COMPLEX PATTERNS: Hey y’all, glad to be writing another blog post! We have a really uncertain few days ahead of us and this is the perfect opportunity to write about some of the weather North Texas will experience in the coming days. One of my favorite parts about winter in Texas is how multiple kinds of weather can occur, often on the same day, throughout the winter. This notion definitely stays true to the time ahead of us as well and leads many of us to ask: what will happen with the upcoming weather pattern? SHORT RANGE: Thursday brings the persistence of a sunny, seasonally warm day with plentiful amounts of blue skies and above average temperatures. However, there will be a noticeable change in winds, with gusts up to 20 miles per hour headed northward. These winds are a sign of the change in the weather pattern North Texas will be seeing. So, while the day will continue to be warm like most of the days this week have been, look for some noticeable breezes and the potential for a few clouds in the evening. Nightfall sees a typical drop in surface temperature, but it won’t be as wild as the temperature swings in the past few days (places like Waco saw a near 50 degree difference between the morning low and the daily maximum high on Wednesday) due to the increase in moisture from the active upper-level jet stream and a detached low pressure system. Rain chances increase as the night continues due to high levels of ascent, which should tap into the active jet and move eastward as Friday morning progresses. The 00z NAM showing model predictions for rainfall at 9 am and 5 pm on Friday. FRIDAY’S STORM POTENTIAL: As models have slowed the progression of the cold front over the past few runs, in addition to the new high resolution mesoscale model guidance, it has increased the potential for severe weather east of the metroplex midday Friday. While moisture is set to move out eastward midday as the front passes through DFW, ahead of the front in portions of NETX, the potential for lightning and thunder is considerable but still unknown. There is NO risk for tornadoes or even hail, but there is a chance for some lightning strikes as the afternoon begins. In addition, some model guidance supports pop up thunderstorms for DFW in the evening as well, with the potential for a squall line to develop behind the front. As the afternoon turns into evening, the potential for scattered thunderstorms increases. Strong storms are improbable but not impossible east of the metroplex. The new pattern, as a result of the upper level low, will bring much cooler and more seasonal weather with highs on Saturday struggling to break out of the 50s, even with clearer skies. The difference between the Euro and Canadian model for potential weather on Sunday. Note the placement of the blue line—that’s upper level freezing line and indicates that the Canadian Model is showing a lower ULL than the Euro. FUTURE UNCERTAINTIES: I’ll admit, I don’t know what’s going to happen for Sunday. A fairly potent shortwave will move into the southern plains overnight Saturday into Sunday. While temperatures will decrease as a result, it’s more of a strengthening of the effects of the initial front on Friday, rather than a separate front. However, coupled with this shortwave is another upper level low that is capable of producing moisture and increases the uncertainty of the forecast. The uncertainty of the moisture potential and severe storm placement as a result of the speed and strength of the front on Friday also impact the significance of the shortwave over the weekend. Shortwaves like this are very hard to track from even a couple days out, meaning the placement of the low is extremely uncertain as of now and can vary by even a hundred miles. A low tracking upper level low moving through central Texas is much more favorable than a higher tracking upper level low that moves across the red river, because the temperatures that produce wintry mix or even snow are going to be found North of the low. The presence of the initial front on Friday makes this even more complex because a small change in timing or variance of temperatures by even two degrees could massively change the placement of the trough. In general, the global models are showing almost unanimous agreement on snow in Oklahoma and rain in Texas. So, as a result of the massive uncertainties associated with the complex, double upper level low setup, and the lack of high resolution guidance due to the proximity from the event, we are going on the conservative route and showing temperatures in the upper 30s overnight Saturday and in the mid 40s for Sunday. Latest Euro Ensemble Mean indicates North Texas snowfall isn’t out of the realm of possibilities. A wintry mix is, however, possible for the red river basin, given high moisture aloft. lt can’t be ruled out for DFW at this time, however, it remains unlikely given current model guidance. We will know more in the upcoming days.
For now, stay safe, stay warm, and stay weather aware! -Colin Welty |
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