Slow Clearing

2pm AST Infrared NOAA-19 Polar Orbiter image shows only limited clearing over the Interior. The 3pm AST ROAB should less than a degree of cooling in the boundary layer from the morning sounding.

Snow is nice

This morning's Feng Yun Polar Orbiter shows a fairly disorganized cloud pattern over Interior Alaska.

Snow here on Keystone Ridge totals over 3 inches of fluffy powder now in the past two days; less in town. We'll take it, as it covers up the ice from the rain and provides a based for traction. The ice will return, though it may be March. Like the Fruit of the Month club, freezing rain is the gift that keeps on giving.

The airmass has cooled to smartly but low level temperatures are forecast to change little until Saturday, when it cools a bit more. At the surface, the clouds and snow will keep temperatures in valleys above normal. Once it clears though, the 20 and 30 below temperatures will quickly materialize.

Rainfall Amounts

From a very day shift…some of these totals include liquid amounts after the rain was mixing with snow.

PUBLIC INFORMATION STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE FAIRBANKS AK
430 PM AKST WED NOV 24 2010

...SECOND HIGHEST WINTER RAINFALL STORM TOTAL ON RECORD IN FAIRBANKS...

AS OF 10AM WEDNESDAY A TOTAL OF 0.94 INCHES OF RAIN AND FREEZING
RAIN HAD FALLEN AT THE FAIRBANKS INTERNATIONAL AIRPORT SINCE
MONDAY. THIS IS THE SECOND GREATEST WINTER RAINFALL OF RECORD FOR
FAIRBANKS. THE GREATEST WINTER RAINFALL OF RECORD IN FAIRBANKS
OCCURRED ON JANUARY 20TH 1937 WHEN 0.99 INCHES OF RAIN WAS
REPORTED. THESE TWO EVENTS ARE THE ONLY OCCURRENCES OF MORE THAN
HALF AN INCH OF RAIN DURING THE PERIOD FROM NOVEMBER THROUGH
MARCH.

COOLER AIR IS SLOWLY MOVING INTO THE REGION FROM THE WEST AND WILL
CONTINUE TO DO SO THROUGH THE EARLY PART OF THE WEEKEND.

BELOW ARE SOME RAINFALL TOTALS FROM MONDAY THE BEGINNING OF THE
EVENT THROUGH 10AM WEDNESDAY:

MCGRATH.................................2.10 INCHES
LAKE MINCHUMINA...............1.63 INCHES
NENANA...................................1.52 INCHES
KEYSTONE RIDGE (MURPHY DOME)............1.37 INCHES
ESTER........................................1.16 INCHES
UAF WEST RIDGE....................0.99 INCHES
TANANA...................................0.99 INCHES
FAIRBANKS AIRPORT.............0.94 INCHES
EAST FT WAINWRIGHT.............0.92 INCHES
GOLDSTREAM CREEK.............0.90 INCHES
EIELSON AFB...........................0.63 INCHES

Portrait of Rain

Here's the NCEP reanalysis of 500 mb heights for 10am AST on Monday. It's a classic pattern for heavy precip in Interior Alaska: big ridge in the Gulf of Alaska and southwest flow that goes around the Alaska Range.

Rain Records again

At Fairbanks International Airport:

Total rainfall: 0.94 inches between 5am Monday and 4am Wednesday. This is the greatest November rainfall of record and the second greatest winter rainfall, just short of the 0.99 inches on January 20, 1937. The maximum 24 hour precipitation was 0.68 inches between 6am Monday and 6am Tuesday, This is well short of the November 24 hour record precip of 0.94 inches in 1935 and has been exceeded several other times as well.

Rain fell continuously from 517am Monday until 808pm Tuesday, and then again from 1009pm Tuesday until 327am Wednesday. Measurable rain fell for 31 consecutive hours; every hour between 6am Monday and 1pm Tuesday. More research will be needed to absolutely confirm this, but is most likely the longest period of record of straight rain (not mixed rain and snow) during the winter in Fairbanks.

Rainfall Totals

Some rainfall totals since Sunday night/Monday morning

Updated at Tuesday 3pm AST

Gilmore Creek in Fox: 0.82 inches (3pm)
Keystone Ridge 1.02 inches (noon)
Ester 0.87 inches (9am)
UAF West Ridge 0.73 inches (9am)
Goldstream Creek 0.64 inches (7am)

Tanana: 0.76 inches (noon)
Fairbanks 0.79 inches 3pm)
Nenana 1.19 inches (3pm)
McGrath 1.63 inches (22-23rd)
Minchumina 1.23 inches (9am)

Rain Records

FYI…

The following records have been set at the Fairbanks airport:

Through 10am AST total rainfall: 0.73 inches; second greatest winter rainfall of record (0.99 inches Jan 20, 1937) and these two events are the only occurrences of more than half an inch of rain November through March (observations since Sept 1904)

24 hour rainfall 5am Monday-5am Tuesday: 0.66 inches; this is the greatest 24 hour November rainfall of record

Precip total for Nov 22 of 0.50 inches (not 0.54 inches) is a record for the date. Previous record 0.21 inches in 1925.

The November maximum 24 hour precip record was not broken; still 0.84 inches set Nov 27-28, 1970.

Rick

Rainfall so far

Some event total rain amounts

Updated through 10pm AST:

ASOS
Delta Junction: 0.16"
Fairbanks Airport: 0.45"
Tanana: 0.46"
McGrath: 1.12" (24 hour total)
Nenana: 0.88"

COOP
Fairbanks area…
Keystone Ridge 0.60" (6pm)
East Farmers Loop 0.43" (10pm)
Golstream Valley Bottom 0.41 (10pm)
Aurora 0.37" (9pm)
Fairbanks CRN at Gilmore Creek 0.35"

Elsewhere…
Kobe Hill (near Clear) 0.51" (5pm)
Clear 0.60" (8pm)
Galena 0.64" (6pm)
Whitestone Farms (near Big Delta) 0.30"
Tok 0.00" (8pm)

Synoptic Situation

As is typical with most big precip events in the winter in Fairbanks, this is not tied to a storm. Rather, precipitation is tied to deep moisture rotating around a North Pacific ridge.

Fairbanks Closed

As of 3pm AST 0.29" of rain has fallen at the Airport, the greatest single day winter rain in Fairbanks since January 20, 1963 and the greatest November rain since Nov 24, 1936.
Here at Keystone Ridge 0.39" so far. The Fairbanks Daily News-Miner details the closing of Fairbanks

Record wamth in Barrow

By 310am Sunday Barrow has already set a new record high for November 21st: 32F. The old record of 31F was set in 1926.

Warm-up underway

The Saturday afternoon sounding from Fairbanks shows warm air pouring in aloft: in the lowest 10,000' of the atmosphere. the temperature only varies from -6 to -1C. Image from U. of Wy.

Winter Rains in Fairbanks

With rain on the way for Monday, here is list of the major winter rain events in Fairbanks:

Feb 8-10, 2003: 0.29 inches of rain with trace of snow. Schools closed for two days due to very icy roads.

Dec 24, 1970: 0.22 inches precip mostly rain; 0.6 inches snow

Jan 20, 1963: 0.44 inches rain, trace snow

Jan 20, 1937: 0.99 inches of rain, no snow and temps in the mid 30s

Jan 10, 1937: 0.20 inches then changed to snow

Nov 24, 1936: 0.42 inches rain, mixed with snow for a while in the evening.

Feb 6-7, 1923: 0.30 inches of precip, Trace snow, temps in the 30s

Mar 6-7, 1921: 0.34 inches rain, trace snow

These are all of the events that I know of between November 15th and March 31st that produced two-tenths of an inch or more of rain.

Through November 18th, average temperature departure for the month thus far:
Barrow: +8.7F
Fairbanks: +7.1F
Anchorage: +5.5F
Valdez: +4.9F with a whooping 2.3" of snow for the month!
Kotzebue: +2.1F
McGrath: +1.9F
Nome: -1.3F
Bethel:-2.4F

So for Mainland Alaska, southwest cool, elsewhere mild. A classic El Niño pattern. Except wait, it's a moderate La Niña! Note that Barrow is reflecting the decreased Arctic sea-ice coverage; historically Barrow temps don't show much correlation with ENSO.

The ever changing Fairbanks rain threat

Numerical guidance is coming into better agreement (as usually happens) on the rain threat for Sunday afternoon/night. There is general consensus now that a cold front will move across the Interior as a trough aloft breaks through the ridge. In this scenario, precipitation would start as rain, changing to snow before ending, though the period of snow, especially in valleys, would not be long. The 18Z GFS is very aggressive with precip amounts. In any event, odds are that Monday morning is going to be a serious mess.

Thurday Snowfall

Snowfalls Thursday around the Fairbanks were pretty tame, though we'll take what we can get:

Mile 42 Steese: 4.0"
Keystone Ridge: 2.3"
Goldstream Valley Bottom: 2.0"
East Fort Wainwright: 2.0"
Woodsmoke (off Badger Road) 2.0"
East Farmers Loop 1.7"
UAF West Ridge: 1.6"
North Pole: 1.6"
Fairbanks Airport: 0.8"

The big winner for snow was Eagle: 9.0" on 0.19" liquid. If this is correct, this 47-1 ratio is in the extreme category for "fluffy snow"

Models continue to vacillate about rain Sunday afternoon through Monday, though no more talk of half an inch! This mornings GFS has rain changing to snow starting Sunday afternoon, with a couple tenths of an inch precip. So we'll see.

Update on Rain for Fairbanks

The morning run of the GFS has backed WAY off on rain for Fairbanks-land late in the weekend, instead opting for a climatologically much more likely scenario of developing a deeper low in the Bering Sea and a run of the mill Chinook over the Interior. Through Wednesday, in spite of two days with slightly below normal temperatures, the November mean temperature was 7 degrees above normal. This pattern will only boast that; 2002 it aint, but it's going to wind up a very mild autumn.

Rain for Fairbanks? Oh No!

Models are increasingly pointing at a major rain event for the central Interior Sunday PM into Monday. Here is the GFS forecast from 00Z Thu valid 3am Monday: 0C line at 850mb is north of Fairbanks, and the 1000-850mb thickness is 1319 gpm, with more than half inch of precip forecast between Sunday evening and noon Monday. That much rain between November and March has occurred at least once (January 1936), but maybe only once, in the 105 years of weather observations in Fairbanks. This could be bad.

North Slope Blizzard

Here is the 10am AST Wednesday Northern Alaska Weather Depiction chart from the Alaska Aviation Weather Unit. Note the 30 to 40 knot sustained winds on the North Slope from Prudhoe Bay westward . Unusually for the North Slope, there is a lot of new snow falling in the strong warm advection over the top of the ridge, though the 40-1 raito snow used at Barrow at 18z is unrealistic.

More on the record high pressure

Here is the Environment Canada analysis for 3am Wednesday. The highest reliable MSLP I've found so far is 1053.0mb at Delta Junction. The 1055.9mb at Galena (an FAA AWIS) looks much too high compared to Kaltag (an ASOS) and Ruby (an AWIS).

The record high pressure over the Interior is helping to fuel a major league blizzard on the North Slope.

A New Record

At 653pm AST Tuesday, the mean sea-level pressure at Fairbanks International was 1049.8mb/31.00 inches. A new record for November. Destined to go higher too.

Update: Mean Sea-Level Pressure maxed out at Fairbanks at 1051.4mb/31.05" at 1253am AST Wednesday. The previous record was 1047.8mb/30.94" set on Nov 26, 1966.

Colder with the Big High

Fairbanks is poised to set a new November record high pressure later Tuesday or early Wednesday, with the high extending across much of mainland Alaska, as seen in this 9am analysis from Environment Canada.

Temperatures fell smartly in the areas with clear skies to the lowest levels of the season many places. The lowest temperatures were along the south side of the Brooks Rage: 39 below at the Coldfoot Snotel, 35 below at Chandalar Lake, 31 below at Bettles. Tonight will be the coldest night on the season so far in Fairbanks-land.

More Snow

Snow Sunday night and Monday was as much or more than fell Saturday in most areas, though based on time of observations the amounts are getting harder to sort out. At any rate, here's whats in thus far:

East Fort Wainwright: 2.5"
UAF West Ridge: 1.8"
Keystone Ridge: 1.7"
Goldstream Creek: 1.6"

Healy reported 8" of snow on 0.36" liquid' not implausible but twice as much as at Denali Park HQ.

Busy weather coming up later this week: lloks to be a major west wind storm for the Chukchi Sea coast. It's early in the year for Ivu problems, but this is a good set-up. Stayed tuned.

New Snow

A general 1 to 3 inches around the Fairbanks area Saturday, though most reports were closer to one inch. Two Rivers and Chena Hot Springs area might be at the upper end too as winds aloft were southwest.

Mile 43 Steese: 3.0"
Keystone Ridge: 1.6"
North Pole" 1.2"
UAF West Ridge: 1.1"
East Farmers Loop: 1.0"
Fairbanks Airport: 0.9"

Meanwhile, a high temp of 36F at Eagle Saturday.

Big High Coming

I usually don't have much to say about models here, but what the heck. For some days most of the models have been forecasting all-time record high pressure over the central Interior. Recent runs have backed off some, but are still close. Here is Saturday morning's GFS valid 3am Tue. That's about a 1048mb high over the Interior. Inversions should be spectacular by mid-week.

Consistent Warmth

Here's a plot of the 850mb temperature at Fairbanks for the past month. This is most notable for the lack of extremes. Normals decline from -5C on Oct 10 to -10C today.

Around the (Sub) Arctic

Low temperatures for Wednesday (through mid-afternoon Alaska Time)

Russia: -44F at Oymyakon (eastern Siberia)
Alaska: -15F at Selawik
Canada, Northwest Territories: -19F at Thomsen River (northern Banks Island)
Canada, Nunavut: -34F at Eureka (central Ellesmere Island)
Greenland: -48F at Summit (near the highest point on the ice cap)
Norway: -18F at Karasjok
Sweden: -23F at Nikkaluokta
Finland -10F at Kevo

Snow Depths around the Interior

It;s not very often that Galena gets top spot, but here is a sampling of snow depths in the Interior as of Tuesday morning:

Galena: 11"
McGrath 10"
Bettles: 7"
Chandalar Lake: 7"
Northway: 6"
Fairbanks: 5"
Tok: 5"
Denali Park HQ: 4"
Dry Creek: 2"
Chicken: 1"

SNOTEL sites:
Coldfoot: 5"
Eagle Summit: 5"
Fort Yukon 5"

October Mean 500 mb Heights

The mean October 500 mb height field from the NCEP reanalysis, showing the persistent low in the eastern Bering Sea, with south flow over much of mainland Alaska.

Inversion Changes

Significant structural changes in the Fairbanks boundary layer temperature profile Monday morning compared to Sunday morning. Sunday morning there a little more than 400 meters of cold air below the elevated inversion top. Monday morning, the lowest kilometer showed a typical radiation induced surface inversion.

Winter comes to Oymyakon

Low temperature this morning (Monday morning local time) of -42F at Oymyakon in eastern Siberia. This isn't the first day this season with a 40 below temperature; it was 43 below on Nov 2nd. Except for the Summit weather station on the Greenland Ice Cap, Oymyakon is the only regular weather station in the northern hemisphere to hit 40 below so far this early winter.

Freeze-up continues at Barrow

Early Sunday afternoon webcam shot from Barrow; still a little open water visible offshore. The National Snow and Ice Data Center Arctic Sea Ice analysis for October showed that inspite of a large seasonal increase in ice coverage, total sea ice extent in the Arctic remains very low for this time of year.

Balmy Bliss

It hasn't really been continuously warmer than normal for the last three months in Fairbanks, it just feels like it. Note temperatures are in degrees C; image from the Climate Prediction Center. With the lack of precipitation, radiational inversions are helping keep valley based temperatures closer to normal than the overall airmass, i.e. hill temperatures are running even more consistently and farther above normal than this plot would suggest.

Inversion

Clear skies, a ridge aloft and the calendar says Novmeber: the outcome is predictable. Lows Saturday morning of 3 below at Goldstream Creek and 1 below at East Fork Wainwright. Meanwhile, overnight temperatures rising overnight in the hills. High at 7am Saturday at Keystone Ridge of 32F, while Cleary Summit's been up to 31F.

November Sunshine

Sunny late Friday morning at Nenana. Note the skimpy snow cover.

What Declining Sea Ice Actually Means on the Ground

The lack of sea ice in October in recent years at Barrow is having a major impact on the climate. Here is a plot of the mean October temperature in Barrow since 1920. Two things to note. First, the running mean is now higher than it has been in the past 85 years. Second, there is very little variation: the bottom brown line is the 5 year running standard deviation, which has collapsed. This is completely attributable to the moderating influence of the water.

Sea Ice Arriving

Webcam shot from Barrow this morning; sea ice finally arriving/forming. NE winds with temps around +5F.

October Snowfall

Here's an updated plot of total October snowfall in Fairbanks, with 7.7" for 2010. The red line is the ten year running mean. While the running mean is now at the lowest value since 1969, it is right in line with the mean before that. Clearly, 1970 through the mid-90s were snowier in October than before or after. The new 1981-2010 mean snowfall is 11.0", down 1.3" from the 1971-2000 normal.

Deeper Yet

From 4pm Saturday, the Ocean Prediction Center analyzed a 939mb center. Whoa!

Another Day, Another storm

Another deep storm, this one in the southwestern Gulf of Alaska. The Ocean Prediction Center analysis had it as a 944 mb center at 10am ADT ; the 6pm ADT GOES-11 IR image shows a very tight circulation center south of Cold Bay. This storm will move into the northeast Gulf of Alaska in a couple days, slinging more warm air over the central and eastern Interior. No winter anytime soon.

Fluff Powder

Most of the Fairbanks area received 2 to 3 inches of snow on Friday. One exception was evidently up the Steese Highway, where the observer at 42 Mile (this station is sometimes referred to as Chatanika for simplicities sake, though it's actually some ways beyond Chatanika). Reported 3.0" of snow on Friday morning and another 4.2" Saturday morning, for a total of 7.2" snow on just 0.24" liquid. This is less than one tenth inch more than liquid than other sites, but 3 times or more snow. Assuming that the measurements are correct, and they look plausible, this would be a case of temperatures in-cloud right at the appropriate levels for dendritic flakes coupled with upslope in the gentle westerly flow Friday.

Halloween Snow

The fractured occlusion from the old Bering Sea storm moved through late Thursday afternoon, with several hours of clearing behind it, but snow has developed now in the weak cold advection.
As of 9am ADT Friday, about an inch of snow in the Fairbanks area, but 3.0" at Mile 42 Steese, beyond Chatanika, and 2 to 3 inches in the Healy-Denali NP area.

Still no Sea-Ice at Barrow

1130am Thursday image from the Barrow Sea-Ice cam. As you can plainly see, there isn't any yet. Temperatures thus far this month are averaging 7.6 degrees above normal in Barrow, and this is why.

Bering Storm: the end

A Polar Orbiter mosaic image from 640am Thursday. The remains of the deep western Bering Sea storm are now centered just west of Saint Lawrence Island, with the ragged occlusion strung out over mainland Alaska. The storm did produce some winds and snow along the West Coast, but nothing unusual for this time of year. There is some snow falling over the western Interior today and will probably bring a little to the central Interior tonight and Friday. However, the overall longwave pattern shows no signs of change,with low pressure in the eastern Bering Sea and a ridge over BC and YT. Nearly all of northern Alaska is going to finish up with above normal temperatures for October, and that looks to continue into early November too. The central and eastern Interior will not be able to get much snow out of this pattern either.

Deep Bering Sea Storm

While the lower 48 set a new all-time low sea-level pressure record Tuesday afternoon (955 mb at Bigfoot, MN), the first mega-storm of the season bombed out in the far western Bering Sea. The analysis from the Ocean Prediction Center at NCEP (right) had a minimum pressure of 948 mb at 4pm ADT Tuesday. Environment Canada analyzed a minimum pressure of 954 mb at 10pm ADT. Unlike the upper Midwest, there was no observation especially close to the center. The closest Russian site, Nikol'Skoe (WMO station 32618), offshore of the Kamchatka Peninsula, did report a sea-level pressure of 954.2 mb with 25kt sustain west wind at 10am ADT Tuesday. This certainly supports a central pressure into the upper 940s.

The strung-out occlusion has ramped up the winds in western Alaska, with gusts (through 10am ADT) to 51 mph at Scammon Bay and 49 mph at Gambell. It's too warm though for the first blizzard of the season, with temperatures already above freezing.

Day of the storms

The 10am ADT surface analysis from Environment Canada shows two mega-storms. The 953 mb low in the southwest Bering and the record deep 957 mb low in the upper Midwest.

Record low pressure

The deepest storm of record is ongoing in the upper mid-west today, with both Minnesota and Wisconsin setting all-time record low pressures. Which of course brings up the question, what's the lowest recorded (sea-level) pressure in Alaska? Turns out that yesterday was the anniversary of the accepted answer, 925 mb (27.31 inches) at Dutch Harbor on October 25, 1977. The NCEP reanalysis though has MSL pressures more than 10 mb higher. No doubt this requires investigation.

Heads up

The innocuous 991 mb low in the southern Sea of Okhotsk at 4am ADT Monday is destined to be a major storm in the Bering Sea in two days. Alas, snow here seems unlikely from this storm. Analysis from Environment Canada

No Snow

The slow start to the snow season is nowhere more extreme than in the central Alaska Range. Both Healy and Denali Park HQ have no snow cover at all, which is unusual enough, but that could be attributed to the persistant southeast flow aloft. Not so near the divide; this FAA webcam image from Monday morning, from the old Summit airstrip south of Cantwell in Broad Pass, shows not only no snow at pass level, but almost nothing even up the mountains.

Snow cover getting Patchy

Snow cover is getting patchy in exposed areas in town. Still solid if thin in the shade and on northern exposures. Photo from Alaska Climate Research Center, 608pm Saturday looking south from UAF West Ridge.

Inversions and Diurnal Ranges

Inversions are a source of constant wonder.

For Friday October 22:

Goldstream Valley Bottom: High 42F, low -1F, for a diurnal range of 43 degrees.

Eight miles away and the same drainage,

Keystone Ridge: High 36F, low 29F, for a diurnal range of 7 degrees.

Amazing

Thusday Morning Inversion

The inversion has grown this morning, with temperatures in the cold valley bottoms not much above zero and the hills not much below freezing.
Yesterday the inversion broke, with temperatures by late afternoon basically isothermal in the lowest few thousand feet. The graphic shows the temperature trace from the Fairbanks RAOB at 3am

At 9am the variation looked like this:

Salcha River RAWS: 0F
Chena Hot Springs: +3F
Woodsmoke (North Pole area): +4F
Goldstream Creek: +5F
Fairbanks Airport : +8F

Meanwhile, on the hills:

Cleary Summit: 32F
McGrath Road: 32F
Stuart Creek RAWS: 32F
Keystone Ridge: 31F

Bigger Inversions

A good set-up this morning for big inversions: warm air aloft, clear skies, snow cover, and what do ya know, at 8am: Goldstream Creek +7F, Keystone Ridge +33F. The inversion is quite shallow of course; the McGrath Road CWOP at 1170' MSL has been up to 35F so far this morning. It will be interesting to see if the inversion holds though the day.

Non-radiational Inversion

It's getting to be that time of the year when inversions are not just for nighttime any more. With maximum solar elevation of just 15 degrees now, inversions getting to be the normal. Tuesday afternoon's RAOB from Fairbanks shows about 2000 feet of cool air and then a nice inversion (with the nose above freezing).

Snow Monday

Snowfall amounts from Monday into early Tuesday are rolling in. Amounts are mostly typical of this kind of pattern. The surface analysis from Environment Canada from late Monday evening tells the story: old low on the Gulf of Alaska coast with redevelopment on the north side of the mountains.

Fairbanks area:
Keystone Ridge: 2.4"
Goldstream Valley: 2.0"
Fairbanks Airport: 1.9"
UAF West Ridge: 1.5"
Goldstream Creek: 1.5"
Chatanika (Mile 42 Steese) 1.4"
Gilmore Creek: 1.4"

East of Fairbanks:
Eagle: 5.0"
Central: 3.1"
Circle Hot Springs: 2.5"
Chicken: 1.0"
Fort Yukon: 0.3"
Tok: none
Alcan Border (on Alaska Highway): none

West of Fairbanks:
Lake Minchumina: 4.4"
Healy 2NW: none
Denali NP: Trace

Sunshine at the Fort

A 15 below sunrise at Fort Yukon Saturday morning. A solid band of stratus is visible toward the horizon.

Chillin

This morning's705AM ADT infrared satellite image of northern Alaska shows a hodgepodge of clouds, but where skies remained clear, temperatures fell to lowest levels of the young winter. The Chalkyitsik RAWS, between Fort Yukon and Chalkyitsik, reported 21 below, and 15 below at the Fort Yukon Airport. The image shows colder temperatures on the inland North Slope, with surface temperatures in the 20s below, though none of the few inland weather stations happen to be in the cold spots. Umiat got to 14 below before the clouds moved in.

Patchy snow

Just from perusing the FAA webcams Thursday afternoon, areas of the Interior remain snowfree. Nenana has snow, but none of note at Minto or Tanana. Denali NP (at the train station) has a very little, while the Summit webcam, in Broad Pass south of Cantwell, as none at all. Also, heard from a colleague as of late Tuesday (after the snowfall in Fairbanks) that between 30 Mile Chena Hot Springs Road and Chena Hot Springs there is no snow at all on the ground, even most of the high terrain is bare except right near CHS.

Thursday Sat Pix

341pm NOAA-19 visible image, showing the stratus packed up against the north side of the Alaska Range and clear skies to north and south. Also stratus in stuck over the Yukon Flats.

Brooks Range sunrise

A pretty morning at Chandalar DOT camp on the Dalton Highway

Chances of Keeping the Snow Cover

This graphic illustrates the historical frequency of keeping a snow cover that is on the ground in mid-October. So, for each day, IF there was one or more inches of snow on the ground, how often did the snow cover remain one inch or more (until the following spring)? The inverse would be how often did the snow cover reduce to less than one inch before the following spring. The change is fairly dramatic over just a few days. So based on the historical frequency, there is a 57% change that the snow cover (1" this morning at the Airport) will remain. If we have an inch on the ground Friday morning, that increases to 73%.

Snowfall

Snow reports dribbling in this morning show generally an inch or two in the Fairbanks area since Sunday morning. Model guidance suggests that temperatures will be near or below freezing for the next week, so this is probably the permanent winter snow cover, though a day of sunshine would reduce the snow cover to patchy at lower elevations, especially south facing hillsides.(Photo from the Alaska Climate Research Center)

October

The view from UAF West Ridge Sunday morning (photo from the Alaska Climate Research Center).
This is all new this morning; the little snow remaining in town from late last week was gone by Saturday afternoon.

Saturday Sunshine

The mid-afternoon NOAA-19 polar orbiter image shows a hodgepodge of clouds over Interior Alaska. Sunshine though over the middle Tanana Valley. Not much snow cover evident below tree-line yet. What snow there is largely hidden in the darker boreal forecast.

Snow Creep

More light snow today: A brief accumulation in town melted by mid-afternoon; the 0.4" at the airport is only about a week later than the normal first measurable snowfal. Not much melting on the hills above 1500' MSL. Photo of Keystone Ridge late in the morning.

Snow at Last

Snow fell throughout the Fairbanks area Wednesday late morning and early afternoon. This was the first snow of the season at Fairbanks Airport, the latest first snow since 1991. Amounts were evidently quite light; no reports so far of more than half an inch. But, we gotta start somewhere!

Another Deep Gulf Storm

3pm ADT GOES-11 image showing the well developed Gulf of Alaska storm center near Yakutat (Environment Canada analyzed this as a 970mb center at 10am ADT), and the still well defined occlusion bowed far out to the east and northeast. This has brought some snow today to the Upper Tanana Valley from Tok eastward.

Another Hot Month in Barrow

The average temperature in September at Barrow was 37.4F. This is the third warmest September of record. Only 1998 and 2007 warmer, and those only by fractions of a degree. The result of warm water instead of ice.

No Snow Yet

NOAK49 PAFG 050958
PNSAFG
AKZ222-060100-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
158 AM AKDT TUE OCT 5 2010

...NO SNOW YET IN FAIRBANKS...

THUS FAR THIS AUTUMN THERE HAS BEEN NO SNOW AT ALL AT THE
FAIRBANKS AIRPORT. THE LAST TIME THE FIRST SNOW CAME THIS LATE IN
THE AUTUMN WAS 1995...WHEN THE FIRST FLURRIES FELL ON OCTOBER 5TH.

THERE IS NO SNOW IN THE FORECAST FOR FAIRBANKS FOR TODAY. THERE IS
A SLIGHT CHANCE OF TOMORROW. THE LAST TIME FAIRBANKS WENT LATER
THAN OCTOBER 6TH WITHOUT ANY SNOW WAS BACK IN 1963.

OVER THE PAST CENTURY...THE AVERAGE DATE OF THE FIRST SNOW IN
THE AUTUMN IN FAIRBANKS IS SEPTEMBER 23RD.

$$
RT OCT 10

October Snowfall

It's been quite a while now since Fairbanks has had a snowy October. The 1970-2000 mean of 12.3 inches has only been exceed twice in past 14 years. This is mostly the result of lower total precipitation rather than more rain=less snow.

Growing Snow Cover

MODIS image (from the Terra satellite, via UAF Swath Viewer) from Friday afternoon showing nearly all of the western North Slope with a solid snow cover. Although partially obscured by clouds, between Barrow and Teshekpuk Lake the snow cover looks to be less solid.

Arctic Sea Ice Minimum

It's catch-up Sunday, so here's one from last week I never got around to mentioning.

The 2010 Arctic sea ice minimum turned out to occur not on September 10th, but on September 19th. According to NSIDC, the minimum Arctic sea ice coverage was 4.60 million square kilometers, the third lowest of record in the satellite era (1979 to present). This is about 10 percent less than the minimum ice coverage last year and about 10 percent above the record low coverage in 2007. For about the last 10 days, ice coverage has been growing rapidly.

September Precip

Precipitation totals for September don't usually show that much variation in the greater Fairbanks area, but it has been an odd year precip-wise.

Total September Precip as a percentage of normal
Fairbanks Airport: 106%
College 5NW: 97%
Keystone Ridge: 59%
North Pole: 26%
Eielson AFB: 19%
Munson Ridge 16%