Please be sure to view our Advisory and Radar Centers for the latest updates and developments.

As always stay tuned to your favorite weather outlet, stay informed, and stay safe!

cheers,

–patrick

This will allow the deep south to laugh heartily as they enjoy temperatures well above normal as onshore flow streams a comforting blanket of warmth into the region. Places such as New Orleans will enjoy highs in the mid 70s through the weekend, while Minot, ND will have lows reaching nearly -20ºF, with wind chills at very serious levels.

No one seems to be discussing the potential for freezing rain / sleet / mixed precipitation we discussed on New Years Eve. The potential is still there as is demonstrated by the afternoon run of our Forecast Precipitation Type product. Today’s run advances the potential to earlier Saturday than Wednesday showed, but surprisingly maintains the same general area beginning around the Iowa Nebraska border, and since we can see further out with a later run, the track leads through New England on Monday morning.

As this system propagates, areas north of the mixed will receive snows ranging from a few inches to potentially six or more in Minnesota and the Michigan U.P., while areas south will receive liquid precipitation. Speaking of the south, thunderstorms will fire along the central and western Gulf tomorrow, with additional potential next week. However I do not see the “Finger of God” (ref: movie “twister”, totally inaccurate, but at least has Helen Hunt) for tomorrow at least.

The PNW will have another jet moving in as the weekend ends adding another foot or so the the Cascades, Idaho, and Oregon. If things look interesting I will write more over the weekend.

Please be sure to view our Advisory and Radar Centers for the latest updates and developments.

As always stay tuned to your favorite weather outlet, stay informed, and stay safe!

cheers,

–patrick

Also a concern with this system is flooding in the lower elevations and coastal regions of the PNW, as our Advisory Center shows, flood watches have already been posted calling for rainfall totals up to 3″ in the valleys, and up to 7″ along the coastal range.

Significant snows will not occur over the next few days for the rest of the country, however a dusting along the northern tier will occur as a weak low ambles through. The interesting story is over the weekend however.

In running our HAMweather Precipitation Type forecast product this afternoon, a possibility for another ice storm seems to be in the future. I have created a loop of the product here for you to view, that allows you control of the animation with such parameters as speed, single frame advancement, and so forth.

When viewing the product note the timestamp on the bottom of “Valid Time,” and the red swath that appears in the middle of the country late Saturday evening into Sunday morning where the animation ends. It seems the models have an idea the possibility of freezing rain / sleet / mixed precipitation is in store for the region before the weekend is out, so if you have travel plans, please stay abreast of weather conditions because if she does come together it could be an ugly situation =)

New Years Eve Midnight Forecasts for Select Cities:

• London, England: Clear Skies, -2ºC, NE winds ~ 10kts - Full Forecast
• New York, NY: Cloudy Skies, 29°F, Light SE Winds - Full Forecast
• Chicago, IL: Cloudy Skies, 36°F, S Winds ~ 9mph - Full Forecast
• Phoenix, AZ: Partly Cloudy, 55°F, Light NW Winds ~ 5mph - Full Forecast
• Los Angeles, CA: Clear Skies, 55°F, Calm Winds - Full Forecast
• Honolulu, HI: Partly Cloudy, 72°F, light NE winds - Full Forecast

Please be sure to view our Advisory and Radar Centers for the latest updates and developments.

As always stay tuned to your favorite weather outlet, stay informed, and stay safe!

cheers,

–patrick

The question is, where will it snow, where will their be a mix of slop, and where will it rain?

In the early morning post we showed you a quick glance of forecast snowdepth, so for this late morning post I thought you might enjoy a look at forecast precipitation type based upon the 12z model run. There are four fields in this product, where precipitation type is defined as either liquid precipitation, snow, freezing rain, or sleet.

To view the animation select the image above left, or click here. Notice the swath of greens, reds, purples, and whites that flow in a general northeastern direction beginning in the southcentral United States (note legend on the graphic where green is rain, white snow etc). This is the progression of the surface low we have been discussing. On this morning’s 12z run, notice that the transition of liquid precipitation and snow is further north than it was, even from the 06z run. This is not an uncommon occurrence as models try to balance out the dynamics of a system, small transitory shifts with forecasts of conditions at the surface nearly always occur.

Also notice that as the first batch of weather moves through, another is forecast for the northern great plains beginning late Thursday evening to Friday morning, where a range from the upper great plains to the midwest will experience another glorious mix of winter muck =)

Of course the Pacific Northwest can’t be left out of the mix, as Christmas Eve ushers in another influx of snow that will transition through the Rockies, with rain falling from the central California Valley all along the southern coast.

Just for grins and giggle I also posted a forecast precipitation type graphic for Christmas Morning. Select the graphic at top right, or click here to see if the early morning conditions are what you want, or turn out as they were forecast! Of course if you want to see precipitation types throughout Christmas day, refer to the animation and note the valid time stamp at the bottom of the graphic.

Please be sure to view our Advisory and Radar Centers for the latest updates and developments.

As always stay tuned to your favorite weather outlet, stay informed, and stay safe!

cheers,

–patrick

Could Hamlet have been trying to determine the track of snow and rain this morning? After viewing the 06z NAM run this morning I decided to share with you the forecast snowdepth product that you have seen from time to time. Recall from previous posts (our search feature above right is an excellent tool for just such a purpose), that forecast snowdepth is essentially if new snow were to fall in some area within a forecast cycle, how much snow is likely to be left on the ground at the end of each interval within that forecast period, above that which is already existing at ground level.

The interesting part for this forecast (recall again that our WRF/NAM product contains forecast intervals of three hours out to 84 hours or 3.5 days from initialization), is the snowdepth forecast to exist along the surface low that we discussed yesterday, in addition to new snowfall from the Central Rockies to the Pacific Northwest.

Note in the animation (click here for full size or the graphic at top left) the swath of snow forecast to remain beginning in northeastern Texas on a track northeasterly through the Ohio valley. This is similar in thinking to yesterday’s outlook, but more on a line south and east to what the models were thinking. There certainly is some more hefty snow in the works for many areas!

Additionally, note how the snow ‘disappears’ as the animation progresses due to the warmer temperatures we discussed will advect into the region. I have the loop speed for the graphic a little faster than normal so you can appreciation the propagation of this system.

Because so much snow is already existing from the central Rockies to the Pacific Northwest, it may be slightly more difficult for you to discern new snowdepth patterns in the animation. This is actually a normal thing, especially for the Cascades this time of year, however new snowfall can be discerned within the region, especially along Northern California northward, and east into Wyoming.

That’s all for now, just wanted to give you a quick look at what NAM was thinking this morning. Oh, I almost forgot! You can see it in the animation, but I also saved a forecast snowdepth image for Christmas Day, valid 21z, December 25 (top right). So if you want to know who NAM thinks will have a white Christmas, just give it a click! =)

Please be sure to view our Advisory and Radar Centers for the latest updates and developments.

As always stay tuned to your favorite weather outlet, stay informed, and stay safe!

cheers,

–patrick