Alert archive / Montana / Frost Advisories in 2011

Frost Advisory 2, NWS Missoula, MT

September 3, 20114 counties in Montana

NWS Missoula, MT issued this frost advisory at Sep 3, 2011, 2:19 PM MDT for 4 counties in Montana. It took effect at Sep 4, 2011, 2:00 AM MDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Sep 3, 2011, 2:19 PM MDT (20:19 UTC)
In effect from
Sep 4, 2011, 2:00 AM MDT
Expired
Sep 4, 2011, 9:00 AM MDT
In force
7 hr
Issued by
NWS Missoula, MT

Counties Flathead County, MT, Lake County, MT, Lincoln County, MT, Sanders County, MT

The radar

The Missoula radar (KMSX), 122 km from the middle of the area, began a volume at 20:17 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

Spokane, WA (KOTX), launched 12:00Z, 8.3 hours before the alert went out and 135 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, Spokane, WA at 12:00Z on 2011-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Spokane, WA at 12:00Z on 2011-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 square meters per square second.1939Sfc1 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
2075 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
47 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.

063 
WWUS75 KMSO 032019
NPWMSO

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MISSOULA MT
219 PM MDT SAT SEP 3 2011

MTZ001-003-040430-
/O.NEW.KMSO.FR.Y.0002.110904T0800Z-110904T1500Z/
KOOTENAI/CABINET REGION-FLATHEAD/MISSION VALLEYS-
219 PM MDT SAT SEP 3 2011

...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM MDT SUNDAY...

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A FROST
ADVISORY...WHICH IS IN EFFECT FROM 2 AM TO 9 AM MDT SUNDAY. 

* IMPACTS/TIMING: CLEAR SKIES WITH CALM WINDS WILL ALLOW
  TEMPERATURES TO FALL BACK INTO THE 30S BY EARLY SUNDAY MORNING.
  THE GREATEST THREAT FOR FROST WILL BE IN THE LOW LYING AREAS.
  FROST SENSITIVE PLANTS MAY NEED TO BE PROTECTED OR MOVED
  INDOORS.

* TEMPERATURES: IN THE LOWER 30S.

* LOCATIONS IMPACTED INCLUDE...HIGHWAY 2 KALISPELL TO LIBBY...
  HIGHWAY 37 EUREKA TO LIBBY...HIGHWAY 56 BULL LAKE ROAD...
  HIGHWAY 93 EUREKA TO WHITEFISH...FLATHEAD VALLEY

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$
2 follow-up statements
884 
WWUS75 KMSO 040328
NPWMSO

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MISSOULA MT
928 PM MDT SAT SEP 3 2011

MTZ001-003-041500-
/O.CON.KMSO.FR.Y.0002.110904T0800Z-110904T1500Z/
KOOTENAI/CABINET REGION-FLATHEAD/MISSION VALLEYS-
928 PM MDT SAT SEP 3 2011

...FROST ADVISORY REMAINS IN EFFECT FROM 2 AM TO 9 AM MDT
SUNDAY...

A FROST ADVISORY REMAINS IN EFFECT FROM 2 AM TO 9 AM MDT SUNDAY. 

* IMPACTS/TIMING: CLEAR SKIES WITH CALM WINDS WILL ALLOW 
  TEMPERATURES TO FALL BACK INTO THE 30S BY EARLY SUNDAY 
  MORNING. THE GREATEST THREAT FOR FROST WILL BE IN THE LOW 
  LYING AREAS. FROST SENSITIVE PLANTS MAY NEED TO BE PROTECTED 
  OR MOVED INDOORS. 

* TEMPERATURES: IN THE LOWER 30S.

* LOCATIONS IMPACTED INCLUDE...HIGHWAY 2 KALISPELL TO LIBBY... 
  HIGHWAY 37 EUREKA TO LIBBY...HIGHWAY 56 BULL LAKE ROAD...
  HIGHWAY 93 EUREKA TO WHITEFISH...FLATHEAD LAKE...FLATHEAD 
  VALLEY... MISSION VALLEY...POLSON

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$
543 
WWUS75 KMSO 041447
NPWMSO

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MISSOULA MT
847 AM MDT SUN SEP 4 2011

MTZ001-003-041600-
/O.EXP.KMSO.FR.Y.0002.000000T0000Z-110904T1500Z/
KOOTENAI/CABINET REGION-FLATHEAD/MISSION VALLEYS-
847 AM MDT SUN SEP 4 2011

...FROST ADVISORY WILL EXPIRE AT 9 AM MDT THIS MORNING...

THE FROST ADVISORY WILL EXPIRE AT 9 AM MDT THIS MORNING. 

* LOCATIONS IMPACTED INCLUDE...HIGHWAY 2 KALISPELL TO LIBBY...
  HIGHWAY 37 EUREKA TO LIBBY...HIGHWAY 56 BULL LAKE ROAD...
  HIGHWAY 93 EUREKA TO WHITEFISH...FLATHEAD VALLEY

$$

Nearby

Frost Advisories in Montana, 2011Every frost advisory in 2011

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.