Alert archive / Montana / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 90, NWS Great Falls, MT
NWS Great Falls, MT issued this severe thunderstorm warning at Aug 18, 2001, 8:10 PM MDT for Toole County, Montana. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.
The facts
- Issued
- Aug 18, 2001, 8:10 PM MDT (02:10 UTC)
- Expired
- Aug 18, 2001, 8:45 PM MDT
- In force
- 35 min
- Issued by
- NWS Great Falls, MT
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
County Toole County, MT
The radar
The Great Falls radar (KTFX), 124 km from the middle of the area, began a volume at 02:11 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
Great_falls, MT (KTFX), launched 00:00Z, 2.2 hours before the alert went out and 149 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
- 492 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 3918 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 12 m²/s²
- 0-3 km storm-relative helicity
- 37 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
110 WUUS55 KTFX 190212 SVRGTF MTC101-190245- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE GREAT FALLS MT 810 PM MDT SAT AUG 18 2001 THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHERN TOOLE COUNTY IN NORTH CENTRAL MONTANA THIS INCLUDES THE CITY OF SHELBY * UNTIL 845 PM MDT * AT 810 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM OVER SHELBY...OR ABOUT 5 MILES SOUTH OF SHELBY...MOVING NORTHEAST AT 25 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... RURAL CENTRAL TOOLE COUNTY AT 820 PM MDT THIS STORM MAY PRODUCE STRONG WINDS IN EXCESS OF 55 MPH AND HAIL UP TO AN INCH IN DIAMETER. REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN GREAT FALLS. LAT...LON 4845 11198 4836 11175 4868 11141 4880 11170
What forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Great Falls, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 18, 3:15 PM MDT, 4 hours 55 minutes earlier.
Area forecast discussion, Aug 18, 3:15 PM MDT, 4 hours 55 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 315 PM MDT SAT AUG 18 2001 HOT HIGH PRESSURE RIDGE TO MOVE INTO THE DAKOTAS THIS EVENING AS ENERGY ASSOCIATED WITH PACIFIC TROUGH PUSHES INLAND. THUNDERSTORMS TO DEVELOP AS EMBEDDED DISTURBANCES AND COLD FRONT ASSOCIATED WITH PACIFIC LOW APPROACH. ONE DISTURBANCE CURRENTLY MOVING INTO SOUTHWEST MT WITH SATELLITE IMAGES INDICATING CONVECTION STARTING. THIS DISTURBANCE TO TRACK NORTHEAST THROUGH SOUTHWEST MT DURING THE AFTERNOON...THEN BE STEERED EAST ACROSS CENTRAL MT BY THE APPROACHING TROUGH. SEVERAL DYNAMIC FEATURES ACCOMPANY THE TROUGH...LEFT FRONT JET QUAD...COUPLING OF UPPER DIVERGENCE AND SURFACE CONVERGENCE... DIFFLUENT FLOW AND A POTENTIAL VORTICITY WAVE. TIME SECTIONS SHOW A BRIEF COUPLING OF OMEGA AND RH DURING THE NIGHT. MOISTURE AVAILABLE THOUGH NOT PLENTIFUL WITH FORECAST SOUNDINGS KEEPING PRECIPITABLE WATER AROUND 0.75 INCHES. BELIEVE THERE IS A POTENTIAL FOR SEVERE THUNDERSTORMS WITH STRONG GUSTY WIND PRIMARY CONCERN. RED FLAG WARNING IN EFFECT LATE THIS AFTERNOON AND CONTINUING THROUGH THE NIGHT. FRONT TO MOVE EAST OF CWA SUNDAY MORNING AS THE FLOW ALOFT BECOME MORE WESTERLY. TEMPERATURES WILL DROP BACK TOWARD OR SLIGHTLY BELOW SEASONAL NORMALS SUNDAY AND MONDAY. BREEZY CONDITIONS EXPECTED SUNDAY...ESPECIALLY ALONG THE NORTHERN FRONT RANGE. EXTENDED...ECMWF DIFFERED FROM THE OTHER MEDIUM RANGE MODELS YESTERDAY...BUT IT HAS FALLEN MORE INTO LINE WITH THE OTHERS TODAY. NCEP ANALYSIS GIVES FAIRLY HIGH CONFIDENCE IN ADJUSTED MRF SOLUTION...SO WILL BASE FORECAST PRIMARILY ON IT...DESPITE MINOR DIVERGENCES IN NOGAPS/ECMWF SOLUTIONS LATER IN THE PERIOD. DRY AND ANTICYCLONIC SOUTHWEST FLOW OVER STATE WITH UPPER RIDGE AXIS EAST OF THE CWA WILL KEEP DRY CONDITIONS AROUND INTO TUESDAY. DURING THIS TIME...A DEEP UPPER LOW OVER THE GULF OF ALASKA WILL MOVE SOUTH INTO THE LINGERING UPPER TROUGH OFF THE PACIFIC NORTHWEST COAST. THIS TROUGH/LOW COMBO WILL FURTHER DIG ON WEDNESDAY...BRINGING A SLIGHT INCREASE IN MOISTURE...ALONG WITH PUSHING A WEAK COLD FRONT THROUGH DURING THE DAY. WILL STAY WITH SLIGHT CHANCE WORDING WITH SOME COMPRESSIONAL HEATING AHEAD OF THE FRONT AND WINDS DEVELOPING BEHIND IT. THE WINDS ALOFT ARE NOT TOO IMPRESSIVE...BUT WILL MENTION THROUGH THURSDAY. THE UPPER TROUGH WILL FILL IN A BIT AND SHIFT EASTWARD...MOVING ONSHORE SATURDAY. THIS WILL BRING INCREASING MOISTURE TO THE AREA THROUGH SATURDAY...BUT WILL BROADBRUSH CHANCE WORDING THURSDAY THROUGH SATURDAY UNTIL BETTER CONFIDENCE CAN BE GAINED. TEMPERATURES WILL ALSO COOL OFF A BIT DURING THIS PERIOD TO MORE NORMAL LEVELS. COULSTON CCF NUMBERS GTF UU 053 084 048 084 052 033000 CTB NU 053 080 046 078 048 032000 HLN UU 052 084 047 085 048 033000 BZN UU 048 083 043 083 045 033010 WEY UU 035 080 030 079 032 033010 DLN UU 047 081 041 081 043 033000 HVR UU 058 087 053 087 054 033000 LWT UU 055 083 050 084 052 033010
Nearby
Severe Thunderstorm Warnings in Montana, 2001Every severe thunderstorm warning in 2001
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.