Alert archive / Michigan / Mesoscale Discussions in 2004
Mesoscale Discussion 366
The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2004, 12:26 PM EDT for 4 counties in Michigan. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 18, 2004, 12:26 PM EDT (16:26 UTC)
- Expired
- Apr 18, 2004, 3:00 PM EDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
Counties Alger County, MI, Dickinson County, MI, Marquette County, MI, Schoolcraft County, MI
The radar
The Marquette radar (KMQT), 61 km from the middle of the area, began a volume at 16:26 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
Green Bay/Straub, WI (KGRB), launched 12:00Z, 4.4 hours before the alert went out and 206 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
- 639 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km storm-relative helicity
- 103 m²/s²
- 0-3 km storm-relative helicity
- 427 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
292 ACUS11 KWNS 181626 SWOMCD SPC MCD 181626 MIZ000-WIZ000-181900- MESOSCALE DISCUSSION 0366 NWS STORM PREDICTION CENTER NORMAN OK 1126 AM CDT SUN APR 18 2004 AREAS AFFECTED...UPPER PENINSULA OF MI CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 181626Z - 181900Z VERY INTENSE SMALL SCALE TSTM COMPLEX IS MOVING EAST OVER MARQUETTE AND DICKINSON COUNTIES IN THE UPPER PENINSULA OF MI THIS MORNING. ACTIVITY APPEARS ROOTED ON STRONG 850MB FRONTAL ZONE SITUATED ACROSS THE REGION AND IS BEING FUELED BY PLUME OF MODERATE INSTABILITY WITH MUCAPE VALUES AROUND 1500 J/KG. APPARENTLY STRORMSCALE UPDRAFT/DOWNDRAFT CIRCULATIONS HAVE BEEN STRONG ENOUGH TO LOCALLY OVERCOME SURFACE-BASED INVERSION AND PRODUCE 50-60KT WIND GUSTS AT THE GROUND...IN ADDITION TO LARGE HAIL. RECENT RADAR IMAGES SUGGEST LEWP AND BOW STRUCTURES HAVE ALSO FORMED BUT VIL AND REFLECTIVITY TRENDS INDICATE A SLIGHT WEAKENING. DESPITE A CONTINUATION OF STRONG LARGE SCALE ASCENT ALONG THE WARM FRONT TO THE SOUTH OF THE UPPER PENINSULA INTO THIS AFTERNOON...IT APPEARS THAT IT WILL BE DIFFICULT TO SUSTAIN SURFACE-BASED CONVECTION WITH EWD EXTENT. WHILE LARGE HAIL SHOULD CONTINUE TO BE A HAZARD FOR A COUPLE MORE HOURS AS THIS SYSTEM MOVES EAST...LIMITED AREAL COVERAGE OF SEVERE THREAT PROBABLY MEANS A WATCH WILL NOT BE ISSUED. ..CARBIN.. 04/18/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...APX...MQT...GRB... 46438561 46048572 45928623 45878704 45858801 45898820 46198828 46728803
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 18, 2:49 AM EDT | Mesoscale Discussion | SPC | Benzie, Grand Traverse, Manistee, Mason, Wexford | 56 min |
| Apr 18, 9:04 AM EDT | Mesoscale Discussion | SPC | Gogebic, Iron, Ontonagon | 86 min |
| Apr 18, 7:35 PM EDT | Tornado Watch | SPC | Iron | 5 hr |
Nearby
Mesoscale Discussions in Michigan, 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.