Avalanche in Idaho, February 22, 2003

EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SPOKANE WASHINGTON
415 AM PST SAT FEB 22 2003

.SYNOPSIS...NORTHWEST FLOW WILL KEEP SNOW SHOWERS ACROSS THE IDAHO
CENTRAL AND SOUTHERN PANHANDLE REGIONS THROUGH MOST OF THE DAY AND
TONIGHT. AN ARCTIC FRONT WILL SAG ACROSS THE REGION...BRINGING DRIER
AND UNSEASONABLE COLDER AIR FOR EARLY NEXT WEEK.

DUE TO THE RAPID DECREASE IN SHOWER ACTIVITY...WILL DROP THE SNOW
HIGHLIGHTS THIS MORNING FOR THE BLUES...THE CAMAS PRAIRIE AND THE
CNTRL PANHDLE MTNS.

.DISCUSSION...SAT-MON...UNSTABLE NW FLOW PREVAILS OVER THE REGION
TODAY WHILE A VIGOROUS SHORTWAVE EXITS INTO WRN MT. THE DYNAMICS
FROM THE WAVE HAVE DECREASED...BUT OROGRAPHIC LIFT HAS HELPED
REJUVENATE THE SHOWER ACTIVITY INTO THE EARLY MORNING HOURS. WILL
KEEP THE CURRENT HIGHLIGHTS INTACT THROUGH EARLY MORNING. OTHERWISE
SKIES HAVE CLEARED FROM THE LEE OF THE CASCADES INTO THE BASIN WITH
ONLY ISOLATED SHOWERS NEAR THE CREST. DESPITE THE WEAK CAA
TODAY...WILL SEE DAYTIME TEMPS CLIMB INTO THE 40S THANKS IN PART TO
GOOD MIXING AND RADIATIONAL HEATING. IN THE INTERIM...WILL WATCH AN
ARCTIC FRONT HANGING FROM C BC TO THE CANADIAN ROCKES GRADUALLY SINK
SOUTHWARD. SOUNDINGS FROM PRINCE GEORGE AND EDMONTON INDICATE THE
DEPTH OF THE COLD AIR IS SUFFICIENT ENOUGH (UP TO 700 MB) TO SPILL
INTO THE REGION. THE UPPER LEVEL PATTERN SHOWS A BROAD LOW OVER
CANADA EXTENDING FROM HUDSON BAY AND A VORT LOBE ROTATING ROUND THE
THE LOW WHICH WILL SWEEP SOUTH AND HELP KICK THIS BOUNDARY ACROSS
THE INTERNATIONAL BORDER BY TONIGHT. AHEAD OF THIS FRONT...A BAND OF
CLOUDS HAS BEEN ENHANCING AND EXPECT SOME SNOW SHOWER ACTIVITY AS IT
REACHES THE NRN TIER ZONES LATE THIS AFTERNOON AND EVENING. THE
FRONT AND ASSOCIATED COLD AIR IS FORECAST TO SEEP THROUGH THE N/S
VALLEYS TONIGHT UNDER BLUSTERY NORTHERLY WINDS...AND GET HUNG UP IN
THE VICNITY OF THE CLEARWATER MTNS OVERNIGHT. THIS COMBINED WITH THE
UPSLOPE MOISTURE WILL LEAD TO ANOTHER ROUND OF SNOW...PRIMARILY FOR
THE CAMAS PRAIRIE. GIVEN THE COLDER TEMPS...EXPECT HIGH SNOW RATIOS
FOR THE LIGHT AMOUNTS OF QPF EXPECTED AND ADVISORY VALUES WILL BE
MET. OTHERWISE...MAINLY LIGHT AMOUNTS OF SNOW WILL BE FOUND IN THE C
PANHANDLE AND THE BLUE MTNS/VLYS ALONG THE LC VALLEY. IN THE WAKE OF
THE FRONT...DRY STABLE AIR WILL FILTER INTO THE REGION LEADING TO
CLEARING SKIES. WILL SEE THE COLDEST TEMPS OVERNIGHT SUNDAY NIGHT
INTO MONDAY MORNING AFTER THE CAA AND WINDS DECREASE. WILL SEE A
SLOW RECOVERY IN TEMPS ON MONDAY. -RFOX

.EXTENDED...TUES-FRI...UNLIKE EARLIER IN THE WEEK...MANY OF THE LONG
RANGE MODELS ARE STARTING TO GEL WITH RUN TO RUN CONSISTENCY. THIS
GIVES A HIGHER DEGREE OF CONFIDENCE IN THE EXTENDED FORECAST THAN
PREVIOUS DAYS. TUE WILL BE THE SECOND DAY OF A RATHER STRONG ARCTIC
BLAST. NO POPS TO SPEAK OF BUT IT WILL BE A COLD BRISK DAY. AS THE
UPPER LEVEL LOW OVER CA/NV STARTS TO WEAKEN AND PROGRESS EAST...THE
UPPER LEVEL FLOW STARTS TO MOVE AGAIN. THIS ALLOWS A SHORTWAVE TO
ENTER THE AREA FROM THE NW. WED WILL SEE A SLIGHT CHANCE OF PCPN
MAINLY IN THE NRN HIGHLANDS AND NE MTNS. LATER ON THURS THE PCPN IS
MORE WIDESPREAD OVER MOST OF THE CWA. THIS WAVE RAPIDLY MOVES EAST
ON FRI AND THE CHANCE OF PCPN GOES WITH IT EXCEPT FOR AREAS OF THE
ID PANHANDLE. /LERICOS

...THE INFORMATION IN THIS PRODUCT CONCERNING WARNINGS AND FORECASTS
IS VALID ONLY AT THE TIME OF ISSUANCE. THE LATEST WARNING AND
FORECAST INFORMATION WILL BE FOUND IN THE APPROPRIATE PRODUCTS...

GEG 044/018/032/008/034 00000
COE 042/019/031/008/032 10000
PUW 045/021/033/010/035 42000
LWS 049/027/039/018/040 54000
CQV 041/013/031/004/033 -0000
SPT 037/013/025/005/026 21000
WWP 034/012/024/005/025 64000
MWH 050/026/037/019/038 00000
EAT 049/027/038/018/039 00000
OMK 047/020/031/008/032 -0000

.OTX...WINTER WEATHER ADVISORY FOR SNOW SOUTHERN LEWIS AND NEZ PERCE
COUNTIES IN IDAHO ABOVE 2000 FEET TONIGHT...

IDZ001>004-026-027-WAZ031>038-041>044-231430-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SPOKANE WA
540 AM PST SAT FEB 22 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN WASHINGTON AND NORTH
IDAHO

.DAY ONE... TODAY

SCATTERED SHOWERS WILL LINGER OVER ACROSS PORTIONS OF THE IDAHO
CENTRAL AND SOUTHERN PANHANDLE TODAY...AND GRADUALLY INCREASE
OVERNIGHT AS A COLD FRONT DROPS FROM THE NORTH. SIGNIFICANT SNOW
AMOUNTS ARE EXPECTED UPON THE HIGHER PLATEAU AREA OF THE CAMAS
PRAIRIE WHERE UP TO 3 INCHES OF NEW SNOW. SEE THE LATEST WINTER
WEATHER BULLETIN /WWUS46 KOTX WSWOTX/ FOR DETAILS.

.DAYS TWO THROUGH SEVEN... SUNDAY THROUGH FRIDAY

AFTER THE PASSAGE OF A COLD FRONT TONIGHT...UNSEASONABLY COLD AIR
WILL SPILL INTO THE REGION AND PERSIST FROM SUNDAY INTO TUESDAY.
BLUSTERY CONDITIONS WILL DEVELOP IN MANY OF THE NORTH SOUTH VALLEYS
BY SUNDAY WITH WINDS TO 25 MPH CREATING WIND CHILL READINGS AS LOW
AS 15 BELOW ZERO. AFTER THE WINDS TAPER OFF...SOME OF THE COLDEST
TEMPERATURES OF THE SEASON ARE EXPECTED BY EARLY MONDAY MORNING
WITH READINGS IN THE SINGLE DIGITS AND TEENS. TEMPERATURES WILL
GRADUALLY RETURN TO NEAR NORMAL BY THE END OF THE WEEK.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.