Heavy Snow in Idaho, March 19 to 20, 2002

Name: Heavy Snow in Idaho, March 19 to 20, 2002
Start: 2002-03-19T20:00
End: 2002-03-20T10:00
Location: Idaho

March 19 to 20, 2002 · NWS OTX · 3 events in 3 counties and zones

Where it happened

Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 3

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS OTX wrote it up.

On this first day of spring, a polar air mass moving in from the north underneath strong moist westerly flow led to heavy snows over the central and northern Idaho panhandle. Early on the morning of the 20th, a narrow east-west band of snow set up directly over Coeur D'Alene and the Silver Valley, further enhancing snowfall there. Snowfall totals include: Lost Lake SNOTEL...43", Humboldt Gulch SNOTEL...28", Lookout Pass Ski Area...22", Mosquito Ridge SNOTEL...22", Bear Mountain SNOTEL...18", Mica Creek SNOTEL...17+", Schweitzer Bowl SNOTEL...12", Silver Mountain Ski Area...10", Wallace...7.9", Alder Creek...7.5", Avery...7.1", Coeur D'Alene...6.5", Priest River...3.4", Moscow...3", and Potlatch...3".

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Spokane, WA wrote its last area forecast discussion before the first event at Mar 19, 2:30 PM PST, 5 hours 30 minutes earlier.

Area forecast discussion, Mar 19, 2:30 PM PST, 5 hours 30 minutes before

EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WASHINGTON
230 PM PST TUE MAR 19 2002

THE FORECAST AREA TODAY HAS BEEN GETTING CAUGHT IN THE SQUEEZE PLAY
BETWEEN A BUILDING DIRTY UPPER LEVEL RIDGE TO OUR SOUTH AND A BROAD
UPPER LEVEL TROUGH OVER B.C. WITH POLAR AIR UNDERNEATH. THE IMMEDIATE
EFFECT OF THIS SQUEEZE PLAY HAS BEEN TO STRENGTHEN THE UPPER JET
OVERHEAD. PLENTY OF MOISTURE IS ENTRAINED IN THE STIFF WESTERLY FLOW
WITH THE CASCADE CREST GETTING POUNDED WITH SNOW TODAY. RADAR ECHOES
HAVE ALSO BEEN INTENSIFYING OVER THE PANHANDLE MTNS TODAY AND WILL
CONTINUE TO DO SO TONIGHT. MEANWHILE...THE LOWER EAST SLOPES AND
BASIN ARE GETTING SHADOWED NICELY. MOST OF THE FORECAST AREA SHOULD
REMAIN MILD TONIGHT EXCEPT WHERE THE POLAR AIR ALREADY IS (THE
OKANOGAN VALLEY). SNOW LEVELS WILL REMAIN ABOVE THE VALLEY FLOORS FOR
MUCH OF THE NIGHT.

HOWEVER...THE POLAR AIR CURRENTLY JUST NORTH OF THE CANADIAN BORDER
WILL START TO DRIVE SOUTH OVERNIGHT AND APPROACH I 90 BY 12Z.
TEMPERATURES AT MANY SPOTS ALONG THE I 90 CORRIDOR COULD FALL 10-15
DEGREES BETWEEN 12Z AND 18Z. THIS MAKES THE SPOT TEMPERATURE NUMBERS
AT THE BOTTOM OF THIS DISCUSSION AWKWARD FOR TONIGHT AND WED...BUT
SUFFICE IT TO SAY AFTERNOON TEMPERATURES WILL BE UNSEASONABLY COLD.
FURTHER SOUTH...THE COLD AIR WILL SPREAD MUCH MORE SLOWLY ACROSS THE
PALOUSE AND FINALLY SEEP INTO THE L-C VALLEY ON WED EVENING. PRECIP
ACROSS THE NRN TIER OF ZONES SHOULD CUT OFF DURING THE MORNING AS
DRIER AIR MOVES IN FROM THE NORTH. FURTHER SOUTH...THE MID-UPPER
LEVEL MOISTURE PLUME WILL HANG UP WITH THE SOUTHWARD-MOVING COLD
FRONT ACTING TO FOCUS PRECIP DEVELOPMENT. SNOWFALL ACCUMULATIONS WILL
BE LARGELY DEPENDENT ON HOW FAST THE COLD AIR MOVES IN AND CHANGES
LOWLAND PRECIP TO SNOW. ALSO...DAYTIME SNOWFALL ACCUMULATIONS IN LATE
MARCH ARE HARD TO COME BY...SO HAVE GEARED SNOWFALL ACCUMULATIONS
MAINLY TO GRASSY SURFACES. EVEN ON OVERCAST DAYS...INFRARED RADIATION
FROM THE HIGHER-ANGLE SUN WORKS WONDER ON PAVEMENT. ON WED NGT...THE
COLD FRONT SHOULD WASH OUT OVER SRN WA/NRN ORE WITH ISENTROPIC LIFT
STILL PRODUCING LIGHT SNOWS FOR ALL BUT THE NE CORNER OF THE FORECAST
AREA.

ON THU...A COLD 1050 MB HIGH WILL INTERACT WITH LOW PRESSURE OFFSHORE
TO SET UP DECENT EASTERLY GRADIENTS. DOWNSLOPING WINDS WILL START A
SLOW WARMUP FROM SPOKANE TO THE PALOUSE...BUT THE CASCADE EAST SLOPES
WILL EXPERIENCE COLD AIR DAMMING AND CONTINUED CHANCE POPS WITH MID-
LEVEL MOISTURE RIDING UP OVER THE COLD AIR. A HEALTHIER WARMING TREND
WILL CONTINUE FRI...BUT A LOW PRESSURE CENTER WILL LIFT NORTH THROUGH
THE OFFSHORE WATERS WITH INCREASED WARM ADVECTION INCREASING POPS AND
CLOUDS. THIS MAY LIMIT BUT NOT STOP THE WARMUP. HARD TO BELIEVE THAT
THE NORMAL HIGH AT SPOKANE WED IS 49F.  HANER

EXTENDED...MODELS IN PRETTY GOOD AGREEMENT ON BRINGING A TROUGH TO
THE WEST COAST THEN DIGGING IT SOUTH INTO NORTHERN CALIFORNIA AND
SOUTHERN OREGON THROUGH THE WEEKEND. THIS SCENARIO CREATES A SPLIT IN
THE UPPER LEVEL FLOW PATTERN OVER THE CWA SO WILL HANG ONTO A CHANCE
MENTION OF VALLEY RAIN AND MOUNTAIN SNOW SATURDAY AND SUNDAY. RIDGING
TAKES OVER ON MONDAY AND TUESDAY SO DRIER FORECAST SEEMS REASONABLE
THESE DAYS. GDB

...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 025/028/019/036/028/046 986212
COE 022/027/018/034/026/044 +96212
PUW 037/038/026/037/031/049 787302
LWS 041/042/033/046/034/053 666101
CQV 024/028/017/034/027/044 743124
SPT 018/024/015/033/026/042 954113
WWP 030/030/017/036/028/044 ++7301
EAT 034/039/028/035/029/047 266436
MWH 035/038/024/036/030/052 266324

.OTX...WINTER STORM WARNING TONIGHT AND WEDNESDAY ID ZN 4 AND WA ZN
       42...
    ...WINTER STORM WARNING TONIGHT ID ZN 1...
    ...WINTER WEATHER ADVISORY FOR SNOW TONIGHT WA ZN 37...
    ...WINTER WEATHER ADVISORY FOR SNOW WEDNESDAY ID ZN 2 AND WA ZN
       36...

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

3 heavy snow. Local standard time, as filed.

Heavy Snow, Northern Panhandle

When: March 19, 8:00 PM PST to March 20, 10:00 AM PST
Where: Northern Panhandle forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 48.247, -116.588 (the zone’s center; the record gives no point)

Heavy Snow, Coeur D'Alene Area

When: March 19, 8:00 PM PST to March 20, 10:00 AM PST
Where: Coeur D'Alene Area forecast zone
Reported by: TRAINED SPOTTER
Coordinates: 47.675, -116.700 (the zone’s center; the record gives no point)

Heavy Snow, Central Panhandle Mountains

When: March 19, 8:00 PM PST to March 20, 10:00 AM PST
Where: Central Panhandle Mountains forecast zone
Reported by: OFFICIAL NWS OBS.
Coordinates: 47.265, -116.491 (the zone’s center; the record gives no point)

What these are

Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Idaho in 2002 Every state in 2002 This day in weather history Warnings in Idaho, March 2002

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5287347, 5287348, 5287349.