Alert archive / Washington / Mesoscale Discussions in 2012
Mesoscale Discussion 33
The Storm Prediction Center issued this mesoscale discussion at Jan 19, 2012, 11:12 AM PST for 13 counties in Washington. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 19, 2012, 11:12 AM PST (19:12 UTC)
- Expired
- Jan 19, 2012, 3:15 PM PST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
Counties Asotin County, WA, Benton County, WA, Columbia County, WA, Cowlitz County, WA, Garfield County, WA, Kitsap County, WA, Klickitat County, WA, Lewis County, WA, Mason County, WA, Pierce County, WA, Skamania County, WA, Thurston County, WA, Walla Walla County, WA
The radar
The Portland,OR radar (KRTX), 189 km from the middle of the area, began a volume at 19:16 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
Salem/Mcnary, OR (KSLE), launched 12:00Z, 7.2 hours before the alert went out and 256 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 465 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km storm-relative helicity
- 200 m²/s²
- 0-3 km storm-relative helicity
- 302 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
602
ACUS11 KWNS 191912
SWOMCD
SPC MCD 191912
ORZ000-WAZ000-192315-
MESOSCALE DISCUSSION 0033
NWS STORM PREDICTION CENTER NORMAN OK
0112 PM CST THU JAN 19 2012
AREAS AFFECTED...WESTERN/SRN WA AND NERN ORE
CONCERNING...FREEZING RAIN
VALID 191912Z - 192315Z
...FREEZING RAIN WILL CONTINUE ACROSS THE PUGET SOUND AND ALONG THE
COLUMBIA RIVER BASIN EAST OF THE CASCADES WELL INTO THE EVENING
HOURS. RATES AT OR ABOVE .03-.05 INCHES PER HOUR WILL BE COMMON...
LATEST SATELLITE IMAGERY CLEARLY DEPICTS A WELL DEFINED UPPER VORT
ROUGHLY 300 MI WEST OF UIL. THIS FEATURE IS MOVING EAST AT ROUGHLY
25KT AND WILL MOVE ONSHORE ALONG THE WA COAST LATER THIS EVENING
BETWEEN 04-06Z. A CONSIDERABLE AMOUNT OF PRECIPITATION CONTINUES
AHEAD OF THIS FEATURE WITH TERMINATION NOT EXPECTED PRIOR TO THE
PASSAGE OF THE SHORT WAVE TROUGH.
OF PARTICULAR CONCERN ARE TWO AREAS OF FREEZING RAIN...BOTH ALONG
THE COLUMBIA RIVER BASIN EAST OF THE CASCADES AND OVER THE SRN PUGET
SOUND. LATEST OBSERVATIONAL DATA AND FORECAST NAMKF/RUC SOUNDINGS
SUGGEST SUB-FREEZING SFC CONDITIONS WILL PERSIST ACROSS THE PUGET
SOUND THROUGH AT LEAST 00Z...PERHAPS UNTIL 06Z IN A FEW LOCATIONS
BEFORE DEEPENING SWLY FLOW ALLOWS WARMER AIR TO SCOUR THIS REGION.
NLY BOUNDARY LAYER FLOW HAS MAINTAINED COLD TRAJECTORIES ACROSS THE
SOUND AND WILL LIKELY DELAY PHASE CHANGE.
EAST OF THE CASCADES COLD AIR REMAINS FIRMLY ENTRENCHED WITH A ZONE
OF FREEZING RAIN EXPECTED TO PERSIST ALONG THE COLUMBIA RIVER
VALLEY. THERE IS LITTLE REASON TO BELIEVE BOUNDARY LAYER CONDITIONS
WILL WARM APPRECIABLY DESPITE THE STRONG WARM ADVECTION AROUND
850MB.
..DARROW.. 01/19/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...OTX...PDT...SEW...PQR...
LAT...LON 47282190 46382151 46341955 46641774 46121707 45571888
45642143 46152258 46462331 47572318 48252248 48222176
47282190SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 19, 3:59 AM PST | Mesoscale Discussion | SPC | Asotin, Columbia, Garfield, Walla Walla | 5 hr |
Nearby
Mesoscale Discussions in Washington, 2012Every 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.