Growing Inversions

The late season heatwave is building, and with the clear skies and deepening darkness, a decent summer inversion developed. Low temp this morning on Goldstream Valley Bottom 44F, while here on Keystone Ridge 59F.The Salcha River RAWS went to 34F.

About 3am I awoke to a brite moon shining in the bedroom window. Not all the way dark, but dark enough for the moon to be noticeable.

High Dew Points

Like most of western North America, dew points above 60F are quite unusual in northern and Interior Alaska. At Fairbanks, sustained dew points above 60F occur only once every few years, and have only occurred during the months of July and August. Today is the anniversary of the highest reliable dew point of record in Fairbanks (based on observations since 1951). On the evening of July 30th, 1994, Fairbanks Airport reported a dew point of 67F (also recorded Aug 15 and 16, 1956). The highest calendar day mean dew point is 61.7F on Aug 6, 1994.

Prelimanary July Numbers

The month is not quite over, but July looks to wind up with above normal precip over much of northern Alaska, with near record rainfall in the eastern Interior. Temps are more of a mixed bag...but in general Arctic and West coasts and warmer than normal and Interior near to slightly below normal, though with exceptions in all areas.

Bogus Heat

Today's official record high in Fairbanks is 99F in 1919, the highest temperature of record and the second warmest ever in Alaska. I am virtually certain that this is bogus, and the graphic on the left shows why. These are the maximum reported temps in late July, 1919, during what was obviously a major late summer heat wave. The 99F at Fairbanks is not only 10 degrees warmer than anywhere else, Fairbanks had three days with high temps in the 90s. No heat wave in the modern, i.e. Weather Bureau/Weather Service era, has ever had that kind of single-station anomaly during a summer heat wave. Other factors make this 99F temperature suspect, including the lateness of the season and what look to be a over-abundance of hot days in the period 1915-1919. The highest reliable temperature in Fairbanks is 96F in June, 1969.

Rainfall this month in the eastern Interior

Info on the rainfall in the eastern Interior...

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
1119 PM AKDT MON JUL 26 2010

...HEAVY JULY RAINFALL IN THE EASTERN INTERIOR...

RAINFALL FOR JULY IN THE UPPER TANANA VALLEY AND FORTYMILE COUNTRY
ARE AT APPROACHING MONTHLY RECORDS.

AT TOK...4.93 INCHES OF RAIN HAS BEEN MEASURED SO FAR THIS MONTH. THIS IS ALREADY THE HIGHEST JULY RAINFALL OF RECORD IN TOK...BREAKING THE PREVIOUS RECORD OF 4.43 INCHES IN 1992. WEATHER OBSERVATIONS HAVE BEEN MADE IN TOK SINCE 1954.

AT THE NORTHWAY AIRPORT...A TOTAL OF 6.12 INCHES OF RAIN HAS FALLEN THUS FAR THIS MONTH. THIS IS THE SECOND HIGHEST JULY TOTAL OF RECORD...EXCEEDED ONLY BY 6.42 INCHES IN 2005. WEATHER OBSERVATIONS HAVE BEEN TAKEN AT NORTHWAY SINCE 1942.

AT EAGLE...4.07 INCHES OF RAIN SO FAR THIS MONTH MAKES THIS THE 4TH WETTEST JULY OF RECORD. THE WETTEST JULY OF RECORD AT EAGLE WAS IN 2008..WHEN 6.04 INCHES OF RAIN FELL. WEATHER RECORDS IN EAGLE HAVE BEEN MADE...WITH SOME BREAKS...SINCE 1898.

OTHER JULY TOTALS THROUGH JULY 26TH FROM COOPERATIVE SITES WITH MUCH SHORTER PERIODS OF WEATHER OBSERVATIONS INCLUDE....

PORT ALCAN ON THE ALASKA HIGHWAY........6.40 INCHES
OBRIEN CREEK ON THE TAYLOR HIGHWAY......6.40 INCHES
CHICKEN.................................5.44 INCHES

the TWRA2 RAWS..NEAR PARADISE HILL...BETWEEN NORTHWAY JUNCTION AND THE BORDER...HAS MEASURED 8.07 INCHES OF RAIN THUS FAR THIS MONTH. THIS STATION RECORDED 9.04 INCHES OF RAIN IN JULY 2001.

Updated Wednesday Morning: Between June 25 and July 24, Northway recorded 9.29" of rain. This is, by far, the highest 30-day precip of record. In second place is June 19 to July 18, 2005, with 6.95".

More Siberian Heat

The extreme heat of early July returned late last week to Siberia. Yakutsk, the largest city in central Siberia (population 186,00 according to wiki) reported high temperatures of 95F on July 22nd and then 96F on July 23rd, when the low was an equally amazing 69F. Verkhoyansk, northwest of Yakutsk, also had three more days with highs in the 90s, including 94F on the 22nd.

July 28th Update: Oymyakon, often the coldest reporting site in Siberia, and at almost 2400'MSL elevation, hit 94F today. In January the low temperature was -74F.

Late Summer Cooling

Since I'm on the theme of changes in late summer in the Interior, here's another one. Hot days are concentrated near and not long after the Solstice. Here is a plot of the frequency of days (by week) with maximum temperatures ≥80F. Notice the sharp peak in early July and then the dramatic fall. This is a reflection of both the increased cloud cover (i.e. the rainy season) and the lowering sun angle. The solar noon sun is now less than half way up the sky.

Interior's Continential Climate

As we move into the last week of July, temperatures are beginning the long fall to winter. The chart shows the average daily temperature in Fairbanks in the past 80 years [technical: 7-Day Binomial Weighted Mean] The max and min of the annual cycle occur just three weeks after Solstice, though means are obviously quite flat.

Rainy Season is upon us

Wednesday was the 9th consecutive day with measurable rain here at Keystone Ridge. The wet season is right on schedule. To the left is a plot of frequency of days with measurable precip, by week (1996-2010). The frequency jumps up to more than 50% early in July and remains high until late August, then falls sharply.

Torrential Rain at Fairbanks Airport

Between 3 and 4pm ADT the Fairbanks Airport ASOS reported 1.15 inches of rain from a thunderstorm. This is an all-time 1 hour precip amount for Fairbanks. The previous record was 0.99 inches on July 13, 1939. Amounts very widely. Only about 0.10" at UAF West Ridge. More to follow.

Summer sunshine

One month beyond the Summer Solstice, and the lowering sun is becoming more evident. In Fairbanks its getting dim, and over the next few days, cloud cover permitting, a few bright stars will be visible around solar midnight, which is 2AM ADT. The sun path chart at the right illustrates how the solar decline will accelerate.

Update July 28th: Jupiter was clearly visible in the southeast sky about 130am on July 27th. Vega was clearly visible about 115am in the southwest sky about 115am on July 28th.

Summer Evening

The view from UAF West Ridge Tuesday evening about 10pm. The CBs in the distance did result in thunder at the airport around midnight

Siberian Heat

The record breaking heat in Asia has had some press, and now it is spilling over into eastern Europe. Jeff Masters over at Weather Underground has had several informative posts about this:

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1546

The heat has extended into central Siberia. Verkhoyansk, on the Yana River, is one of the coldest reporting sites in Siberia in the winter. While summers there are typically warm (average July temp in the lower 60sF), this month has been extreme; the daily max temp has been above 30C (86F) on 8 days this month, with a high of 35.3C (96) on July 6, 95F on July 5th and 94F on July 18th.

Updated Arctic Sea Ice

Here is the updated sea ice analysis, from Sunday, May 18th

Thunderstorms around Fairbanks

A series of thunderstorms in the Fairbanks area Saturday evening brought copious rain and unusually widespread hail. Rainfall amounts exceeding an inch were reported around town, including 1.6 inches in Hamilton Acres and Creamers Field. 1.4 inches at Fairbanks midtown and 1.3 inches in Lemeta (there was a small amount, mostly less then 0.1" of rain in the morning, so hard to tell exactly how much from the thunderstorms). There was a sharp line to the south of town, with either zero or trace amounts in the North Pole area south of Badger Road. Most of the hail reports were of pea-sized, though a few larger, up too one-half inch. Some spots had multiple hail episodes. Here is the lightning strike map from the Alaska Fire Service.

Rains in Northwest Alaska

Soaking rain in northwest Alaska as closed low aloft drops SE from north of Siberian coast; 24 hour totals include
1.35" Dall Creek near Kobuk
1.33" Kelly River RAWS north of Noatak
0.97" Kotzebue
0.81" Kivalina
0.78" Deering

Cooler Nights

Low of 35F this morning in Tanana tied the record low for the date, last set in 1936. Bettles low of 36F was a degree from the record. Ruby and Denali Park HQ both reported 37F; 33F at the Livengood RAWS, 37F at the Beaver Creek and Seven Mile RAWS, 38F at Goldstrem Valley Bottom coop station.

Arctic Sea Ice

Here is the view of the Arctic Basin sea ice coverage from last Saturday from The University of Illinois. Of note is the large area near the North Pole that has some ice loss. This could be important in a few weeks.

Ice back at Barrow

Persistent west winds have pushed some ice back on the shoreline at Barrow. Last week there was no ice at all visible.

Cool Morning

In the fairly narrow clear area between a front moving east across the West Coast and clouds from the old occlusion from the Gulf, it was a cool morning. Lows of 36F at Tanana, 39F at the Livengood RAWS, 40F at the Round Lake RAWS and 45F here on Keystone Ridge.

Chill Deepens at Barrow

Subfreezing though the entire atmosphere at Barrow this morning. Not bad for mid-July.

Snow at Barrow

Some light snow today at Barrow. Not that this is too unusual...about 75% of Julys have a trace (or more) of snow at Barrow.

Spectacular Rainfall in the Fortymile Country

The Chicken RAWS wound up with 2.75" of rain for the 24 hours ending at 120am ADT, and an event total of 2.83". The cooperative observer at Chicken, who lives several miles from the RAWS, reported an event total of 3.20" with, unsurprisingly, flooding on area creeks. The cooperative observer at OBrien Creek, on the Taylor Highway between Chicken and Eagle, reported about 3.20" of rain for the event. the Fortymile River at the Taylor Highway Bridge had the highest crest of record. This is really remarkable for this part of the world. The Alaska-Pacific RFC map of 24 hour precip ending 4AM Monday illustrates the storm nicely.

Update 830am Tuesday

The News-Miner reports flooding has closed the Taylor Highway north of Chicken, with some folks stranded:


http://www.newsminer.com/view/full_story/8742860/article-Taylor-Highway-blocked-by-washouts--motorists-stranded?instance=home_news_window_left_top_1

Updated 330pm Tuesday

I added the hydrograph for the Fortymile River showing the record crest.

Rainy in the Upper Tanana Valley

Closed low aloft chugging across the northern Gulf of Alaska has brought copious rain to the upper Tanana Valley and 40 Mile Country. Saturday evening through 7am Sunday, Northway has over an inch of rain, Tok and Chicken around three-quarters of an inch of rain. Snow level in the eastern Alaska Range around 7Kft. Much less rain farther west.

11am Update: Event rainfall amounts now exceed an inch at Tok and Chicken and 1.25" at Northway. This is the third heavy rain event in the upper Tanana Valley in the last three weeks.

2pm Update Event total rainfalls so far:
Chicken 1.63"
Tok 1.47"
Northway 1.38"
Mineral Lakes RAWS(Tok Cutoff) 1.19"
Eagle Airport 1.18"

5pm Update:
Rainfall rates are generally decreasing but storm totals are getting to be quite impressive:
Northway 2.02"
Chicken 2.01"
Tok CWOP 1.50"
Mineral Lakes RAWS(Tok Cutoff) 1.33"
Eagle Airport 1.29"

The higher amounts are close to 20% of the annual mean precip

Northern Interior is Hot

In spite of a couple of bogus obs, it really is hot in the northern Interior.

The high of 84F at Bettles on Friday was one degree shy of the record for July 9th. Coldfoot and Eagle had maxs of 86F Friday and Central 85F .

At 1230pm today, the Beaver Creek RAWS reported 91F and the usually (slightly) too warm Chalkyitsik RAWS (which is actually half way between Chalkyitsik and Fort Yukon) reported 89F.

Lightning on Friday

AFS website was down for a couple days, but back now.

Strike map for Friday: fairly impressive area over the northeastern Seward Peninsula.

Warmest Day of the Summer

Friday was (probably) the warmest day of the summer in Fairbanks-land.
Highs: Fairbanks Airport....85F
North Pole...........85F
Fairbanks Midtown....85F
Chena Hot Springs....82F
Keystone Ridge.......79F

850mb temps are about 2C warmer on the 12Z RAOB but clouds from the Gulf of Alaska front are already on the north side of the Alaska Range and headed this way.

Denali Friday Morning

Great shot from the NPS webcam at Wonder Lake from Friday 8am

Problems with Interior Temps

Problems with manual obs on Friday: Fort Yukon 104F (FYRA2 RAWS had 86F) and 92F at Chandalar Lake, and 84F at 11am. I don't think so.

The problem at Fort Yukon has been ongoing for months: the AWOS has been out of commission since the comms lines were back-hoed over the winter, and the FAA contractor appears to have a thermometer in the window that gets evening sun. On May 27th Fort Yukon reported a temp of 102F. The RAWS is on the airport grounds, and looks reasonable.

Hot and Almost Stable

00Z Fairbanks RAOB is weakly capped but isolated cells popped thru. Photo looking northeast from Keystone Ridge about 5pm. Note the high flat base: almost 10Kft. LDS detected just a couple strikes in the upper Goldstream Valley.

First Post

So the idea here is that this is my blog on whatever strikes me of interest concerning Alaska and high latitude weather and climate, mostly with an emphasis on Interior and Fairbanks-land.

So, nice mid-summer inversion this morning, with a low of 45F on Goldstream Valley Bottom and 62F on Keystone Ridge; now the hottest day so far this summer. Thru 4pm, 84F at Fairbanks International, and 79F at Keystone Ridge. The 88F at Goldstream Valley Bottom seems a bit too high.