As discussed, a powerful storm system will be affecting the area for the next couple of days. This storm system will be responsible for a variety of weather across the state, including a historic blizzard in West Texas to heavy rainfall and severe weather in our area. The Storm Prediction Center has placed our entire forecast area in an enhanced risk area for severe weather. Abundant moisture, indicative of dewpoints well into the 60s, very warm temperatures well into the 70s, will create convective instability around 2000 J/Kg. Combined with adequate shear, approaching cold front, and destabilization from storm system, the parameters are in place for severe weather across our area. The main threats will likely be heavy rainfall, but damaging winds and large hail will also be possible. In any discrete storms that can become rooted in the boundary layer may be able to spin up an isolated tornado. Most of the convection will be tied to a strong Arctic cold front that will move across the area and force the convection to take on a linear storm mode which should lessen the tornado threat. The cold front should be around DFW in the 10:00 PM to 12:00 AM timeframe. Behind this front much colder air will spread into the region lessening the severe weather threat.

Severe weather threat for December 26, 2015 as issued by the Storm Prediction Center.

Current watches/warnings across the state as of 10:00 AM December 26, 2015.

Persons traveling across the Lone Star State should be aware of all the different watches and warnings posted as a powerful winter storm impacts the region. Residents of North Texas should be aware that the Winter Storm Watch has been expanded to just outside this website’s forecast area border. Accumulating snowfall will be possible in this area Sunday night. Wet snowflakes may fall as far east as the DFW Metroplex, though confidence in this is not high and highly depends on the track of the upper-level low and what dry slotting develops. Anyone traveling to West Texas should note that traveling in this region is strongly discouraged as a historical blizzard is going to take shape.

Satellite image for December 24, 2015 depicting next potent upper-level storm system, to affect the area the weekend after Christmas, coming ashore in the Pacific northwest.

For those wanting a taste of winter, the exceptionally warm weather we have been experiencing for the last several weeks is about to come to an abrupt end. Unfortunately, this will not be in time for Christmas. Expect unseasonably warm conditions to persist the next couple of days.

A strong upper-level storm system is now entering the Pacific northwest. This will be our next major weather maker for not only us, but much of Texas as well. This system is expected to dig down into the desert southwest and strengthen and become a closed low.  It will continue digging into northern Mexico, and then, swing east northeast across Texas over the post-Christmas weekend. A deep trough will envelop much of the Western CONUS and allow a big chunk of Arctic air to spill southward along the lee of the Rockies. This strong, Arctic cold front will begin moving across Texas on Saturday and reach the DFW area in the very early hours on Sunday morning while spreading a shallow, low-level Arctic airmass in its wake. The coldest air so far this season will follow the passage of this front and bring an abrupt end to our warm weather pattern.

Out ahead of the upper-low, strong southwest flow aloft and southerly flow at the surface will advect warm moisture laden air into the region. PWATs (precipitable water) will climb to the 99th percentile for late December across the area. What this means is the potential for another very heavy rainfall event for our area on Saturday into Sunday. It is too early to pinpoint exact amounts, but rest assured it does look like another multi-inch rain event for our area. This will promise to bring already extraordinary annual rainfall totals above the 60 inch mark for DFW. In addition to the heavy rainfall, areas east of the I-35 corridor will have the potential for severe weather with this system. Nearly all modes of severe weather will be possible. More details on the severe weather will unfold in coming days as we have a better idea of mesoscale parameters.

While we have rain in our area, much of west Texas will be experiencing what may become a historical blizzard for that region. Very heavy snowfall is expected in that part of the state with some potential for major accumulations. Near blizzard to blizzard conditions will be possible across much of West Texas from the Permian Basin into the Texas Panhandle. Winter Storm Watches have already begun posting for that part of the state. Travelers heading into that region should be extremely cautious of the weather and plan to make alternative travel plans.

The snow may begin to spread into the western half of North Texas Sunday night into Monday, as the cold air deepens in our area due to the track of the upper-low passing nearly over top of the area. Rain may begin to mix with or change to snow as far south as the DFW area during this time frame. This is all dependent on the exact tract of the low and where the dry slot sets up with this system. Any deviation to the northwest of the tract of the low will keep the cold air warm enough for the precipitation to remain all liquid in our area. If the low moves further south or southeast, then a changeover to all snow could produce some minor impacts to our area. Stay tuned as this part of the forecast could change significantly.

Lows by Tuesday morning will likely drop into the 20s most areas with temps struggling to make it into the 40s for Monday and Tuesday.

Stubborn pattern over the United States that has what cold is available in the west and warmth for the eastern half of the country. This pattern has been dominant for much of December and will continue through Christmas with near record heat in some places.

For those hoping to see some actual winter weather or temperatures this year for Christmas are going to be very disappointed. Temperatures well above normal will be the rule this week as with much of December 2015. In fact, December 2015 is in the running of being the all time hottest December on record for DFW. As has been the case this year, intense southern stream storm systems have brought copious amounts of rains to the area. It looks like the storm system we are watching post Christmas will be no different.

In the meantime, there a couple of smaller features to discuss in the short-term. Today, a weak cold front will push the soupier air and fog from this morning southeastward as it sweeps across the area. This will allow clouds to clear and temperatures to fall into the 40s overnight (still well above normal for this time of year). Tomorrow morning will likely be the coolest morning of the week. The radiational cooling setup tonight combined with light winds and lingering moisture will set the stage for the potential for fog tonight after midnight. Some of this fog could be dense and may take sometime Tuesday morning to burn off.

A weak short wave trough will dive out of the Rockies into the Central Plains Tuesday and rapidly intensify. This will draw the soupier air back over DFW by Tuesday afternoon, setting the stage for scattered convection from the I-35 corridor points eastward by early Tuesday evening. The official forecast will carry POPs at 20 percent to account for any storms. Any storms that form will have the potential to become strong to even severe as 1000 to 2000 J/Kg of CAPE can be realized by Tuesday evening across the area. Any severe storms would be capable of damaging winds and the threat of moderate to large hail. An isolated tornado threat cannot be entirely ruled out east of the Metroplex, but the tornado threat looks low. Storms will quickly move eastward as the shortwave lifts northeast away from the region.

In its wake, southwest flow aloft will dominate out ahead of potent storm system that moves onto the Pacific northwest. This system is expected to dive into the desert southwest and intensify while becoming partially closed off. The computer models diverge substantially in the handling of this system, but it looks like it will be our next big storm system post Christmas. Warm air advection showers will begin to break out across the area as early as Christmas Day afternoon. This system will have a good fetch of moisture to work with, given the long stretch of southerly flow ahead of it, bringing with it a potential for heavy rainfall as a rather strong cold front dives in from the north on Saturday. It is too soon to tell how much rain we will get, but it does look like at least enough to send us over the 60 inch mark at DFW for the year. This system will need to be watched closely for heavy rainfall leading to more flooding problems and if the precipitation shuts off before the significantly colder air arrives. Stay tuned for inevitable updates to this forecast as the week progresses.

12/9/2015 Current satellite image of next storm system and path.

After a good reprieve from the excessive rainfall over the Thanksgiving Holidays, rain will return to North Texas this weekend. Rain chances will be highest on Saturday evening into Saturday night. The greatest threat for flash flooding will be along and east of the I-35 corridor where the heaviest rains fell last time. Grounds are still saturated from the last event, and coupled with the dormant vegetation, flash flooding will be a real concern. Instability with this system will be small with high shear, thus a rogue strong to severe storm cannot be ruled out.

A warm air advection pattern will continue through Saturday as southwest flow aloft prevails across the area out ahead of the storm system. This will advect moisture and ridiculously warm temperatures into our area. In fact, they will be downright hot for December. Highs on Friday may flirt with the record high at DFW which is 80°F set in 1938 and 1996. This will be highly dependent on cloud cover and moisture, thus the dfwweather.org forecast has officially kept highs just shy of the record. Overnight lows will be well above the normal high for early December Friday night (in the low to mid 60s) which is about 59°F. These temperatures are nearly 30 degrees above normal for this time of year. A Pacific cold front will push across the area Saturday night and this will be the main focus for shower and thunderstorm development. Some lingering rain showers behind the front may be possible on Sunday, especially if the slower ECMWF scenario pans out. Otherwise, temperatures will return to more seasonable levels behind the front with lows in the 40s and highs in the 50s.

It is too early to forecast rain amounts with the weekend system, but early indications are that amounts will generally be around an inch or less. It must be stressed, we are not expecting anywhere close to the amounts received over Thanksgiving.

We will be watching another storm system taking shape for next week that may bring even more rain to the area.

DFW Weather forecasted rain amounts through Sunday 12/13/2015.