Atwood, Logan Corners and North
Sterling Reservoir.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4047 10339 4052 10341 4055 10343 4085 10347
      4087 10305 4048 10300
TIME...MOT...LOC 0454Z 264DEG 32KT 4064 10325 

HAIL...1.00IN
WIND...60MPH
 
$$

RPK

857 
WWUS55 KBOU 040502
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
1102 PM MDT Sun May 3 2020

COC075-040530-
/O.CON.KBOU.SV.W.0012.000000T0000Z-200504T0530Z/
Logan CO-
1102 PM MDT Sun May 3 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1130 PM MDT
FOR CENTRAL LOGAN COUNTY...

At 1102 PM MDT, a severe thunderstorm was located near Sterling,
moving east at 35 mph.

HAZARD...Golf ball size hail and 70 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings. People and animals outdoors 
         will be injured. Expect hail damage to roofs, siding, 
         windows, and vehicles.

Locations impacted include...
Sterling, Iliff, North Sterling Reservoir, Padroni and Atwood. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

&&

LAT...LON 4047 10333 4051 10334 4056 10334 4085 10331
      4087 10305 4048 10300
TIME...MOT...LOC 0502Z 262DEG 29KT 4065 10316 

HAIL...1.75IN
WIND...70MPH
 
$$

RPK

570 
WWUS55 KBOU 040516
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
1116 PM MDT Sun May 3 2020

COC075-040525-
/O.CAN.KBOU.SV.W.0012.000000T0000Z-200504T0530Z/
Logan CO-
1116 PM MDT Sun May 3 2020

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL LOGAN COUNTY IS
CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

LAT...LON 4047 10333 4051 10334 4056 10334 4085 10331
      4087 10305 4048 10300
TIME...MOT...LOC 0515Z 262DEG 29KT 4067 10301 

$$

RPK

Area Forecast Discussion
National Weather Service Denver/Boulder CO
737 PM MDT Sun May 3 2020

.UPDATE...
Issued at 736 PM MDT Sun May 3 2020

A corridor of 500-1000 J/kg CAPE from the far northeastern corner
back southwest toward the Palmer Divide is finally starting to be
able to be utilized evident on radar. Lift ahead of the upper
trough may be finally weakening the cap that has been shown on
ACARS soundings around 620mb. With the jet nearby and bulk shear
of 50-70 kts, will continue to see threats of large hail and
damaging winds tonight, and won't be able to rule out a tornado.
The biggest threat of severe strength storms will be mainly along
and east of a line from Sterling down to western Elbert County.
Main pressure rises still up in southwestern to northern Wyoming,
so a cold frontal timing of near midnight into the metro areas
still looks good. Will continue to see a chance of showers and
thunderstorms ahead of this front, as well as behind it into the
early morning hours with lift increasing ahead of the upper
trough.

&&

.SHORT TERM...(This evening through Monday)
Issued at 146 PM MDT Sun May 3 2020

Latest RAP/HRRR runs still want to initiate showers/thunderstorms
over the Cheyenne Ridge and Palmer Divide after 3 pm. A few storms
are developing along the northern border in closer to a broad 100+
kt jet stream that northern CA into eastern NE. Most of activity
through 8 pm this evening looks like it will be confined to these
areas. Temperatures have warmed up into the lower 70s, not enough
to break the cap and generate more storms. Sufficient CAPES
around to still produce an isolated severe thunderstorm with the
best chance along the northern border. Main concerns will be hail
to one inch and wind gusts to 60 mph. Outflow boundaries generated
by these storms may help get the storms going elsewhere. CAPES
over the northeast plains this afternoon, ranging from 500-1000
j/kg, highest over the northeast corner of the state. Models start
to enhance the thunderstorms over the northeast plains late this
evening and overnight. Better lift develops in the mid and upper
levels as an embedded short wave moved across northern. Good shear
profile as well, with the models showing stronger thunderstorms
developing mainly north and east of Denver from 9pm to 2am, with
some lingering activity continuing on the northern border through
6am Monday morning. Weak to moderate mid level QG ascent over the
forecast area this evening, weaker ascent after midnight, with
moderate subsidence spreading from northwest to southeast across
the forecast area on Monday. Late tonight into Monday morning, a
cold front will push north to south across the Denver area.
Coverage for showers and thunderstorms with be lower. Some low
level instability around on Monday, but overall the storms will be
weaker as well.

.LONG TERM...(Monday night through Sunday)
Issued at 146 PM MDT Sun May 3 2020

Flat upper level ridge will be over the western states with a
west- northwest flow aloft over Colorado. A cold front that pushes
through Colorado Monday should leave dry and stable conditions in
its wake. A few models show weak convection forming over the
higher terrain Monday evening and Tuesday afternoon. Will have low
PoPs for this. If anything forms it should be weak and short
lived. Temperatures on Tuesday will be near normal with highs in
the upper 60s to lower 70s.

The ridge over the western U.S. will slide east across the
Central Rockies Wednesday. This will bring warmer temperatures
with highs in the mid 70s across northeast Colorado. Surface high
pressure over the Northern and Central Plains will cause surface
winds to turn southeasterly Wednesday. This could transport enough
moisture for convection. With the ridge overhead, any convective
development will be battling warm air aloft and subsidence. Thus
will keep PoPs on the low side.

A ridge over the western U.S. will amplify into Canada Thursday.
This ridge will remain nearly stationary through Sunday. A long
wave trough will reside over the Great Lakes and eastern Canada
during this time frame. For Colorado, this will result in a
northwest flow aloft. Models show 2-3 short wave troughs embedded
in the northwest flow from Thursday to Sunday. Colorado will be on
the edge of the cooler air that each of these trough will bring.
Still a good amount of uncertainty on how far western each of
these troughs will dig. There should be a cold front sometime
Thursday, after this timing any front is difficult. Will have a
cooler day for Friday behind the front. For the weekend will keep
temperatures at or slightly below normal. This is not a good setup
for convection or precipitation. Can't rule out something late
next week due to the uncertainty, so will have low PoPs for this.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 736 PM MDT Sun May 3 2020

Instability is increasing across the area, bringing a better
chance to see showers and thunderstorms over the terminals. The
chance will be increasing toward the cold frontal passage expected
around midnight. Until then, VFR conditions will be expected with
north-northeasterly winds. Occasional ILS restrictions due to
showers and thunderstorms this evening with ceilings 050-060 kft,
before the cold front will likely bring prevailing ceilings of
050-060 kft through about 12z. The cold front will likely have
winds of 15g25kts associated with it, then the winds should trend
down but stay northerly. Northerly winds will persist through the
day on Monday, with some slight backing to the northwest during
the afternoon.

&&

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

UPDATE...Kriederman
SHORT TERM...Cooper
LONG TERM...Meier
AVIATION...Kriederman

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1032 AM MDT Sun May 3 2020

COZ030>051-041645-
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-
1032 AM MDT Sun May 3 2020

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

.DAY ONE...Today and Tonight

A few severe storms may develop this afternoon and evening over
the plains especially closer to the Wyoming, Nebraska border.
Further south over the plains activity may be more isolated. Hail
to one inch in diameter along with wind gusts to 60 mph will be
possible. Locally heavy rain will also be possible over the far
northeast plains tonight as thunderstorm activity becomes more
widespread.

Over the higher terrain look for scattered showers and
storms this afternoon with gusty winds to 50 mph and small hail.
Overnight there will be some accumulating snow above 10000 feet,
with amounts ranging from a trace to 3 inches.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Thunderstorms chances for the upcoming week will be very low. If
any storms from, they are expected to be weak.

.SPOTTER INFORMATION STATEMENT...

Spotter reports will be appreciated this afternoon and tonight.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
735 PM MDT SUN MAY 3 2020

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

0734 PM     HAIL             8 ENE MATHESON          39.20N 103.83W
05/03/2020  M1.00 INCH       ELBERT             CO   TRAINED SPOTTER

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
915 PM MDT SUN MAY 3 2020

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

0830 PM     HAIL             6 SSW LONE STAR         40.27N 102.88W
05/03/2020  M1.00 INCH       WASHINGTON         CO   TRAINED SPOTTER

&&

Special Weather Statement
National Weather Service Denver CO
1019 PM MDT Sun May 3 2020

COZ043-040500-
Central and South Weld County CO-
1019 PM MDT Sun May 3 2020

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL WELD COUNTY UNTIL
1100 PM MDT...

At 1019 PM MDT, Doppler radar was tracking a strong thunderstorm 4
miles northwest of Greeley, moving northeast at 25 mph.

Penny size hail will be possible with this storm.

Locations impacted include...
Greeley, Windsor, Evans, Eaton, Severance, Ault and Lucerne.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4058 10463 4052 10463 4052 10458 4046 10454
      4035 10480 4051 10494 4052 10494 4058 10482
TIME...MOT...LOC 0419Z 241DEG 21KT 4047 10481

RPK