Alert archive / Montana / Areal Flood Advisories in 2013

Areal Flood Advisory 21, NWS Great Falls, MT

July 17, 2013Jefferson County, Lewis and Clark County, Montana

NWS Great Falls, MT issued this areal flood advisory at Jul 17, 2013, 5:43 PM MDT for Jefferson County, Lewis and Clark County, Montana. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued: Jul 17, 2013, 5:43 PM MDT (23:43 UTC)
Expired: Jul 17, 2013, 11:30 PM MDT
In force: 6 hr
Issued by: NWS Great Falls, MT
Area: Storm-based polygon

Counties Jefferson County, MT, Lewis and Clark County, MT

The radar

The Great Falls radar (KTFX), 112 km from the middle of the area, began a volume at 23:45 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.

What forecasters said that day

The local office's own words before this areal flood advisory 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 areal flood advisory went out at Jul 17, 5:03 PM MDT, 40 minutes earlier.

Area forecast discussion, Jul 17, 5:03 PM MDT, 40 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
503 PM MDT Wed Jul 17 2013

.DISCUSSION...

Tonight through Friday...Convective activity getting started this
afternoon with thunderstorms rapidly developing over west and
southwest Montana in response to an upper trof moving across
northwest Montana and into southern Alberta along with jet streak
energy. Convective parameters are not overly impressive but strong
to severe storms are possible. Additionally, precipitable water
values are very high across the area and may translate to heavy rain
with some storms. Convective activity should end after midnight with
an upper ridge rebuilding over the area Thursday. With a stronger
westerly flow aloft on Thursday, along with favorable mixing,
surface winds will become breezy during the afternoon. As the ridge
axis retrogrades a little to the west on Friday, northwest flow
aloft will develop over the area but conditions will remain dry.
Temperatures will warm to above seasonal averages through the
period. Emanuel

Friday night through Wednesday...Models appear to be in decent
agreement for the early portion of the medium range period. The
weekend starts off with a broad upper level ridge centered over
Nevada and the associated ridge axis extending into British
Columbia. Models indicate that the core of the high pressure system
will move to the California coast while shortwave energy moving over
the top of the ridge brings a dry west to northwest flow aloft to
Montana by Sunday night. Models differ on the strength of this
shortwave but both agree that the airmass will remain dry during
this period. Model solutions diverge beyond the weekend with the GFS
rebuilding the ridge over the Northern Rocky Mountains while the
ECMWF keeps high pressure over the Eastern Pacific and nearly zonal
flow aloft over Montana. Despite these differences in upper air
patterns both models remain dry and warm through the middle of next
week. Have made only minor temperatures to the going forecast for
what appears to be shaping up as a relatively quiet mid summer. mpj

&&

.AVIATION...
UPDATED 2302Z.
Scattered showers and thunderstorms will move east and diminish
during the evening...most storms should be east of KLWT by 08z. Some
storms could have large hail and gusty winds. Dry conditions will
continue through Thursday. MVFR conditions are possible near showers
and thunderstorms this evening...elsewhere VFR conditions will
prevail through the next 24 hours.

&&

.FIRE WEATHER...
Widespread rain and thunderstorms are possible this afternoon and
evening as ample monsoonal moisture, instability and wind shear
combined with an upper-level disturbance move over the forecast
area. Some storms may be strong to severe with strong erratic
winds, hail and locally heavy rainfall, however confidence remains
low with regards to heavy rainfall location and coverage. Over
recent burn areas, heavy rain could cause rapid runoff and/or
debris flows. With better chances of widespread thunderstorms, the
threat for lightning- induced fire starts will increase with
holdover ignitions possibly triggering some fires later in the
week.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  58  89  54  89 /  40  10   0   0
CTB  56  83  52  84 /  20  10   0   0
HLN  59  90  56  90 /  50  10   0   0
BZN  55  88  51  89 /  40  20  10   0
WEY  45  82  42  83 /  40  20  10  10
DLN  56  87  51  88 /  40  10   0  10
HVR  60  85  55  88 /  20  10  10  10
LWT  57  84  53  84 /  50  10  10   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH until 10 PM MDT this evening
Beaverhead...Broadwater...Cascade...Central and Southern Lewis
and Clark...Chouteau...Eastern Glacier...Eastern Pondera...
Eastern Teton...Gallatin...Hill...Jefferson...Judith Basin...
Liberty...Madison...Meagher...Northern Rocky Mountain Front...
Southern Rocky Mountain Front...Toole.

&&

weather.gov/greatfalls

Hazardous weather outlook, Jul 17, 4:16 AM MDT, 13 hours 27 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
416 AM MDT WED JUL 17 2013

MTZ008>015-044>055-181030-
BEAVERHEAD-NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL-
CASCADE-CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-
TOOLE-LIBERTY-EASTERN PONDERA-BLAINE-
SOUTHERN ROCKY MOUNTAIN FRONT-EASTERN TETON-JUDITH BASIN-FERGUS-
JEFFERSON-BROADWATER-MEAGHER-GALLATIN-
416 AM MDT WED JUL 17 2013

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

.DAY ONE...TODAY AND TONIGHT

STRONG TO SEVERE THUNDERSTORMS WITH STRONG TO DAMAGING WINDS...HAIL
AND LOCALLY HEAVY RAIN ARE EXPECTED THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE PROBABILITY IS LOW FOR WIDESPREAD HAZARDOUS WEATHER.

.SPOTTER INFORMATION STATEMENT...

ANY REPORTS OF STRONG WINDS...HAIL AND/OR STORM DAMAGE WOULD BE
GREATLY APPRECIATED AND CAN BE RELAYED TO THE NWS GREAT FALLS OR
LOCAL LAW ENFORCEMENT.

In the hours before

Local storm report, Jul 17, 4:46 PM MDT, 57 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
446 PM MDT WED JUL 17 2013

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

0438 PM     HAIL             3 W HELENA              46.60N 112.08W
07/17/2013  E0.75 INCH       LEWIS AND CLARK    MT   TRAINED SPOTTER

            PENNY SIZE HAIL ON THE WEST SIDE OF HELENA.

&&

BRUSDA

Local storm report, Jul 17, 4:48 PM MDT, 55 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
448 PM MDT WED JUL 17 2013

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

0446 PM     HAIL             ENNIS                   45.35N 111.73W
07/17/2013  E0.25 INCH       MADISON            MT   TRAINED SPOTTER

            PEA SIZE HAIL

&&

BRUSDA

Special weather statement, Jul 17, 4:51 PM MDT, 52 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
451 PM MDT WED JUL 17 2013

MTZ015-172330-
MADISON MT-
451 PM MDT WED JUL 17 2013

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL MADISON COUNTY UNTIL 530
PM MDT...

AT 448 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 8 MILES SOUTHWEST OF SHERIDAN...MOVING NORTHEAST
AT 25 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.

* LOCATIONS IMPACTED INCLUDE...
   LAURIN AND  ALDER...
   SHERIDAN AND  LAURIN...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM MDT
WEDNESDAY EVENING FOR WESTERN MONTANA.

LAT...LON 4573 11192 4541 11170 4526 11231 4541 11245
TIME...MOT...LOC 2251Z 239DEG 23KT 4538 11227

NL

Special weather statement, Jul 17, 4:52 PM MDT, 51 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
452 PM MDT WED JUL 17 2013

MTZ008-015-172330-
BEAVERHEAD MT-MADISON MT-
452 PM MDT WED JUL 17 2013

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MADISON AND NORTHERN
BEAVERHEAD COUNTIES UNTIL 530 PM MDT...

AT 454 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 13 MILES WEST OF TWIN BRIDGES...OR 21 MILES
NORTHWEST OF SHERIDAN...MOVING NORTHEAST AT 20 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.

* LOCATIONS IMPACTED INCLUDE...
  RURAL NORTHWESTERN MADISON COUNTY...
  RURAL NORTHERN BEAVERHEAD COUNTY...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM MDT
WEDNESDAY EVENING FOR WESTERN MONTANA.

LAT...LON 4566 11270 4564 11269 4569 11257 4577 11250
      4575 11247 4575 11217 4569 11207 4547 11255
      4556 11277
TIME...MOT...LOC 2252Z 211DEG 18KT 4559 11259

NL

Special weather statement, Jul 17, 5:20 PM MDT, 23 minutes before

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Local storm report, Jul 17, 5:40 PM MDT, 3 minutes before

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  <meta name="viewport" content="width=device-width, initial-scale=1">
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  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 2:53 PM MDT	Special Weather Statement	TFX	Madison	52 min
Jul 17, 3:19 PM MDT	Special Weather Statement	TFX		41 min
Jul 17, 3:59 PM MDT	Special Weather Statement	TFX	Beaverhead	46 min
Jul 17, 4:02 PM MDT	Special Weather Statement	TFX	Beaverhead	43 min
Jul 17, 4:07 PM MDT	Special Weather Statement	TFX	Madison	38 min
Jul 17, 4:23 PM MDT	Severe Thunderstorm Warning	TFX	Lewis and Clark	37 min
Jul 17, 4:30 PM MDT	Special Weather Statement	TFX	Lewis and Clark	45 min
Jul 17, 4:31 PM MDT	Severe Thunderstorm Warning	TFX	Beaverhead, Madison	44 min
Jul 17, 4:44 PM MDT	Special Weather Statement	TFX	Broadwater	46 min
Jul 17, 4:51 PM MDT	Special Weather Statement	TFX	Madison	39 min
Jul 17, 4:52 PM MDT	Special Weather Statement	TFX	Silver Bow	38 min
Jul 17, 5:00 PM MDT	Severe Thunderstorm Warning	TFX	Gallatin, Madison	45 min
Jul 17, 5:20 PM MDT	Special Weather Statement	TFX	Lewis and Clark	40 min
Jul 17, 5:45 PM MDT	Special Weather Statement	TFX	Pondera	45 min
Jul 17, 5:46 PM MDT	Special Weather Statement	TFX	Gallatin	44 min

Nearby

Areal Flood Advisories in Montana, 2013 Every areal flood advisory 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; radar from the NEXRAD Level II archive.