Alert archive / Alaska / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 9, NWS Fairbanks, AK

July 8, 2017

NWS Fairbanks, AK issued this severe thunderstorm warning at Jul 8, 2017, 8:13 PM AKDT. It was in force for 32 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
Jul 8, 2017, 8:13 PM AKDT (04:13 UTC)
Expired
Jul 8, 2017, 8:45 PM AKDT
In force
32 min
Issued by
NWS Fairbanks, AK
Area
Storm-based polygon

The radar

The Fairbanks Faa radar (PAPD), 86 km from the middle of the area, began a volume at 04:15 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.

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

Fairbanks, (PFAI), launched 00:00Z, 4.2 hours before the alert went out and 78 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, Fairbanks, at 00:00Z on 2017-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 98 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, Fairbanks, at 00:00Z on 2017-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
98 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
1441 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
123 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

040 
WUAK59 PAFG 090414
SVRAFG
AKZ223-090445-
/O.NEW.PAFG.SV.W.0009.170709T0414Z-170709T0445Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Fairbanks AK
813 PM AKDT Sat Jul 8 2017

The National Weather Service in Fairbanks has issued a

* Severe Thunderstorm Warning for...
  North central Deltana and Tanana Flats in Alaska...

* Until 845 PM AKDT

* At 813 PM AKDT, Doppler radar indicated a severe thunderstorm
  capable of producing large hail up to ping pong ball size and
  damaging winds in excess of 60 mph. This storm was located 16 miles
  southeast of Salcha, or 21 miles northwest of Quartz Lake, and
  moving west at 25 mph.

* Locations impacted include...
  Harding Lake and Birch Lake. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Severe thunderstorms produce damaging winds, destructive hail, deadly
lightning and very heavy rain. For your protection, move to an
interior room on the lowest floor of your home or business. Heavy
rains flood roads quickly so do not drive into areas where water
covers the road.

&&

LAT...LON 6439 14626 6430 14637 6433 14686 6453 14687
TIME...MOT...LOC 0413Z 106DEG 20KT 6437 14645 

$$

NS
1 follow-up statement
336 
WWAK59 PAFG 090442
SVSAFG

Severe Weather Statement
National Weather Service Fairbanks AK
840 PM AKDT Sat Jul 8 2017

AKZ223-090450-
/O.EXP.PAFG.SV.W.0009.000000T0000Z-170709T0445Z/
Deltana and Tanana Flats-
840 PM AKDT Sat Jul 8 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL DELTANA AND
TANANA FLATS WILL EXPIRE AT 845 PM AKDT...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning will be allowed to expire.

Remember, a Severe Thunderstorm Warning still remains in effect for 
north central Deltana and the Tanana Flats, including Salcha and 
Birch and Hardings Lakes.

LAT...LON 6439 14626 6430 14637 6433 14686 6453 14687
TIME...MOT...LOC 0440Z 106DEG 20KT 6441 14675 

$$

NS

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 Fairbanks, AK wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 8, 1:28 PM AKDT, 6 hours 45 minutes earlier.

Area forecast discussion, Jul 8, 1:28 PM AKDT, 6 hours 45 minutes before
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
128 PM AKDT Sat Jul 8 2017

.DISCUSSION...
Active weather pattern continues over the interior with a triple
shot of weather systems bringing periods of rain over the
southeastern interior and Alaska Range through Wednesday of next
week. The triple shot of precipitation will add to ongoing
elevated water levels along streams and rivers draining the Alaska
Range and southeastern interior. Fire weather remains active with
persistent hot, dry and windy weather conditions and ongoing Red
Flag Warnings over the northeast interior. In addition another
active thunderstorm day is expected late late afternoon and
evening along a line from near Eagle to Fairbanks to near Lake
Minchumina with the potential for hail, heavy rain and strong
winds.

Aloft at 500 mb, an eat-west oriented ridge stretches along a Nome
to Fort Yukon line and will continue to move slowly north over
the next several days to be located along the crest of the Brooks
Range Sunday and over the North Slope and McKenzie Delta Monday.
As the ridge moves slowly north a series of shortwaves will
move from east to west along the southern boundary of the ridge.
The timing and track of each of these waves varies slightly with
each model run and model family however the concensus of the
models indicate a very wet weekend and start to the work week for
the southern interior and Alaska Range.

Multi rain events to impact the southeast interior and eastern
Alaska Range. The first rain event will move over the Alaska
Range this evening. The heaviest rain is expected over the Alaska
Range and areas just north of the range. Special Weather
Statements covering rapidly rising water levels, elevated water
levels and outdoor activities have been issued. The first round of
rain should be winding down mid day Sunday with storm totals on
in the Alaska Range expected to be in the 1 to 1.5 range. The
second round of rain is expected to begin late Sunday night and
continue into Monday. Areas just north of the Alaska Range are in
the cross hairs on this event with storm totals on this event
reaching 0.5 to 1 inch by mid day Monday. The latest models
continue to indicate yet another round of rain moving over the
southeast interior and eastern Alaska Range Tuesday and Wednesday.
Favorable upslope flow for the Eastern Alaska Range could produce
another 1 to 1.5 inches of rain on Tuesday and Wednesday.

Over the northeast interior Hot, dry and breezy conditions will
continue today with Red Flag Warnings ongoing for the southeast
Brooks Range as well as for the Yukon Flats and surrounding
uplands. Temperatures will climb again today into the 80s while
minimum relative humidities fall into the 20s this afternoon and
evening. Winds are expected to increase this afternoon and
continue overnight as a pressure gradient between a 1016 mb high
over the North Slope and a devloping 1006 low over the southeast
interior increases. Humidity levels will increase on Sunday as the
rain maker over the southern interior pulls in a more moist
airmass into the northern interior. Red Flag criteria for minimum
humidity is not expected to be reached Sunday or Monday.
Thunderstorm activity over the northeast interior and southeast
interior is expected to increase Sunday and Monday as the capping
upper level ridge moves north and low level moisture moves into
the area.

Coastal Hazard Potential Days 3 and 4...None.

&&

.FIRE WEATHER...
Fire weather concerns continue to focus on the northeast interior
as Hot, dry and breezy conditions continue today. Red Flag
Warnings are ongoing for the southeast Brooks Range as well as
for the Yukon Flats and surrounding uplands. Temperatures will
climb again today into the 80s while minimum relative humidities
fall into the 20s this afternoon and evening. Winds are expected
to increase this afternoon and continue overnight as a pressure
gradient between a 1016 mb high over the North Slope and a
devloping 1006 low over the southeast interior increases. Humidity
levels will increase on Sunday as the rain maker over the
southern interior pulls in a more moist airmass into the northern
interior. Red Flag criteria for minimum humidity is not expected
to be reached Sunday or Monday. Thunderstorm activity over the
northeast interior and southeast interior is expected to increase
Sunday and Monday as the capping upper level ridge moves north and
low level moisture moves into the area.

&&

.HYDROLOGY...
Multiple rain events to impact the southeast interior and eastern
Alaska Range through Wednesday of next week. The first rain event
will move over the Alaska Range and adjacent areas to the north this
evening. The heaviest rain is expected over the Alaska Range and
areas just north of the range. Special Weather Statements covering
rapidly rising water levels, elevated water levels and outdoor
activities have been issued. The first round of rain should be
winding down mid day Sunday with storm totals on in the Alaska
Range expected to be in the 1 to 1.5 range. The second round of
rain is expected to begin late Sunday night and continue into
Monday. Areas just north of the Alaska Range are in the cross
hairs on this event with storm totals on this event reaching 0.5
to 1 inch by mid day Monday. The latest models continue to
indicate yet another round of rain moving over the southeast
interior and eastern Alaska Range Tuesday and Wednesday. Favorable
upslope flow for the Eastern Alaska Range could produce another 1
to 1.5 inches of rain on Tuesday and Wednesday.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning for AKZ218-AKZ220.
&&

CCC JUL 17

In the hours before

Special weather statement, Jul 8, 2:56 PM AKDT, 5 hours 17 minutes before
Special Weather Statement
National Weather Service Fairbanks AK
256 PM AKDT Sat Jul 8 2017

AKZ221>224-100200-
Central Interior-Middle Tanana Valley-Deltana and Tanana Flats-
Upper Tanana Valley and the Fortymile Country-
Including Nenana, Anderson, Tanana, Minto, Manley Hot Springs,
Rampart, Lake Minchumina, Livengood, Fairbanks, Fort Wainwright,
Eielson AFB, Ester, North Pole, Moose Creek, Two Rivers, Fox,
Chatanika, Chena Hot Springs, Sourdough Camp, Salcha,
Delta Junction, Fort Greely, Harding/Birch Lake, Dry Creek,
Dot Lake, Healy Lake, Tok, Tanacross, Eagle, Tetlin, Northway,
Alcan, Chicken, and Boundary
256 PM AKDT Sat Jul 8 2017

...Rising Water Levels on the Tanana River...

The Tanana River will gradually rise through next week and may
approach bankfull levels in some locations. This rise in water
levels is due to recent heavy rain in the Eastern Alaska Range and
warm temperatures which have increased glacial runoff. Several
weather systems are forecast to move into the eastern Interior
this weekend and early next week and bring more rain to the
region. In addition to rising water levels, bank erosion is
expected to increase and most sandbars will be covered with water
through much of next week.

CCC
Special weather statement, Jul 8, 6:12 PM AKDT, 2 hours 1 minute before
Special Weather Statement
National Weather Service Fairbanks AK
612 PM AKDT Sat Jul 8 2017

AKZ223-224-090415-
Deltana and Tanana Flats-
Upper Tanana Valley and the Fortymile Country-
Including Salcha, Delta Junction, Fort Greely,
Harding/Birch Lake, Dry Creek, Dot Lake, Healy Lake, Tok,
Tanacross, Eagle, Tetlin, Northway, Alcan, Chicken, and Boundary
612 PM AKDT Sat Jul 8 2017

...Strong to Severe Thunderstorms Possible this Evening...

At 545 pm, a line of strong to severe thunderstorms was detected
by radar about 10 miles east of Healy Lake, moving west at 30 mph.
If this line of thunderstorms can maintain strength, they will
impact the Delta Junction area around 7 pm this evening. Residents
in the Delta Junction area should monitor weather conditons
closely and be alert for possible warnings this evening.
Local storm report, Jul 8, 7:48 PM AKDT, 25 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FAIRBANKS AK
748 PM AKDT SAT JUL 8 2017

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

0705 PM     TSTM WND GST     3 SW FORT GREELY        63.92N 145.84W
07/08/2017  E58 MPH          SOUTHEAST FAIRBANKSAK   OTHER FEDERAL

            SENSOR INDICATED WIND GUST TO 58.4MPH.

&&

HFL
Local storm report, Jul 8, 7:51 PM AKDT, 22 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FAIRBANKS AK
751 PM AKDT SAT JUL 8 2017

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

0656 PM     TSTM WND GST     DELTA JUNCTION          64.06N 145.71W
07/08/2017  E55 MPH          SOUTHEAST FAIRBANKSAK   ASOS

            SENSOR INDICATED WIND GUST OF 55.6MPH FROM
            LINE OF SEVERE TSTMS THAT MOVED OVER THE
            AREA.

&&

HFL
Local storm report, Jul 8, 7:53 PM AKDT, 20 minutes before
PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE FAIRBANKS AK
753 PM AKDT SAT JUL 8 2017

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

0705 PM     TSTM WND GST     3 SW FORT GREELY        63.92N 145.84W
07/08/2017  E58 MPH          SOUTHEAST FAIRBANKSAK   MESONET

            SENSOR INDICATED WIND GUST TO 58.4MPH.

&&

HFL
Local storm report, Jul 8, 7:57 PM AKDT, 16 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FAIRBANKS AK
757 PM AKDT SAT JUL 8 2017

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

0755 PM     TSTM WND GST     DELTA JUNCTION          64.07N 145.71W
07/08/2017  E55 MPH          SOUTHEAST FAIRBANKSAK   LAW ENFORCEMENT

            CALLED AK STATE TROOPERS IN DELTA JUNCTION,
            THEY REPORTED AT LEAST ONE TREE DOWN DUE TO
            WINDS.

&&

HFL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 8, 5:46 PM AKDTSevere Thunderstorm WarningAFG44 min
Jul 8, 6:04 PM AKDTSevere Thunderstorm WarningAFG41 min
Jul 8, 6:36 PM AKDTSevere Thunderstorm WarningAFG39 min
Jul 8, 7:08 PM AKDTSevere Thunderstorm WarningAFG52 min
Jul 8, 8:38 PM AKDTSevere Thunderstorm WarningAFG52 min
Jul 9, 3:44 AM AKDTBrisk Wind AdvisoryAFG25 hr
Jul 9, 3:48 AM AKDTSmall Craft AdvisoryAFG35 hr
Jul 9, 4:25 AM AKDTWind AdvisoryAFG9 hr
Jul 9, 3:27 PM AKDTSmall Craft AdvisoryAFG59 hr
Jul 9, 3:36 PM AKDTSmall Craft AdvisoryAFG23 hr

Nearby

Severe Thunderstorm Warnings in Alaska, 2017Every severe thunderstorm warning in 2017

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.