Alert archive / Washington / Mesoscale Discussions in 2003

Mesoscale Discussion 29

January 22, 2003Chelan County, Kittitas County, Washington

The Storm Prediction Center issued this mesoscale discussion at Jan 22, 2003, 5:04 AM PST for Chelan County, Kittitas County, Washington. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jan 22, 2003, 5:04 AM PST (13:04 UTC)
Expired
Jan 22, 2003, 11:00 AM PST
In force
6 hr
Issued by
the Storm Prediction Center

Counties Chelan County, WA, Kittitas County, WA

The radar

The Seattle radar (KATX), 114 km from the middle of the area, began a volume at 13:05 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Quillayute State, WA (KUIL), launched 12:00Z, 1.1 hours before the alert went out and 264 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Quillayute State, WA at 12:00Z on 2003-01-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Quillayute State, WA at 12:00Z on 2003-01-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 353 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
687 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
353 m²/s²
0-3 km storm-relative helicity
561 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

643 
ACUS11 KWNS 221305
SWOMCD
SPC MCD 221304 
WAZ000-221900-

MESOSCALE DISCUSSION 0029
NWS STORM PREDICTION CENTER NORMAN OK
0704 AM CST WED JAN 22 2003

AREAS AFFECTED...NRN CASCADES

CONCERNING...HEAVY SNOW 

VALID 221304Z - 221900Z

SNOWFALL RATES AROUND 1 INCH PER HOUR LIKELY AT ELEVATIONS
BETWEEN 4-5 KFT IN THE NORTHERN CASCADE MOUNTAINS THROUGH THIS
MORNING.



SIGNIFICANT PLUME OF PACIFIC MOISTURE AND INCREASING WARM AIR
ADVECTION AND OROGRAPHIC ASCENT ON THE WRN SLOPES OF THE CASCADE
MOUNTAINS WILL CONTRIBUTE TO HEAVY WET SNOW OVER THE NRN CASCADES
OVER THE NEXT SEVERAL HOURS. SATELLITE IMAGERY WAS SHOWING
COOLING CLOUD TOPS ADVANCING INLAND ACROSS THE COAST OF WA EARLY
TODAY IN ADVANCE OF STRONG SHORT WAVE TROUGH LOCATED AROUND 42N
131W. SATURATED UPSTREAM AIRMASS IMPINGING UPON THE WRN SLOPES
AND  FAVORABLE LARGE SCALE FORCING FOR ASCENT AHEAD OF THE UPPER
TROUGH WILL PROMOTE HEAVY SNOWFALL. LIQUID PRECIPITATION AMOUNTS
ACROSS THE LOWER ELEVATIONS WERE RUNNING ABOUT 0.10 INCH PER HOUR
AND EXPECT THESE RATES TO CORRELATE TO AT LEAST 1 INCH PER HOUR
RATES IN THE MOUNTAINS THROUGH ABOUT 18Z. WHILE SNOW LEVELS MAY
RISE SLIGHTLY ACROSS PORTIONS OF THE CNTRL CASCADES...ADIABATIC
COOLING  DUE TO FORCED ASCENT IN DEEPLY SATURATED AIRMASS SHOULD
RESULT IN NEAR ISOTHERMAL PROFILES AROUND 0C AOA 4KFT.

..CARBIN.. 01/22/2003

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

48822164 48992035 47291970 46802149

Nearby

Mesoscale Discussions in Washington, 2003Every mesoscale discussion in 2003

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.