Alert archive / Washington / Mesoscale Discussions in 2012

Mesoscale Discussion 32

January 19, 2012Umatilla County, Oregon; 4 counties in Washington

The Storm Prediction Center issued this mesoscale discussion at Jan 19, 2012, 3:59 AM PST for Umatilla County, Oregon; 4 counties in Washington. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jan 19, 2012, 3:59 AM PST (11:59 UTC)
Expired: Jan 19, 2012, 9:00 AM PST
In force: 5 hr
Issued by: the Storm Prediction Center

Counties Umatilla County, OR, Asotin County, WA, Columbia County, WA, Garfield County, WA, Walla Walla County, WA

The radar

The Pendleton radar (KPDT), 41 km from the middle of the area, began a volume at 12:02 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

Spokane, WA (KOTX), launched 00:00Z, 12.0 hours before the alert went out and 252 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 593 m above ground
0-6 km bulk shear: 109 kt
0-1 km storm-relative helicity: 293 m²/s²
0-3 km storm-relative helicity: 927 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.

657 
ACUS11 KWNS 191159
SWOMCD
SPC MCD 191159 
IDZ000-ORZ000-WAZ000-191700-

MESOSCALE DISCUSSION 0032
NWS STORM PREDICTION CENTER NORMAN OK
0559 AM CST THU JAN 19 2012

AREAS AFFECTED...NE ORE INTO SE WA

CONCERNING...FREEZING RAIN 

VALID 191159Z - 191700Z

LIGHT TO INTERMITTENTLY HEAVY FREEZING RAIN WILL CONTINUE THROUGH
THE MORNING HOURS ACROSS THE BLUE MOUNTAIN FOOTHILLS OF NE ORE/SE WA
AND LOWER COLUMBIA BASIN OF ORE /INCLUDING PENDLETON/.

SHALLOW COLD AIR HAS SETTLED INTO THE BASIN AND FOOTHILLS AREA WITH
TEMPERATURES IN THE UPPER TEENS TO MID 20S NEAR PDT AND ALW.
ALOFT...A WARM NOSE OF AROUND 2-4 DEGREES C WAS INDICATED BY POINT
FORECAST SOUNDINGS. WITH A DEEP SATURATED BOUNDARY LAYER...FREEZING
RAIN WILL CONTINUE THROUGH THE MORNING HOURS. AS THE UPPER WAVE OFF
THE PACIFIC NORTHWEST COAST CONTINUES TO MOVE INLAND...WEAK FORCING
FOR ASCENT WILL CONTINUE ACROSS THE REGION AND COUPLED WITH WLY
UPSLOPE FLOW...PRECIPITATION RATES COULD BE HEAVY AT TIMES. OVERALL
QPF AMOUNTS ARE EXPECTED TO REMAIN LIGHT...HOWEVER GIVEN PW AMOUNTS
LESS THAN .70 EAST OF THE CASCADES ANY HEAVY FREEZING RAIN EPISODES
SHOULD BE SHORT LIVED WITH MAINLY ONLY LIGHT FREEZING RAIN EXPECTED
THROUGH THE AFTERNOON. AS COLDER ARCTIC AIR CONTINUES TO MOVE SWD
INTO THE REGION...MID LEVEL TEMPERATURES WILL COOL AND PRECIPITATION
WILL EVENTUALLY CHANGE TO SNOW...BUT THIS IS NOT EXPECTED UNTIL
LATER IN THE AFTERNOON/EARLY EVENING.

..LEITMAN.. 01/19/2012

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

ATTN...WFO...OTX...PDT...

LAT...LON   45541834 45451908 45561946 45671955 45871948 46151909
            46361851 46491769 46391705 46101698 45791754 45541834

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 19, 11:12 AM PST	Mesoscale Discussion	SPC	Asotin, Benton, Columbia, Cowlitz, Garfield, Kitsap and 7 more	4 hr

Nearby

Mesoscale Discussions in Washington, 2012 Mesoscale Discussions in Oregon, 2012 Every mesoscale discussion in 2012

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.