Alert archive / Alaska / Red Flag Warnings in 2018

Red Flag Warning 1, NWS Anchorage, AK

July 22, 2018

NWS Anchorage, AK issued this red flag warning at Jul 22, 2018, 6:17 AM AKDT. It took effect at Jul 22, 2018, 3:00 PM AKDT. It was in force for 53 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 22, 2018, 6:17 AM AKDT (14:17 UTC)
In effect from
Jul 22, 2018, 3:00 PM AKDT
Expired
Jul 24, 2018, 8:00 PM AKDT
In force
53 hr
Issued by
NWS Anchorage, AK

The text

As transmitted.

613 
WWAK61 PAFC 221417
RFWAER

URGENT - FIRE WEATHER MESSAGE
National Weather Service Anchorage AK
617 AM AKDT Sun Jul 22 2018

AKZ141-230400-
/O.NEW.PAFC.FW.W.0001.180722T2300Z-180723T0400Z/
617 AM AKDT Sun Jul 22 2018

...RED FLAG WARNING IN EFFECT FROM 3 PM THIS AFTERNOON TO 8 PM
AKDT THIS EVENING FOR HOT DRY AND WINDY CONDITIONS FOR THE 
COPPER RIVER BASIN...

The National Weather Service in Anchorage has issued a Red Flag
Warning FOR HOT DRY AND WINDY CONDITIONS, which is in effect from
3 PM this afternoon to 8 PM AKDT this evening.

* Winds...South 15 mph with gusts to 25 mph.

* Relative Humidity...As low as 22 percent.

* Temperatures...In the lower to mid 80s.

* Timing...South winds will develop in the early afternoon and
  become gusty in the mid to late afternoon, strongest along and
  near the Copper River. This will coincide with the warmest and
  driest time of day. Winds will linger into the early evening,
  though temperatures will begin to slowly fall.  

* Impacts...Rapid ignition, growth and spread of fires will be 
  possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are imminent or occurring now, or will shortly. It is directed
toward fire agencies, and through them to the public.

&&

$$
6 follow-up statements
274 
WWAK61 PAFC 222313
RFWAER

URGENT - FIRE WEATHER MESSAGE
National Weather Service Anchorage AK
313 PM AKDT Sun Jul 22 2018

AKZ141-231515-
/O.EXT.PAFC.FW.W.0001.000000T0000Z-180724T0300Z/
313 PM AKDT Sun Jul 22 2018

...RED FLAG WARNING NOW IN EFFECT UNTIL 7 PM AKDT MONDAY FOR HOT
DRY AND WINDY CONDITIONS FOR THE COPPER RIVER BASIN...

* Winds...South 15 mph with gusts to 25 mph. Strongest in the
  afternoon and early evening. 

* Relative Humidity...As low as 22 percent.

* Temperatures...In the lower to mid 80s.

* Timing...South winds will be strongest along and near the Copper
  River. The temperatures will drop this evening and humidity will
  increase. Temperatures will rise above 75 tomorrow afternoon and
  the humidity will drop below 25 percent. This will be coincident
  to the south wind of 15 gusting to 25 mph and result in the red
  flag conditions. 

* Impacts...Rapid ignition, growth and spread of fires will be 
  possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are imminent or occurring now, or will shortly. It is directed
toward fire agencies, and through them to the public.

&&

$$
981 
WWAK61 PAFC 231515
RFWAER

URGENT - FIRE WEATHER MESSAGE
National Weather Service Anchorage AK
715 AM AKDT Mon Jul 23 2018

AKZ141-240400-
/O.EXT.PAFC.FW.W.0001.000000T0000Z-180724T0400Z/
715 AM AKDT Mon Jul 23 2018

...RED FLAG WARNING NOW IN EFFECT UNTIL 8 PM AKDT THIS EVENING
FOR HOT DRY AND WINDY CONDITIONS FOR THE COPPER RIVER BASIN...

* Winds...South to southeast 15 mph with gusts to 25 mph.

* Relative Humidity...As low as 18 percent.

* Temperatures...In the upper 70s to mid 80s.

* Timing...Red flag conditions will develop again today during the
  late afternoon through early evening hours. Humidities will then
  gradually recover as temperatures cool and winds die down
  through the evening and overnight hours.  

* Impacts...Rapid ignition, growth and spread of fires will be
  possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are imminent or occurring now, or will shortly. It is directed
toward fire agencies, and through them to the public.

&&

$$
012 
WWAK61 PAFC 232301
RFWAER

URGENT - FIRE WEATHER MESSAGE
National Weather Service Anchorage AK
301 PM AKDT Mon Jul 23 2018

AKZ141-241600-
/O.EXT.PAFC.FW.W.0001.000000T0000Z-180725T0400Z/
301 PM AKDT Mon Jul 23 2018

...RED FLAG WARNING NOW IN EFFECT UNTIL 8 PM AKDT TUESDAY FOR HOT
DRY AND WINDY CONDITIONS FOR THE COPPER RIVER BASIN...

* Winds...South to southeast 15 mph with gusts to 25 mph.

* Relative Humidity...As low as 18 percent.

* Temperatures...In the upper 70s to mid 80s.

* Timing...Red flag conditions will abate by 8 PM this evening
  then develop again Tuesday during the late afternoon through 
  early evening hours. Humidities will then gradually recover as 
  temperatures cool and winds die down through the evening and 
  overnight hours.

* Impacts...Rapid ignition, growth and spread of fires will be 
  possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are imminent or occurring now, or will shortly. It is directed
toward fire agencies, and through them to the public.

&&

$$
866 
WWAK61 PAFC 241439
RFWAER

URGENT - FIRE WEATHER MESSAGE
National Weather Service Anchorage AK
639 AM AKDT Tue Jul 24 2018

AKZ141-250400-
/O.CON.PAFC.FW.W.0001.000000T0000Z-180725T0400Z/
639 AM AKDT Tue Jul 24 2018

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM AKDT THIS
EVENING FOR HOT DRY AND WINDY CONDITIONS FOR THE COPPER RIVER
BASIN...

* Winds...South to southeast 15 mph with gusts to 25 mph.

* Relative Humidity...As low as 20 percent.

* Temperatures...In the upper 70s to lower 80s.

* Timing...Red flag conditions will develop this afternoon through
  early evening hours. Humidities will then gradually recover as
  temperatures cool and winds diminish through the evening and 
  overnight hours.

* Impacts...Rapid ignition, growth and spread of fires will be 
  possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are imminent or occurring now, or will shortly. It is directed
toward fire agencies, and through them to the public.

&&

$$
064 
WWAK61 PAFC 242318
RFWAER

URGENT - FIRE WEATHER MESSAGE
National Weather Service Anchorage AK
318 PM AKDT Tue Jul 24 2018

AKZ141-250400-
/O.CON.PAFC.FW.W.0001.000000T0000Z-180725T0400Z/
318 PM AKDT Tue Jul 24 2018

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM AKDT THIS
EVENING FOR HOT DRY AND WINDY CONDITIONS FOR THE COPPER RIVER
BASIN...

* Winds...South to southeast 15 mph with gusts to 25 mph.

* Relative Humidity...As low as 20 percent.

* Temperatures...In the upper 70s to lower 80s.

* Timing...Red flag conditions will develop this afternoon 
  through early evening hours. Humidities will then gradually 
  recover as temperatures cool and winds diminish through the 
  evening and overnight hours.

* Impacts...Rapid ignition, growth and spread of fires will be 
  possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A red flag warning means that critical fire weather conditions
are imminent or occurring now, or will shortly. It is directed
toward fire agencies, and through them to the public.

&&

$$
340 
WWAK61 PAFC 250401
RFWAER

URGENT - FIRE WEATHER MESSAGE
National Weather Service Anchorage AK
801 PM AKDT Tue Jul 24 2018

AKZ141-250515-
/O.EXP.PAFC.FW.W.0001.000000T0000Z-180725T0400Z/
801 PM AKDT Tue Jul 24 2018

...RED FLAG WARNING HAS EXPIRED...

The red flag warning has expired.

$$

What forecasters said that day

The local office's own words before this red flag 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 red flag warning went out at Jul 22, 4:52 AM AKDT, 1 hour 25 minutes earlier.

Area forecast discussion, Jul 22, 4:52 AM AKDT, 1 hour 25 minutes before
Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
452 AM AKDT Sun Jul 22 2018

.ANALYSIS AND UPPER LEVELS...
The longwave pattern features a high amplitude ridge centered over
the eastern portion of the Gulf Of Alaska with the ridge axis
extending into the Yukon Territory. There is a negatively tilted
shortwave southwest of Kodiak associated with a frontal boundary
at the surface. Currently, there are some showers detected on the
radar at King Salmon. Over the Bering, the latest ASCAT/advanced
scatterometer pass has detected the remnants of a decaying low
over the Central Bering. There is already another new low just
east of Kamchatka

&&

.MODEL DISCUSSION...
Good run to run continuity with the models. Models remain in good
synoptic agreement through 72 hrs. The primary forecast challenge
at hand is again the progression of the marine layer over Cook
Inlet. There are a number of fine scale factors that influence the
development and the ebbing/flowing of the marine layer, and none
of the models have been resolving it particularly well. Expect the
marine layer kerfuffle for one more day/this morning. And then
the low that is southwest of Kodiak will move into the region and
mix the atmosphere, putting the kibosh on the marine layer
potential near Anchorage.

&&

.AVIATION...
There is a marine layer that is detectable via satellite imagery
over Cook Inlet. The current thinking is that the marine layer
will stay away from PANC. The progression of the stratus is
actively being monitored and updates/amendments will be made if
needed.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
After some fog and low stratus in a few areas this morning,
most of Southcentral can expect another warm and sunny day.
The upper level ridge responsible for this weather will continue
to shift slowly eastward, allowing for a high amplitude negatively
tilted trough to swing into the Gulf from the Bering Sea/Aleutians
today. A series of short-waves and surface fronts will then lift
northward across the western Gulf through Tuesday, providing
a cool rainy period for Kodiak Island and a trend toward cooler
ands cloudier conditions across all of Southcentral.

With deep southeast flow for much of the period, the northward
progression of these features into Southcentral will be slow.
The bulk of rain which spreads northward to Southcentral will
be confined to the southern to eastern Kenai Peninsula, with
downslope flow keeping most of the western Kenai Peninsula dry.
The surface high currently over the Gulf will shift to the north
Gulf coast as the surface fronts swing into the western Gulf,
leading to development of the typical gap winds on Monday and
Tuesday.

&&

.FIRE WEATHER...
The surface high over the Gulf will begin to shift north and
eastward today, with conditions becoming more favorable for
southerly winds along and near the Copper River. Winds won't be
real strong, but based on instability off the surface, think they
will reach critical thresholds. Thus, With temperatures and
humidity values expected to be similar to yesterday, have decided
to go ahead and issue a Red Flag Warning. The winds will be even
stronger on Monday, but there will be a slight cooling trend as
the ridge slides eastward. Still, there will not be much in the
way of low level moisture, so the winds could mix down drier air
from aloft and criteria could be met again. Will make a decision
by this afternoon on whether to extend the warning to Monday
afternoon/evening.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (through Wednesday morning)...
The mainland will be under the influence of a Bering Sea upper
trough through the short term forecast. A separate short-wave
trough will merge into the Bering system today as it comes over
the mainland, acting to increase easterly winds, mainly through
the gaps of the Aleutian Range. The disturbance will bring
steadier rain to the Wood River Mountains, and eastward toward
Dillingham. The lee-side of the Aleutians will remain downslope
dried, but a stray sprinkle or shower can not be ruled out. Rain
will be more showery for the Kuskokwim Delta, again with downslope
conditions closer to the mountains. A stronger disturbance rotates
through the trough on Monday, which will spread rain over the
Bristol Bay area as well as the Kuskokwim Valley while the
Kuskokwim Delta remains drier. The upper trough to the west
lingers through Wednesday, keeping cloudy and showery conditions
in the forecast. Temperatures will be near normal for most
locations. Winds will be generally out of the east at light to
moderate strength.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (through Wednesday
morning)... A low pressure system and front will keep the eastern
Bering Sea active with rain and rain showers for the next few
days. Winds will remain generally light across the area. For the
western Bering Sea/Aleutians, a good moisture stream and jet is
parked over the area, which will bring some decent rain from
Shemya through Atka today. Behind this front, a ridge will build
overhead, promoting a long period of low stratus and fog beginning
tonight.

&&

.LONG TERM FORECAST (Days 3 through 7: Tuesday through Saturday)...

Tuesday will feature a wave of moisture moving northwestward
around the upper level low centered near Sand Point moving into
mainland Southern Alaska. The heaviest rains will be along the
coast of the Kenai Peninsula, primarily staying south and west of
Prince William Sound until later in the day, and Kodiak. With
ongoing downsloping continuing through Turnagain Arm and the Knik
River Valley, most communities from Anchorage north should remain
dry until the evening hours. Tuesday night into Wednesday morning
will feature better chances for the precipitation to get into
Anchorage and the Matanuska Valley as a reinforcing wave of
moisture in the upper levels moves into Southcentral. Scattered
showers will be prevalent Tuesday and Wednesday across Southwest
Alaska, with the most favored locations for precipitation being
the east facing mountains. Precipitation chances will diminish the
farther north and west one goes as well. From midday onwards on
Wednesday, Anchorage and the Matanuska Valley should be drier
behind the wave as the downsloping winds continue.

Another round of rain moves into Southcentral, including Anchorage
and the Matanuska Valley on Wednesday Night. This wave moves north
into the Susitna Valley during the day Thursday, with scattered
showers continuing for much of the rest of the area. The passage
of the front will allow Kodiak to dry out relatively speaking as
the rain becomes much more intermittent there on Thursday.
Meanwhile that moisture will also spread westward into Southwest
Alaska during the day Thursday. Outside of some isolated showers,
Friday should be a generally drier day, though unfortunately still
mainly cloudy for most areas, as the upper level low and its
associated moisture retreats south and westward.

The models diverge greatly late Friday into Saturday area-wide,
due to different handling of a strong low and its associated
fronts moving into the western Bering on Thursday then pushing
eastward through the rest of the Bering and potentially Southwest
Alaska by Saturday. The models are generally agreeing on the
ridging over the Panhandle and western Canada slowly building back
to the west into the Copper River Basin late in the week. That
should help keep that area warmer and sunnier than the rest of
Southern Alaska this week with the exception of the front and
associated rain moving through there as well on Thursday. Breezy
conditions and relatively warmer temperatures may be cause for the
continuation of fire weather concerns Tuesday in the Copper River
Basin.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

SYNOPSIS AND MODEL DISCUSSION...PJS
SOUTHCENTRAL ALASKA...SEB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MTL
LONG TERM...JW

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 3:52 AM AKDTSmall Craft AdvisoryAFC35 hr
Jul 22, 3:54 AM AKDTSmall Craft AdvisoryAFC48 hr
Jul 22, 3:15 PM AKDTSmall Craft AdvisoryAFC36 hr
Jul 22, 3:24 PM AKDTSmall Craft AdvisoryAFC12 hr

Nearby

Red Flag Warnings in Alaska, 2018Every red flag warning in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text.