Alert archive / Alaska / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 5, NWS Anchorage, AK

June 21, 2007

NWS Anchorage, AK issued this severe thunderstorm warning at Jun 21, 2007, 5:44 PM AKDT. It was in force for 55 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: Jun 21, 2007, 5:44 PM AKDT (01:44 UTC)
Expired: Jun 21, 2007, 6:39 PM AKDT
In force: 55 min
Issued by: NWS Anchorage, AK
Area: Counties, with a storm outline in the text

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Anchorage Iap/Pt. Campbe, (PANC), launched 00:00Z, 1.7 hours before the alert went out and 74 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2242 m above ground
0-6 km bulk shear: 5 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 23 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.

000
WWAK58 PAFC 220217
SVSAFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
615 PM ADT THU JUN 21 2007

AKZ121-220245-
/O.CON.PAFC.SV.W.0005.000000T0000Z-070622T0245Z/
WESTERN KENAI PENINSULA AK-
615 PM AKDT THU JUN 21 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM AKDT
FOR WESTERN KENAI PENINSULA...

AT 612 PM AKDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A SEVERE THUNDERSTORM POSSIBLY PRODUCING PENNY SIZED HAIL.  
THIS STORM WAS LOCATED NEAR COOPER LANDING...AND IS DRIFTING SLOWLY 
WESTWARD. THE STRONGEST PART OF THE STORM IS JUST NORTH OF THE MAIN 
HIGHWAY.

LAT...LON 6058 14953 6064 14987 6041 15017 6033 14985

$$

2 follow-up statements

000
WWAK58 PAFC 220239
SVSAFC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
637 PM ADT THU JUN 21 2007

AKZ121-220247-
/O.CAN.PAFC.SV.W.0005.000000T0000Z-070622T0245Z/
WESTERN KENAI PENINSULA AK-
637 PM AKDT THU JUN 21 2007

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN KENAI PENINSULA IS
CANCELLED...

THE STORM AROUND COOPER LANDING IS WEAKENING AS IT DRIFTS WEST 
TOWARD SKILAK LAKE...THUS THE SEVERE THUNDERSTORM WARNING HAS BEEN 
CANCELLED. HOWEVER...EXPECT CONTINUED LOCALLY HEAVY 
DOWNPOURS...GUSTY WINDS...AND SMALL HAIL THROUGH AT LEAST 800 PM 
FROM SKILAK LAKE NORTH.

LAT...LON 6058 14953 6064 14987 6041 15017 6033 14985

$$

000
WUAK58 PAFC 220148
SVRAFC
AKZ121-220245-
/O.NEW.PAFC.SV.W.0005.070622T0144Z-070622T0245Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ANCHORAGE AK
544 PM AKDT THU JUN 21 2007

THE NATIONAL WEATHER SERVICE IN ANCHORAGE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN KENAI PENINSULA AREA OF ALASKA...

* UNTIL 645 PM AKDT

* AT 542 PM AKDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM JUST EAST OF COOPER LANDING.  THIS STORM IS 
DRIFING SLOWLY WESTWARD. THIS STORM WILL MOVE OVER COOPER LANDING BY 
615 PM. PENNY SIZED HAIL HAS BEEN REPORTED WITH THE STORMS IN THIS 
AREA...AND CAN BE EXPECTED THROUGH 645 PM WITH THIS STORM.

LAT...LON 6058 14953 6064 14987 6041 15017 6033 14985

$$

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 Anchorage, AK wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 21, 8:40 AM AKDT, 9 hours 4 minutes earlier.

Area forecast discussion, Jun 21, 8:40 AM AKDT, 9 hours 4 minutes before

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
140 PM ADT THU JUN 21 2007

.ANALYSIS AND UPPER LEVELS...
THIS AFTERNOON...A HUGE RIDGE OF HIGH PRESSURE OVER NORTH PACIFIC
EXTENDS NORTH INTO THE EASTERN ALEUTIANS. OVER SOUTHCENTRAL...THERE
IS A WEAKER NORTH SOUTH ORIENTED UPPER LEVEL HIGH WITH A WEAK BUT
IMPORTANT SURFACE TROUGH UNDERLYING IT. A COLD UPPER LEVEL LOW WITH
A WEAK SURFACE LOW UNDERNEATH IS PRESENT AROUND THE YUKON DELTA.
ANOTHER LOW IS PRESENT OVER THE FAR SOUTHWEST BERING.

.MODEL DISCUSSION...
GOOD MODEL AGREEMENT EXISTS.

.SHORT TERM FORECAST...
SOUTHCENTRAL...
MOST IMMEDIATE CONCERN IS FOR THUNDERSTORMS THROUGH THIS (THURSDAY)
EVENING AND THEIR INFLUENCE ON EXISTING FIRES AND ON ANY NEW FIRES.
MAIN FOCUS OF STORMS THROUGH THIS EVENING WILL BE FROM INLAND KENAI
PENINSULA NORTHEAST TO THE CHUGACH AND NORTH TO THE TALKEETNA
MOUNTAINS AND NORTH/WEST PART OF THE COPPER RIVER BASIN. POTENTIAL
FOR THUNDERSTORMS LOOKS ABOUT AS GOOD AS IT EVER GETS AROUND HERE.
ACTIVITY ALREADY GETTING GOING AS OF THIS WRITING. EXPECT
CONVECTION TO BY FAR BE AT ITS MAX LATE THIS AFTERNOON AND THIS
EVENING COMPARED TO UPCOMING DAYS. THE UPPER LEVEL TROUGH NEAR THE
YUKON DELTA WILL APPROACH THE AREA FROM THE WEST TONIGHT...WITH
STRONGER...WETTER...AND COOLER ONSHORE FLOW BEGINNING. THE MARINE
STRATUS WHICH IS CURRENTLY PRESENT OVER THE NORTHERN GULF AND
PRINCE WILLIAM SOUND IS LIKELY TO PERSIST. MOISTURE WILL GRADUALLY
INCREASE INTO THE WEEKEND WITH PRECIPITATION BEING MORE STRATIFORM
IN NATURE RATHER THAN CONVECTIVE.

SOUTHWEST MAINLAND...
THE SOUTHWEST MAINLAND IS IN FOR WET AND COOL WEATHER TO CONTINUE
INTO THE WEEKEND. LOW NEAR THE YUKON DELTA WILL CONTINUE TO BRING
RAIN TO THE BETHEL AREA. RAIN WILL SPREAD EAST INTO THE REST OF THE
SOUTHWEST MAINLAND THURSDAY AS A LOW MOVING EAST ACROSS THE BERING
TONIGHT MERGES WITH THE ALREADY PRESENT LOW AROUND THE YUKON DELTA.
A COLD UPPER LEVEL LOW WILL PERSIST OVER THE SOUTHWEST MAINLAND
INTO THE WEEKEND...KEEPING THE RAIN AROUND.

ALEUTIANS/BERING...
A LOW WITH FAIRLY WEAK WINDS BUT COPIOUS RAIN WILL MOVE EAST ACROSS
THE BERING TONIGHT AND INTO BRISTOL BAY BY FRIDAY NIGHT. THIS WILL
BRING RAIN TO PRETTY MUCH EVERYWHERE SOUTH OF SAINT MATTHEW
TONIGHT. RAIN WILL GRADUALLY TAPER OFF FROM WEST TO EAST FRIDAY AS
HIGH PRESSURE BUILDS INTO THE REGION. SOMEWHAT MOIST NORTHERLY FLOW
WILL CONTINUE OVER THE EASTERN BERING/ALEUTIANS THROUGH THE WEEKEND
AS A RESULT OF THE UPPER LEVEL LOW OVER THE SOUTHWEST MAINLAND.
RAIN WILL MOVE BACK INTO THE WESTERN ALEUTIANS ON SUNDAY WITH HIGH
PRESSURE SQUEEZED IN BETWEEN THESE TWO AREAS.

.LONG TERM FORECAST...
NOT MUCH CONFIDENCE IN ANYTHING BEYOND THIS WEEKEND. IN
GENERAL...IT LOOKS LIKE THE COLD UPPER LEVEL LOW OVER SOUTHWEST
ALASKA WILL GRADUALLY WEAKEN. WEAK HIGH PRESSURE WILL PROBABLY BE
OVER THE EASTERN BERING...WITH UNSETTLED WEATHER AND LOW PRESSURE
OVER THE CENTRAL TO WESTERN BERING/ALEUTIANS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...RED FLAG WARNING 141.

FOISY JUN 07

In the hours before

Local storm report, Jun 21, 12:40 PM AKDT, 5 hours 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
540 PM ADT THU JUN 21 2007

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

0538 PM     HAIL             MOOSE PASS              60.47N 149.39W
06/21/2007  E0.75 INCH                          AK   TRAINED SPOTTER

            A TRAINED SPOTTER REPORTED PENNY-SIZED HAIL NEAR MOOSE
            PASS. HAIL LASTED APPROXIMATELY 10 MINUTES.

&&

DANG

Local storm report, Jun 21, 1:06 PM AKDT, 4 hours 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ANCHORAGE AK
606 PM ADT THU JUN 21 2007

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

0538 PM     HAIL             MOOSE PASS              60.47N 149.39W
06/21/2007  E0.75 INCH                          AK   PUBLIC

            GENERAL PUBLIC ESTIMATE UP TO 1/2 INCH OF RAIN AND 3/4
            INCH HAIL AT MOOSE PASS. RAINING MORE THAN HALF
            HOUR...HARD AT TIMES...CREATING PUDDLES ON ROADS.

&&

DANG

The office that day

Everything else NWS Anchorage, AK issued on the same UTC day.

Issued	Product	Office	Lasted
Jun 21, 5:24 PM AKDT	Dense Fog Advisory	AFC	45 hr
Jun 21, 5:40 PM AKDT	Severe Thunderstorm Warning	AFC	65 min
Jun 21, 6:44 PM AKDT	Severe Thunderstorm Warning	AFC	56 min
Jun 21, 11:00 PM AKDT	Small Craft Advisory	AFC	48 hr
Jun 21, 11:00 PM AKDT	Small Craft Advisory	AFC	12 hr
Jun 22, 2:44 AM AKDT	Red Flag Warning	AFC	16 hr
Jun 22, 11:00 AM AKDT	Small Craft Advisory	AFC	60 hr

Nearby

Severe Thunderstorm Warnings in Alaska, 2007 Every severe thunderstorm warning in 2007

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.