Alert archive / Colorado / Winter Storm Warnings in 2015

Winter Storm Warning 16, NWS Denver/Boulder, CO

December 11, 2015Grand County, Jackson County, Colorado

NWS Denver/Boulder, CO issued this winter storm warning at Dec 11, 2015, 3:28 AM MST for Grand County, Jackson County, Colorado. It took effect at Dec 11, 2015, 6:34 AM MST. It was in force for 28 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Dec 11, 2015, 3:28 AM MST (10:28 UTC)
In effect from
Dec 11, 2015, 6:34 AM MST
Expired
Dec 12, 2015, 10:49 AM MST
In force
28 hr
Issued by
NWS Denver/Boulder, CO

Counties Grand County, CO, Jackson County, CO

The radar

The Cheyenne radar (KCYS), 147 km from the middle of the area, began a volume at 10:32 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

Grand Junction, CO (KGJT), launched 00:00Z, 10.5 hours before the alert went out and 239 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.

Skew-T log-pSkew-T log-p diagram, Grand Junction, CO at 00:00Z on 2015-12-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 00:00Z on 2015-12-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1791 m above ground
0-6 km bulk shear
89 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
483 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

786 
WWUS45 KBOU 111028
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
328 AM MST FRI DEC 11 2015

...WINTER STORM SYSTEM HEADING TOWARDS COLORADO...

A STORM SYSTEM WILL MOVE INTO WESTERN COLORADO TODAY...THEN MAKE
ITS WAY ACROSS THE REST OF THIS STATE TONIGHT AND SATURDAY. SNOW
WILL DEVELOP IN THE MOUNTAINS TODAY...HEAVIEST IN THE PARK RANGE
IN WESTERN JACKSON COUNTY. THE SNOW WILL INCREASE IN COVERAGE
AND INTENSITY ALONG THE FRONT RANGE MOUNTAINS AND FOOTHILLS
TONIGHT AND SATURDAY...WITH THE HEAVIEST AMOUNTS POSSIBLE 
NORTH OF INTERSTATE 70.

COZ031-111830-
/O.UPG.KBOU.WS.A.0012.151212T0100Z-151213T0100Z/
/O.NEW.KBOU.WS.W.0016.151211T1900Z-151213T0000Z/
WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...
EAST SLOPES PARK AND NORTHERN GORE RANGES...GORE PASS...
RABBIT EARS PASS
328 AM MST FRI DEC 11 2015

...WINTER STORM WARNING IN EFFECT FROM NOON TODAY TO 5 PM MST
SATURDAY...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A WINTER STORM
WARNING FOR SNOW AND BLOWING SNOW...WHICH IS IN EFFECT FROM NOON
TODAY TO 5 PM MST SATURDAY. THE WINTER STORM WATCH IS NO LONGER IN
EFFECT.

* TIMING...SNOW...HEAVY AT TIMES...WILL BECOME WIDESPREAD THIS
  AFTERNOON AND CONTINUE THROUGH THE DAY SATURDAY.

* SNOW ACCUMULATIONS...8 TO 18 INCHES.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO
  35 MPH THROUGH TONIGHT...THEN SHIFTING TO THE WEST AND
  NORTHWEST ON SATURDAY. VISIBILITIES WILL BE REDUCED TO LESS THAN
  A QUARTER MILE AT TIMES IN HEAVIER SNOWFALL.

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  FRIDAY NIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE 
  EXPECTED DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SEVERE WINTER WEATHER
CONDITIONS ARE EXPECTED OR OCCURRING.  SIGNIFICANT AMOUNTS OF
SNOW ARE FORECAST THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN
AN EMERGENCY. IF YOU MUST TRAVEL...KEEP AN EXTRA FLASHLIGHT...
FOOD...AND WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.

&&

$$

COZ033>035-111830-
/O.EXT.KBOU.WS.A.0012.151212T0100Z-151213T0000Z/
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-
INCLUDING THE CITIES OF...CAMERON PASS...
LARAMIE AND MEDICINE BOW MOUNTAINS...RABBIT EARS RANGE...
ROCKY MOUNTAIN NATIONAL PARK...WILLOW CREEK PASS...
BERTHOUD PASS...BRECKENRIDGE...EAST SLOPES MOSQUITO RANGE...
EAST SLOPES SOUTHERN GORE RANGE...EISENHOWER TUNNEL...
INDIAN PEAKS...KENOSHA MOUNTAINS...MOUNT EVANS...
WILLIAMS FORK MOUNTAINS...WINTER PARK...ESTES PARK...GLENDEVEY...
NEDERLAND...RED FEATHER LAKES
328 AM MST FRI DEC 11 2015

...WINTER STORM WATCH IN EFFECT FROM THIS EVENING THROUGH
SATURDAY AFTERNOON...

* TIMING...SNOW WILL BECOME WIDESPREAD THIS EVENING AND CONTINUE
  THROUGH SATURDAY. SNOW COULD BE HEAVY AT TIMES ESPECIALLY NORTH
  OF THE INTERSTATE 70 CORRIDOR.

* SNOW ACCUMULATIONS...6 TO 13 INCHES POSSIBLE WITH THE HIGHEST
  AMOUNTS NORTH OF THE INTERSTATE 70 CORRIDOR. EXPECT LOWER
  AMOUNTS OF 4 TO 8 INCHES OVER MOUNTAIN VALLEYS AND SUMMIT
  COUNTY.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO
  40 MPH THROUGH TONIGHT...SHIFTING TO THE WEST AND NORTHWEST ON
  SATURDAY. VISIBILITIES WILL BE REDUCED TO LESS THAN A QUARTER
  MILE AT TIMES IN HEAVIER SNOWFALL.

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED TONIGHT
  AND SATURDAY. WINTER DRIVING CONDITIONS ARE EXPECTED DURING THE
  SNOWFALL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW THAT MAY IMPACT TRAVEL. CONTINUE TO MONITOR THE LATEST
FORECASTS.

&&

$$
6 follow-up statements
728 
WWUS45 KBOU 111334
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
634 AM MST FRI DEC 11 2015

...WINTER STORM SYSTEM HEADING TOWARDS COLORADO...

A STORM SYSTEM PUSHING INTO WESTERN COLORADO TODAY WILL MAKE ITS
WAY ACROSS THE REST OF THIS STATE TONIGHT AND SATURDAY. SNOW WILL
DEVELOP IN THE MOUNTAINS THIS MORNING...HEAVIEST IN THE PARK
RANGE IN WESTERN JACKSON COUNTY. THE SNOW WILL INCREASE IN
COVERAGE AND INTENSITY ALONG THE FRONT RANGE MOUNTAINS AND
FOOTHILLS TONIGHT AND SATURDAY...WITH THE HEAVIEST AMOUNTS
POSSIBLE NORTH OF INTERSTATE 70.

COZ031-112300-
/O.EXT.KBOU.WS.W.0016.151211T1334Z-151213T0000Z/
WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...
EAST SLOPES PARK AND NORTHERN GORE RANGES...GORE PASS...
RABBIT EARS PASS
634 AM MST FRI DEC 11 2015

...WINTER STORM WARNING NOW IN EFFECT UNTIL 5 PM MST SATURDAY...

* TIMING...SNOW...HEAVY AT TIMES...WILL DECREASE SLIGHTLY THIS
  AFTERNOON...THEN INCREASE AGAIN THIS EVENING AND CONTINUE
  THROUGH THE DAY SATURDAY.

* SNOW ACCUMULATIONS...8 TO 18 INCHES.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS 
  TO 35 MPH THROUGH TONIGHT...THEN SHIFTING TO THE WEST AND 
  NORTHWEST ON SATURDAY. VISIBILITIES WILL BE REDUCED TO LESS 
  THAN A QUARTER MILE AT TIMES IN HEAVIER SNOWFALL. 

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  FRIDAY NIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE 
  EXPECTED DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SEVERE WINTER WEATHER
CONDITIONS ARE EXPECTED OR OCCURRING.  SIGNIFICANT AMOUNTS OF
SNOW ARE FORECAST THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN
AN EMERGENCY. IF YOU MUST TRAVEL...KEEP AN EXTRA FLASHLIGHT...
FOOD...AND WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.

&&

$$

COZ033>035-112300-
/O.CON.KBOU.WS.A.0012.151212T0100Z-151213T0000Z/
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-
INCLUDING THE CITIES OF...CAMERON PASS...
LARAMIE AND MEDICINE BOW MOUNTAINS...RABBIT EARS RANGE...
ROCKY MOUNTAIN NATIONAL PARK...WILLOW CREEK PASS...
BERTHOUD PASS...BRECKENRIDGE...EAST SLOPES MOSQUITO RANGE...
EAST SLOPES SOUTHERN GORE RANGE...EISENHOWER TUNNEL...
INDIAN PEAKS...KENOSHA MOUNTAINS...MOUNT EVANS...
WILLIAMS FORK MOUNTAINS...WINTER PARK...ESTES PARK...GLENDEVEY...
NEDERLAND...RED FEATHER LAKES
634 AM MST FRI DEC 11 2015

...WINTER STORM WATCH REMAINS IN EFFECT FROM 6 PM MST THIS
EVENING THROUGH SATURDAY AFTERNOON...

* TIMING...SNOW WILL BECOME WIDESPREAD THIS EVENING AND CONTINUE 
  THROUGH SATURDAY. SNOW COULD BE HEAVY AT TIMES ESPECIALLY 
  NORTH OF THE INTERSTATE 70 CORRIDOR. 

* SNOW ACCUMULATIONS...6 TO 13 INCHES POSSIBLE WITH THE HIGHEST 
  AMOUNTS NORTH OF THE INTERSTATE 70 CORRIDOR. EXPECT LOWER 
  AMOUNTS OF 4 TO 8 INCHES OVER MOUNTAIN VALLEYS AND SUMMIT 
  COUNTY. 

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS 
  TO 40 MPH THROUGH TONIGHT...SHIFTING TO THE WEST AND NORTHWEST 
  ON SATURDAY. VISIBILITIES WILL BE REDUCED TO LESS THAN A 
  QUARTER MILE AT TIMES IN HEAVIER SNOWFALL. 

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  TONIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE EXPECTED 
  DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW THAT MAY IMPACT TRAVEL. CONTINUE TO MONITOR THE LATEST
FORECASTS.

&&

$$
763 
WWUS45 KBOU 111514
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
814 AM MST FRI DEC 11 2015

...WINTER STORM SYSTEM HEADING TOWARDS COLORADO...

A STORM SYSTEM PUSHING INTO WESTERN COLORADO TODAY WILL MAKE ITS
WAY ACROSS THE REST OF THIS STATE LATER TONIGHT AND SATURDAY.
SNOW WILL DEVELOP IN THE MOUNTAINS THIS MORNING...HEAVIEST IN THE
PARK RANGE IN WESTERN JACKSON COUNTY. THERE WILL BE A LULL IN THE
SNOWFALL LATER THIS AFTERNOON AND EVENING BEFORE INCREASING AGAIN
ON SATURDAY. 

COZ031-112315-
/O.CON.KBOU.WS.W.0016.000000T0000Z-151213T0000Z/
WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...
EAST SLOPES PARK AND NORTHERN GORE RANGES...GORE PASS...
RABBIT EARS PASS
814 AM MST FRI DEC 11 2015

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 PM MST
SATURDAY...

* TIMING...SNOW...HEAVY AT TIMES...WILL DECREASE SLIGHTLY THIS 
  AFTERNOON...THEN INCREASE AGAIN THIS EVENING AND CONTINUE 
  THROUGH THE DAY SATURDAY. 

* SNOW ACCUMULATIONS...8 TO 18 INCHES.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS 
  TO 35 MPH THROUGH TONIGHT...THEN SHIFTING TO THE WEST AND 
  NORTHWEST ON SATURDAY. VISIBILITIES WILL BE REDUCED TO LESS 
  THAN A QUARTER MILE AT TIMES IN HEAVIER SNOWFALL. 

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  FRIDAY NIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE 
  EXPECTED DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SEVERE WINTER WEATHER
CONDITIONS ARE EXPECTED OR OCCURRING.  SIGNIFICANT AMOUNTS OF
SNOW ARE FORECAST THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN
AN EMERGENCY. IF YOU MUST TRAVEL...KEEP AN EXTRA FLASHLIGHT...
FOOD...AND WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.

&&

$$

COZ033-112315-
/O.UPG.KBOU.WS.A.0012.151212T0100Z-151213T0000Z/
/O.NEW.KBOU.WW.Y.0029.151211T1514Z-151213T0000Z/
SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...CAMERON PASS...
LARAMIE AND MEDICINE BOW MOUNTAINS...RABBIT EARS RANGE...
ROCKY MOUNTAIN NATIONAL PARK...WILLOW CREEK PASS
814 AM MST FRI DEC 11 2015

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 PM MST SATURDAY...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW...WHICH IS IN EFFECT UNTIL 5 PM MST
SATURDAY. THE WINTER STORM WATCH IS NO LONGER IN EFFECT.

* TIMING...SNOW WILL CONTINUE TODAY...BUT DECREASING LATER THIS
  AFTERNOON AND EARLY EVENING. THE SNOW WILL INCREASE AGAIN LATER
  TONIGHT AND SATURDAY. SNOW COULD BE HEAVY AT TIMES THIS MORNING
  AND AGAIN ON SATURDAY.

* SNOW ACCUMULATIONS...6 TO 12 INCHES BY LATE SATURDAY. 

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO
  35 MPH THROUGH TONIGHT...SHIFTING TO THE WEST AND NORTHWEST ON
  SATURDAY. VISIBILITIES WILL BE REDUCED TO LESS THAN A QUARTER
  MILE AT TIMES IN HEAVIER SNOWFALL.

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  TONIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE EXPECTED 
  DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$

COZ034-035-112315-
/O.UPG.KBOU.WS.A.0012.151212T0100Z-151213T0000Z/
/O.NEW.KBOU.WW.Y.0029.151212T1200Z-151213T0000Z/
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-
INCLUDING THE CITIES OF...BERTHOUD PASS...BRECKENRIDGE...
EAST SLOPES MOSQUITO RANGE...EAST SLOPES SOUTHERN GORE RANGE...
EISENHOWER TUNNEL...INDIAN PEAKS...KENOSHA MOUNTAINS...
MOUNT EVANS...WILLIAMS FORK MOUNTAINS...WINTER PARK...
ESTES PARK...GLENDEVEY...NEDERLAND...RED FEATHER LAKES
814 AM MST FRI DEC 11 2015

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 AM TO 5 PM MST
SATURDAY...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW...WHICH IS IN EFFECT FROM 5 AM TO 5 PM
MST SATURDAY. THE WINTER STORM WATCH IS NO LONGER IN EFFECT.

* TIMING...SNOW WILL BECOME WIDESPREAD ON SATURDAY BEFORE
  DECREASING SATURDAY EVENING...

* SNOW ACCUMULATIONS...5 TO 11 INCHES BY SATURDAY EVENING.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS 
  TO 40 MPH THROUGH TONIGHT...SHIFTING TO THE WEST AND NORTHWEST 
  ON SATURDAY. VISIBILITIES WILL BE REDUCED TO LESS THAN A 
  QUARTER MILE AT TIMES IN HEAVIER SNOWFALL. 

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  TONIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE EXPECTED 
  DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$
361 
WWUS45 KBOU 112239
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
339 PM MST FRI DEC 11 2015

...WINTER STORM SYSTEM HEADING TOWARDS COLORADO...

A STORM SYSTEM DEVELOPING ACROSS THE SOUTHERN GREAT BASIN WILL
SHIFT EAST INTO NEW MEXICO ON SATURDAY. SNOW WILL REDEVELOP IN
THE MOUNTAINS TONIGHT AND BECOMING MORE WIDESPREAD OVER ALL THE
MOUNTAINS ON SATURDAY. THE HEAVIEST SNOW WILL BE IN THE PARK
RANGE IN WESTERN JACKSON COUNTY TONIGHT AND THEN SHIFTING FURTHER
SOUTH ACROSS THE INTERSTATE 70 CORRIDOR ON SATURDAY.

COZ031-120645-
/O.CON.KBOU.WS.W.0016.000000T0000Z-151213T0000Z/
WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...
EAST SLOPES PARK AND NORTHERN GORE RANGES...GORE PASS...
RABBIT EARS PASS
339 PM MST FRI DEC 11 2015

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 PM MST
SATURDAY...

* TIMING...SNOW...HEAVY AT TIMES...WILL CONTINUE THROUGH MUCH OF
  SATURDAY...BUT GRADUALLY DECREASING LATER SATURDAY IN THE
  AFTERNOON.

* SNOW ACCUMULATIONS...8 TO 18 INCHES.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 30 MPH THROUGH
  TONIGHT...THEN SHIFTING TO THE WEST AND NORTHWEST ON SATURDAY.
  VISIBILITIES WILL BE REDUCED TO LESS THAN A QUARTER MILE AT
  TIMES IN HEAVIER SNOWFALL.

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  FRIDAY NIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE 
  EXPECTED DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SEVERE WINTER WEATHER
CONDITIONS ARE EXPECTED OR OCCURRING.  SIGNIFICANT AMOUNTS OF
SNOW ARE FORECAST THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN
AN EMERGENCY. IF YOU MUST TRAVEL...KEEP AN EXTRA FLASHLIGHT...
FOOD...AND WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.

&&

$$

COZ033-120645-
/O.CON.KBOU.WW.Y.0029.000000T0000Z-151213T0000Z/
SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...CAMERON PASS...
LARAMIE AND MEDICINE BOW MOUNTAINS...RABBIT EARS RANGE...
ROCKY MOUNTAIN NATIONAL PARK...WILLOW CREEK PASS
339 PM MST FRI DEC 11 2015

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 PM MST
SATURDAY...

* TIMING...SNOW WILL BECOME MORE WIDESPREAD AGAIN THIS EVENING AND
  CONTINUE THROUGH MUCH OF SATURDAY. 

* SNOW ACCUMULATIONS...7 TO 14 INCHES BY SATURDAY EVENING.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS 
  TO 35 MPH THROUGH TONIGHT...SHIFTING TO THE WEST AND NORTHWEST 
  ON SATURDAY. VISIBILITIES WILL BE REDUCED TO LESS THAN A 
  QUARTER MILE AT TIMES IN HEAVIER SNOWFALL. 

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  TONIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE EXPECTED 
  DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$

COZ034-035-120645-
/O.CON.KBOU.WW.Y.0029.151212T1200Z-151213T0000Z/
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-
INCLUDING THE CITIES OF...BERTHOUD PASS...BRECKENRIDGE...
EAST SLOPES MOSQUITO RANGE...EAST SLOPES SOUTHERN GORE RANGE...
EISENHOWER TUNNEL...INDIAN PEAKS...KENOSHA MOUNTAINS...
MOUNT EVANS...WILLIAMS FORK MOUNTAINS...WINTER PARK...
ESTES PARK...GLENDEVEY...NEDERLAND...RED FEATHER LAKES
339 PM MST FRI DEC 11 2015

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 5 AM TO 5 PM
MST SATURDAY...

* TIMING...SNOW WILL BECOME WIDESPREAD LATE TONIGHT AND SATURDAY
  MORNING BEFORE DECREASING SATURDAY EVENING...

* SNOW ACCUMULATIONS...5 TO 11 INCHES BY SATURDAY EVENING.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS 
  TO 40 MPH THROUGH TONIGHT...SHIFTING TO THE WEST AND NORTHWEST 
  ON SATURDAY. VISIBILITIES WILL BE REDUCED TO LESS THAN A 
  QUARTER MILE AT TIMES IN HEAVIER SNOWFALL. 

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  TONIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE EXPECTED 
  DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$
346 
WWUS45 KBOU 120447
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
947 PM MST FRI DEC 11 2015

...WINTER STORM SYSTEM HEADING TOWARDS COLORADO...

A WINTER STORM MOVING OVER THE SOUTHWESTERN U.S. TONIGHT AND
SATURDAY WILL BRING AREAS OF MODERATE TO HEAVY SNOWFALL ACROSS
COLORADO THROUGH SATURDAY EVENING. LIGHT AND MODERATE SNOWFALL HAS
BEEN FALLING OVER WESTERN COLORADO THIS EVENING WHICH WILL BE
SPREADING EASTWARD LATER TONIGHT. PARTS OF THE NORTH CENTRAL
COLORADO MOUNTAINS HAVE ALSO BEEN GETTING SNOW THIS EVENING. AS
THE SNOW CONTINUES FALLING IN THE NORTHERN COLORADO MOUNTAINS
TONIGHT AND SATURDAY...TRAVEL WILL BECOME DIFFICULT DUE TO SNOW
COVERED ROADWAYS.

COZ031-121300-
/O.CON.KBOU.WS.W.0016.000000T0000Z-151213T0000Z/
WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...
EAST SLOPES PARK AND NORTHERN GORE RANGES...GORE PASS...
RABBIT EARS PASS
947 PM MST FRI DEC 11 2015

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 PM MST
SATURDAY...

* TIMING...SNOW...HEAVY AT TIMES...WILL CONTINUE THROUGH MUCH OF
  SATURDAY...BUT GRADUALLY DECREASE LATER SATURDAY AFTERNOON AND
  EVENING.

* SNOW ACCUMULATIONS...8 TO 18 INCHES.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 30 MPH THROUGH
  TONIGHT WILL SHIFT TO THE WEST AND NORTHWEST BY SATURDAY
  AFTERNOON. VISIBILITIES WILL BE REDUCED TO LESS THAN A QUARTER
  MILE AT TIMES IN HEAVIER SNOWFALL.

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED TONIGHT
  AND SATURDAY. WINTER DRIVING CONDITIONS ARE EXPECTED DURING
  THE SNOWFALL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SEVERE WINTER WEATHER
CONDITIONS ARE EXPECTED OR OCCURRING.  SIGNIFICANT AMOUNTS OF
SNOW ARE FORECAST THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN
AN EMERGENCY. IF YOU MUST TRAVEL...KEEP AN EXTRA FLASHLIGHT...
FOOD...AND WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.

&&

$$

COZ033-121300-
/O.CON.KBOU.WW.Y.0029.000000T0000Z-151213T0000Z/
SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...CAMERON PASS...
LARAMIE AND MEDICINE BOW MOUNTAINS...RABBIT EARS RANGE...
ROCKY MOUNTAIN NATIONAL PARK...WILLOW CREEK PASS
947 PM MST FRI DEC 11 2015

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 PM MST
SATURDAY...

* TIMING...SNOW WILL BECOME MORE WIDESPREAD OVERNIGHT AND
  CONTINUE THROUGH MUCH OF SATURDAY.

* SNOW ACCUMULATIONS...7 TO 14 INCHES BY SATURDAY EVENING.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS 
  TO 35 MPH THROUGH TONIGHT...SHIFTING TO THE WEST AND NORTHWEST 
  ON SATURDAY. VISIBILITIES WILL BE REDUCED TO LESS THAN A 
  QUARTER MILE AT TIMES IN HEAVIER SNOWFALL. 

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  TONIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE EXPECTED 
  DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$

COZ034-035-121300-
/O.CON.KBOU.WW.Y.0029.151212T1200Z-151213T0000Z/
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-
INCLUDING THE CITIES OF...BERTHOUD PASS...BRECKENRIDGE...
EAST SLOPES MOSQUITO RANGE...EAST SLOPES SOUTHERN GORE RANGE...
EISENHOWER TUNNEL...INDIAN PEAKS...KENOSHA MOUNTAINS...
MOUNT EVANS...WILLIAMS FORK MOUNTAINS...WINTER PARK...
ESTES PARK...GLENDEVEY...NEDERLAND...RED FEATHER LAKES
947 PM MST FRI DEC 11 2015

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 5 AM TO 5 PM
MST SATURDAY...

* TIMING...SNOW WILL BECOME WIDESPREAD LATE TONIGHT AND SATURDAY
  MORNING AND THEN CONTINUE INTO SATURDAY EVENING...

* SNOW ACCUMULATIONS...5 TO 11 INCHES BY SATURDAY EVENING.

* WIND/VISIBILITY...SOUTHWEST WINDS OF 15 TO 25 MPH WITH GUSTS TO
  40 MPH THROUGH TONIGHT...SHIFTING TO THE WEST AND NORTHWEST
  SATURDAY AFTERNOON. VISIBILITIES WILL BE REDUCED TO LESS THAN A
  QUARTER MILE AT TIMES IN HEAVIER SNOWFALL.

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  TONIGHT AND SATURDAY. WINTER DRIVING CONDITIONS ARE EXPECTED 
  DURING THE SNOWFALL. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$
657 
WWUS45 KBOU 121046
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
346 AM MST SAT DEC 12 2015

...WINTER STORM SYSTEM HEADING TOWARDS COLORADO...

A WINTER STORM MOVING OVER THE SOUTHWESTERN U.S. TODAY THROUGH 
TONIGHT SATURDAY WILL BRING MORE SNOW TO THE MOUNTAINS OF NORTHERN
COLORADO. AS THE SNOW CONTINUES FALLING THROUGH THE DAY...TRAVEL
WILL BECOME DIFFICULT DUE TO ICY AND SNOW COVERED ROADWAYS.

COZ031-121845-
/O.CON.KBOU.WS.W.0016.000000T0000Z-151213T0000Z/
WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...
EAST SLOPES PARK AND NORTHERN GORE RANGES...GORE PASS...
RABBIT EARS PASS
346 AM MST SAT DEC 12 2015

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 PM MST THIS
AFTERNOON...

* TIMING...SNOW WILL CONTINUE THROUGH THIS AFTERNOON THEN DECREASE
  THIS EVENING.

* SNOW ACCUMULATIONS...ADDITIONAL SNOWFALL OF 3 TO 6 INCHES.

* WIND/VISIBILITY...VISIBILITIES WILL BE REDUCED TO LESS THAN A
  HALF MILE AT TIMES IN HEAVIER SNOWFALL.

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED TODAY.
  WINTER DRIVING CONDITIONS ARE EXPECTED DURING THE SNOWFALL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING FOR HEAVY SNOW MEANS SEVERE WINTER WEATHER
CONDITIONS ARE EXPECTED OR OCCURRING.  SIGNIFICANT AMOUNTS OF
SNOW ARE FORECAST THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN
AN EMERGENCY. IF YOU MUST TRAVEL...KEEP AN EXTRA FLASHLIGHT...
FOOD...AND WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.

&&

$$

COZ033-121845-
/O.CON.KBOU.WW.Y.0029.000000T0000Z-151213T0000Z/
SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...CAMERON PASS...
LARAMIE AND MEDICINE BOW MOUNTAINS...RABBIT EARS RANGE...
ROCKY MOUNTAIN NATIONAL PARK...WILLOW CREEK PASS
346 AM MST SAT DEC 12 2015

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 PM MST THIS
AFTERNOON...

* TIMING...SNOW WILL CONTINUE THROUGH THIS AFTERNOON THEN
  DECREASE THIS EVENING.

* SNOW ACCUMULATIONS...ADDITIONAL SNOWFALL OF 4 TO 6 INCHES.

* WIND/VISIBILITY...VISIBILITIES WILL BE REDUCED TO LESS THAN A
  HALF MILE AT TIMES IN HEAVIER SNOWFALL.

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED
  TODAY...BE PREPARED FOR WINTER DRIVING CONDITIONS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$

COZ034-035-121845-
/O.CON.KBOU.WW.Y.0029.151212T1200Z-151213T0000Z/
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-
INCLUDING THE CITIES OF...BERTHOUD PASS...BRECKENRIDGE...
EAST SLOPES MOSQUITO RANGE...EAST SLOPES SOUTHERN GORE RANGE...
EISENHOWER TUNNEL...INDIAN PEAKS...KENOSHA MOUNTAINS...
MOUNT EVANS...WILLIAMS FORK MOUNTAINS...WINTER PARK...
ESTES PARK...GLENDEVEY...NEDERLAND...RED FEATHER LAKES
346 AM MST SAT DEC 12 2015

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 PM MST THIS
AFTERNOON...

* TIMING...SNOW WILL CONTINUE THROUGH THE DAY...THEN GRADUALLY
  DECREASE THIS EVENING.

* SNOW ACCUMULATIONS...ADDITIONAL SNOWFALL 4 TO 8 INCHES.

* WIND/VISIBILITY...VISIBILITIES WILL BE REDUCED TO LESS THAN A
  HALF MILE AT TIMES IN HEAVIER SNOWFALL.

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED...BE
  PREPARED FOR WINTER DRIVING CONDITIONS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$
718 
WWUS45 KBOU 121749
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1049 AM MST SAT DEC 12 2015

...FINALLY SNOWING ACROSS MUCH OF NORTHERN AND NORTHEAST
COLORADO...

A WINTER STORM WHICH HAS BEEN VERY SLOW TO EVOLVE ACROSS THE
REGION IS FINALLY SPREADING SNOW OVER MUCH OF NORTHERN COLORADO.
SNOW WILL CONTINUE TO BECOME MORE WIDESPREAD THIS AFTERNOON. AS
THE SNOW CONTINUES FALLING THROUGH THE DAY...TRAVEL WILL BECOME
DIFFICULT DUE TO ICY AND SNOW COVERED ROADWAYS OVER MOUNTAIN ROADS
AND PASSES. 

THE WINTER STORM WARNING HAS BEEN CANCELLED ACROSS THE
MOUNTAINS OF WESTERN JACKSON COUNTY AS SNOWFALL FOCUS HAS SHIFTED
FURTHER EAST AND SOUTH. DESPITE LOCALLIZED HEAVY BANDS OF SNOW
ACROSS LARIMER AND NORTHERN WELD COUNTIES THIS MORNING...ROADS
HAVE BEEN MAINLY WET. A WINTER WEATHER ADVISORY HAS BEEN ADDED TO
PARK COUNTY FOR THIS AFTERNOON. 

COZ031-121900-
/O.CAN.KBOU.WS.W.0016.000000T0000Z-151213T0000Z/
WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...
EAST SLOPES PARK AND NORTHERN GORE RANGES...GORE PASS...
RABBIT EARS PASS
1049 AM MST SAT DEC 12 2015

...WINTER STORM WARNING IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN DENVER HAS CANCELLED THE WINTER
STORM WARNING. 

ONLY LIGHT SNOWFALL IS EXPECTED THROUGH THIS EVENING WITH AN
ADDITIONAL 1 TO 3 INCHES. 

$$

COZ037-130000-
/O.EXA.KBOU.WW.Y.0029.000000T0000Z-151213T0000Z/
CENTRAL AND SOUTHEAST PARK COUNTY-
INCLUDING THE CITIES OF...FAIRPLAY...HARTSEL...LAKE GEORGE...
SOUTH PARK
1049 AM MST SAT DEC 12 2015

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 PM MST THIS
AFTERNOON...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW...WHICH IS IN EFFECT UNTIL 5 PM MST
THIS AFTERNOON.

* TIMING...SNOW WILL CONTINUE THROUGH THE DAY...THEN GRADUALLY 
  DECREASE THIS EVENING. 

* SNOW ACCUMULATIONS...4 TO 8 INCHES.

* WIND/VISIBILITY...VISIBILITIES WILL BE REDUCED TO LESS THAN A 
  HALF MILE AT TIMES IN HEAVIER SNOWFALL. 

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED...BE 
  PREPARED FOR WINTER DRIVING CONDITIONS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$

COZ033-130000-
/O.CON.KBOU.WW.Y.0029.000000T0000Z-151213T0000Z/
SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-
INCLUDING THE CITIES OF...CAMERON PASS...
LARAMIE AND MEDICINE BOW MOUNTAINS...RABBIT EARS RANGE...
ROCKY MOUNTAIN NATIONAL PARK...WILLOW CREEK PASS
1049 AM MST SAT DEC 12 2015

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 PM MST THIS
AFTERNOON...

* TIMING...SNOW WILL CONTINUE THROUGH THIS AFTERNOON THEN 
  DECREASE THIS EVENING. 

* SNOW ACCUMULATIONS...ADDITIONAL SNOWFALL OF 3 TO 6 INCHES.

* WIND/VISIBILITY...VISIBILITIES WILL BE REDUCED TO LESS THAN A 
  HALF MILE AT TIMES IN HEAVIER SNOWFALL. 

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED 
  TODAY...BE PREPARED FOR WINTER DRIVING CONDITIONS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$

COZ034-035-130000-
/O.CON.KBOU.WW.Y.0029.000000T0000Z-151213T0000Z/
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-
INCLUDING THE CITIES OF...BERTHOUD PASS...BRECKENRIDGE...
EAST SLOPES MOSQUITO RANGE...EAST SLOPES SOUTHERN GORE RANGE...
EISENHOWER TUNNEL...INDIAN PEAKS...KENOSHA MOUNTAINS...
MOUNT EVANS...WILLIAMS FORK MOUNTAINS...WINTER PARK...
ESTES PARK...GLENDEVEY...NEDERLAND...RED FEATHER LAKES
1049 AM MST SAT DEC 12 2015

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 PM MST THIS
AFTERNOON...

* TIMING...SNOW WILL CONTINUE THROUGH THE DAY...THEN GRADUALLY 
  DECREASE THIS EVENING. 

* SNOW ACCUMULATIONS...ADDITIONAL SNOWFALL 4 TO 8 INCHES.

* WIND/VISIBILITY...VISIBILITIES WILL BE REDUCED TO LESS THAN A 
  HALF MILE AT TIMES IN HEAVIER SNOWFALL. 

* IMPACTS...MOUNTAIN PASSES WILL BECOME ICY AND SNOWPACKED...BE 
  PREPARED FOR WINTER DRIVING CONDITIONS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER WEATHER ADVISORY FOR SNOW MEANS THAT PERIODS OF SNOW
WILL CAUSE PRIMARILY TRAVEL DIFFICULTIES. BE PREPARED FOR SNOW
COVERED ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE
DRIVING.

&&

$$

What forecasters said that day

The local office's own words before this winter storm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Denver/Boulder, CO wrote its last area forecast discussion before this winter storm warning went out at Dec 11, 3:28 AM MST, 0 minutes earlier.

Area forecast discussion, Dec 11, 3:28 AM MST, 0 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
328 AM MST FRI DEC 11 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 244 AM MST FRI DEC 11 2015

A STRONG SOUTHWESTERLY FLOW ALOFT WILL BE OVER COLORADO TODAY.
SNOW ALREADY DEVELOPING IN THE MOUNTAINS THIS MORNING AND HAVE
UPGRADED THE WINTER STORM WATCH TO A WARNING IN ZONE 31. THIS AREA
MOST FAVORED OROGRAPHICALLY AND WITH A 140 KT JET OVERHEAD TODAY
AND THIS EVENING...IT SHOULD GET STARTED SOONER. STILL ON THE
FENCE WITH A WARNING VS A WINTER WEATHER ADVISORY FOR ZONES 33>35
SO WILL HANG ONTO THE WATCH FOR NOW. BEST TIME FOR SNOW IN THESE
ZONE WILL BE OVERNIGHT INTO SATURDAY. ACROSS THE URBAN
CORRIDOR...WITH RADAR ALREADY SHOWING PCPN OVER LARIMER
COUNTY...SOME RAIN SHOWERS WILL GET STARTED THERE FIRST.
WARMEST TEMPERATURES AT FT COLLINS WL BE THIS MORNING WITH
READINGS STILL IN THE UPPER 40S. WESTERLY WINDS WILL SO
NORTH/NORTHEASTERLY LATER TODAY AS THE SFC LOW SLIDES TO THE
SOUTH. SHOULD BE MAINLY RAIN SHOWERS DEVELOPING TODAY...WITH MIX
OF RAIN AND SNOW THIS EVENING. INCREASING DYNAMICS WITH THE UPPER
LEVEL JET SHIFTING EASTWARD TONIGHT AND ENHANCED UPSLOPE. WL GO
WITH SNOW AFTER 06Z THIS EVENING. HIGHEST SNOW AMOUNTS
OVERNIGHT STILL APPEAR TO BE EASTERN LARIMER AND NORTHERN WELD
COUNTY. MAY NEED SOME SORT OF ADVISORY FOR THE PLAINS AS THE MDLS
DO SHOW BANDED TYPE OF PATTERN WITH THE QPF...WHICH WOULD INFER
SOME CSI SNOWFALL ONCE WE GET ON THE COLD SIDE OF THE UPPER JET.
HARD TO SAY HOWEVER WHERE THESE BANDS WILL FORM.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 244 AM MST FRI DEC 11 2015

MODELS HAVE STRONG SOUTHWESTERLY FLOW ALOFT FOR THE CWA
SATURDAY MORNING. AN UPPER TROUGH AXIS IS PROGGED OVER THE
WESTERN COLORADO BORDER AT 18Z SATURDAY NOONTIME. THE TROUGH AXIS
IS OVER THE EASTERN COLORADO BORDER AT 12Z SUNDAY MORNING. THERE
IS NORTHWESTERLY FLOW ALOFT ALL DAY SUNDAY...BECOMING DUE WESTERLY
SUNDAY EVENING...THE SOUTHWESTERLY BY MONDAY MORNING. THERE IS
WEAK TO MODERATE UPWARD QG VERTICAL VELOCITY ON SATURDAY INTO
EARLY EVENING. DOWNWARD ENERGY IS OVER THE CWA BY SUNDAY AND
SUNDAY EVENING...THEN WEAK UPWARD MOTION MOVES IN BY MONDAY
MORNING. THE BOUNDARY LAYER FLOW IS EASTWARD UPSLOPE FOR THE
PLAINS AND FOOTHILLS ON SATURDAY BECOMING MORE NORTHEASTERLY SATURDAY
EVENING...THEN NORTHERLY SATURDAY NIGHT LATE. SUNDAY SHOWS ALL
NORTHWESTERLIES. THERE ARE NORMAL DRAINAGE WINDS EXPECTED SUNDAY
NIGHT. MOISTURE-WISE...IT IS FAIRLY DEEP ON ALL THE MODELS FOR ALL
THE CWA SATURDAY AND SATURDAY EVENING. IT STAYS PRETTY DEEP OVER
THE EASTERN HALF OF THE CWA INTO SUNDAY MORNING MORE SO ON THE
SLIGHTLY SLOWER ECMWF. THE NAM AND GFS SHOW THE CWA PRETTY DRY
ALREADY BY 12Z SUNDAY MORNING. THE EASTERN CWA STAYS PRETTY DRY
THROUGH 12Z MONDAY MORNING. THERE IS SOME MOISTURE OVER THE
MOUNTAINS SUNDAY AND SUNDAY NIGHT...BUT NOTHING SIGNIFICANT. THE
QPF FIELDS HAVE DECENT SNOWFALL OVER THE MOUNTAINS SATURDAY AND
SATURDAY EVENING...THEN A TAD THROUGH 12Z SUNDAY MORNING. FOR THE
PLAINS...THERE IS SOME SNOWFALL PROGGED ON SATURDAY...THEN JUST
MINOR AMOUNTS SATURDAY EVENING. THERE IS NO MEASURABLE SNOWFALL
SUNDAY OR SUNDAY NIGHT. CONCERNING POPS...WILL STAY THE COURSE AND
HAVE 60-90%S ALL DAY SATURDAY FOR ALL THE CWA. THERE WILL BE
OROGRAPHIC ENHANCEMENT IN THE HIGH MOUNTAINS BY LATE MORNING
ONWARD. HOWEVER THE MOISTURE DOES SIGNIFICANTLY DECREASE AFTER 00Z
SATURDAY LATE DAY FROM WEST TO EAST. CONCERNING THE HIGHLIGHTS...
AGREE WITH SHORT TERM FORCASTER'S THINKING. THE PLAINS MIGHT SEE
BETTER SNOWFALL AMOUNTS...BUT THE UPSLOPE IS ONLY FAIR AND NOT
VERY DEEP. ALSO THE SYNOPTIC SCALE ENERGY IS JUST FAIR. FOR
TEMPERATURES...SATURDAY'S HIGHS ARE 6-12 C COLDER THAN TODAY'S.
SUNDAY'S HIGHS COME UP 2-5 C FROM SATURDAY'S AND THERE WILL BE
SOME SUN IN MOST AREAS. FOR THE LATER DAYS...MONDAY THROUGH
THURSDAY...THERE IS PRETTY STRONG SOUTHWESTERLY FLOW ALOFT
ON MONDAY AHEAD OF ANOTHER INCOMING UPPER TROUGH. THIS ONE IS
BROADER AND SOME OF THE MODELS DEVELOP A CIRCULATION WITH IT BUT
ITS OVER EASTERN COLORADO MONDAY NIGHT. THE UPPER TROUGH IS SLOW
IN MOVING EAST AND THE TROUGH AXIS DOESN'T MOVE OVER THE CWA UNTIL
WEDNESDAY NIGHT INTO MID DAY THURSDAY. THERE IS A PROLONGED PERIOD
OF DEEP MOISTURE...BUT THE SYNOPTIC SCALE ENERGY IS UPWARD ONLY
UNTIL TUESDAY SOMETIME. IT IS ALL DOWNWARD TUESDAY NIGHT THROUGH
THURSDAY. THERE IS NEVER ANY REAL UPSLOPE PROGGED FOR THE PLAINS
AND FOOTHILLS EITHER. IT SHOULD BE SOMEWHAT UNSETTLED BUT IT DOES
NOT LOOK LIKE A SIGNIFICANT SNOWSTORM. TEMPERATURES STAY BELOW
SEASONAL NORMALS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 244 AM MST FRI DEC 11 2015

THE SFC LOW EAST OF DENVER THIS MORNING IS EXPECTED TO SHIFT TO
THE SOUTH LATER THIS MORNING...WITH THE WINDS BECOMING NNELY LATER
THIS MORNING WITH A COLD FRONT PUSHING IN FROM THE NORTH BY EARLY
AFTN. VFR CONDITIONS THROUGH 22Z WITH JUST ISOLD RAIN SHOWERS IN
THE VICINITY...COULD SEE BKN ILS CIGS OF 6K FT AGL DEVELOPING BY
THAT TIME. CIGS WILL CONTINUE TO LOWER THIS EVENING WITH MIX OF
RAIN AND SNOW...MVFR RESTRICTIONS DEVELOPING 04Z-06Z...THEN IFR
CIG/VSBY RESTRICTIONS AS PCPN TURNS OVER TO SNOW...ESPECIALLY
AFTER 09Z. SURFACE WINDS SHOULD REMAIN NELY THIS EVENING INTO
SATURDAY MORNING.
&&

.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH SATURDAY AFTERNOON
FOR COZ033>035.

WINTER STORM WARNING FROM NOON TODAY TO 5 PM MST SATURDAY FOR
COZ031.

&&

SHORT TERM...COOP
LONG TERM...KOOP
AVIATION...COOP
Hazardous weather outlook, Dec 10, 11:24 AM MST, 16 hours 4 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1124 AM MST THU DEC 10 2015

COZ030>051-111830-
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-
1124 AM MST THU DEC 10 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL
COLORADO.

.DAY ONE...TODAY AND TONIGHT

MOUNTAIN RIDGES AND FRONT RANGE FOOTHILL AREAS WILL CONTINUE TO
BE WINDY TODAY ALTHOUGH SPEEDS WILL BE LESS TODAY WITH THE HIGHEST
GUSTS IN THE 40 TO 50 MPH RANGE. TEMPERATURES WILL REMAIN WELL
ABOVE AVERAGE...BUT SEVERAL DEGREES COOLER THAN YESTERDAY IN MANY
AREAS. OVERNIGHT..THERE IS A CHANCE OF LIGHT SNOW OVER THE NORTHERN
MOUNTAIN RANGES AFTER MIDNIGHT AHEAD OF A POTENT PACIFIC STORM
SYSTEM MOVING ACROSS THE GREAT BASIN.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A STRONG SOUTHWESTERLY FLOW ALOFT WILL BE OVER COLORADO ON FRIDAY
AHEAD OF THE NEXT APPROACHING PACIFIC STORM SYSTEM. SNOW WILL
DEVELOP IN THE MOUNTAINS LATE TONIGHT AND FRIDAY MORNING...SPREADING
INTO THE FRONT RANGE FOOTHILLS AND NORTHEAST PLAINS FRIDAY NIGHT
AND SATURDAY. PERIODS OF ACCUMULATING SNOWFALL WILL BE LIKELY IN
THE HIGH COUNTRY FRIDAY AND FRIDAY NIGHT...THEN ACROSS THE LOWER
ELEVATIONS FRIDAY NIGHT AND SATURDAY.

AT THIS TIME...THE HEAVIEST SNOWFALL IS EXPECTED TO OCCUR NORTH
AND NORTHWEST OF DENVER...ESPECIALLY ACROSS LARIMER...JACKSON AND
NORTHERN WELD COUNTIES. STORM TOTALS OF 6 TO 12 INCHES WILL BE
POSSIBLE IN THE MOUNTAINS AND FOOTHILLS...WITH ANYWHERE FROM 2 TO
6 INCHES ACROSS THE URBAN CORRIDOR AND NORTHEAST PLAINS.

THE MOUNTAINS AND HIGH VALLEYS COULD SEE ANOTHER SHOT OF GUSTY
WINDS AND SNOW SUNDAY NIGHT AND MONDAY. THEN ANOTHER SYSTEM IS
EXPECTED TO BRING ANOTHER CHANCE OF SNOW TO COLORADO MONDAY NIGHT
AND TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

BAKER/ENTREKIN

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 11, 8:14 AM MSTWinter Weather AdvisoryBOUBoulder, Clear Creek, Gilpin, Grand, Jackson, Jefferson and 3 more31 hr

Nearby

Winter Storm Warnings in Colorado, 2015Every winter storm warning in 2015

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.