000 WWUS45 KMSO 211042 WSWMSO URGENT - WINTER WEATHER MESSAGE NATIONAL WEATHER SERVICE MISSOULA MT 340 AM MST (240 AM PST) FRI NOV 21 2003 .A VIGOROUS PACIFIC SYSTEM IS MOVING OVER NORTH CENTRAL IDAHO INTO WEST CENTRAL MONTANA TODAY. AT THE SAME TIME AN ARCTIC FRONTAL BOUNDARY IS PUSHING SOUTH THROUGH WESTERN MONTANA. AS THESE TWO SYSTEMS INTERACT...WINTER WEATHER CONDITIONS WILL CONTINUE TO WORSEN OVER MUCH OF WESTERN MONTANA AND PORTIONS OF NORTH CENTRAL IDAHO THROUGH THE AFTERNOON. BY LATE AFTERNOON WIDESPREAD SNOW WILL TAPER TO SNOW SHOWERS OVER MUCH OF THE AREA BUT GUSTY WINDS...BLOWING SNOW AND LOW WIND CHILL VALUES WILL CONTINUE INTO THE EVENING HOURS. IDZ007-008-211200- OROFINO/GRANGEVILLE REGION-LOWER HELLS CANYON/SALMON RIVER- INCLUDING...KOOSKIA...WHITE BIRD...RIGGINS ...WINTER WEATHER ADVISORY FOR OROFINO GRANGEVILLE AREA CANCELED... DRIER AIR HAS MOVED OVER THE OROFINO GRANGEVILLE AREA THIS MORNING WHICH WILL KEEP SNOW ACCUMULATIONS BELOW ADVISORY CRITERIA. THEREFORE THE WINTER WEATHER ADVISORY FOR THE AREA HAS BEEN CANCELED. WIDESPREAD LIGHT SNOW IS STILL EXPECTED TODAY WITH ACCUMULATIONS UP TO 2 INCHES WITH LOCALLY HIGHER AMOUNTS ON THE CAMAS PRAIRIE. $$ MTZ001-004-211700- KOOTENAI/CABINET REGION-LOWER CLARK FORK REGION- INCLUDING...LIBBY...EUREKA...NOXON...THOMPSON FALLS...SUPERIOR ...WINTER STORM WARNING CONTINUES FOR THE KOOTENAI CABINET AND LOWER CLARK FORK REGIONS THROUGH 3 PM TODAY... 6 TO 8 INCHES OF SNOW WILL ACCUMULATE OVER THE KOOTENAI CABINET AND LOWER CLARK FORK REGIONS BY THIS AFTERNOON. IN ADDITION TO THE SNOW...NORTHEAST WINDS OF 15 TO 25 MPH WILL DEVELOP BY AFTERNOON AS AN ARCTIC FRONT CROSSES THE AREA. THE COMBINATION OF SNOW AND WINDS WILL CREATE DANGEROUS DRIVING CONDITIONS WITH BLOWING AND DRIFTING SNOW ALONG WITH REDUCED VISIBILITIES. SNOW WILL TAPER TO SNOW SHOWERS BY LATE AFTERNOON. $$ MTZ043-211700- BLACKFOOT REGION- INCLUDING...DRUMMOND...SEELEY LAKE ...WINTER STORM WARNING FOR THE BLACKFOOT REGION THROUGH 5 PM TODAY... 6 TO 8 INCHES OF SNOW WILL ACCUMULATE OVER THE BLACKFOOT REGION BY LATE THIS AFTERNOON. THEREFORE THE WINTER WEATHER ADVISORY PREVIOUSLY IN EFFECT FOR THE AREA HAS BEEN UPGRADED TO A WINTER STORM WARNING. IN ADDITION TO THE SNOW...NORTHEAST WINDS OF 15 TO 25 MPH WILL DEVELOP BY NOON AS AN ARCTIC FRONT CROSSES THE AREA. THE COMBINATION OF SNOW AND WINDS WILL CREATE DANGEROUS DRIVING CONDITIONS WITH BLOWING AND DRIFTING SNOW ALONG WITH REDUCED VISIBILITIES. SNOW WILL TAPER TO SNOW SHOWERS THIS EVENING. $$ MTZ005-006-211700- MISSOULA/BITTERROOT VALLEYS-BITTERROOT/SAPPHIRE MOUNTAINS- INCLUDING...HAMILTON...DARBY...SULA ...WINTER WEATHER ADVISORY FOR SNOW FOR THE MISSOULA VALLEY AND THE BITTERROOT AND SAPPHIRE MOUNTAINS CONTINUES THROUGH 5 PM TODAY... SNOW ACCUMULATIONS OF 2 TO 6 INCHES...LOCALLY UP TO 7 INCHES...ARE EXPECTED BY LATE THIS AFTERNOON IN THE MISSOULA VALLEY AND THE BITTERROOT AND SAPPHIRE MOUNTAINS. IN ADDITION...LOCAL GUSTY EAST TO NORTHEAST WINDS 15 TO 20 MPH THROUGH EAST WEST ORIENTED CANYONS WILL CAUSE BLOWING AND DRIFTING OF SNOW BY THIS AFTERNOON. $$ MTZ002-003-211700- WEST GLACIER REGION-FLATHEAD/MISSION VALLEYS- INCLUDING...KALISPELL...POLSON...ST. IGNATIUS...SWAN LAKE ...WINTER WEATHER ADVISORY FOR SNOW AND BLOWING SNOW CONTINUES FOR THE FLATHEAD MISSION VALLEYS AND WEST GLACIER REGION THROUGH 3 PM TODAY... SNOW ACCUMULATIONS OF 2 TO 6 INCHES ARE EXPECTED OVER THE FLATHEAD AND MISSION VALLEYS AND THE WEST GLACIER REGION BY THIS AFTERNOON. IN ADDITION TO THE SNOW...GUSTY EAST TO NORTHEAST WINDS OF 15 TO 25 MPH WILL CREATE BLOWING AND DRIFTING SNOW AND REDUCED VISIBILITIES... ESPECIALLY ALONG AND NEAR THE CONTINENTAL DIVIDE. SNOW WILL TAPER TO SNOW SHOWERS BY LATE AFTERNOON. $$ IDZ005-006-211700- NORTHERN CLEARWATER MOUNTAINS-SOUTHERN CLEARWATER MOUNTAINS- INCLUDING...ELK RIVER...PIERCE...POWELL...ELK CITY...DIXIE ...WINTER WEATHER ADVISORY FOR SNOW IN THE CLEARWATER MOUNTAINS CONTINUES THROUGH 4 PM PST TODAY... SNOW ACCUMULATIONS OF 2 TO 6 INCHES...LOCALLY UP TO 7 INCHES...ARE EXPECTED BY LATE THIS AFTERNOON OVER THE CLEARWATER MOUNTAINS. IN ADDITION TO THE SNOW...LOCAL GUSTY EAST TO NORTHEAST WINDS 15 TO 20 MPH THROUGH EAST WEST ORIENTED CANYONS WILL CAUSE BLOWING AND DRIFTING OF SNOW BY THIS AFTERNOON. $$ WRIGHT