Alert archive / Idaho / Mesoscale Discussions in 2003

Mesoscale Discussion 1978

July 24, 200318 counties in Idaho; Humboldt County, Nevada; 5 counties in Oregon

The Storm Prediction Center issued this mesoscale discussion at Jul 24, 2003, 4:24 PM MDT for 18 counties in Idaho; Humboldt County, Nevada; 5 counties in Oregon. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Jul 24, 2003, 4:24 PM MDT (22:24 UTC)
Expired: Jul 24, 2003, 7:00 PM MDT
In force: 3 hr
Issued by: the Storm Prediction Center

All 24 counties

Ada County, ID, Adams County, ID, Blaine County, ID, Boise County, ID, Camas County, ID, Canyon County, ID, Custer County, ID, Elmore County, ID, Gem County, ID, Gooding County, ID, Jerome County, ID, Lincoln County, ID, Minidoka County, ID, Owyhee County, ID, Payette County, ID, Twin Falls County, ID, Valley County, ID, Washington County, ID, Humboldt County, NV, Baker County, OR, Grant County, OR, Harney County, OR, Lake County, OR, Malheur County, OR

The radar

The Boise radar (KCBX), 147 km from the middle of the area, began a volume at 22:26 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, 10.4 hours before the alert went out and 153 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: 3609 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: -119 m²/s²
0-3 km storm-relative helicity: 17 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.

000 
ACUS11 KWNS 242225
SWOMCD
SPC MCD 242224 
IDZ000-NVZ000-ORZ000-CAZ000-250100-

MESOSCALE DISCUSSION 1978
NWS STORM PREDICTION CENTER NORMAN OK
0524 PM CDT THU JUL 24 2003

AREAS AFFECTED...NERN CA...NRN NV...SRN/ERN OR...SRN ID

CONCERNING...SEVERE THUNDERSTORM POTENTIAL...HEAVY RAINFALL 

VALID 242224Z - 250100Z

STRONG TO SEVERE STORMS WILL CONTINUE TO INCREASE IN AREAL COVERAGE/
INTENSITY DURING THE LATE AFTERNOON INTO THE EVENING... WITH A
THREAT FOR A FEW ISOLATED DOWNBURST WINDS AND HAIL.  WW IS NOT
ANTICIPATED.

WV IMAGERY SHOWS A SHORT WAVE TROUGH NEAR RNO AND A SECOND SHORT
WAVE TROUGH JUST N OF SFO...WITH AN AREA MID-LEVEL DRYING IN THE
IMMEDIATE WAKE OF THESE FEATURES.  COMPOSITE RADAR AND SATELLITE
LOOPS WERE SHOWING CONVECTION INCREASING RAPIDLY ACROSS CENTRAL OR/
EXTREME NRN CA SEWD INTO NRN NV AS STRONG HEATING AND A MOIST AIR
MASS CONTRIBUTE TO DESTABILIZATION. AS UPPER FORCING WITH THE SHORT
WAVE TROUGHS MOVE NNEWD ACROSS THE AREA OF CONCERN DURING THE NEXT
SEVERAL HOURS...STORMS WILL CONTINUE TO INCREASE IN AREAL COVERAGE
WITHIN A WEAKLY CAPPED ENVIRONMENT.  VWP DATA AT BOI/EKO INDICATE
20-25 KT OF SSWLY MID-LEVEL SLOW SUPPORTING MODEST DEEP LAYER SHEAR
FOR SOME STORM ORGANIZATION.  MARGINAL INSTABILITY /MLCAPE AROUND
500 J/KG/ WILL LIMIT THE SEVERE THREAT...THOUGH 30-40 DEGREE
DEWPOINT DEPRESSIONS WILL FAVOR DOWNBURST WINDS WITH THE STRONGEST
STORMS.  

HEAVY RAINFALL RATES WILL BE LIKELY GIVEN A VERY DEEP MOIST AIR MASS
WITH PRECIPITABLE WATER VALUES RANGING FROM 1-1.25 INCHES WHICH IS
150-200 PERCENT OF NORMAL.

..PETERS.. 07/24/2003

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

ATTN...WFO...PIH...MSO...BOI...LKN...PDT...REV...MFR...

42902144 44761976 45221720 44391319 42191383 41521492
41371820 41732128

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 24, 1:07 PM MDT	Mesoscale Discussion	SPC	Clark, Eureka, Lander, Lincoln, White Pine	2 hr

Nearby

Mesoscale Discussions in Idaho, 2003 Mesoscale Discussions in Oregon, 2003 Mesoscale Discussions in Nevada, 2003 Every 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.