Deep Storm

Here's the 3am AST Thursday GOES-15 image showing an intense cyclone over the eastern Aleutians. The minimum Sea Level Pressure at Dutch Harbor was 945.8mb at 2AM AST. Dutch had a peak wind from this storm of 76KT late Monday afternoon.

Solar Noon at Prudhoe Bay

Here's a photo, looking south from Prudhoe Bay (thanks to the FAA webcam) from just after solar noon on Wednesday.

Let it Snow

Snowfall during mid-winter in Interior Alaska often does not show much of valley to ridge difference. After all, precipitation is almost always snow, and the elevations where people live vary by perhaps 2000 feet (say, Nenana to Ester Dome), trivial compared to, say the vertical change over similar distances in the Rockies.

That has most definitely not been the case so far month. Here is a chart of the daily snowfall thus far this month at Fairbanks International Airport and Keystone Ridge.



There was similar, though less extreme difference last month, when the Airport measured 9.2 inches of snow and Keystone Ridge 20.7 inches.

Below is a plot the difference in total December snowfall since 1996 between the Airport and Keystone Ridge. Monthly differences have not exceeded six inches, and the difference has not been more than 50% of the total at Fairbanks: thus far this month, the difference of 14.0 inches is a stunning 241% of the Fairbanks total.



Of course, with more than two weeks left in December this difference will likely narrow, but given the usual minimal differences is unlikely to dramatically change.

Messy Image

This 430pm AST Monday GOES-15 image shows lots of (disorganized) clouds across eastern mainland Alaska, while a tight cyclone is impacting the central Aleutians.

The Anchorage area received 6-12 inches of snow in town and up to two feet of new snow on the upper hillside. Amounts in Fairbanks-land have been mostly an inch or two, but with enough southwest wind to blow the snow around in town, always a notable event. However, it remains very mild, with temperatures so far stuck in the teens and 20s.

The Sea Level Pressure at Adak at 5pm AST Monday was 959mb with the low center just to their east.

Updated: The minimum pressure in this storm at Adak was 951.2mb at 1016pm AST Monday.

Another Seward Pen Blizzard

Here's the FAA webcam shot from Nome at 1pm AST Saturday. Nome's been reporting blizzard conditions since before 10am, with winds gusting to nearly 50 mph. Similar at Golovin.




The 9am AST Saturday surface analysis from NWS Anchorage shows a complex low in the western Bering Sea.

Snowfall Friday

Nice little snowfall in Fairbanks-land Friday.

Some totals include:
Fairbanks Airport: 2.9 inches (most any day so far this winter)
Fairbanks Mid-town: 2.5"
UAF West Ridge: 2.4"
Goldstream Creek: 2.1"
Keystone Ridge: 5.4"

The much higher amount here on the ridge was probably an elevation effect: low level west winds lifted a 1000' up from the Minto Flats, with the atmosphere unstable enough for that lift to enhance snow crystal production. Just a guess of course. However, on my home from work late Friday evening the snow amounts did not look to increase much until I started up the hill.

Solar Noon at Arctic Village

From the FAA, this photo from Arctic Village Friday 1240pm, is close to solar noon.

Clocks Don't Matter

Classic December Day: High temperature at 1am, low temperature in the middle of the afternoon…

CDAK49 PAFG 090937
CLIFAI

CLIMATE REPORT
NATIONAL WEATHER SERVICE FAIRBANKS AK
1237 AM AKST FRI DEC 9 2011

...................................

...THE FAIRBANKS AK CLIMATE SUMMARY FOR DECEMBER 8 2011...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1904 TO 2011


WEATHER ITEM OBSERVED TIME RECORD YEAR NORMAL DEPARTURE LAST
VALUE (LST) VALUE VALUE FROM YEAR
NORMAL
..................................................................
TEMPERATURE (F)
YESTERDAY
MAXIMUM 22 1258 AM 55 1934 6 16 -16
MINIMUM 0 340 PM -53 1935 -10 10 -28
AVERAGE 11 -3 14 -22

Winds

Fairbanks Airport reported a peak wind of 51 mph at 1021AM Monday. Gust data is only available at Fairbanks since the mid-1980s, but since then this is the highest gust of record for December. The previous record was just 38 mph on Christmas Eve 1985.

Here is a plot of winds from the NRCS SNOTEL up on Eagle Summit at Mile 107 Steese Highway (elevation 3750' MSL). Winds between an ASOS/AWOS and SNOTEL are not directly comparable, but you get the idea. The anemometer often ices up on Eagle Summit, but evidently not today.



It's been a really windy day up there! The highest gust has been 55 mph, and a quick look shows nothing that high in the past couple winters (50 mph was the highest reported in the storms last February)

Storm Aftermath

Here's the 3am Monday Surface Analysis from Environment Canada. The 975mb low near Banks Island is responsible for the re-surge of winds across the area this morning.

Impacts:
Fairbanks North Star Borough Schools and State Offices are closed today (Monday) due to poor road conditions. FNSB Borough Offices and UAF are open. Fort Wainwright has "late arrival" policy in place.

Weather:

Record High Temps for December set Sunday:

North Pole: 49F (old record 47F on Dec 29 1982)
Eielson AFB: 48F (old record 47F on Dec 24 1985)
UAF West Ridge: 45F (old record 44F Dec 24 1985)

The high of 47F at Fairbanks International is the highest temperature of record in December except for Dec 4-8, 1934, when every day had a high in the 50s.

There were some big snow amounts:
Bettles: 14.3 inches Sunday
Ruby 14NE: 13.5 inches (cooperative station upriver from Ruby)
Galena: 8.0 inches

Rain

Rain in Fairbanks Sunday afternoon evidently did not amount to much (trace to a couple hundredths), though this time of year any is a problem for roads, walkways, etc. Much higher amounts though occurred near Denali National Park, with 0.20" reported from Park Headquarters this morning and 0.30" at Healy. Nenana also received almost a tenth of an inch of rain Sunday afternoon before it changed over to snow.

Big Chinook

It appears that the temperature spiked to 47F at 1119am at the Fairbanks Airport right as the front came through, mixing out the weak inversion that was present. If this is correct, this is the highest temperature of record in December EXCEPT for the five days from December 4-8 1934, when the temperature got to 50F or higher each day. More on this to follow.

Here's the plot of temperatures from the 3am and 3pm RAOBs from Fairbanks.



That's a lot of cooling!

Record High Temperatures

Here's the METAR plot from 10am Sunday observations: a wind shift just came through Fairbanks: the surgace front is probably lagging a bit behind.



For climate sites that do not have records going back to the great December 1934 Chinook appear to have set or tied new December high temperatures. The following are all preliminary and subject to revision:

Eielson AFB: 48F (47F on Dec 24 1985)
UAF West Ridge: 45F (44F on Dec 24 1985)
North Pole current record for December is 47F

other daily records:
Fort Greely/Big Delta: 51F

Other high temperatures:
Rex Brige RWIS: 49F (Mile 276 Parks Hwy)
Mile 42 Steese Hwy: 47F
Nenana Hills RWIS 44F (at FNSB Borough Boundary on Parks Hwy)

Also of note:
Antler Creek RWIS (south of Healy) peak wind 81 mph at 505pm Saturday Dec 03

Extreme Heat in the Central Interior

3AM Sunday surface analysis from NWS Anchorage:



7-8am Sunday Temperatures around the central Interior

Kantishna SNOTEL: 51F
Chena Hot Springs: 50F
Nenana: 50F
Woodsmoke PWS: 49F
Eielsion AFB: 48F
Birch Lake RWIS: 48F
Denali Park AWOS: 45F
Cleary Summit: 41F
Keystone Ridge: 40F
Fairbanks Airport: 36F
Eagle Summit SNOTEL: 36F

Much more to come after I've had some coffee…

Surface Analysis

Here's the 3pm AST Saturday surface analysis from NOAA's Ocean Prediction Center. The deep southerly flow, at least a breeze and thick cloud cover has boasted temperatures across area, resulting in frosty roads.




6pm Saturday…

Two Rivers PWS: 30F
Keystone Ridge: 30F
Clearly Summit: 29F
Fairbanks Airport 28F
Woodsmoke PWS: 28F
Eielson AFB: 25F
Goldstream Creek: 22F

Warming Up

Here's the 3pm Saturday RAOB from Fairbanks. I've plotted temperatures on the left and wind speed of the right for the lowest 1500 meters of the atmosphere. Temperatures vary between -1 and -5C and winds speeds are on the way. Free air wind speeds are nearly always higher than that reported from surface stations at similar elevation (excepting ridge top locations, e.g. like Mt Washington, New Hampshire).

Thermometer Yoyo

Here's a plot of temperatures over the past few days here at Keystone Ridge. The sharp dip there on the morning of December 1st is accurate: the inversion very briefly sloshed up before retreating down the hillside.

And the swings of the yoyo will increase over the next 36 hours.

Early December Storm

Here's the 850mb temperature forecast for Fairbanks from the 12Z Saturday GFS. It is quite similar to yesterday's run; warm in the morning (no chance of record though as this is the anniversary of the great 1934 chinook); the cold front is a smidge faster, coming through during the afternoon followed, by about 12 hours of snow and 24 hours of gusty west to southwest winds. It's not out of the realm of reasonablity that there could be a little freezing rain right at the start, but it would not last more than minutes before changing to snow.

No Rest for the Weary

Another big storm is on the way for northern Alaska. Here are forecasts from the GFS for 3am and 3pm AST Sunday. What does this mean for Fairbanks-land?



First, Saturday night into Sunday morning, big chinook. It is very likely that it will get significantly above freezing throughout the area. Then, about as strong a cold front as ever is seen in Interior Alaska comes blasting through late Sunday afternoon or evening. Here's the forecast for the 850mb temperatures (about 4500' MSL, a decent guide to the temperature of the low level airmass).



Yes, that's plotted correctly: the model is forecasting an almost 9C fall between 3pm and 6pm Sunday. There will be snow and lots of southwest wind as the cold air returns. Above tree-line on the highways north of Fairbanks it's really going to howl. The southwest winds will break through in town too; I would not be surprised to see Fairbanks Airport report blowing snow at some point Sunday night/Monday morning.

November Weather Summary

November Summary for Fairbanks...

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
1155 AM AKST THU DEC 1 2011

...MONTHLY WEATHER SUMMARY FOR FAIRBANKS ALASKA...
...OUTSTANDING COLD SNAP MID-MONTH...

NOVEMBER 2011 WILL LONG BE REMEMBERED FOR THE MID-WINTER-LIKE COLD
SNAP WHICH SETTLED IN THE WEEK BEFORE THANKSGIVING. THE WEEK OF
NOVEMBER 15TH TO 21ST...WITH AN AVERAGE TEMPERATURE OF
30.1 BELOW...IS THE COLDEST WEEK EVER RECORDED IN FAIRBANKS BEFORE
THANKSGIVING DAY. SIX DAILY RECORD LOWS WERE SET DURING THIS
TIME...WHICH IS TRULY OUTSTANDING FOR A LOCATION WITH MORE THAN A
CENTURY OF UNBROKEN WEATHER OBSERVATIONS.

THE FIRST HALF OF NOVEMBER...WITH AN AVERAGE TEMPERATURE OF 3.0
DEGREES ABOVE ZERO WAS ONLY A BIT COOLER THAN NORMAL.
HOWEVER...THE SECOND HALF OF THE MONTH...WITH AN AVERAGE
TEMPERATURE OF MINUS 19.2 DEGREES WAS THE COLDEST SECOND HALF OF
NOVEMBER SINCE 1963.

FOR THE MONTH AS A WHOLE...AT THE AIRPORT THE AVERAGE HIGH
TEMPERATURE WAS ZERO AND THE AVERAGE LOW 17 BELOW. THE AVERAGE
TEMPERATURE LAST MONTH OF 8.2 BELOW MADE THIS THE SIXTH COLDEST
NOVEMBER OF RECORD. DURING THE PAST 50 YEARS...THE ONLY COLDER
NOVEMBER WAS IN 2006...WHEN THE AVERAGE TEMPERATURE WAS 9.9 BELOW.
THE COLDEST NOVEMBER OF RECORD WAS IN 1927...WHEN THE AVERAGE
TEMPERATURE WAS MINUS 11.2 DEGREES.

THE HIGH FOR THE MONTH WAS 25 DEGREES ON THE 4TH. THE LOWEST
TEMPERATURE AT THE AIRPORT WAS 41 BELOW ON THE 17TH...AND IS THE
FIRST TIME THE TEMPERATURE HAS FALLEN PAST 40 BELOW IN NOVEMBER
SINCE 1994. SEVEN DAYS HAD LOW TEMPERATURES OF 30 BELOW OR
LOWER...THE MOST IN A NOVEMBER SINCE 1963. SOMEWHAT LOWER
TEMPERATURES WERE RECORDED IN THE NORMALLY COLDER SPOTS...INCLUDING
49 BELOW IN NORTH POLE ON THE 17TH.

SNOWFALL WAS GENERALLY A BIT BELOW NORMAL IN THE IMMEDIATE FAIRBANKS
AREA...AND NEARLY ALL OF IT FELL DURING THE FIRST TWO WEEKS OF THE
MONTH. THE TOTAL AT THE AIRPORT OF 9.2 INCHES WAS ABOUT 4 INCHES
BELOW NORMAL. THIS MELTED DOWN TO 0.46 INCHES OF WATER...WHICH IS
ABOUT TWO-THIRDS OF NORMAL. SNOW DEPTHS INCREASED FROM 3 INCHES ON
THE FIRST TO A STEADY 7 INCHES THE LAST TWO WEEKS OF THE MONTH.

HIGHER SNOWFALL AMOUNTS WERE OBSERVED NORTH OF TOWN. FOR NOVEMBER
12.0 INCHES OF SNOW WAS MEASURED AT MILE 42 STEESE HIGHWAY. THE
KEYSTONE RIDGE COOPERATIVE STATION...NEAR MURPHY DOME...REPORTED
20.7 INCHES OF SNOW FOR THE MONTH.

WINDS WERE CHARACTERISTICALLY LIGHT IN NOVEMBER...ESPECIALLY
DURING THE COLDEST WEATHER. AVERAGE DAILY WIND SPEEDS WERE LESS
THAN TWO MPH EVERY DAY AFTER THE 13TH. ICE FOG DURING THE COLDEST
WEATHER WAS NOT ESPECIALLY DENSE.

LOOKING AHEAD TO DECEMBER...NORMAL TEMPERATURES SLOWLY DECLINE...
FROM 2 BELOW ON THE FIRST TO 7 BELOW ON NEW YEARS EVE. OVER THE
PAST 106 YEARS...DECEMBER TEMPERATURES HAVE RANGED FROM A HIGH OF
58 DEGREES IN 1934 TO 62 BELOW IN 1961. ON AVERAGE A FOOT OF NEW
SNOW FALLS DURING THE MONTH...BUT HAS RANGED FROM 50.7 INCHES IN
1984 TO JUST A TRACE IN 1969. POSSIBLE SUNSHINE DECREASES FROM 4
HOUR 42 MINUTES ON THE FIRST TO 3 HOURS 42 MINUTES FOR A FEW DAYS
AROUND THE WINTER SOLSTICE...AND THEN INCREASES THEREAFTER.

$$
RT DEC 11