Alert archive / Montana / Special Weather Statements in 2013

Special Weather Statement, NWS Great Falls, MT

August 5, 2013Toole County, Montana

NWS Great Falls, MT issued this special weather statement at Aug 5, 2013, 4:09 PM MDT for Toole County, Montana. It was in force for 51 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 5, 2013, 4:09 PM MDT (22:09 UTC)
Expired
Aug 5, 2013, 5:00 PM MDT
In force
51 min
Issued by
NWS Great Falls, MT

County Toole County, MT

The radar

The Great Falls radar (KTFX), 117 km from the middle of the area, began a volume at 22:09 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 12:00Z, 10.2 hours before the alert went out and 148 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, Great_falls, MT at 12:00Z on 2013-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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, Great_falls, MT at 12:00Z on 2013-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1833 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
97 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.

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What forecasters said that day

The local office's own words before this special weather statement 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 special weather statement went out at Aug 5, 2:59 PM MDT, 1 hour 10 minutes earlier.

Area forecast discussion, Aug 5, 2:59 PM MDT, 1 hour 10 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
259 PM MDT Mon Aug 5 2013

.DISCUSSION...

This afternoon through Wednesday...Scattered thunderstorms have
developed this afternoon across north central and southwest
Montana ahead of a shortwave trough moving southeast out of
Alberta. A weak cold front has also moved south into north central
Montana, providing a focus for thunderstorm development. Moderate
to strong wind shear with moderate to high precipitable water has
caused many of the storms across north central Montana to become
strong with small hail, brief heavy rainfall, and gusty winds. A
few of these storms have even become severe with large hail. The
convective activity extends north only into far southern Alberta,
so am expecting the activity to generally decrease after 6 pm MDT,
with the threat for small hail, heavy rain, and gusty winds
continuing into the early evening hours. The primary additional
threat will be the potential for localized flooding from the brief
heavy rainfall. Will continue to monitor this situation for
possible flood highlights. Thunderstorms will likely diminish
before midnight as the shortwave trough moves into the area
overnight. An upper level ridge of high pressure will then begin
to build back into the area for Tuesday through Wednesday, for a
more anticyclonic northwesterly flow aloft. A few weak
disturbances will move through this flow through the period, for
at least a slight chance of showers/thunderstorms across north
central Montana, mainly during the afternoon/evening hours. The
airmass should remain dry enough to prevent storm development
across southwest Montana. Temperatures will remain about 5 degrees
below seasonal averages through Tuesday, but the rebuilding ridge
will help warm temperatures closer to normal into Wednesday.
Coulston

Wednesday night through Monday...A slightly unstable summer like
weather pattern will continue to reside over the region for the
second half of the work week and into next weekend. Again tonight
both the GFS/EC models differ in the exact timing/placement with
the upper level disturbances moving through the region. Thus
isolated thunderstorms look possible most days from Thursday
through Monday. However...there looks to be just enough model
support to try and keep the lower elevations drier from Wednesday
night through Thursday night...thus pops have been lowered just a
touch for many lower elevation locations. Otherwise...isolated to
scattered thunderstorms are expected across the region later this
week...through the weekend...and into early next week. In terms of
temperatures...summer like temperatures will continue through the
period...with afternoon highs near normal most days. The only
change was to lower the afternoon highs a touch for next
weekend...especially in southwest MT...as the latest forecast
models indicate afternoon highs in southwest MT should now
generally be in the upper 80s rather than near or just above 90
degrees. Brusda

&&

.AVIATION...
UPDATED 1755Z.
An upper-level trough and accompanying plume of Pacific moisture
will move along the US/Can border today, sparking scattered
thunderstorms across central and southwest MT this afternoon/
evening. A weak surface cold front from this system is currently
near KCTB and should only make slow southward progress through 00Z.
There is potential for isolated stronger storms near/along the
front, mainly vcnty KCTB/KHVR, but could come as far south as KGTF
by late aftn. Main threat would be gusty outflow winds and brief
heavy rainfall. Expect VFR conditions for the most part, though
brief MVFR is possible near any stronger storms. Convective activity
will dissipate this evening with gradually decreasing cloud cover.
Waranauskas

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  51  80  54  85 /  40  10  10  10
CTB  48  77  53  79 /  30  10  10  20
HLN  55  84  57  87 /  40  10  10  10
BZN  49  82  49  85 /  20  10  10  10
WEY  33  76  36  78 /  10  10   0  10
DLN  48  82  49  84 /  20  10  10  10
HVR  53  78  54  80 /  40  20  10  30
LWT  50  75  51  81 /  50  20  10  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

SHORT TERM...COULSTON
LONG TERM...BRUSDA
AVIATION...WARANAUSKAS

weather.gov/greatfalls
Hazardous weather outlook, Aug 5, 4:16 AM MDT, 11 hours 53 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
416 AM MDT MON AUG 5 2013

MTZ009>014-044>051-054-061030-
NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL-CASCADE-
CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-TOOLE-LIBERTY-
EASTERN PONDERA-BLAINE-SOUTHERN ROCKY MOUNTAIN FRONT-
EASTERN TETON-JUDITH BASIN-FERGUS-MEAGHER-
416 AM MDT MON AUG 5 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA.

.DAY ONE...TODAY AND TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS MUCH OF
NORTH CENTRAL AND CENTRAL MONTANA THIS AFTERNOON AND EVENING. A
FEW OF THE THUNDERSTORMS WILL HAVE BRIEF HEAVY RAINFALL...GUSTY
WINDS TO 40 MPH AND SMALL HAIL.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

MTZ008-015-052-053-055-061030-
BEAVERHEAD-MADISON-JEFFERSON-BROADWATER-GALLATIN-
416 AM MDT MON AUG 5 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
MONTANA.

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

In the hours before

Local storm report, Aug 5, 2:47 PM MDT, 1 hour 22 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
247 PM MDT MON AUG 05 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0240 PM     HAIL             11 S DEVON              48.30N 111.52W
08/05/2013  M1.00 INCH       TOOLE              MT   TRAINED SPOTTER

&&

HOENISCH
Local storm report, Aug 5, 3:02 PM MDT, 1 hour 7 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
302 PM MDT MON AUG 05 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0301 PM     HAIL             HAVRE                   48.54N 109.68W
08/05/2013  E0.25 INCH       HILL               MT   PUBLIC

            PEA SIZE HAIL COVERING THE GROUND IN HAVRE. BREIF HEAVY
            RAIN OBSERVED AS WELL. STORM IS PASSING.

&&

HOENISCH
Local storm report, Aug 5, 3:08 PM MDT, 1 hour 1 minute before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
308 PM MDT MON AUG 05 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0302 PM     HAIL             HAVRE                   48.55N 109.68W
08/05/2013  M1.00 INCH       HILL               MT   TRAINED SPOTTER

            HAIL RANGING FROM PEA TO QUARTER SIZED.

&&

HOENISCH
Local storm report, Aug 5, 3:39 PM MDT, 30 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
339 PM MDT MON AUG 05 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0328 PM     HAIL             5 NNE LOMA              48.00N 110.47W
08/05/2013  M1.00 INCH       CHOUTEAU           MT   TRAINED SPOTTER

            NICKEL TO QUARTER SIZE HAIL. 50 MPH WINDS.

&&

HOENISCH
Local storm report, Aug 5, 3:46 PM MDT, 23 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
346 PM MDT MON AUG 05 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0315 PM     HAIL             21 S CHESTER            48.21N 110.89W
08/05/2013  M0.50 INCH       LIBERTY            MT   TRAINED SPOTTER

            HALF INCH DIAMETER HAIL AND 30 MPH WIND GUSTS.

&&

NJL
Special weather statement, Aug 5, 4:09 PM MDT, 0 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 1:17 PM MDTSpecial Weather StatementTFXToole43 min
Aug 5, 1:34 PM MDTSevere Thunderstorm WarningTFXGlacier, Pondera, Toole41 min
Aug 5, 2:25 PM MDTSpecial Weather StatementTFXLiberty65 min
Aug 5, 2:36 PM MDTSpecial Weather StatementTFXHill39 min
Aug 5, 2:45 PM MDTSevere Thunderstorm WarningTFXChouteau, Liberty, Toole60 min
Aug 5, 3:18 PM MDTSevere Thunderstorm WarningTFXGlacier, Toole42 min
Aug 5, 3:20 PM MDTSevere Thunderstorm WarningTFXChouteau55 min
Aug 5, 3:55 PM MDTSevere Thunderstorm WarningTFXToole50 min
Aug 5, 4:18 PM MDTSpecial Weather StatementTFX42 min
Aug 5, 4:28 PM MDTSpecial Weather StatementTFXBroadwater47 min
Aug 5, 4:30 PM MDTSpecial Weather StatementTFXGallatin45 min
Aug 5, 4:41 PM MDTSpecial Weather StatementTFXLiberty49 min
Aug 5, 5:18 PM MDTSevere Thunderstorm WarningTFXBlaine, Chouteau, Hill57 min

Nearby

Special Weather Statements in Montana, 2013Every special weather statement in 2013

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.