Area Forecast Discussion
Issued by NWS Dallas/Fort Worth, TX
Issued by NWS Dallas/Fort Worth, TX
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357 FXUS64 KFWD 270548 AFDFWD Area Forecast Discussion National Weather Service Fort Worth TX 1248 AM CDT Mon May 27 2024 ...New Short Term, Aviation... .SHORT TERM... /NEW/ /Memorial Day Into Tuesday/ ...More Severe Weather Returns Late Today Into This Evening... ...More Numerous Showers/Storms Tuesday With Locally Heavy Rainfall... After a much-needed quiet period yesterday and through much of Memorial Day, things unfortunately become quite unstable and volatile by this evening with unsettled weather continuing off and on Tuesday. The highest likelihood for isolated to scattered severe storms will be very late this afternoon and through midnight, with lesser chances overnight. Locally heavy rain and flooding gets added to the mix by later on Tuesday, as a very energized northwest flow aloft regime evolves across the area. A weak frontal boundary has stalled this evening along the I-20/30 corridors with tropical-like moisture and very light winds both ahead and behind this feature. I expect some fog to develop across especially eastern Central Texas where surface dew points are pushing around 80 degrees in spots. That`s unheard of this time of year across our region. It`s possible dense fog could develop across the far southeast counties enough for a brief advisory this morning, but will await development to occur. Our weak stalled front will mix readily north across possibly all but our northeast counties, as a strong shortwave induces pressure falls well west of the area. Peak heating will see temperatures soaring into the 90s with heat index values right to around 105 degrees across particularly eastern Central Texas where a Heat Advisory remains in effect through mid evening. In addition, the heat and rich moisture will help surface-based instability to soar up to 5000-6000 J/KG as additional mid level energy lifts northeast from Mexico. Combined with very steep lapse rates => than 8 Deg C/km, the atmosphere as noted beforehand becomes very volatile. This should help ignite isolated to scattered severe storms with all modes of severe weather possible, including tornadoes by this evening with discrete storms that can develop. The only thing missing is a surface focus, or coverage would be higher than the 20%-40% advertised. Still, most CAMs are showing the potential with the strong mid level impulse arriving late today. With this still being the end of the holiday weekend, those planning to be outdoors in this oppressive heat will need to keep a close eye on forecast updates and radar if possible. Though a few storms will linger near the stalled boundary across our northeast counties just past midnight, a downward trend in coverage and intensity of storms will occur as temperatures cool and subsidence briefly takes over overnight and Tuesday morning. Morning conditions will remain very humid and warm with lows in the 70s. After the reprieve Tuesday morning, the aforementioned evolving and energetic northwest flow regime sets up across the Southern Plains as the shortwave ridge to our immediate west dampens. Though more expansive cloud cover will hold high temperatures Tuesday to the mid-80s to the lower 90s, plenty of strong deep layer shear >40 kts, large-scale ascent, and steep lapse rates will again result in some severe weather with the added addition of flooding late in the day as localized heavy rainfall from more widespread convection evolves late in the day. Details are more murky on Tuesday regarding coverage and timing of impacts as models struggle with these scenarios of high moisture, instability, and energy aloft, so my advice is too stay abreast of the forecasts early this week. It looks like May is definitely going out like a lion versus a lamb. Wish I had better news. 05/Marty && .LONG TERM... /Issued 322 PM CDT Sun May 26 2024/ /Monday Night into the weekend/ With a mid/upper-level ridge building over the western U.S. and consolidating lows/troughs over the Great Lakes, North and Central Texas will be on the southern fringe of a northwest flow pattern by late Monday. Regional models and high-resolution CAMs show rain chances may return as early as Monday evening as a cold front continues to slowly move across the region. This will kick-off the next multi-day period of unsettled weather across North and Central Texas. Daily thunderstorm complexes are expected to develop across the High Plains in response to a series of subtle shortwaves/perturbations embedded along the northern periphery of the larger scale ridge. Convection will spread eastward nightly, bringing periodic rain and storm chances to the region through the end of the week. The pattern will become increasingly messy as the week wears on as mesoscale features evolve. This lowered predictability has resulted in some broad-brushing of PoPs, especially mid/late week. The main change with this forecast update will be the introduction of slight chance (20% of less) PoPs after 00Z Tuesday (7 PM Monday) generally near and west of the I-35 corridor. As the backdoor front temporarily stalls over the region late Monday, the moist/unstable and briefly uncapped airmass south of the front will be primed for storm development with the potential for severe weather given the 50 kts of available effective shear. A strengthening low level jet during the evening will also enhance moisture advection and isentropic ascent through the overnight period. If storms develop, all severe hazards will be possible. By Thursday into Friday, the front should lift back northward as a warm front, repositioning the warm/moist airmass more directly overhead and fueling thunderstorm development through the end of the week and into the weekend. With PWATs approaching 1.75 to 2 inches at times, periods of locally heavy rainfall are likely. Due to lingering moist soils, localized flooding issues may also emerge, especially wherever higher convective rain rates occur. Temperatures will be fairly steady throughout the week though tempered slightly by the expected cloud cover and precipitation. Highs will generally be in the 80s to lower 90s with lows in the mid 60s to lower 70s. 12 && .AVIATION... /NEW/ /06Z TAFs/ A weak FROPA made it to about I-20(I-30 out E), but has since lost any upper support with AFW/FTW/DFW seeing light NE around 5-7 kts with light S or VRB winds at DAL/GKY 5 kts or less. Moisture to the south of this boundary is very tropical-like and high and with only light S or calm winds, I can`t rule out spotty 5-6sm BR near GKY and possible DAL/FTW by 12z, but the better bet for MVFR/IFR and possibly LIFR conditions will be at ACT between 10z-14z. Once the old boundary and ESE/SE winds pick up to between 10-15 kts, then all sites will see VFR with SCT Cu and high clouds. With the old surface front out of the area, scattered TSRA are expected over the DFW D10 area by 00z Tuesday and have an added a VCTS until almost 03z per latest CAMs. The only driver will be mid level energy arriving at peak heating. However, with a very unstable airmass, look for TS+ and GS/GR to occur with TSRA. 05/Marty && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 74 95 72 87 69 / 0 10 40 50 60 Waco 75 93 72 89 69 / 0 20 20 40 60 Paris 69 92 67 85 66 / 10 5 20 40 50 Denton 68 93 69 84 67 / 0 5 40 50 60 McKinney 70 93 69 83 68 / 0 10 30 50 60 Dallas 75 95 73 88 69 / 0 20 30 50 60 Terrell 73 91 70 86 68 / 5 20 30 50 50 Corsicana 75 91 71 90 70 / 5 20 20 40 50 Temple 75 92 72 89 68 / 0 30 20 40 50 Mineral Wells 68 95 70 88 67 / 0 10 40 50 70 && .FWD WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM CDT Monday for TXZ135-145>148-158>162- 174-175. && $$