Snow showers are popping up across the area this morning. This should continue for most of the morning. Towards mid-day and the afternoon, the snow should fall in earnest for a while. Not a huge storm, but potentially a messy one. Temperatures should be cooler with this round than over the weekend.

The Rim should be seeing the worst of it as the uplift takes effect with a flow out of the south-south-west.

Thursday may bring another round of snow. This weekend should be a nice break, maybe.

As late as last evening about 8pm, it still looked like we would get 4-8 more inches. For Flagstaff it never materialized. But, don’t worry, today could bring some widely scattered snow, more looks to be on the way for tomorrow. The storm did hold temperatures very constant. Here is an interesting record report:

... Record high low temperatures for northern Arizona on Mar 07 2010...
City (period of record) new high low previous record/year
Cottonwood-tuzigoot (1977 - 2010) 44 44 (tied) in 2001

... Record low high temperatures for northern Arizona on Mar 07 2010...
City (period of record) new low high previous record/year
Cottonwood-tuzigoot (1977 - 2010) 49 50 in 1981

Temperatures just didn’t change much yesterday. I can’t remember seeing this happen before.

While we didn’t end up with piles of snow yesterday, we did set a new precipitation record:

...THE FLAGSTAFF AZ AIRPORT CLIMATE SUMMARY FOR MARCH 7 2010...

CLIMATE NORMAL PERIOD 1971 TO 2000
CLIMATE RECORD PERIOD 1898 TO 2010

WEATHER ITEM   OBSERVED TIME   RECORD YEAR NORMAL DEPARTURE LAST
                VALUE   (LST)  VALUE       VALUE  FROM      YEAR
                                                  NORMAL
..................................................................
TEMPERATURE (F)
 YESTERDAY
  MAXIMUM         35   1133 AM  66    1972  48    -13       42
                                      1910
  MINIMUM         27   1159 PM  -1    1945  22      5       19
  AVERAGE         31                        35     -4       31

PRECIPITATION (IN)
  YESTERDAY        0.53R         0.52 1918   0.09   0.44      T
  MONTH TO DATE    0.81                      0.67   0.14      T
  SINCE SEP 1     12.79                     13.15  -0.36     8.57
  SINCE JAN 1      8.08                      5.41   2.67     2.21

SNOWFALL (IN)
  YESTERDAY        5.1           7.6  2000   0.8    4.3       T
  MONTH TO DATE    7.1                       5.9    1.2       T
  SINCE SEP 1    129.0                      83.8   45.2     80.7
  SINCE JUL 1    129.0                      83.8   45.2     80.7
  SNOW DEPTH      15

We received 2-3 inches of snow overnight. But, the air stayed warm, with temperatures hoovering right at freezing.

Switzer Canyon Temperatures - 3-6-10 to 3-7-10

We should expect to see snow falling off and on through Tuesday. By tomorrow morning, we will add another 4-8 inches of snow in Flagstaff. South of the city, down to the Mogollon Rim, snowfall amounts could reach 8-15 inches depending on location. The snow level should be around 5500 feet.

Cut-off low pressure systems are notorious hard to forecast. USATODAY: Cut-Off Lows So, this is all subject to change  in any direction.

So, 3-6 inches seems to be the consensus for Saturday night through Sunday night. But the North Atlantic Mesoscale Model is showing at least an 1 inch of precipitation through Monday morning. It is March. It has been a while since we have had a strong storm. It should be interesting to see what happens.

Also, the dry trend for next week is up in the air. A small storm is looking to drop into the area around Wednesday.

North American Mesoscale Precipitation Model - 60 hours ending mid-Monday

We should almost definitely be cooler after this weekend’s storm. But, the amount of any snowfall is proving hard to predict. It appears that a cut-off low will form over the Pacific and move over Arizona on Sunday. But, predicted precipitation amounts keep varying. The Navy NoGaps model is show up to an inch of water precipitation. Others vary between 0.5 and 0.75 inches. So, some where between 3-12 inches of snow seems likely.

After this weekend, we should see clear, dry and cool conditions into spring break.

A side note for perspective: Yesterday seemed pleasantly warm, didn’t it? It was. But, the average temperature for the day was only normal, and the high temperature was 4 degrees below normal.

If you remember the following picture from 2-13-10, you will be interested to know that the weather service still reports 17 inches of snow on the ground. That’s 13 extra days equal to or greater than 1 inch, for a total of 85 days. This puts us in 3rd place for this category (snow cover ≥ 1 inch).

Corrected Flagstaff Snowcoverage??? - National Weather Service Flagstaff

But, we are doing well (poorly?) in a whole host of other categories. I believe today we are still the snowiest city with a population greater than 60,000  for this winter. For other snow fall categories, here is how things stacked up at the end of February (National Weather Service):

...CONSECTUTIVE DAYS OF VARIOUS SNOW DEPTH RECORDS FOR FLAGSTAFF...

 GREATER THAN 20"
    RANK    #DAYS     END DATE
     1        34       2/2/1937
     2        32      1/14/1968
     3        27      2/15/2010
     4        18      2/11/1979
     5        15       4/6/1973

 GREATER THAN 10"
    RANK    #DAYS     END DATE
     1        94      2/28/1906
     2        54       2/5/1968
     3        49      2/14/1937
     4        47       3/4/1979
     5        42      2/28/2010*

 GREATER THAN 5"
    RANK    #DAYS     END DATE
     1        95      2/28/1906
     2        84      2/28/2010*
     3        60      4/12/1973
     4        58       3/4/2008
     5        57       2/8/1968

 GREATER THAN OR EQUAL TO 1"
    RANK    #DAYS     END DATE
     1       140      4/23/1973
     2        95      2/28/1906
     3        93      3/10/2008
     4        83      2/28/2010*
     5        80      3/10/1960

 * RECORD STILL BEING SET

There is still snow on the ground, and a wavering chance for more this weekend. A storm this weekend keeps fading in and out of the forecast. Longer term, it looks like we may be in for a cold, dry spell after this weekend. March is still forecasted to be wetter than normal.

Finally, to sum things up, here is a post of interest:

2001-2010 was the Snowiest Decade on Record – wattsupwiththat.com

Many of you probably saw this article in the Arizona Daily Sun:

King of the hill: Flagstaff atop snowfall total so far

The national news media is picking up on this article. We are the snowist city in the country. Even the battered East Coast cities are well behind us.

Well, this morning we stand at a season total of 120.7 inches. We have crossed the 10 foot mark. The average annual snowfall for all years recorded is just over 7 feet (86 inches). There have been years that were much snowier. But, keep in mind that March is typically the snowiest month. The monthly outlook from the Climate Prediction Center is for a wet month.

30 day Precipitation Outlook - Climate Prediction Center

It’s been a fairly dry month. No, I am not crazy in this belief. December and January were quite strong, but February is still about half an inch below normal. I think this weekend will see us picking that up. This is roughly the amount shown on the NOAA Graphical Forecast.

Most are forecasting somewhere between 3 and7 inches of snow. Personally, I think that those forecasts may be on the low side. I will go out on a limb and say, as of Friday morning, we could be looking at 8-12 inches. I will update my number tomorrow.

It’s been a cold month, as I mentioned yesterday. Even though it was quite sunny, the temperatures rarely climbed very high.

Monthly Summary from Weather Underground (wunderground.com)

So far, Flagstaff is about a half inch below normal precipitated water. I think this weekend’s storm stand a good chance of making up the deficit. I think Accuweather was the most accurate with the last storm. They are forecasting just over 7 inches. There is still some inconsistency in the outlook.

The below-normal temperature trend should continue.

From National Weather Service WINTER STORM WATCH

FROM NATIONAL WEATHER SERVICE WINTER STORM WARNING Issued 330pm Sunday.

But, when is the weather ever fair. The precipitation models continue to shift around, but seem to be aligning for 12-24 inch snow accumulations for parts of the Northland between now and Monday night. Accuweather is sticking to a meager 7.5 inches. Wunderground has 15-23 inches in their forecast. Foxnews just said 1-3 feet across the 4-Corners area. For my house, the National Weather Service Point Forecast shows 7-16 inches. For the airport, they show 9-17 inches. As I said, the models keep shifting.

Here is a good post from Friday by Ken Clark at Accuweather.com: Model Mayhem Equals Changing Forecasts. If it makes you feel better, next weekend should bring a repeat.

330 PM MST SUN FEB 21 2010

...WINTER STORM WARNING IN EFFECT FROM 11 PM THIS EVENING TO 3 PM
MST MONDAY FOR ELEVATIONS ABOVE 5000 FT...

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A WINTER
STORM WARNING FOR HEAVY SNOW AND BLOWING SNOW...WHICH IS IN
EFFECT FROM 11 PM THIS EVENING TO 3 PM MST MONDAY FOR ELEVATIONS
ABOVE 5000 FT. THE WINTER STORM WATCH IS NO LONGER IN EFFECT.

* TIMING: A STRONG WINTER STORM IS MOVING INTO ARIZONA FROM THE
  NORTH AND WILL BEGIN AFFECTING THE AREA LATE SUNDAY NIGHT INTO
  MONDAY AFTERNOON.

* SNOW ACCUMULATIONS: STORM TOTAL SNOW AMOUNTS WILL RANGE FROM 4
  TO 8 INCHES BETWEEN 5000 TO 6000 FT AND 8 TO 14 INCHES ABOVE
  6000 FT WITH LOCALLY HIGHER AMOUNTS POSSIBLE.



631 AM MST SUN FEB 21 2010
...WINTER STORM WATCH REMAINS IN EFFECT FROM 6 PM MST THIS

EVENING THROUGH MONDAY EVENING ABOVE 5000 FEET...
* TIMING: THE SECOND PART OF THIS WINTER STORM IS FORECAST TO

BEGIN AFFECTING THE AREA LATE SUNDAY NIGHT INTO EARLY MONDAY

MORNING WITH THE MOST SIGNIFICANT SNOWFALL BEGINNING BEFORE

MIDNIGHT MONDAY AND CONTINUING THROUGH MONDAY NIGHT.
* SNOW ACCUMULATIONS: POSSIBLE SNOW ACCUMULATION OF 5 TO 8

INCHES FROM 5000 TO 6000 FEET...8 TO 16 INCHES FROM 6000

FEET TO 7000 FEET WITH LOCALLY HIGH AMOUNTS CLOSER TO THE

MOGOLLON RIM...WITH 12 TO 24 INCHES ABOVE 7000 FEET WITH

LOCALLY HIGHER AMOUNTS POSSIBLE .