Check out the image below. The little pink dot over the Flagstaff means that there is still a chance for March to have normal, or even a bit above normal precipitation. Even with the warm temperatures over the weekend, there is a change coming. The storm track will be crossing Arizona for the rest of the month. Temperatures will drop slowly during the rest of the month. This means the first storm will start as rain on Wednesday. Any snow will probably be wet. Future storms should be colder and snowier.
Reader: Stu, that title is in German.
Stu: I know, but it will make sense later on.
Bis Freitag scheinen sich die Wettermodelle noch sehr einig zu sein, was am Wetterhimmel passiert. Aber schon am Wochenende sind sie sich schon nicht mehr einig, die Temperaturspanne wird breiter. Und in der nächsten Woche liegen die Prognosen derzeit sogar 20 Grad auseinander. Das Wetter weiß noch nicht, wohin die Reise geht. Winter oder Frühling? Beides ist noch möglich. (wetter.de)
The computer models have been crazy with changes lately. As I read this brief story yesterday on wetter.de, it appeared very relevant to me. The computer models for the Southwestern US have been subjects to wild swings when predicting precipitation for the rest of the month, let alone this weekend. According to this brief article, there is a 20 degree C difference between computer model runs. That means it could be sunny and 68 degree F on Saturday, or it could be freezing. I’m hoping for warm, and we are heading to Bamberg to test drive smoked beer.
This weekend will be wet, and the rain and possible snow will continue through Tuesday. Snow levels will start high, but drop through this time. Snowbowl should get a nice recharge. Somewhere between 1 and 2 inches of precipitation will probably fall between now and the middle of next week.
If you go to Google translate, you can copy and past the German text above and get a rough translation.
The pattern for the rest of February is looking similar to the holidays. Very unstable and hard to predict, but with a few chances for significant rain and snow.
The first serious round is shaping up for this weekend. The timing, length and intensity keep shifting. This is due to a cut-off low forming after the first storm line moves across Flagstaff. If the cut-off low forms mostly over Arizona, the rain will become snow and stick around longer. If it forms east of Arizona, then Flagstaff will get it’s scraps. The current GFS model run shows mostly rain falling on Saturday afternoon and evening, and then we get table scraps. A GFS run earlier today had a strong impact from Saturday evening through Tuesday morning with snow after Sunday morning. The Navy NAVGEM model predicts a stronger and longer storm.
The next, and probably stronger storm, is focusing on the following weekend. If the outlook continues as it is now, it will bring many forms of precipitation.
Details with both storms are likely to change.
With nearly 9 inches of precipitation between December and January, Things have been mostly dry since January 25. Next week, there is an occasional chance for flurries or light rain. It has been quite a change as the main storm track has been to the north. The current longer range outlooks for the second half of February are looking wetter.
Last Thursday, the Climate Prediction Center published their experimental 3 and 4 week outlook. It shows the potential for another round of wet weather.
This outlook is for February 18-March 3. Today, a run of the GFS model shows the potential for a significant storm around February 19. This is still a long way in the future. There are a few weaker storms in the computer model in the meantime. Stay tuned.
UPDATED (9:52AM, January 22): Winter Storm Warning in effect. See below
Answers: I don’t know. And, on the ground, of course.
The National Weather Service provides two great products for looking at Flagstaffs weather. The Daily Climate Report and the Preliminary Monthly Climate Data Report. Yesterday, both reports were showing MM, or missing data for snowfall on both days. This has been repaired in the Monthly, but the Daily for January 20 still shows MM. The total snow fall was 12.6 inches. In the January 20 report, the record snowfall for the date was 7.1 inches in 1954. I wonder if it is still a record. Also, a Record Event Report archive is available. There is no report for January 20 or 21. I hope we don’t lose the data. This was a significant event.
Another interesting aspect, the snowfall amount broke the record, but the total precipitation amount did not. Must have been a warmer storm in 1954.
The bigger question is how deep will the next chunk of snow be? The GFS model caps it at a foot. The NAM model shows more, around 18 inches. You can see the difference in the image below. The Navy’s NoGaps model doesn’t run a snowfall calculation. But adding up the individual precipitation amounts and going with a rough 10 inches of snow for 1 inch of water, it looks like it is on the 18 inch side of the discussion. In any of these cases, it looks like the snow starts in earnest again on Sunday evening and goes through Tuesday. Current a Winter Winter Storm Watch is in effect. I would expect a that to change to a warning.
URGENT - WINTER WEATHER MESSAGE NATIONAL WEATHER SERVICE FLAGSTAFF AZ 945 AM MST SUN JAN 22 2017 ...THE THIRD AND FINAL STORM IS EXPECTED TODAY INTO LATE MONDAY NIGHT... .THE NEXT STORM HAS ALREADY BEGUN TO AFFECT THE WESTERN HALF OF ARIZONA THIS MORNING...AND WILL SPREAD EASTWARD LATER THIS EVENING THROUGH MONDAY NIGHT. THERE IS A THREAT OF HEAVY SNOW ACCUMULATION FOR AREAS ABOVE 6000 FEET ELEVATION...WITH LIGHTER ACCUMULATIONS DOWN TO NEAR THE 5000 FOOT LEVEL. AZZ004-006>008-015-230300- /O.EXT.KFGZ.WS.W.0002.170122T1645Z-170124T1200Z/ KAIBAB PLATEAU-GRAND CANYON COUNTRY-COCONINO PLATEAU- YAVAPAI COUNTY MOUNTAINS-WESTERN MOGOLLON RIM- INCLUDING THE CITIES OF...JACOB LAKE...GRAND CANYON VILLAGE... VALLE...FLAGSTAFF 945 AM MST SUN JAN 22 2017 ...WINTER STORM WARNING NOW IN EFFECT UNTIL 5 AM MST TUESDAY ABOVE 6000 FEET... * TIMING...LIGHT TO MODERATE SNOW WILL CONTINUE THROUGH LATE THIS AFTERNOON...INCREASING IN INTENSITY AND CONTINUING THROUGH EARLY TUESDAY MORNING. SNOW WILL SPREAD FROM WEST TO EAST SUNDAY AFTERNOON AND EVENING...CONTINUING THROUGH TUESDAY MORNING. * GENERAL EVENT TOTAL SNOW ACCUMULATIONS...8 TO 15 INCHES FOR AREAS ABOVE 6000 FEET ELEVATION. HIGHER AMOUNTS POSSIBLE ALONG SOUTHWEST FACING SLOPES OF THE MOGOLLON RIM AND THE KAIBAB PLATEAU. CONSULT POINT SPECIFIC FORECAST AT: WEATHER.GOV/FLAGSTAFF. * SNOWFALL FORECAST FROM 9 AM MST TODAY UNTIL 5 AM MST TUESDAY... DONEY PARK 5 TO 9 INCHES FLAGSTAFF 9 TO 15 INCHES GRAND CANYON 9 TO 15 INCHES JACOB LAKE 11 TO 17 INCHES NORTH RIM 20 TO 26 INCHES VALLE 4 TO 8 INCHES WILLIAMS 6 TO 10 INCHES * WINDS...GUSTY WINDS ARE EXPECTED THROUGHOUT THE EVENT...WITH THE STRONGEST WINDS LATE TONIGHT THROUGH MONDAY AFTERNOON. SUSTAINED WINDS OVER 20 MPH WITH GUSTS UP TO 45 WILL SEVERELY REDUCE VISIBILITIES IN BLOWING AND DRIFTING SNOW. * OTHER IMPACTS...DANGEROUS TRAVEL CONDITIONS ARE LIKELY DUE TO SNOW PACKED AND SLICK ROADS. VISIBILITY COULD ALSO BE SEVERELY REDUCED DUE TO BLOWING AND DRIFTING SNOW. PRECAUTIONARY/PREPAREDNESS ACTIONS... A WINTER STORM WARNING MEANS SEVERE WINTER WEATHER CONDITIONS ARE EXPECTED OR OCCURRING...DUE TO SIGNIFICANT AMOUNTS OF SNOW AND STRONG WINDS PRODUCING LIMITED VISIBILITIES. DRIVING WILL BE EXTREMELY DANGEROUS DURING THIS STORM. FOR THE LATEST ROAD CONDITIONS AND CLOSURES...CALL THE ADOT FREEWAY MANAGEMENT SYSTEM AT 1 888 411 7623 OR VISIT THEIR WEB SITE AT WWW.AZ511.COM. ADDITIONAL WEATHER INFORMATION IS ON THE WEB AT WWW.WEATHER.GOV/FLAGSTAFF.
A significant snow event, or two, is on the way. Month to date, Flagstaff has received more than double the average snowfall. The snowy winter of 2016-2017 will continue until everyone needs new skis for next year.
The timing for this next storm is pretty clear. Snow will start Thursday and continue through Sunday. As you can see below, the accumulation by Sunday could easily be 12 or more inches for Flagstaff. Much more is possible.
But, that is only chapter 1. By the following Wednesday morning, current models have a second cut-off low moving through Northern Arizona, at least doubling the snow on the ground. There will be little break from cold temperatures during this time. Be ready to figure out where to store the snow!
6-12 inches for Snowbowl, Flagstaff gets mostly rain. Next weekend?
Checking the point forecast for Snowbowl at the National Weather Service, it will get 6-12 inches of new snow between Saturday afternoon and Sunday morning. Flagstaff will remain mostly warm. Snow levels will be around 7000-7500 feet. So, being careful is important. A slight move in temperature could change the expected rainfall to snow. Driving across Northern Arizona on I-40 could be tricky this weekend.
The bigger news is centered around next weekend. A major winter storm is on the way. Currently, we should expect light snow to start on Thursday, intensify on Friday evening and Saturday, and continue into Sunday. The San Francisco Peaks are clearly in the “green” zone expecting 12-18 inches during this time. As always, it’s difficult to tell how deep in the heavy snow area Flagstaff will be. Also, this is only for the 24-hour period. More snow will fall on either side of this time. The forecast should become clearer on Monday.
The next few days will bring precipitation now and then to the area, while temperatures remain warm. But, this current version of the 24 hour snowfall computer model shows that heavy snow could fall on Saturday night. Notice the small area of pink, white and green on the image below. Some locations, particularly at higher elevations, may receive over a foot.
The following weekend is still looking very snowy.
It looks like the computer models are focusing on a weaker version of last weekend. Just a few inches of snow are possible. Most likely, it will be on Saturday, with lighter precipitation on either side. In any case, I would be ready for winter weather this weekend, particularly if you are traveling. Here is the 24-hour precipitation probability for Saturday from the Climate Prediction Center.
The 6-10 and 8-14 day outlooks continue to look wetter than average. When I look at the long range computer models, I don’t see that trend. We’ll see what actually happens.
The Navy NoGaps or NAVGEM model isn’t matching the GFS model again. But this time, it’s the other way around. The Navy model from this morning so a dry spell ahead with no repeat of last weekend. The GFS model shows a pair of major storms hitting Arizona again. The one-two punch of last week could still be repeated this weekend.
Rain and/or snow are in the forecast for Thursday through Monday. Travel could be difficult for the entire holiday weekend. The GFS model shows heavy snow hitting Sunday. Currently, the Climate Prediction Center outlooks call for above average precipitation for the next two weeks. The 6-10 day precipitation outlook is below.
Since Tuesday is the first day of this work week, we will see how things change by the end of the day today. December is already way above average for precipitation.