PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE DENVER CO 643 PM MDT SAT MAY 10 2003 ...ADDITIONAL SNOW REPORTS... TIME LOCATION COUNTY SNOWFALL LIQUID (INCHES) (INCHES) ------------------------------------------------------- 630 PM HIGHLANDS RANCH DOUGLAS 9.0 125 PM CENTENNIAL (NW) ARAPAHOE 5.0 116 PM AURORA (SE) ARAPAHOE 7.5 1.60 1240 PM GOLDEN 4.5W JEFFERSON 8.5 1200 PM RAND 3S JACKSON 7.0 1200 PM FORT LUPTON WELD 8.6 1.61 1158 AM COAL CRK CANYON JEFFRSON 9.4 0.86 1111 AM AURORA (SE) ARAPAHOE 6.0 1045 AM BROOMFIELD BROOMFIELD 8.0 1030 AM FORT COLLINS LARIMER 1.6 1030 AM NIWOT BOULDER 5.0 1022 AM ROXBOROUGH S.P. DOUGLAS 4.5 0.72 1015 AM ARVADA (N) JEFFERSON 4.0 1000 AM AURORA/BUCKLEY AFB ARAPAHOE 6.0 950 AM COAL CRK CANYON JEFFERSON 10.0 937 AM BYERS 22S ELBERT 2.5 934 AM GREELEY WELD 3.3 1.95 922 AM THORNTON (NE) ADAMS 9.8 910 AM HIGHLANDS RANCH (SE) DOUGLAS 5.3 910 AM BOULDER 5W BOULDER 8.0 905 AM LIMON LINCOLN T 0.21 900 AM BLACKHAWK 3N GILPIN 6.9 833 AM LITTLETON ADAMS 6.3 831 AM JAMESTOWN 3W BOULDER 15.4 1.20 830 AM CENTENNIAL ARAPAHOE 6.8 826 AM LEROY LOGAN 0.0 0.66 824 AM LOUISVILLE BOULDER 11.5 820 AM GENESSE 1SE JEFFERSON 4.5 810 AM EVERGREEN 1SSW JEFFERSON 5.0 0.50 805 AM NEDERLAND 7E BOULDER 11.2 802 AM AURORA (CENTRAL) ARAPAHOE 5.0 800 AM BRIGHTON 7E ADAMS 7.0 800 AM GEORGETOWN CLEAR CREEK 3.8 0.58 800 AM VIRGINIA DALE 7ENE LARIMER 10.0 1.30 800 AM ELIZABETH 6.1N ELBERT 1.7 0.43 800 AM BENNETT 4S ARAPAHOE 4.1 755 AM LOUVIERS DOUGLAS 4.9 755 AM EVERGREEN 4S JEFFERSON 5.7 0.69 755 AM CHIEF HOSA JEFFERSON 8.0 750 AM BUCKHORN MTN LARIMER 7.5 1.42 750 AM SEDGWICK SEDGWICK 0.0 0.70 750 AM AURORA 7SSE ARAPAHOE 5.5 1.02 750 AM DENVER 4E DENVER 6.0 1.09 750 AM MORRISON JEFFERSON 6.5 1.41 750 AM ROLLINSVILLE GILPIN 8.6 0.83 748 AM LOVELAND 1.5N LARIMER 2.0 1.06 745 AM NEDERLAND 4ENE BOULDER 9.5 745 AM EAST CENTENNIAL ARAPAHOE 8.0 735 AM CHERRY CRK RSVR ARAPAHOE 5.0 0.90 730 AM STRASBURG ADAMS 5.0 1.09 730 AM ESTES PARK 1E LARIMER 9.7 1.06 723 AM SEDALIA 8S DOUGLAS 4.2 720 AM WESTMINSTER LARIMER 6.0 0.73 713 AM CROW HILL PARK 1.3 700 AM HOHNHOLZ RANCH LARIMER 12.0 0.93 700 AM LAKEWOOD JEFFERSON 5.2 1.46 700 AM PARKER 3NE DOUGLAS 5.0 0.61 700 AM EVERGREEN JEFFERSON 2.0 700 AM PARKER 1E DOUGLAS 4.8 700 AM BOULDER 5E BOULDER 7.3 700 AM CENTENNIAL ARPT 2.8WSW DOUGLAS 6.2 659 AM BENNETT 7SE ARAPAHOE 3.8 652 AM KEN CARYL VALLEY JEFFERSON 4.7 1.00 650 AM STAPLETON ARPT DENVER 7.0 1.96 648 AM NIWOT BOULDER 5.5 646 AM THORNTON ADAMS 5.5 639 AM MASONVILLE 4E LARIMER 5.0 630 AM EVERGREEN JEFFERSON 5.0 630 AM WESTMINSTER JEFFERSON 5.0 630 AM PARKER 6E DOUGLAS 3.5 628 AM WHEAT RIDGE JEFFERSON 7.4 1.59 625 AM AKRON WASHINGTON 1.5 621 AM STORM MOUNTAIN LARIMER 12.0 620 AM LOOKOUT MOUNTAIN JEFFERSON 8.0 615 AM PINEWOOD LAKE LARIMER 14.0 610 AM MEADE 3E WELD 1.5 1.30 603 AM PARKER DOUGLAS 3.7 600 AM GENESEE JEFFERSON 6.0 600 AM BOULDER 10W BOULDER 15.0 556 AM ESTES PARK LARIMER 9.0 517 AM BROOMFIELD BROOMFIELD 7.8 449 AM LOUISVILLE BOULDER 10.0 448 AM EAST CENTENNIAL ARAPAHOE 5.0 409 AM THORNTON ARAPAHOE 7.2 330 AM GREELEY WELD 3.0 330 AM FORT COLLINS LARIMER 1.0 328 AM THORNTON ARAPAHOE 4.8 325 AM ARVADA JEFFERSON 3.0 300 AM BROOMFIELD BROOMFIELD 4.8 235 AM LOUISVILLE BOULDER 7.0 205 AM BROOMFIELD BROOMFIELD 4.0 151 AM LONGMONT 1S BOULDER 3.3 106 AM JAMESTOWN 3W BOULDER 12.0 -------------------FROM 05/09/2003-------------------------- 1015 PM ALLENSPARK LARIMER 8.0 1007 PM ALLENSPARK 3N LARIMER 6.0 1005 PM TABERNASH GRAND 1.0 1004 PM JAMESTOWN 3W BOULDER 3.8 1000 PM GENESEE JEFFERSON 2.5 940 PM BOULDER 7SW BOULDER 3.0 935 PM EVERGREEN 4S JEFFERSON 1.4 914 PM ESTES PARK 1N LARIMER 1.5 840 PM EVERGREEN JEFFERSON 0.5 800 PM CONIFER 3W JEFFERSON 0.5 $$ BENTON/FREDIN/RAY ======================= COZ038>040-091100- 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- INCLUDING FORT COLLINS...HEREFORD...LOVELAND...NUNN...ARVADA... BOULDER...GOLDEN...LAKEWOOD...LONGMONT...AURORA...BRIGHTON...CITY OF DENVER...DENVER INTERNATIONAL AIRPORT...HIGHLANDS RANCH... LITTLETON...PARKER 331 PM MDT THU MAY 08 2003 .TONIGHT...PARTLY CLOUDY WITH ISOLATED RAIN SHOWERS IN THE EVENING. LOWS IN THE MID 30S. .FRIDAY...CLOUDY WITH ISOLATED RAIN SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. HIGHS IN THE MID 50S TO LOWER 60S. CHANCE OF RAIN 20 PERCENT. .FRIDAY NIGHT...CLOUDY WITH SCATTERED RAIN SHOWERS AND THUNDERSTORMS IN THE EVENING THEN SNOW SHOWERS LIKELY AFTER MIDNIGHT. ACCUMULATIONS LESS THAN 2 INCHES. LOWS IN THE LOWER TO MID 30S. CHANCE OF RAIN OR SNOW 70 PERCENT. .SATURDAY...COOLER. MOSTLY CLOUDY. RAIN AND SNOW SHOWERS LIKELY IN THE MORNING...DECREASING IN THE AFTERNOON. HIGHS IN THE LOWER TO MID 40S. CHANCE OF RAIN 70 PERCENT. COZ039-092200- BOULDER AND JEFFERSON COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY- INCLUDING ARVADA...BOULDER...GOLDEN...LAKEWOOD...LONGMONT 444 AM MDT FRI MAY 09 2003 .TODAY...CLOUDY WITH SCATTERED RAIN SHOWERS. ISOLATED AFTERNOON THUNDERSTORMS. HIGHS AROUND 50. CHANCE OF RAIN 30 PERCENT. .TONIGHT...RAIN SHOWERS LIKELY AND ISOLATED THUNDERSTORMS IN THE EVENING THEN SNOW SHOWERS LIKELY AFTER MIDNIGHT. LOWS IN THE LOWER 30S. SNOW ACCUMULATIONS OF 1 TO 3 INCHES. NORTH WINDS 10 TO 20 MPH. .SATURDAY...MOSTLY CLOUDY WITH SCATTERED RAIN AND SNOW SHOWERS IN THE MORNING THEN ISOLATED RAIN SHOWERS IN THE AFTERNOON. HIGHS IN THE MID TO UPPER 40S. NORTH WINDS 10 TO 20 MPH. CHANCE OF RAIN OR SNOW 50 PERCENT. COZ039-092200- BOULDER AND JEFFERSON COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY- INCLUDING ARVADA...BOULDER...GOLDEN...LAKEWOOD...LONGMONT 1238 PM MDT FRI MAY 09 2003 UPDATE .THIS AFTERNOON...CLOUDY WITH SCATTERED LIGHT RAIN SHOWERS OR AREAS OF DRIZZLE. ISOLATED THUNDERSTORMS POSSIBLE. HIGHS IN THE UPPER 30S TO MID 40S. CHANCE OF RAIN 60 PERCENT. .TONIGHT...RAIN SHOWERS LIKELY AND ISOLATED THUNDERSTORMS IN THE EVENING THEN OCCASIONAL SNOW SHOWERS. LOWS IN THE LOWER 30S. SNOW ACCUMULATIONS OF 2 TO 4 INCHES. NORTH WINDS 10 TO 20 MPH. .SATURDAY...MOSTLY CLOUDY WITH SCATTERED RAIN AND SNOW SHOWERS IN THE MORNING THEN ISOLATED RAIN SHOWERS IN THE AFTERNOON. HIGHS IN THE MID TO UPPER 40S. NORTH WINDS 10 TO 20 MPH. CHANCE OF RAIN OR SNOW 50 PERCENT. COZ038-039-101100- LARIMER COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-BOULDER AND JEFFERSON COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY- INCLUDING FORT COLLINS...HEREFORD...LOVELAND...NUNN...ARVADA... BOULDER...GOLDEN...LAKEWOOD...LONGMONT 419 PM MDT FRI MAY 09 2003 ...WINTER WEATHER ADVISORY TONIGHT AND SATURDAY MORNING... .TONIGHT...RAIN SHOWERS LIKELY IN THE EVENING...CHANGING TO SNOW BY MIDNIGHT. ACCUMULATIONS OF 3 TO 6 INCHES...MAINLY ON GRASSY AREAS. LOWS IN THE MID 20S TO LOWER 30S. .SATURDAY...SNOW SHOWERS LIKELY IN THE MORNING THEN ISOLATED RAIN SHOWERS IN THE AFTERNOON. HIGHS IN THE MID 40S. NORTH WINDS 10 TO 20 MPH. CHANCE OF PRECIPITATION 60 PERCENT. COZ038-039-101100- LARIMER COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-BOULDER AND JEFFERSON COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY- INCLUDING FORT COLLINS...HEREFORD...LOVELAND...NUNN...ARVADA... BOULDER...GOLDEN...LAKEWOOD...LONGMONT 559 PM MDT FRI MAY 09 2003 ...WINTER WEATHER ADVISORY TONIGHT AND SATURDAY MORNING... .TONIGHT...RAIN...CHANGING TO SNOW BY MIDNIGHT. ACCUMULATIONS OF 3 TO 6 INCHES...MAINLY ON GRASSY AREAS. LOWS IN THE MID 20S TO LOWER 30S. .SATURDAY...SNOW SHOWERS LIKELY IN THE MORNING THEN ISOLATED RAIN SHOWERS IN THE AFTERNOON. HIGHS IN THE MID 40S. NORTH WINDS 10 TO 20 MPH. CHANCE OF PRECIPITATION 60 PERCENT. COZ038-039-101100- LARIMER COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-BOULDER AND JEFFERSON COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY- INCLUDING FORT COLLINS...HEREFORD...LOVELAND...NUNN...ARVADA... BOULDER...GOLDEN...LAKEWOOD...LONGMONT 1254 AM MDT SAT MAY 10 2003 ...WINTER WEATHER ADVISORY TONIGHT AND SATURDAY MORNING... .REST OF TONIGHT...SNOW...HEAVY AT TIMES. ACCUMULATIONS OF 2 TO 5 INCHES. LOWS IN THE LOWER 30S. .SATURDAY...SNOW SHOWERS LIKELY IN THE MORNING THEN ISOLATED RAIN SHOWERS IN THE AFTERNOON. ADDITIONAL SNOW ACCUMULATIONS AN INCH OR LESS. HIGHS IN THE MID 40S. NORTH WINDS 10 TO 20 MPH. CHANCE OF PRECIPITATION 60 PERCENT. COZ039-040-102200- 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- INCLUDING ARVADA...BOULDER...GOLDEN...LAKEWOOD...LONGMONT... AURORA...BRIGHTON...CITY OF DENVER...DENVER INTERNATIONAL AIRPORT...HIGHLANDS RANCH...LITTLETON...PARKER 505 AM MDT SAT MAY 10 2003 ...WINTER STORM WARNING THIS MORNING... .TODAY...SNOW...HEAVY AT TIMES...IN THE MORNING THEN ISOLATED RAIN AND SNOW SHOWERS IN THE AFTERNOON. ADDITIONAL SNOW ACCUMULATION OF 3 TO 6 INCHES...WITH STORM TOTALS 6 TO 12 INCHES. HIGHS IN THE LOWER 40S. NORTH WINDS 10 TO 20 MPH. COZ039-040-102200- 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- INCLUDING ARVADA...BOULDER...GOLDEN...LAKEWOOD...LONGMONT... AURORA...BRIGHTON...CITY OF DENVER...DENVER INTERNATIONAL AIRPORT...HIGHLANDS RANCH...LITTLETON...PARKER 831 AM MDT SAT MAY 10 2003 ...WINTER STORM WARNING THIS MORNING... .TODAY...SNOW...HEAVY AT TIMES...IN THE MORNING THEN ISOLATED RAIN AND SNOW SHOWERS IN THE AFTERNOON. ADDITIONAL SNOW ACCUMULATION OF 3 TO 6 INCHES...WITH STORM TOTALS 6 TO 12 INCHES. HIGHS IN THE LOWER 40S. NORTH WINDS 10 TO 20 MPH. COZ039-040-102200- 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- INCLUDING ARVADA...BOULDER...GOLDEN...LAKEWOOD...LONGMONT... AURORA...BRIGHTON...CITY OF DENVER...DENVER INTERNATIONAL AIRPORT...HIGHLANDS RANCH...LITTLETON...PARKER 1108 AM MDT SAT MAY 10 2003 UPDATED. .REST OF TODAY...MOSTLY CLOUDY WITH SCATTERED RAIN OR SNOW SHOWERS THROUGH THE AFTERNOON. HIGHS IN THE UPPER 30S TO LOWER 40S. NORTH WINDS 10 TO 20 MPH. .TONIGHT...PARTLY CLOUDY WITH ISOLATED RAIN SHOWERS IN THE EVENING. LOWS IN THE UPPER 20S TO LOWER 30S. NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 250 PM MDT THU MAY 8 2003 SHORT TERM DISCUSSION...UPR LOW CONTS TO CIRCULATE OVR SRN UT WITH MSTR AHD OF THE SYSTEM ALRDY SPREAD ACRS WRN CO. THERE HAS BEEN SOME LTNG OVR UT EARLIER TODAY...INDICATIVE OF THE INSTABILITY AND DYNAMICS ASSOCD WITH THE SYS. MODELS ARE ALL CONSISTENT IN BRINGING THE UPR LOW ACRS THE STATE OVERNIGHT. SFC LOW HA FORMED OVR NERN NM/SERN CO WITH GOOD PRES FALLS DUE TO STRONG WARMING THEY HAVE HAD TODAY. OMEGA FIELDS SHOW VALUES ACRS OUR CWA EXCEEDING 10 UBAR/SEC OVERNIGHT. THE DYNAMIC LIFTING WITH THE UPR SYSTEM SHOULD COMBINE WITH PLAINS TEMPS ALRDY IN THE UPR 30S AND LOWER 40S TO PRODUCE SNOW ACRS MUCH OF THE FCST AREA. MODEL TEMPS AT LOW AND MID LVLS HAVE BEEN TOO WARM FOR TODAY...BUT SOUNDINGS STILL SHOW ENOUGH COOLING OVERNIGHT TO PRODUCE SNOW DOWN TO ELEVS AS LOW AS 5000 FEET. MTN SNOWS WL BE ENHANCED BY THE INSTABILITY...SO WILL GO WITH 4-8 INCHES...AND A WINTER WX ADVISORY. THE FOOTHILLS WILL SEE A COMBINATION OF INSTABILITY AND FORCING ALOFT AND STRONG/DEEP UPSLP WINDS AT LOW LVLS. WILL FCST 6-12 INCH ACCUMS WITH A WINTER STORM WRNG. ALG THE URBAN CORRIDOR...THE UPSLP FLOW AND DYNAMICS WL PRODUCE 3-6 INCHES OF SNOW...MAINLY ON GRASSY AREAS. WL ISSUE AN ADVISORY IN THIS AREA SINCE THE SNOW COULD BE HEAVY ENOUGH TO BRING DOWN TREE BRANCHES AND POSSIBLY CAUSE SOME POWER OUTAGES. .DEN...WINTER STORM WRNG FRNT RANGE FTHLS TONITE...ZNS 35 AND 36. WINTER WX ADVISORY MTNS...URBAN CORRIDOR AND ADJACENT PLAINS TONITE...ZNS 31..33..34..38>40..41>43..45. AFDDEN NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 1255 AM MDT FRI MAY 9 2003 UPGRADING ADVISORY IN MOUNTAINS ABOVE 9000 FEET TO A WINTER STORM WARNING. SNOTEL/SPOTTER REPORTS INDICATE 4-8 INCHES IN 4-6 HOURS IN AREAS NORTH OF INTERSTATE 70 THIS EVENING. THESE ZONES LOOK IDEALLY SITUATED FROM THE SYNOPTIC SCALE...AND WILL EVENTUALLY TRANSITION TO DECENT CONVECTIVE OROGRAPHIC COMBO. REST OF THE FORECAST LOOKING PRETTY GOOD...CHANGING TO SNOW THE LAST HOUR IN GREELEY. GIMMESTAD .DEN...WINTER STORM WRNG NRN CO MTNS TONIGHT AND SAT MORNING... ZNS 31..33>36. WINTER WEATHER ADVISORY URBAN CORRIDOR AND ADJACENT PLAINS TONIGHT AND SAT MORNING...ZNS 38>40..41>43..45. NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 345 AM MDT SAT MAY 10 2003 SHORT TERM DISCUSSION...UPPER LOW HAS TWO CIRCULATION CENTERS...NEW ONE HAS DEVELOPED OVER NWRN CO WHILE THE OLD PIECE IS ROTATING UNDERNEATH SOUTH OF GRAND JUNCTION. MOIST UNSTABLE AIR IS BEING LIFTED IN SOUTHERLY FLOW AHEAD OF THE LOW...WITH STEADY PRECIP OVER NRN HALF OF CO AND A TRANSITION ZONE OF SHOWERS AND A FEW THUNDERSTORMS GENERALLY JUST SOUTH OF INTERSTATE 70. IMPORTANT DETAILS A MESS THIS MORNING. THE MAIN CIRCULATION CENTER SEEMS TO BE MOVING EAST A FEW HOURS SLOWER THAN EXPECTED. GENERAL PRECIPITATION SEEMS TO BE DECREASING A BIT BUT BANDS OF HEAVY SHOWERS KEEP GENERATING AND MOVING NE ACROSS DENVER. IT LOOKS LIKE WE WILL STILL BE DESTABILIZING THROUGH THE MORNING...AND THE QG FORCING MAY INCREASE AGAIN AS THE REMNANTS OF THE OLD LOW SWING AROUND THE NEW CENTER. AT THE SURFACE THINGS ARE ALSO MUDDLED...BUT THERE MAY BE A BIT OF UPSLOPE TURNING AS THE LOW PIECES SWING PAST US. SIGNIFICANT DRYING FROM NW WINDS SEEM UNLIKELY UNTIL AT LEAST LATE MORNING. WE ARE APPROACHING WINTER STORM WARNING CRITERIA FOR SNOWFALL IN ZONES 39 AND 40...SO I WILL GO AHEAD WITH THAT. MOUNTAINS SEEM TO BE CHURNING ALONG WITH THEIR SNOWFALL AS WELL. NOT MUCH CHANGE TO THIS AFTERNOON AND TONIGHT...JUST TO SLOW THE DEPARTURE OF THE SYSTEM BY A FEW HOURS. GIMMESTAD .DEN...WINTER STORM WARNING THROUGH SATURDAY MORNING FOR THE MOUNTAINS ABOVE 9000 FEET...THE FRONT RANGE FOOTHILLS... AND THE DENVER METRO AREA ZNS 031-033>36..39 AND 40. WINTER WEATHER ADVISORY THROUGH SATURDAY MORNING FOR THE ADJACENT PLAINS...CO ZNS 038-41>043 AND 45.