Alert archive / Alaska / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 2, NWS Fairbanks, AK

June 19, 2017

NWS Fairbanks, AK issued this severe thunderstorm warning at Jun 19, 2017, 4:56 PM AKDT. It was in force for 22 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 19, 2017, 4:56 PM AKDT (00:56 UTC)
Expired
Jun 19, 2017, 5:18 PM AKDT
In force
22 min
Issued by
NWS Fairbanks, AK
Area
Storm-based polygon

The radar

The Fairbanks Faa radar (PAPD), 56 km from the middle of the area, began a volume at 00:58 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, 0.9 hours before the alert went out and 50 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 2017-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 101 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 2017-06-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 square meters per square second.193958Sfc1 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
101 J/kg
Mixed-layer CIN
-36 J/kg
Mixed-layer LCL
2133 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
192 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

809 
WUAK59 PAFG 200057
SVRAFG
AKZ222-200130-
/O.NEW.PAFG.SV.W.0002.170620T0057Z-170620T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Fairbanks AK
456 PM AKDT Mon Jun 19 2017

The National Weather Service in Fairbanks has issued a

* Severe Thunderstorm Warning for...
  South central Middle Tanana Valley in Alaska...

* Until 530 PM AKDT

* At 456 PM AKDT, Doppler radar indicated a severe thunderstorm
  capable of producing quarter size hail and damaging winds in excess
  of 60 mph. This storm was located 7 miles north of Salcha, or 9
  miles southeast of Eielson AFB, and moving west at 15 mph.

* Locations impacted include...
  Richardson Highway south of Eielson AFB.

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 6463 14670 6455 14669 6456 14711 6470 14713
TIME...MOT...LOC 0056Z 082DEG 12KT 6457 14686 

$$

NS
1 follow-up statement
927 
WWAK59 PAFG 200119
SVSAFG

Severe Weather Statement
National Weather Service Fairbanks AK
518 PM AKDT Mon Jun 19 2017

AKZ222-200128-
/O.CAN.PAFG.SV.W.0002.000000T0000Z-170620T0130Z/
Middle Tanana Valley-
518 PM AKDT Mon Jun 19 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL MIDDLE TANANA
VALLEY IS CANCELLED...
        
The storm which prompted the warning has weakened below severe limits
and exited the warned area. Therefore the warning has been cancelled.
However small hail and gusty winds are still possible with this
thunderstorm.

LAT...LON 6463 14670 6455 14669 6456 14711 6470 14713
TIME...MOT...LOC 0115Z 082DEG 12KT 6456 14704 

$$

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 Jun 19, 1:56 PM AKDT, 3 hours earlier.

Area forecast discussion, Jun 19, 1:56 PM AKDT, 3 hours before
Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
156 PM AKDT Mon Jun 19 2017

.DISCUSSION...

Models...Good run to run continuity continues, and initialized
well today against the 19/18Z local surface analysis. Diverging
a bit as they move into the midrange and extended periods.

Aloft...At 500 hpa...A 538 dam low still hanging out near Point
Hope will remain stationary tonight then start moving northeast
Tuesday afternoon and will be over Barrow early Wednesday morning,
and 300 nm north of Demarcation Point be Wednesday evening. The
associated shortwave will move east across the western Brooks
Range and eastern Arctic coast. Ridging persists north of the
Alaska Range and east of the middle Yukon River Valley and extends
north over the eastern Arctic and Beaufort Sea this afternoon. A
558 dam center will break off the main ridge over the northern
Yukon Territory and slide west as ridging builds southwest across
mainland Alaska and weakens over the eastern Arctic. By Tuesday
afternoon the ridge axis will lie from Old Crow YT to King Salmon
with multiple 561 dam centers. As the low over Point Hope moves
across the Arctic it will push the eastern half of the ridge to
the south and the ridge axis will lie from Eagle to Dillingham
with the center building to 568 dam. A 537 dam low south of the
Gulf of Alaska will move slowly northeast to 100 nm west of Sitka
by Wednesday morning, then moves inland with troughing extending
west over the Gulf of Alaska. At 850 hpa...Temperatures in the
interior slightly warming, or steady. Out west temperatures will
be on a roller coaster as they warm through Thursday then some
cooling Friday and Saturday before warming again.

Surface...1021 mb high over the Beaufort Sea will become
stationary over northern Banks Island through Wednesday night
merging with ridging over the Northwest Territories. A 999 mb low
over the Copper River Basin will move north into the interior this
evening with troughing extending east in the Yukon Territory and
southeast into British Columbia. by Tuesday morning troughing will
lie from Point Lay to Beaver to northeast British Columbia as the
trough slowly moves northeast, and by Tuesday evening will lie
from Barrow to Chalkyitsik to Mayo YT. A 996 mb low in the Gulf of
Alaska will remain stationary as it weakens and dissipates near
Sitka Wednesday. A 1026 mb high over the north Pacific will move
south of the central Aleutians with ridging building over the
southwest mainland Tuesday evening and into the Central and
Eastern Interior as the trough pulls out to the northeast. The
thermal trough will remain along the north slopes of the Alaska
Range through the week.

Arctic Coast and Brooks Range...Not much going on right now,
expect the stratus and fog to move back in for a few hours
overnight, then some clearing on Tuesday. On the northwest
coast and western Brooks Range it will remain mostly cloudy, and
expect some isolated thunderstorms and showers tonight, and
isolated thunderstorms and scattered showers on Tuesday evening as
the upper level low over the area moves out to the northeast. The
low will also spread some scattered showers to the Arctic plain
and central and eastern Arctic coast. Slightly warmer
temperatures Tuesday and Wednesday. Winds mainly northeast to east
5 to 15 mph will become southwest to west as the trough across
the state moves over the coast and offshore.

West Coast and Western Interior...Low over the point Hope
continues to spin showers into the most of the area. Isolated
embedded thunderstorms possible inland again this evening,
mainly north of Galena. Temperatures warmer Tuesday, then cooler
Wednesday. Winds generally light and variable inland, and
southwest to west on the coast to 15 mph.

Central and Eastern Interior...Isolated thunderstorms and
scattered showers developing later this evening, and Tuesday
afternoon and evening as the trough over the Copper River Basin
moves north into the interior and merges with the thermal trough.
As the trough continues to move north the ridging building in
behind it will stabilize the area Thursday and Friday.
Temperatures generally steady. Northeast winds kicking up a bit
to around 15 mph east of Fort Yukon and in the upper Yukon River
valley this evening, then diminishing Tuesday morning. Remainder
of the area winds will be less than 10 mph.

&&

Coastal Hazard Potential Days 3 and 4...Models are not in complete
agreement, but a 975ish low moving across the Arctic/Chukchi Sea
could present some issues along the northwest Arctic coast Friday
night with high surf, but right now it looks like the strongest
winds will remain offshore.

&&

.FIRE WEATHER...Will maintain the Red Flags for the Upper Yukon
Flats, Upper Porcupine River Valley, and Upper Yukon River Valley
through the evening hours. In the interior conditions will be
relatively static with not much change in temperatures, and only a
slight drying trend as dew point values fall a couple degrees over
the next couple days. In the western zones, temperatures slightly
warmer or flat with a similar drying trend to the interior.
Thunderstorm activity will be limited, but expect isolated
thunderstorms south and east of the White Mountains this evening
and Tuesday evening and west of Galena to the Brooks Range this
evening. Winds kicking up a bit this evening in the upper Yukon
Valley and Flats, but diminishing tonight and remaining generally
light Tuesday and Wednesday.

&&

.HYDROLOGY...No current concern. Some areas in the Alaska Range
will see around an inch of rain over the next couple days, but do
not anticipate any issues at this time.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Red Flag Warning for AKZ220-AKZ224.

Small Craft Advisory for PKZ210-PKZ220.

Brisk Wind Advisory for PKZ240-PKZ245.

&&

SDB JUN 17

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 19, 4:37 PM AKDTSevere Thunderstorm WarningAFG23 min
Jun 20, 2:13 PM AKDTSmall Craft AdvisoryAFG62 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.