Severe Thunderstorm Warning 47, NWS Denver/Boulder, CO

548 
WWUS55 KBOU 122202
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
402 PM MDT MON JUN 12 2017

COC123-122212-
/O.CAN.KBOU.SV.W.0047.000000T0000Z-170612T2215Z/
Weld CO-
402 PM MDT MON JUN 12 2017

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL WELD COUNTY IS
CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore the warning has
been cancelled.

A tornado watch remains in effect until 800 PM MDT for northeastern
Colorado.

LAT...LON 4048 10485 4056 10489 4075 10471 4067 10441
TIME...MOT...LOC 2200Z 220DEG 26KT 4080 10459 

$$

BAKER

Area Forecast Discussion
National Weather Service Denver/Boulder CO
320 PM MDT Mon Jun 12 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 220 PM MDT Mon Jun 12 2017

Isolated but intense thunderstorms over eastern Larimer and
northwestern Weld Counties this aftn. Best low level convergence
with strong easterly winds ahead of these storms with strong flow
aloft. Tornado Watch in effect through 8 pm, with the greatest
potential north of highway 34. Dry line will push northward this
evening with the storm expect to continue to track north into
Wyoming. A strong closed upper low over south central ID this aftn
will move into southwestern MT by 12z, with the flow aloft
transitioning fm southwesterly to westerly over CO. Best chc of
pcpn late tngt and Tuesday will be in Zone 31. Otherwise gusty
westerly winds in the mountains, foothills and along the Cheyenne
Ridge on Tuesday. Surface pressure gradient loosens up in the aftn
so wind across the plains should decrease by the aftn, but breezy
to windy conditions will persist in the mountains and higher
foothills. Cooler as well on Tuesday, with the warmest 700 mb
temperatures going from 12-17.5c this aftn to 5-10c Tuesday aftn,
so 12-18 degrees cooler at the sfc. Snowmelt is still being
handled well by streams. A Flood Advisory continues for the Cache
La Poudre at the canyon mouth another day, then cooler weather
should slow runoff a bit.

.LONG TERM...(Tuesday night through Monday)
Issued at 220 PM MDT Mon Jun 12 2017

A weak upper trough is progged to push eastward across the CWA
Tuesday evening. Zonal flow is progged from late Tuesday night
through Wednesday night. The flow aloft is west-northwest early
Thursday and Thursday night. Weak downward motion is progged in
the synoptic scale all five periods. The boundary layer winds are
downsloping Tuesday evening, then normal drainage Tuesday night.
There is a weak gradient around Wednesday, then a weak cold front
and some upslope Wednesday evening. There looks to be
southeasterlies Thursday, then normal drainage Thursday night. The
precipitable water progs show values of 0.25 to 0.50 for all the
CWA all five periods. The surface dewpoints are progged in the 20s
and 30s F for all the CWA all five periods. There is very little
CAPE progged for the CWA Tuesday night through Thursday night,
just a tiny bit in the mountains late day Wednesday and late day
Thursday. There is tiny bit of measurable rainfall on the QPF
fields Wednesday evening and night only. No pops through the
periods. For temperatures, Wednesday's highs are 2-4 C warmer than
Tuesday. Thursday's highs are 0-2 C warmer than Wednesday's. For
the later days, Friday through Monday, models have a weak upper
trough move down in west-northwesterly flow just to our north on
Saturday. The flow aloft for the CWA is west- northwesterly all
four days. There is a limited moisture for isolated late day
convection Saturday through Monday. Temperatures will be a tad
above seasonal normals.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 220 PM MDT Mon Jun 12 2017

Gusty southerly winds to 30 kts possible until 01Z. Then expect a
gradual weakening through 06Z with lighter drainage winds
overnight. No thunderstorms expected the rest of this aftn with
VFR conditions. west/northwest winds Tuesday aftn 8-14 kt.

&&

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

SHORT TERM...Coop
LONG TERM....Koop
AVIATION.....Coop

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1105 AM MDT Mon Jun 12 2017

COZ030>051-131715-
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-
1105 AM MDT Mon Jun 12 2017

...severe storm threat today...

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

.DAY ONE...Today and Tonight

A few severe thunderstorms will be possible across portions of
the plains this afternoon. A dryline will organize and shift
northward, and be the focus for isolated to scattered thunderstorm
development. By mid afternoon, this dryline is expected to be
extend from near or just north of the Denver metro area eastward
to between Limon and Akron, around Last Chance. This feature and
threat of thunderstorms will then shift northward to the Wyoming
and Nebraska border area by late afternoon into early evening.

If thunderstorms are able to develop along this dryline and break
through the cap, severe storms would be likely with large hail,
damaging winds, and a damaging tornado or two possible. The main
threat for severe weather after 2 PM will be roughly along and
north of a line from Loveland to Wiggins to around Anton in
southern washington county. Any storms that develop are expected
to move northeast out of Colorado by 6 PM.

Behind the dryline, it will turn hot and windy this afternoon.
Winds will slowly subside in most areas by late this evening.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Isolated light snow showers are possible Tuesday morning over the
northern Colorado mountains. Snow amounts will be light. Strong
west winds Tuesday will be gusting to near 50 mph over the high
country and up to 25 mph over the plains. It will be dry most of
the week. A slight chance of late day showers and thunderstorms
will remain, mainly to the mountains for the weekend.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be required over the northern
portions of the plains by 2 PM.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
229 PM MDT MON JUN 12 2017

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

0226 PM     HAIL             3 E LOVELAND            40.42N 105.02W
06/12/2017  M1.00 INCH       LARIMER            CO   TRAINED SPOTTER

&&

CGIMMEST

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DENVER CO
250 PM MDT MON JUN 12 2017

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

0226 PM     HAIL             3 E LOVELAND            40.42N 105.02W
06/12/2017  M1.00 INCH       LARIMER            CO   TRAINED SPOTTER

0243 PM     FUNNEL CLOUD     TIMNATH                 40.53N 104.98W
06/12/2017                   LARIMER            CO   PUBLIC

&&

SULLIVAN

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DENVER CO
252 PM MDT MON JUN 12 2017

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

0243 PM     FUNNEL CLOUD     TIMNATH                 40.53N 104.98W
06/12/2017                   LARIMER            CO   PUBLIC

0232 PM     HAIL             1 WNW WINDSOR           40.49N 104.93W
06/12/2017  M2.00 INCH       WELD               CO   PUBLIC

0232 PM     HAIL             5 ESE FORT COLLINS      40.52N 104.99W
06/12/2017  M0.75 INCH       LARIMER            CO   TRAINED SPOTTER

0226 PM     HAIL             3 E LOVELAND            40.42N 105.02W
06/12/2017  M1.00 INCH       LARIMER            CO   TRAINED SPOTTER

&&

CGIMMEST

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DENVER CO
304 PM MDT MON JUN 12 2017

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

0243 PM     FUNNEL CLOUD     TIMNATH                 40.53N 104.98W
06/12/2017                   LARIMER            CO   PUBLIC

0232 PM     HAIL             1 WNW WINDSOR           40.49N 104.93W
06/12/2017  M2.00 INCH       WELD               CO   PUBLIC

0232 PM     HAIL             5 ESE FORT COLLINS      40.52N 104.99W
06/12/2017  M0.75 INCH       LARIMER            CO   TRAINED SPOTTER

0230 PM     HAIL             2 SE TIMNATH            40.51N 104.95W
06/12/2017  M1.75 INCH       LARIMER            CO   COCORAHS

0228 PM     HAIL             3 W WINDSOR             40.48N 104.97W
06/12/2017  M1.75 INCH       LARIMER            CO   COCORAHS

0226 PM     HAIL             3 E LOVELAND            40.42N 105.02W
06/12/2017  M1.00 INCH       LARIMER            CO   TRAINED SPOTTER

&&

SULLIVAN

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DENVER CO
322 PM MDT MON JUN 12 2017

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

0318 PM     HAIL             NUNN                    40.70N 104.78W
06/12/2017  M1.00 INCH       WELD               CO   TRAINED SPOTTER

0313 PM     FUNNEL CLOUD     6 W PIERCE              40.63N 104.86W
06/12/2017                   WELD               CO   TRAINED SPOTTER

0243 PM     FUNNEL CLOUD     TIMNATH                 40.53N 104.98W
06/12/2017                   LARIMER            CO   PUBLIC

0232 PM     HAIL             1 WNW WINDSOR           40.49N 104.93W
06/12/2017  M2.00 INCH       WELD               CO   PUBLIC

0232 PM     HAIL             5 ESE FORT COLLINS      40.52N 104.99W
06/12/2017  M0.75 INCH       LARIMER            CO   TRAINED SPOTTER

0230 PM     HAIL             2 SE TIMNATH            40.51N 104.95W
06/12/2017  M1.75 INCH       LARIMER            CO   COCORAHS

0228 PM     HAIL             3 W WINDSOR             40.48N 104.97W
06/12/2017  M1.75 INCH       LARIMER            CO   COCORAHS

0226 PM     HAIL             3 E LOVELAND            40.42N 105.02W
06/12/2017  M1.00 INCH       LARIMER            CO   TRAINED SPOTTER

0215 PM     HAIL             3 E LOVELAND            40.41N 105.01W
06/12/2017  M1.25 INCH       LARIMER            CO   COCORAHS

&&

CGIMMEST