Alert archive / Oregon / Mesoscale Discussions in 2004

Mesoscale Discussion 2049

August 19, 20044 states

The Storm Prediction Center issued this mesoscale discussion at Aug 19, 2004, 2:46 PM MDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 19, 2004, 2:46 PM MDT (20:46 UTC)
Expired
Aug 19, 2004, 5:15 PM MDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Adams County, ID, Owyhee County, ID, Payette County, ID, Washington County, ID, Elko County, NV, Baker County, OR, Grant County, OR, Malheur County, OR, Union County, OR, Wallowa County, OR, Asotin County, WA

The radar

The Boise radar (KCBX), 20 km from the middle of the area, began a volume at 20:48 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

Boise Airport, ID (KBOI), launched 12:00Z, 8.8 hours before the alert went out and 29 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, Boise Airport, ID at 12:00Z on 2004-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 207 joules per kilogram.LCLLFCEL10008507005003002001001 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, Boise Airport, ID at 12:00Z on 2004-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 square meters per square second.1939Sfc1 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
207 J/kg
Mixed-layer CIN
-188 J/kg
Mixed-layer LCL
1693 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

307 
ACUS11 KWNS 192047
SWOMCD
SPC MCD 192046 
UTZ000-IDZ000-NVZ000-ORZ000-WAZ000-192315-

MESOSCALE DISCUSSION 2049
NWS STORM PREDICTION CENTER NORMAN OK
0346 PM CDT THU AUG 19 2004

AREAS AFFECTED...PORTIONS ERN ORE...EXTREME SERN WA...SWRN ID...NERN
NV...EXTREME NWRN UT

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 192046Z - 192315Z

WIDELY SCATTERED TSTMS WILL CONTINUE TO DEVELOP -- PRIMARILY OVER
HIGHER TERRAIN -- AND MOVE GENERALLY SEWD WITH POTENTIAL FOR
OCCASIONAL STRONG-SEVERE GUSTS AND HAIL.  WW NOT ANTICIPATED ATTM
BECAUSE OF MARGINAL AND LOOSELY ORGANIZED CHARACTER OF SEVERE
THREAT.

MOISTURE CHANNEL IMAGERY INDICATES SHORTWAVE TROUGH WITH TWO
MID/UPPER LEVEL VORTICITY MAXIMA -- ONE OVER NWRN ORE AND THE OTHER
OVER NWRN MT.  THESE FEATURES WILL MOVE SEWD ACROSS NRN PART OF
DISCUSSION AREA THROUGH REMAINDER AFTERNOON AND...IN COMBINATION
WITH INSOLATION...CONTRIBUTE TO FAVORABLE DESTABILIZATION.  MODIFIED
12Z RAOBS AND RUC SOUNDINGS INDICATE STEEP LOW-MIDLEVEL LAPSE RATES
8-9 DEG C/KM ABOVE WELL-MIXED...INVERTED-V THERMODYNAMIC PROFILE IN
BOUNDARY LAYER.  MAX INSTABILITY SHOULD REMAIN WITHIN ABOUT 50-60 NM
EITHER SIDE OF LINE FROM ALW...BKE...50 SW BOI...ENV.  SFC DEW
POINTS COMMONLY RANGE FROM MID 40S TO UPPER 50S F...WITH MLCAPE
REACHING 1000-1500 J/KG NEAR INSTABILITY AXIS. VERTICAL WIND SHEAR
WILL REMAIN LIMITED GIVEN RELATIVELY WEAK LOW-MIDLEVEL WIND FIELDS
OF BELOW 20 KT...HOWEVER BOUNDARY/OROGRAPHIC ENHANCEMENTS TO
NEAR-SFC KINEMATIC FIELDS MAY AUGMENT BOUNDARY LAYER SHEAR PROFILES
AND CONTRIBUTE TO CONVECTIVE INTENSITY LOCALLY.

..EDWARDS.. 08/19/2004

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

ATTN...WFO...SLC...PIH...MSO...BOI...LKN...OTX...PDT...MFR...

40681463 41181607 41921753 42271963 43431841 44512039
45411858 45591820 45891792 46291756 46351714 46141663
45541633 45091626 44201667 43361687 42751593 42161440
41951354 41661338 41261343 40911380 40701429

Nearby

Mesoscale Discussions in Oregon, 2004Mesoscale Discussions in Idaho, 2004Mesoscale Discussions in Nevada, 2004Every mesoscale discussion in 2004

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.