Severe Thunderstorm Warning 1, NWS Denver/Boulder, CO

000 
WWUS55 KBOU 240031
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
630 PM MDT SUN APR 23 2006

COC001-031-240040-
/O.EXP.KBOU.SV.W.0001.000000T0000Z-060424T0030Z/
ADAMS CO-DENVER CO-
630 PM MDT SUN APR 23 2006

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL DENVER AND WEST
CENTRAL ADAMS COUNTIES EXPIRED AT 630 PM MDT...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS EXITED THE AREA.

THE STORM PRODUCED HAIL UP TO ONE INCH IN DIAMETER IN DENVER 
COUNTY.

LAT...LON 3983 10504 3970 10504 3970 10490 3977 10488   
      3979 10484 3984 10479 3990 10469 3993 10488
      3988 10504

$$

RJK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
230 PM MDT SUN APR 23 2006

.SHORT TERM DISCUSSION...FIRST OF SECOND SFC FRONTS ALREADY THROUGH
NERN COLORADO AT THIS HOUR. THIS FIRST BOUNDARY LARGELY MARKED BY A
WIND SHIFT. SOUTH OF THIS BNDRY VERY LOW RHS/DEWPOINTS AND GUSTY
SWLY WINDS. FOR THAT REASON ISSUED A SHORT FUSED RED FLAG WARNING FOR
SOUTH PARK...SRN FOOTHILLS AND PALMER DIVIDE. WARNING IN 2 SEGMENTS...
ONE PART EXPIRES AT 22Z TODAY...WHILE THE 2ND SEGMENT FOR SOUTH PARK
EXPIRES AT 00Z/MON.

NOW BACK TO BIG WEATHER CHANGE. A SECOND MUCH STRONG FRONTAL SYSTEM
STRETCHING ACROSS SERN WYOMING AT THIS HOUR SLIDES SWRD THRU NERN
COLORADO THIS EVENING. 4-5MB/3HR PRES RISES BEHIND THIS FRONT...
QUITE IMPRESSIVE FOR THIS TIME OF DAY. UNDER A LOW OVERCAST CURRENT
TEMPS 50-75 MILES BEHIND THIS FRONT IN THE MID/UPR 30S. THIS IS THE
AIRMASS EXPECTED TO BLANKET NERN COLORADO ON MONDAY. MEANWHILE DEEP
UPR TROUGH OVER THE GREAT BASIN MAKE VERY SLOW EASTWARD PROGRESS
NEXT 24 HOURS. ACTUALLY MODELS SHOW THE TROUGH AND UPR LOW FILLING
AS THEY TRACK EWRD ACROSS WYOMING AND WRN COLORADO ON MONDAY. UPWARD
QG FORCING RELATIVELY WEAK AS IT PASSES BY AND MID-LEVEL AIR ROUNDING
BOTTOM OF THIS TROUGH LOOKS QUITE DRY. SO MOISTURE FOR PRECIPITATION
NEXT 24 HOURS LARGELY TRANSPORTED IN FROM THE NRN AND CNTRL GREAT
PLAINS.

SHOULD SEE SNOW LEVELS LOWERING TO AROUND 5000-5500 FT MSL AFTER 06Z
TONIGHT ALONG THE FRONT RANGE AS CIGS LOWER TO BLOW A THOUSAND FEET
AGL OR SO. WILL STICK WITH LIKELY AND CATEGORICAL PCPN PROBABILITIES
IN CURRENT FCST FOR ZONES EAST OF THE CONTINENTAL DIVIDE LATE TONIGHT
AND MONDAY. HOWEVER...BASED ON CURRENT WX CONDITIONS...HAVE DELAYED
HIGHEST POPS UNTIL EITHER LATE EVENING OR AFTER MIDNIGHT. ACCUMULATING
SNOW STILL A VERY GOOD BET FOR THE FOOTHILLS WHERE 3-7 INCHES
SHOULD ACCUMULATE BY LATE MONDAY AFTERNOON. MEANWHILE NEAR BASE OF
FOOTHILLS...OVER THE CHEYENNE RIDGE IN LARIMER CTY...AND ON THE
PALMER DIVIDE IN ERN DOUGLAS AND WRN ELBERT CTYS...COULD SEE A COUPLE
INCHES OF WET SNOW ACCUMULATING BETWEEN 06Z AND 18Z/MON. HOWEVER...
THE DRASTIC DROP IN TEMPERATURES WILL LIKELY BE BIGGEST SHOCK TO OUR
SYSTEMS. DO NOT SEE DAYTIME TEMPS ON THE PLAINS CLIMBING ABOVE THE
LOWER 40S NEAR THE EASTERN BORDER AND NOT ABOVE THE UPR 30S ALONG THE
FRONT RANGE.

.LONG TERM DISCUSSION...ANY LIQUID PRECIPITATION OCCURRING MONDAY
EVENING SHOULD BE CHANGING OVER TO SNOW SINCE DAYTIME HEATING EFFECT
WILL BE GONE.  HOWEVER...Q-G FORCING LEFT OVER FROM SHEARING TROUGH
IS WINDING DOWN BY MONDAY EVENING SO PRECIPITATION IS EXPECTED TO BE
ON THE LIGHT SIDE.  CANT RULE OUT SOME ISOLATED STORMS IN THE
MOUNTAINS GIVEN INSTABILITY OVER THE HIGHER TERRAIN.

BY TUESDAY...AIRMASS DRIES SOMEWHAT AND SUBSIDENCE ASSOCIATED WITH
WEAK RIDGING WILL MOVE OVER THE STATE. AS A RESULT...WILL SCALE BACK
POPS A BIT AND KEEP THEM MOSTLY CONFINED TO THE HIGHER TERRAIN.

THERE IS STILL A LOT OF UNCERTAINTY WITH REGARD TO NEXT POTENTIAL
STORM SYSTEM.  MOST ENSEMBLE RUNS HAVE TRENDED A BIT SOUTHWARD AND
SLOWER WITH SYSTEM.  AS A RESULT...WILL REMOVE MOST THURSDAY POPS.
EVEN FOR FRIDAY THROUGH SUNDAY...PRECIPITATION CHANCES WOULD BE
LIMITED IF STORM SYSTEM EVENTUALLY GETS SHEARED FARTHER SOUTH AS
EASTERN U.S. TROUGH DEVELOPS.  UNTIL MORE CLARITY DEVELOPS REGARDING
THIS STORM...SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS IS APPROPRIATE.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING FIRE WEATHER
  ZONES 216 AND 241 UNTIL 4 PM MDT...AND ZONE 214 UNTIL 6 PM MDT.

&&

BAKER/BARJENBRUCH

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
1128 AM MDT SUN APR 23 2006

COZ030>051-241200-
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-
1128 AM MDT SUN APR 23 2006

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

.DAY ONE...TODAY AND TONIGHT

STRONG HEATING AND THE PASSAGE OF A COLD FRONT WILL SPARK A FEW
SHOWERS AND THUNDERSTORMS OVER THE FRONT RANGE AND ADJACENT HIGH
PLAINS LATER THIS AFTERNOON. INITIALLY SHOWERS MOVING OFF THE FRONT
RANGE WILL BE HIGH BASED RESULTING IN LITTLE RAINFALL. BUT AS
MOISTURE INCREASES WITH DEEPENING UPSLOPE FLOW...SHOWERS WILL BECOME
MORE NUMEROUS...PARTICULARLY OVER AND NEAR THE FRONT RANGE AND
WESTERN PORTIONS OF THE PALMER DIVIDE. ISOLATED THUNDERSTORMS
FORMING AFTER 4 PM MAY PRODUCE WIND GUSTS TO AROUND 40 MPH AND SMALL
HAIL...ESPECIALLY THOSE OVER AND NEAR THE PALMER DIVIDE. TONIGHT A
REINFORCING SURGE OF MUCH COOLER AND VERY MOIST AIR WILL BLANKET THE
FRONT RANGE AND NORTHEAST PLAINS. RAIN SHOWERS THIS EVENING WILL MIX
WITH SNOW ON THE PLAINS AFTER MIDNIGHT. WHEREAS THE FRONT RANGE...
PALMER DIVIDE AND HIGHER TERRAIN NORTH OF FORT COLLINS ACCUMULATING
SNOWFALL WILL OCCUR AFTER MIDNIGHT. AMOUNTS WILL RANGING FROM 2 TO 5
INCHES IN THE FOOTHILLS...TO A COUPLE INCHES ON THE PALMER DIVIDE
AND CHEYENNE RIDGE.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

VERY COOL AND UNSETTLED WEATHER CAN BE EXPECTED MONDAY AND MONDAY
NIGHT.  SNOW WILL CONTINUE ALONG THE FRONT RANGE MOUNTAINS AND
FOOTHILLS MONDAY WITH ANOTHER 1 TO 3 INCHES OF SNOWFALL.  ON THE
PLAINS...A MIX OF RAIN AND SNOW CAN BE EXPECTED.  TEMPERATURES WILL
BE JUST COLD ENOUGH TO BRING A POTENTIAL OF SOME LIGHT SNOW
ACCUMULATIONS TO ELEVATIONS ABOVE 5000 FEET.  AT THIS TIME...IT
APPEARS LOCATIONS OVER THE PALMER DIVIDE...CHEYENNE RIDGE...AND NEAR
THE FOOTHILLS COULD SEE AN INCH OR TWO OF SLUSHY ACCUMULATION ON
VEGETATED SURFACES.

IT WILL BE DRIER ON TUESDAY BUT REMAIN QUITE COOL.  TEMPERATURES
WILL THEN RETURN TO NEAR NORMAL LEVELS BY MIDWEEK WITH POTENTIAL FOR
ANOTHER STORM SYSTEM AND SHOWERS AND THUNDERSTORMS BY LATE NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

BAKER/BARJENBRUCH