Alert archive / Montana / Flash Flood Warnings in 2001

Flash Flood Warning 20, NWS Glasgow, MT

July 20, 2001Garfield County, McCone County, Montana

NWS Glasgow, MT issued this flash flood warning at Jul 20, 2001, 6:28 PM MDT for Garfield County, McCone County, Montana. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 20, 2001, 6:28 PM MDT (00:28 UTC)
Expired: Jul 20, 2001, 9:30 PM MDT
In force: 3 hr
Issued by: NWS Glasgow, MT
Area: Whole counties

Counties Garfield County, MT, McCone County, MT

The radar

The Glasgow radar (KGGW), 85 km from the middle of the area, began a volume at 00:31 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

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 0.5 hours before the alert went out and 86 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: 996 J/kg
Mixed-layer CIN: -183 J/kg
Mixed-layer LCL: 1651 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 331 m²/s²
0-3 km storm-relative helicity: 373 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.6

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Glasgow, MT wrote its last area forecast discussion before this flash flood warning went out at Jul 20, 2:15 PM MDT, 4 hours 13 minutes earlier.

Area forecast discussion, Jul 20, 2:15 PM MDT, 4 hours 13 minutes before

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
215 PM MDT FRI JUL 20 2001

SW FLOW WITH DISTURBANCES RIPPLING THROUGH THE FLOW WILL CONTINUE AFFECT
THE AREA INTO SATURDAY NIGHT. THIS MEANS SEVERE WEATHER POTENTIAL WILL
CONTINUE. ETA AND AVN IN FAIR AGREEMENT THROUGH THE PERIOD WITH
PLACEMENT OF SYSTEMS. 500 MB VORT LOBE OVER ALBERTA WITH THE TROF
EXTENDING DOWN INTO THE PAC NW LIFTS OUT INTO MANITOBA BY LATE
SUNDAY. AT 00Z MON...LI/S DROP TO BELOW 0 IN A PORTION OF THE CWA WITH
A WEAK UPPER RIDGE PUSHING IN FROM WESTERN MT. JAMBA

EXTENDED...MRF IN DISAGREEMENT WITH ECMWF AND CANADIAN GEM MODELS
BEYOND DAY 4. A REX BLOCK THAT THE MODELS AGREE WITH SUN/MON SPINS
INTO A DIFFERENT SOLUTION BY ALL MODELS BY TUE. MRF PULLS THE
LOW ACROSS MT AND KEEPS THE CHANCES OF THUNDERSTORMS ACROSS THE CWA
THROUGH FRI...WHILE THE CANADIAN AND THE ECMWF BUILD THE RIDGE OVER
MT WITH THE LOW STAYING NEAR THE WEST COAST. WILL KEEP WITH THE
CHANCES OF STORMS THROUGH WED...WITH A MAINLY DRY CONDITIONS FOR THU
AND FRI. JAMBA

KGGW 062/088 064/085 057/082 058/083 058/083 058/084 057/085
     TTTTTBB  764352/7633322
KGDV 065/089 064/085 059/084 059/084 059/084 058/085 057/086
     TTTTTBB  765352/7633322

The office that day

Everything else NWS Glasgow, MT issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 6:15 PM MDT	Tornado Warning	GGW	McCone	60 min
Jul 20, 6:41 PM MDT	Severe Thunderstorm Warning	GGW	Sheridan	64 min
Jul 20, 6:56 PM MDT	Tornado Warning	GGW	Dawson	64 min
Jul 20, 7:09 PM MDT	Severe Thunderstorm Warning	GGW	Richland	66 min
Jul 20, 7:15 PM MDT	Severe Thunderstorm Warning	GGW	McCone	60 min
Jul 20, 7:24 PM MDT	Severe Thunderstorm Warning	GGW	Roosevelt	66 min
Jul 20, 7:25 PM MDT	Severe Thunderstorm Warning	GGW	Prairie	65 min
Jul 20, 7:57 PM MDT	Tornado Warning	GGW	Dawson	63 min
Jul 20, 8:14 PM MDT	Tornado Warning	GGW	Richland	61 min
Jul 20, 8:30 PM MDT	Severe Thunderstorm Warning	GGW	Prairie	60 min
Jul 20, 8:35 PM MDT	Flash Flood Warning	GGW	Dawson, Prairie	6 hr
Jul 20, 8:43 PM MDT	Tornado Warning	GGW	Wibaux	62 min
Jul 20, 9:27 PM MDT	Severe Thunderstorm Warning	GGW	Dawson	63 min
Jul 20, 10:15 PM MDT	Severe Thunderstorm Warning	GGW	Wibaux	60 min
Jul 21, 5:23 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	67 min

Nearby

Flash Flood Warnings in Montana, 2001 Every flash flood 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.