Alert archive / Colorado / Winter Storm Watches in 2012

Winter Storm Watch 5, NWS Denver/Boulder, CO

December 17, 201216 counties in Colorado

NWS Denver/Boulder, CO issued this winter storm watch at Dec 17, 2012, 3:36 PM MST for 16 counties in Colorado. It took effect at Dec 19, 2012, 5:00 AM MST. It was in force for .

The area

The counties it named.

The facts

Issued
Dec 17, 2012, 3:36 PM MST (22:36 UTC)
In effect from
Dec 19, 2012, 5:00 AM MST
Expired
Dec 18, 2012, 1:56 PM MST
In force
Issued by
NWS Denver/Boulder, CO

Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Denver County, CO, Douglas County, CO, Elbert County, CO, Jefferson County, CO, Larimer County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 42 km from the middle of the area, began a volume at 22:36 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

Denver, CO (KDNR), launched 12:00Z, 10.6 hours before the alert went out and 80 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, Denver, CO at 12:00Z on 2012-12-17Temperature 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, Denver, CO at 12:00Z on 2012-12-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 127 square meters per square second.1939587897117Sfc1 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
2625 m above ground
0-6 km bulk shear
71 kt
0-1 km storm-relative helicity
127 m²/s²
0-3 km storm-relative helicity
371 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.

953 
WWUS45 KBOU 172236
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER CO
336 PM MST MON DEC 17 2012

...SNOW AND BLOWING SNOW TO CONTINUE FOR THE NORTHERN MOUNTAINS
OF COLORADO...

.A STRONG UPPER LEVEL JET STREAM RACING OFF THE PACIFIC WILL
CONTINUE TO BRING STRONG WINDS AND SEVERAL WAVES OF PACIFIC
MOISTURE INTO NORTHERN COLORADO. SNOW WILL CONTINUE OVER THE
MOUNTAINS THROUGH TONIGHT...WITH THE HEAVIEST SNOW IN THE PARK...
GORE... AND SIERRA MADRE RANGES...INCLUDING RABBIT EARS PASS AND
THE MOUNT ZIRKEL WILDERNESS AREAS. STRONG WINDS WILL PRODUCE
CONSIDERABLE BLOWING AND DRIFTING SNOW AND POOR VISIBILITIES.
WINTER DRIVING CONDITIONS WILL OCCUR ACROSS ALL OF THE HIGH
MOUNTAIN PASSES ALONG AND NORTH OF THE I-70 CORRIDOR.

SNOW IS EXPECTED TO DEVELOP ACROSS THE URBAN CORRIDOR AND
NORTHEAST PLAINS LATE TUESDAY NIGHT INTO WEDNESDAY. THE
COMBINATION OF SNOW AND BLOWING SNOW WILL PRODUCE THE POTENTIAL
FOR WINTER DRIVING CONDITIONS ALONG INTERSTATES 70 AND 76 AS
WELL.

COZ031-180645-
/O.CON.KBOU.WS.W.0009.000000T0000Z-121218T1200Z/
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
336 PM MST MON DEC 17 2012

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
TUESDAY...

* TIMING...SNOW AND STRONG WIND WILL CONTINUE THROUGH TONIGHT. 
  THE SNOW WILL BE HEAVY AT TIMES. THE STRONG WINDS WILL CREATE 
  CONSIDERABLE BLOWING AND DRIFTING SNOW. 

* SNOW ACCUMULATIONS...10 TO 16 INCHES BY EARLY TUESDAY MORNING. 
  ADDITIONAL ACCUMULATING SNOWFALL IS EXPECTED TUESDAY INTO 
  WEDNESDAY. 

* WIND...WEST WINDS 20 TO 30 MPH WITH GUSTS UP TO 45 MPH OVER 
  EXPOSED RIDGES. 

* MAIN IMPACT...STRONG WINDS AND PERIODS OF HEAVY SNOW WILL 
  PRODUCE HARSH WINTER CONDITIONS AND DANGEROUS TRAVEL. MANY 
  SECONDARY ROADS WILL BECOME IMPASSABLE DUE TO HEAVY SNOW 
  ACCUMULATION AND SIGNIFICANT DRIFTING SNOW. VISIBILITIES MAY 
  BE REDUCED TO ZERO AT TIMES. 

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.

&&

$$

COZ034-180645-
/O.EXB.KBOU.WW.Y.0021.121218T0000Z-121218T1200Z/
SOUTH AND SOUTHEAST GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/
GILPIN/CLEAR CREEK/SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE
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
336 PM MST MON DEC 17 2012

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 AM MST TUESDAY...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW AND BLOWING SNOW WHICH IS IN EFFECT
UNTIL 5 AM MST TUESDAY.

* TIMING...SNOW WILL CONTINUE THROUGH TONIGHT AND WILL BE HEAVY 
  AT TIMES. 

* SNOW ACCUMULATIONS...4 TO 8 INCHES BY EARLY TUESDAY MORNING.
  ADDITIONAL ACCUMULATING SNOWFALL IS EXPECTED TUESDAY INTO
  WEDNESDAY.

* WIND...WEST WINDS 20 TO 30 MPH WITH GUSTS IN EXCESS OF 50 MPH
  ABOVE TIMBERLINE.

* MAIN IMPACT...SNOW AND CONSIDERABLE BLOWING SNOW WILL CREATE 
  HAZARDOUS DRIVING CONDITIONS. WHITEOUT CONDITIONS CAN BE 
  EXPECTED AT TIMES OVER THE HIGHER MOUNTAINS AND PASSES. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

COZ033-180645-
/O.CON.KBOU.WW.Y.0021.000000T0000Z-121218T1200Z/
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
336 PM MST MON DEC 17 2012

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 AM MST
TUESDAY...

* TIMING...SNOW WILL CONTINUE THROUGH TONIGHT AND WILL BE HEAVY 
  AT TIMES. 

* SNOW ACCUMULATIONS...5 TO 10 INCHES BY EARLY TUESDAY MORNING.
  ADDITIONAL ACCUMULATING SNOWFALL IS EXPECTED TUESDAY INTO
  WEDNESDAY.

* WIND...WEST WINDS 25 TO 35 MPH WITH GUSTS IN EXCESS OF 60 MPH
  ABOVE TIMBERLINE.

* MAIN IMPACT...SNOW AND CONSIDERABLE BLOWING SNOW WILL CREATE 
  HAZARDOUS DRIVING CONDITIONS. WHITEOUT CONDITIONS CAN BE 
  EXPECTED AT TIMES OVER THE HIGHER MOUNTAINS AND PASSES. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

COZ038>051-180645-
/O.NEW.KBOU.WS.A.0005.121219T1200Z-121220T0000Z/
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-
INCLUDING THE CITIES OF...FORT COLLINS...HEREFORD...LOVELAND...
NUNN...ARVADA...BOULDER...GOLDEN...LAKEWOOD...LONGMONT...AURORA...
BRIGHTON...CITY OF DENVER...DENVER INTERNATIONAL AIRPORT...
HIGHLANDS RANCH...LITTLETON...PARKER...CASTLE ROCK...ELBERT...
FONDIS...KIOWA...LARKSPUR...BRIGGSDALE...GROVER...PAWNEE BUTTES...
RAYMER...STONEHAM...EATON...FORT LUPTON...GREELEY...ROGGEN...
BRUSH...FORT MORGAN...GOODRICH...WIGGINS...BENNETT...BYERS...
DEER TRAIL...LEADER...AGATE...HUGO...LIMON...MATHESON...FORDER...
KARVAL...KUTCH...PUNKIN CENTER...CROOK...MERINO...STERLING...
PEETZ...AKRON...COPE...LAST CHANCE...OTIS...JULESBURG...OVID...
SEDGWICK...AMHERST...HAXTUN...HOLYOKE
336 PM MST MON DEC 17 2012

...WINTER STORM WATCH IN EFFECT FROM LATE TUESDAY NIGHT THROUGH
WEDNESDAY AFTERNOON...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A WINTER STORM
WATCH...WHICH IS IN EFFECT FROM LATE TUESDAY NIGHT THROUGH
WEDNESDAY AFTERNOON. 

* TIMING...SNOW WILL DEVELOP LATE TUESDAY NIGHT AND CONTINUE
  THROUGH WEDNESDAY AFTERNOON.

* MAIN IMPACT...TOTAL SNOW ACCUMULATIONS OF 4 TO 8 INCHES
  POSSIBLE. NORTH TO NORTHEAST WINDS 20 TO 30 MPH WITH GUSTS TO 40
  MPH WILL PRODUCE EXTENSIVE BLOWING AND DRIFTING SNOW.

* OTHER IMPACTS...ROAD CLOSURES POSSIBLE DUE TO BLOWING AND
  DRIFTING SNOW...INCLUDING INTERSTATES 70 AND 76.

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.

&&

$$
3 follow-up statements
110 
WWUS45 KBOU 180544
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1044 PM MST MON DEC 17 2012

...SNOW AND BLOWING SNOW CONTINUES TONIGHT FOR THE NORTHERN
MOUNTAINS OF COLORADO... 
...WINTER STORM WATCH FOR THE NORTHEAST COLORADO PLAINS FOR LATE
TUESDAY NIGHT AND WEDNESDAY... 

.A PERIOD OF HEAVY SNOW WILL OCCUR OVERNIGHT IN THE NORTH CENTRAL
COLORADO MOUNTAINS. THE HEAVIEST SNOW WILL SHIFT FROM RABBIT EARS
AND CAMERON PASSES ACROSS THE INTERSTATE 70 CORRIDOR DURING THE
EARLY MORNING HOURS...WITH SNOW BECOMING LIGHTER TUESDAY MORNING.
GUSTY WINDS WILL PRODUCE BLOWING AND DRIFTING SNOW AND POOR
VISIBILITIES ABOVE 10 THOUSAND FEET. SNOW WILL INCREASE AGAIN IN
THE MOUNTAINS TUESDAY NIGHT AND WEDNESDAY.

SNOW IS EXPECTED TO DEVELOP ACROSS THE URBAN CORRIDOR AND
NORTHEAST PLAINS LATE TUESDAY NIGHT INTO WEDNESDAY. THE
COMBINATION OF SNOW AND BLOWING SNOW WILL PRODUCE THE POTENTIAL
FOR WINTER DRIVING CONDITIONS ALONG INTERSTATES 70 AND 76 AS
WELL.

COZ031-181200-
/O.CON.KBOU.WS.W.0009.000000T0000Z-121218T1200Z/
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
1044 PM MST MON DEC 17 2012

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
TUESDAY...

* TIMING...SNOW AND STRONG WIND WILL CONTINUE THROUGH TONIGHT. 
  THE SNOW WILL BE HEAVY AT TIMES. THE STRONG WINDS WILL CREATE 
  CONSIDERABLE BLOWING AND DRIFTING SNOW. 

* SNOW ACCUMULATIONS...STORM TOTALS OF 10 TO 16 INCHES BY EARLY
  TUESDAY MORNING. LIGHTER SNOW IS EXPECTED ON TUESDAY...BUT SNOW
  WILL INCREASE AGAIN TUESDAY NIGHT INTO WEDNESDAY.

* WIND...WEST WINDS 20 TO 30 MPH WITH GUSTS UP TO 40 MPH OVER
  EXPOSED RIDGES.

* MAIN IMPACT...STRONG WINDS AND PERIODS OF HEAVY SNOW WILL
  PRODUCE HARSH WINTER CONDITIONS AND DANGEROUS TRAVEL WITH LOW
  VISIBILITIES IN EXPOSED AREAS.

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.

&&

$$

COZ033-181200-
/O.CON.KBOU.WW.Y.0021.000000T0000Z-121218T1200Z/
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
1044 PM MST MON DEC 17 2012

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 AM MST
TUESDAY...

* TIMING...SNOW WILL CONTINUE THROUGH TONIGHT AND WILL BE HEAVY 
  AT TIMES. 

* SNOW ACCUMULATIONS...5 TO 10 INCHES BY EARLY TUESDAY MORNING.
  LIGHTER SNOW IS EXPECTED ON TUESDAY...BUT THE SNOW WILL INCREASE
  AGAIN TUESDAY NIGHT INTO WEDNESDAY.

* WIND...WEST WINDS 20 TO 30 MPH WITH GUSTS TO 50 MPH ABOVE
  TIMBERLINE.

* MAIN IMPACT...SNOW AND CONSIDERABLE BLOWING SNOW WILL CREATE 
  HAZARDOUS DRIVING CONDITIONS. WHITEOUT CONDITIONS CAN BE 
  EXPECTED AT TIMES OVER THE HIGHER MOUNTAINS AND PASSES. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

COZ034-181200-
/O.CON.KBOU.WW.Y.0021.000000T0000Z-121218T1200Z/
SOUTH AND SOUTHEAST GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/
GILPIN/CLEAR CREEK/SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE
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
1044 PM MST MON DEC 17 2012

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 5 AM MST
TUESDAY...

* TIMING...SNOW WILL CONTINUE THROUGH TONIGHT AND WILL BE HEAVY 
  AT TIMES. 

* SNOW ACCUMULATIONS...4 TO 8 INCHES BY EARLY TUESDAY MORNING.
  LIGHTER SNOW IS EXPECTED ON TUESDAY...BUT SNOW WILL INCREASE
  AGAIN TUESDAY NIGHT INTO WEDNESDAY.

* WIND...WEST WINDS 20 TO 30 MPH WITH GUSTS TO 50 MPH ABOVE
  TIMBERLINE.

* MAIN IMPACT...SNOW AND CONSIDERABLE BLOWING SNOW WILL CREATE 
  HAZARDOUS DRIVING CONDITIONS. WHITEOUT CONDITIONS CAN BE 
  EXPECTED AT TIMES OVER THE HIGHER MOUNTAINS AND PASSES. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

COZ038>051-181300-
/O.CON.KBOU.WS.A.0005.121219T1200Z-121220T0000Z/
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-
INCLUDING THE CITIES OF...FORT COLLINS...HEREFORD...LOVELAND...
NUNN...ARVADA...BOULDER...GOLDEN...LAKEWOOD...LONGMONT...AURORA...
BRIGHTON...CITY OF DENVER...DENVER INTERNATIONAL AIRPORT...
HIGHLANDS RANCH...LITTLETON...PARKER...CASTLE ROCK...ELBERT...
FONDIS...KIOWA...LARKSPUR...BRIGGSDALE...GROVER...PAWNEE BUTTES...
RAYMER...STONEHAM...EATON...FORT LUPTON...GREELEY...ROGGEN...
BRUSH...FORT MORGAN...GOODRICH...WIGGINS...BENNETT...BYERS...
DEER TRAIL...LEADER...AGATE...HUGO...LIMON...MATHESON...FORDER...
KARVAL...KUTCH...PUNKIN CENTER...CROOK...MERINO...STERLING...
PEETZ...AKRON...COPE...LAST CHANCE...OTIS...JULESBURG...OVID...
SEDGWICK...AMHERST...HAXTUN...HOLYOKE
1044 PM MST MON DEC 17 2012

...WINTER STORM WATCH REMAINS IN EFFECT FROM LATE TUESDAY NIGHT
THROUGH WEDNESDAY AFTERNOON...

* TIMING...SNOW WILL DEVELOP LATE TUESDAY NIGHT AND CONTINUE 
  THROUGH WEDNESDAY AFTERNOON. 

* MAIN IMPACT...TOTAL SNOW ACCUMULATIONS OF 4 TO 8 INCHES 
  POSSIBLE. NORTH TO NORTHEAST WINDS 20 TO 30 MPH WITH GUSTS TO 
  40 MPH WILL PRODUCE EXTENSIVE BLOWING AND DRIFTING SNOW. 

* OTHER IMPACTS...ROAD CLOSURES POSSIBLE DUE TO BLOWING AND 
  DRIFTING SNOW...INCLUDING INTERSTATES 70 AND 76. 

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.

&&

$$

GIMMESTAD
690 
WWUS45 KBOU 181216
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
516 AM MST TUE DEC 18 2012

...WINTER STORM WATCH FOR THE NORTHEAST COLORADO PLAINS FOR LATE
TONIGHT AND WEDNESDAY...

.SNOW IS EXPECTED TO DEVELOP ACROSS THE URBAN CORRIDOR AND
NORTHEAST PLAINS LATE TONIGHT INTO WEDNESDAY. THE COMBINATION OF
SNOW AND BLOWING SNOW WILL PRODUCE THE POTENTIAL FOR WINTER
DRIVING CONDITIONS INCLUDING ON INTERSTATES 70 AND 76.

COZ031-181330-
/O.EXP.KBOU.WS.W.0009.000000T0000Z-121218T1200Z/
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
516 AM MST TUE DEC 18 2012

...WINTER STORM WARNING HAS EXPIRED...

SNOWFALL WILL BEGIN TO DIMINISH TODAY FROM YESTERDAYS STORM.
HOWEVER ANOTHER 2 TO 4 INCHES OF SNOW COULD FALL THROUGHOUT THE
COURSE OF THE DAY TODAY.

$$

COZ033-034-181330-
/O.EXP.KBOU.WW.Y.0021.000000T0000Z-121218T1200Z/
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-
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
516 AM MST TUE DEC 18 2012

...WINTER WEATHER ADVISORY HAS EXPIRED...

SNOWFALL WILL BEGIN TO DIMINISH TODAY FROM YESTERDAYS STORM.
HOWEVER ANOTHER 1 TO 4 INCHES OF SNOW COULD FALL THROUGHOUT THE
COURSE OF THE DAY TODAY.

$$

COZ038>051-182315-
/O.CON.KBOU.WS.A.0005.121219T1200Z-121220T0000Z/
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-
INCLUDING THE CITIES OF...FORT COLLINS...HEREFORD...LOVELAND...
NUNN...ARVADA...BOULDER...GOLDEN...LAKEWOOD...LONGMONT...AURORA...
BRIGHTON...CITY OF DENVER...DENVER INTERNATIONAL AIRPORT...
HIGHLANDS RANCH...LITTLETON...PARKER...CASTLE ROCK...ELBERT...
FONDIS...KIOWA...LARKSPUR...BRIGGSDALE...GROVER...PAWNEE BUTTES...
RAYMER...STONEHAM...EATON...FORT LUPTON...GREELEY...ROGGEN...
BRUSH...FORT MORGAN...GOODRICH...WIGGINS...BENNETT...BYERS...
DEER TRAIL...LEADER...AGATE...HUGO...LIMON...MATHESON...FORDER...
KARVAL...KUTCH...PUNKIN CENTER...CROOK...MERINO...STERLING...
PEETZ...AKRON...COPE...LAST CHANCE...OTIS...JULESBURG...OVID...
SEDGWICK...AMHERST...HAXTUN...HOLYOKE
516 AM MST TUE DEC 18 2012

...WINTER STORM WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH
WEDNESDAY AFTERNOON...

* TIMING...SNOW WILL DEVELOP LATE TONIGHT AND CONTINUE THROUGH
  WEDNESDAY AFTERNOON. THE HEAVIEST SNOWFALL RATES WILL OCCUR IN
  THE MORNING.

* MAIN IMPACT...TOTAL SNOW ACCUMULATIONS OF 3 TO 8 INCHES 
  POSSIBLE. NORTH TO NORTHEAST WINDS 20 TO 30 MPH WITH GUSTS TO 
  45 MPH WILL PRODUCE EXTENSIVE BLOWING AND DRIFTING SNOW. 

* OTHER IMPACTS...ROAD CLOSURES POSSIBLE DUE TO BLOWING AND
  DRIFTING SNOW...INCLUDING INTERSTATES 70 AND 76. TRAVEL MAY BE
  DIFFICULT AREA-WIDE DURING THE MORNING HOURS.

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.

&&

$$
577 
WWUS45 KBOU 182056
WSWBOU

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE DENVER CO
156 PM MST TUE DEC 18 2012

...WINTER STORM WILL SPREAD ACROSS COLORADO TONIGHT AND
WEDNESDAY...

.SNOW IS EXPECTED TO CONTINUE IN THE MOUNTAINS THROUGH WEDNESDAY
MORNING...WITH HEAVY SNOW POSSIBLE LATE TONIGHT AND WEDNESDAY
MORNING. SNOW WILL SPREAD ACROSS THE PLAINS LATE TONIGHT ANDDEVELOP
ACROSS THE URBAN CORRIDOR AND NORTHEAST PLAINS LATE
TONIGHT...COMBINING WITH WIND ON WEDNESDAY. THE COMBINATION OF
SNOW AND BLOWING SNOW WILL PRODUCE THE POTENTIAL FOR WINTER
DRIVING CONDITIONS INCLUDING ON INTERSTATES 70 AND 76.

COZ041-046>051-190500-
/O.UPG.KBOU.WS.A.0005.121219T1200Z-121220T0000Z/
/O.NEW.KBOU.BZ.W.0003.121219T1500Z-121220T0300Z/
ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES ABOVE 6000 FEET-
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-
INCLUDING THE CITIES OF...CASTLE ROCK...ELBERT...FONDIS...KIOWA...
LARKSPUR...AGATE...HUGO...LIMON...MATHESON...FORDER...KARVAL...
KUTCH...PUNKIN CENTER...CROOK...MERINO...STERLING...PEETZ...
AKRON...COPE...LAST CHANCE...OTIS...JULESBURG...OVID...SEDGWICK...
AMHERST...HAXTUN...HOLYOKE
156 PM MST TUE DEC 18 2012

...BLIZZARD WARNING IN EFFECT FROM 8 AM TO 8 PM MST WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A BLIZZARD
WARNING...WHICH IS IN EFFECT FROM 8 AM TO 8 PM MST WEDNESDAY. THE
WINTER STORM WATCH IS NO LONGER IN EFFECT. 

* TIMING...SNOW WILL DEVELOP LATE TONIGHT AND CONTINUE THROUGH 
  WEDNESDAY AFTERNOON. THE HEAVIEST SNOWFALL RATES WILL OCCUR IN 
  THE MORNING. 

* WINDS/VISIBILITY...NORTH WINDS OF 25 TO 40 MPH WITH SOME HIGHER
  GUSTS WILL CREATE EXTENSIVE BLOWING AND DRIFTING CONDITIONS AND
  WIDESPREAD AREAS OF VISIBILITIES BELOW A QUARTER MILE.

* SNOW ACCUMULATIONS...SNOW AMOUNTS OF 3 TO 6 INCHES WILL FALL BY
  SUNSET WEDNESDAY. 

* IMPACTS...ROAD CLOSURES POSSIBLE DUE TO BLOWING AND DRIFTING
  SNOW...INCLUDING INTERSTATES 70 AND 76. TRAVEL MAY BE DIFFICULT
  AREA-WIDE DURING THE MORNING HOURS. WIND CHILL VALUES WILL HOVER
  NEAR ZERO WEDNESDAY AFTERNOON.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A BLIZZARD WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE
EXPECTED OR OCCURRING. FALLING AND BLOWING SNOW WITH STRONG WINDS
AND POOR VISIBILITIES ARE LIKELY. THIS WILL LEAD TO WHITEOUT
CONDITIONS...MAKING TRAVEL EXTREMELY DANGEROUS. DO NOT TRAVEL. IF
YOU MUST TRAVEL...HAVE A WINTER SURVIVAL KIT WITH YOU. IF YOU GET
STRANDED...STAY WITH YOUR VEHICLE.

&&

$$

COZ038>040-042>045-190500-
/O.UPG.KBOU.WS.A.0005.121219T1200Z-121220T0000Z/
/O.NEW.KBOU.WW.Y.0022.121219T1000Z-121220T0000Z/
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-NORTHEAST WELD COUNTY-
CENTRAL AND SOUTH WELD COUNTY-MORGAN COUNTY-
CENTRAL AND EAST ADAMS AND ARAPAHOE COUNTIES-
INCLUDING THE CITIES OF...FORT COLLINS...HEREFORD...LOVELAND...
NUNN...ARVADA...BOULDER...GOLDEN...LAKEWOOD...LONGMONT...AURORA...
BRIGHTON...CITY OF DENVER...DENVER INTERNATIONAL AIRPORT...
HIGHLANDS RANCH...LITTLETON...PARKER...BRIGGSDALE...GROVER...
PAWNEE BUTTES...RAYMER...STONEHAM...EATON...FORT LUPTON...
GREELEY...ROGGEN...BRUSH...FORT MORGAN...GOODRICH...WIGGINS...
BENNETT...BYERS...DEER TRAIL...LEADER
156 PM MST TUE DEC 18 2012

...WINTER WEATHER ADVISORY IN EFFECT FROM 3 AM TO 5 PM MST
WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW AND BLOWING SNOW...WHICH IS IN EFFECT
FROM 3 AM TO 5 PM MST WEDNESDAY. THE WINTER STORM WATCH IS NO
LONGER IN EFFECT.

* TIMING...SNOW WILL DEVELOP LATE TONIGHT AND CONTINUE THROUGH 
  WEDNESDAY AFTERNOON. THE HEAVIEST SNOWFALL RATES WILL OCCUR IN 
  THE MORNING. 

* MAIN IMPACT...TOTAL SNOW ACCUMULATIONS OF 3 TO 8 INCHES
  POSSIBLE. NORTH TO NORTHEAST WINDS 20 TO 30 MPH WITH GUSTS TO 40 MPH
  WILL PRODUCE EXTENSIVE BLOWING AND DRIFTING SNOW.

* OTHER IMPACTS...ROAD CLOSURES POSSIBLE DUE TO BLOWING AND 
  DRIFTING SNOW...INCLUDING INTERSTATES 70 AND 76. TRAVEL MAY BE 
  DIFFICULT AREA-WIDE DURING THE MORNING HOURS. 

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.

&&

$$

COZ031-033-034-190500-
/O.NEW.KBOU.WW.Y.0022.121219T0600Z-121220T0000Z/
WEST JACKSON AND WEST GRAND COUNTIES ABOVE 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-
INCLUDING THE CITIES OF...
EAST SLOPES PARK AND NORTHERN GORE RANGES...GORE PASS...
RABBIT EARS PASS...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
156 PM MST TUE DEC 18 2012

...WINTER WEATHER ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO
5 PM MST WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW...WHICH IS IN EFFECT FROM 11 PM THIS
EVENING TO 5 PM MST WEDNESDAY.

* TIMING...SNOW WILL INCREASE ACROSS THE MOUNTAINS THIS
  EVENING...BECOMING HEAVY LATE TONIGHT.

* SNOW AMOUNTS...6 TO 14 INCHES OF NEW SNOW CAN BE EXPECTED.

* MAIN IMPACT...TRAVEL WILL BE IMPACTED DUE TO SNOWFALL.
  INCREASING WINDS LATE TONIGHT WILL CREATE AREAS OF BLOWING AND
  DRIFTING WHICH WILL RESTRICT VISIBILITIES.

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.

&&

$$

COZ035-036-190500-
/O.NEW.KBOU.WW.Y.0022.121219T1000Z-121220T0000Z/
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-
INCLUDING THE CITIES OF...ESTES PARK...GLENDEVEY...NEDERLAND...
RED FEATHER LAKES...BAILEY...CENTRAL CITY...EVERGREEN...
GEORGETOWN...IDAHO SPRINGS...WESTCREEK
156 PM MST TUE DEC 18 2012

...WINTER WEATHER ADVISORY IN EFFECT FROM 3 AM TO 5 PM MST
WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A WINTER
WEATHER ADVISORY FOR SNOW...WHICH IS IN EFFECT FROM 3 AM TO 5 PM
MST WEDNESDAY.

* TIMING...SNOW WILL SPREAD ACROSS THE FOOTHILLS LATE TONIGHT AND
  CONTINUE WEDNESDAY.  

* MAIN IMPACT...SNOW AMOUNTS OF 4 TO 8 INCHES CAN BE EXPECTED. 

* OTHER IMPACTS...TRAVEL MAY BECOME IMPACTED WITH SNOWPACKED
  ROADWAYS.

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 watch 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 watch went out at Dec 17, 3:34 PM MST, 2 minutes earlier.

Area forecast discussion, Dec 17, 3:34 PM MST, 2 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
334 PM MST MON DEC 17 2012

.SHORT TERM...WEB CAMS SHOWING SNOW ACROSS MOUNTAINS
CONTINUING...THOUGH A BIT IMPROVEMENT IN THE LAST FEW HOURS. ALSO
SOME GUSTS AROUND 50 MPH ALONG THE DIVIDE...WHICH HAS BEEN
CREATING AREAS OF BLOWING AND DRIFITING SNOW. LATEST SNOWTELL OBS
SUGGESTING ABOUT 6 INCHES OF SNOW HAD FALLEN ACROSS ZONE 31 IN THE
LAST 6 HOURS...WITH PERHAPS 2 TO 4 INCHES FOR ZONES 33 AND 34.
ACROSS FOOTHILLS AND ALONG URBAN CORRIDOR...WESTERLY WINDS GUSTING
IN THE 30-40 MPH RANGE MOST AREAS. STRONG PACIFIC JET STILL
EXPECTED TO MOVE ACROSS NORTHERN COLORADO DURING THE EVENING AND
OVERNIGHT WITH STRONGER WINDS LOWERING TO NEAR MOUNTAIN TOP. MODEL
CROSS SECTIONS INDICATING INCREASING LAPSE RATES ALONG WITH MID
LEVEL ASCENT. SHOULD SEE MOUNTAIN SNOW BEGIN TO INCREASE AGAIN
DURING THE EVENING AS THE LIFT INCREASES. LOCAL SNOW MODEL STILL
YIELDING ROUGHLY 5-10 INCHES ACROSS ZONE 31 TONIGHT...WITH AROUND
4-8 INCHES FOR ZONES 33 AND 34. THIS LOOKS REASONABLE BUT MAY NEED
TO ADD A FEW INCHES FOR THE DYNAMICS. FEEL CURRENT WARNING FOR
ZONE 31 AND ADVISORY FOR 33 STILL ON TRACK. BUT WILL ALSO INCLUDE
ZONE 34 IN THE ADVISORY...THOUGH AMOUNTS MAY NOT MEET CRITERIA
THERE WILL BE SUFFICIENT BLOWING SNOW. ACROSS PLAINS SHOULD SEE
WINDS BEGIN TO DECOUPLE THOUGH WILL REMAIN A BIT GUSTY NEAR THE
FOOTHILLS. LATEST RUC SHOWS SOME LIGHT PRECIP ACROSS ZONE 38 THIS
EVENING...STILL LOOKS REASONABLE WITH THE APPROACHING LIFT. ON
TUESDAY...FLOW ALOFT WEAKENS A BIT AS THE JET CORE HEADS EAST AND
BECOMES MORE SOUTHWEST AS AN UPPER TROUGH APPROACHES THE GREAT
BASIN. WILL STILL BE A BIT GUSTY ACROSS THE RIDGES. SOUTHWEST
FLOW NOT FAVORABLE FOR DECENT MOUNTAIN SNOWFALL. MID LEVEL QG
ACENT ALSO DECREASES. WOULD EXPECT SNOW TO CONTINUE WITH FAIRLY
GOOD MOISTURE...BUT SHOULD BE LIGHT. WILL NOT EXTEND HILITES
BEYOND 12Z. ACROSS PLAINS...SURFACE WINDS TO BECOME EASTERLY WITH
THE DEVELOPMENT OF AN ANTICYCLONE. LATEST GFS AND ECMWF SHOWS SOME
LIGHT QPF DURING THE AFTERNOON...MAY BE A BIT OVERDONE AS LOW
LEVEL STILL LOOK DRY.

.LONG TERM...MODELS CONTINUE TO ADVERTISE A SIGNIFICANT WINTER
WEATHER EVENT ACROSS THE FORECAST AREA ON WEDNESDAY. FROM TUESDAY
EVENING THROUGH WEDNESDAY EVENING AN UPPER TROUGH WILL BE MOVING
OVER THE STATE WHILE A SURFACE LOW OVER SOUTHEAST COLORADO
UNDERGOES STRONG CYCLOGENESIS. A STRONG COLD FRONT WILL MOVE OVER
NORTHERN COLORADO...INCLUDING THE MOUNTAINS...TUESDAY EVENING.
UPSLOPE WINDS WILL THEN CONTINUE THROUGH THE PRE-DAWN HOURS AND
STRENGTHEN THROUGH THE DAY WEDNESDAY. THE UPPER TROUGH WILL
CONTAIN PLENTY OF DYNAMICS ACCORDING TO THE Q-G DIAGNOSTICS
PACKAGE. THE PRESENCE OF THE STRONG UPPER LEVEL JET OVER THE PAST
FEW DAYS MAKE THE MODEL SOLUTIONS VERY BELIEVABLE. THE NAM QPF
AMOUNTS ARE A FAIR AMOUNT HIGHER THAN THE GFS AND ECMWF SOLUTIONS
CONCERNING HOW MUCH SNOW WE GET ON WEDNESDAY. ALL MODELS AGREE
QUITE A BIT OF WIND DEVELOPING. WITH THE THREAT OF SIGNIFICANT
BLOWING SNOW BECAUSE OF THE WIND...WILL ISSUE A WINTER STORM WATCH
ACROSS THE PLAINS. SNOW AMOUNTS OF 3 TO 6 INCHES WILL BE TOO LIGHT
IF THE NAM IS RIGHT. WIND GUSTS OF 25 TO 40 MPH MIGHT BE COMMON AT
THE HEIGHT OF THE STORM. PERIODS OF SNOW WILL BE ONGOING IN THE
MOUNTAINS DUE TO THE DYNAMICS OVER THE STATE.

THE UPPER TROUGH WILL BE MOVING EAST OF COLORADO BY WEDNESDAY
EVENING WHICH WILL BRING A RAPID END TO THE SNOW EVENT. LINGERING
SHOWERS IN THE EVENING WILL COME TO AN END OVERNIGHT. FOR THE
PERIOD THURSDAY THROUGH SUNDAY...STRONG UPPER RIDGING WILL BE OVER
THE STATE WITH DRY WEATHER FROM THE MOUNTAINS EASTWARD WITH
TEMPERATURES TRENDING TOWARD SEASONAL NORMALS.

EARLY NEXT WEEK LOOKS LIKE ANOTHER TROUGH MAY BE APPROACHING THE
STATE IF THE ECMWF IS CORRECT. FOR THE TIME BEING WILL JUST
MENTION AN INCREASING CHANCE OF SNOW IN THE MOUNTAINS AS THE STATE
COMES UNDER THE SOUTHWESTERLY FLOW AHEAD OF THE TROUGH.

&&

.AVIATION...WESTERLY WINDS TO CONTINUE ACROSS THE DENVER
AREA THROUGH 02Z...WITH SOME GUSTS TO TO 35 KTS. WINDS TO DECREASE
AT DEN AND APA AND BECOME SOUTHWESTERLY DURING THE EVENING BUT
SHOULD REMAIN WESTERLY AND GUSTY AT BJC. AFTER 15Z TUESDAY...
MODELS SHOW THE DEVELOPMENT OF AN ANTICYCLONE IN THE DENVER
AREA...WITH WIND BECOMING EASTERLY. VFR TO CONTINUE WITH NO
PRECIPITATION EXPECTED.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
AFTERNOON FOR COZ038>051.

WINTER WEATHER ADVISORY UNTIL 5 AM MST TUESDAY FOR COZ034.

WINTER WEATHER ADVISORY UNTIL 5 AM MST TUESDAY FOR COZ033.

WINTER STORM WARNING UNTIL 5 AM MST TUESDAY FOR COZ031.

&&

SHORT TERM...D-L
LONG TERM....DANKERS
AVIATION...D-L
Hazardous weather outlook, Dec 17, 11:10 AM MST, 4 hours 26 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1110 AM MST MON DEC 17 2012

COZ030>051-181815-
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-
1110 AM MST MON DEC 17 2012

...SNOW AND STRONG WINDS TO AFFECT THE NORTHERN COLORADO HIGH
COUNTRY...

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

.DAY ONE...TODAY AND TONIGHT

SNOW AND GUSTY WINDS WILL AFFECT THE HIGH COUNTRY THROUGH
TONIGHT...ESPECIALLY ALONG AND WEST OF THE CONTINENTAL DIVIDE.
HEAVY SNOWFALL IS LIKELY BY NIGHTFALL IN THE GORE AND PARK RANGES
ROUGHLY NORTH OF I-70 WHERE 10 TO 16 INCHES OF SNOW COULD
ACCUMULATE BY TUESDAY MORNING. MOUNTAIN AREAS FARTHER EAST IN
EASTERN JACKSON...EASTERN GRAND AND SUMMIT COUNTIES...COULD SEE
UPWARDS OF 5 TO 10 INCHES OF NEW SNOW ACCUMULATION BY MORNING. IN
ADDITION TO THE SNOWFALL...WESTERLY WINDS OF 20 TO 35 MPH AND
GUSTS AS HIGH AS 65 MPH WILL ALSO PRODUCE CONSIDERABLE BLOWING AND
DRIFTING SNOW ABOVE TIMBERLINE AND ON MANY OF THE HIGH MOUNTAIN
PASSES. DIVING CONDITIONS COULD DETERIORATE TO A POINT WHERE MANY
HIGH COUNTRY ROADS MAY BECOME IMPASSABLE OVERNIGHT. PEOPLE
PLANNING TRAVEL IN THE HIGH COUNTRY ARE URGED TO CHECK WITH THE
COLORADO DEPARTMENT OF TRANSPORTATION FOR THE LATEST ROAD
CONDITIONS BEFORE DEPARTING.

ACROSS THE PLAINS...WESTERLY WINDS OF 20 TO 30 MPH WILL PREVAIL
THIS AFTERNOON WITH GUSTS AS HIGH AS 50 MPH ALONG THE URBAN
CORRIDOR. THE WINDS WILL DECREASE DURING THE EVENING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

STRONG WESTERLY FLOW ALOFT AND UPPER LEVEL DISTURBANCES WILL
CONTINUE MOVING ACROSS NORTHERN COLORADO THROUGH WEDNESDAY.
OCCASIONAL SNOW AND GUSTY WINDS WILL CONTINUE OVER THE MOUNTAINS
WITH WIND GUSTS UP TO 60 MPH OVER RIDGES AND ALONG EASTERN
MOUNTAIN SLOPES. PERIODS OF MODERATE SNOWFALL MAY CAUSE DIFFICULT
TRAVEL AT TIMES.

ON TUESDAY NIGHT...A STRONG COLD FRONT WILL MOVE INTO NORTHEAST
COLORADO AND COMBINE WITH A VIGOROUS UPPER LEVEL TROUGH TO PRODUCE
A ROUND OF SNOW AND WIND ACROSS THE PLAINS THAT WILL LAST THROUGH
WEDNESDAY. COLDER TEMPERATURES...GUSTY NORTH WINDS AND SNOW ARE
EXPECTED TO CONTINUE THROUGH THE DAY. THERE IS THE POTENTIAL FOR
3 TO 6 INCHES OF SNOW ON THE PLAINS BY WEDNESDAY EVENING. AREAS OF
BLOWING AND DRIFTING SNOW WILL ALSO CAUSE POOR VISIBILITIES AND
MAY MAKE TRAVEL DIFFICULT ACROSS THE PLAINS. SNOW WILL ALSO
CONTINUE FALLING IN THE MOUNTAINS.

DRIER CONDITIONS AND GRADUALLY WARMING TEMPERATURES WILL RETURN
THURSDAY THROUGH SUNDAY ACROSS NORTHERN COLORADO AS AN UPPER
RIDGE BUILDS OVER THE STATE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

Nearby

Winter Storm Watches in Colorado, 2012Every winter storm watch in 2012

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.