Area Forecast Discussion
Issued by NWS Little Rock, AR
Issued by NWS Little Rock, AR
876 FXUS64 KLZK 120908 AFDLZK Area Forecast Discussion National Weather Service Little Rock AR 408 AM CDT Wed Mar 12 2025 ...New SHORT TERM, LONG TERM, AVIATION... .SHORT TERM... (Today through Thursday Night) Issued at 336 AM CDT Wed Mar 12 2025 In the near term, the focus will be on a storm system exiting the southern Rockies into the southern Plains this afternoon. Moisture will gradually increase ahead of the system, and temperatures will be well above average under a partly sunny sky. By late this afternoon/early this evening, most unstable CAPE values could be as high as 1500 Joules/kilogram in the far western counties. Scattered showers/storms are expected to initiate in southeast Oklahoma/northeast Texas during this time frame, and head into west central/southwest Arkansas. There is a small window of opportunity for very large hail/damaging wind gusts in this part of the state. As the night wears on and precipitation heads to the east, a weakening trend is likely. Forecast rainfall is nothing impressive, and mostly from a tenth of an inch to perhaps a half inch in places. Some rain will linger toward the Mississippi River Thursday morning before precipitation ends. The air mass will not change much at all Thursday, with temperatures remaining well above seasonal and dewpoints in the upper 40s to upper 50s. This will be ahead of a new and more powerful storm system that will be in the process of organizing in eastern Colorado. The system will be the main player in the long term. && .LONG TERM... (Friday through Tuesday) Issued at 336 AM CDT Wed Mar 12 2025 To begin the PD, a seasonably potent and anomalous upper trof and asctd sfc low are progged to be moving Ewrd quickly acrs the Cont Divide and Cntrl High Plains on Fri mrng. At this point, there is high confidence on the general overlap of modest instability and deep layer wind shear over a large portion of the Srn Cntrl US and greater Arkansas region. A significant 100+ kt cyclonic jet streak is progged to eject acrs the Ozark Plateau on Fri aftn to evng, w/ the asctd sfc low quickly deepening and advancing N/Ewrd over the Cntrl Plains and Midwest. This jet streak and asctd broad synoptic ascent should overspread modest low-lvl Srly flow and poleward moisture transport thru the day Fri. In addition to strong kinematics, a strong component of dry air momentum transport to the west of the warm sector should yield a dryline acrs Ern OK. Based on most guidance as of now, this dryline is expected to mix Ewrd into at least Wrn AR sometime Fri aftn, and could serve as a source of local convective development. A few problematic uncertainties that have yet to be determined include the magnitude of low-lvl moisture content on Fri aftn, and the role that widespread capping could serve. Most members of the 12/00Z deterministic guidance continue to advertise a narrow corridor of >60F dewpoints extending over at least the S/Ern quarter of the state near 21Z on Fri aftn. Greater potential instability wl certainly accompany higher moisture content, though lesser sfc moisture over Nrn to N/Ern AR could be compensated for by synoptic scale ascent/destabilization and anomalously warm sfc temps. Regarding capping, select point fcst soundings suggest strong capping wl be in place over much of the state thru the early aftn timeframe. Synoptic ascent and low-lvl WAA/moisture transport wl certainly help w/ slowly eroding capping up to convective initiation, but there is still moderate uncertainty on how strong capping could be, how quickly is it eroded, or wl it be eroded over the FA before stronger forcing departs. Given an ideal scenario, e.g., capping inhibits early onset precip activity, and the fcst parameter space materializes, the potential for severe weather over the Ern half of the state is concerning, particularly if discrete cell development happens along the fcst dryline. A conducive parameter space for supercell development is expected invof this sfc bndry, at least initially Fri aftn to evng. If supercells can maintain a discrete storm-mode, a greater threat for all severe hazards, including tornadoes wl be seen. By the later evng timeframe, upscale growth into a more linear segment wl be possible given the strong kinematic parameter space, and the threat for damaging winds wl increase. The threat for severe weather would lkly persist into the later evng timeframe acrs far Ern AR and the MS River Valley as a strong LLJ develops. W/ these uncertainties in mind, a possible failure mode to acknowledge would be capping not eroding enough to allow for convective initiation during the aftn hours, and storms developing later in the evng and more Ewrd where the aforementioned LLJ would promote stronger local ascent. In addition to the severe weather threat, significant gradient (or background) winds are expected over much of the Srn Cntrl US, including the greater Arkansas region given the proximity and track of the fcst sfc low. Strong and gusty winds wl be possible over much of the state on Fri, and possibly into early Sat mrng. Thru the remainder of the PD (Sat-Tues), drier air is expected to filter into the state in the wake of the departing sfc low. Sfc high pressure should settle in over the Srn Cntrl US, and promote a warm/dry pattern locally w/ settled weather expected. && .AVIATION... (06Z TAFS) Issued at 1233 AM CDT Wed Mar 12 2025 Some low level wind shear is expected this morning. Winds at 2000 feet will be southwest at 40 to 45 knots. Otherwise, high clouds will increase today, with scattered cumulus this afternoon at 4000 to 5000 feet in central/southern Arkansas. Overall, VFR conditions are in the forecast. The wind today will be south to southwest at 10 to 15 knots with higher gusts. Scattered showers and thunderstorms will develop this evening in western sections of the state and will spread to the east. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 78 56 77 56 / 0 50 10 0 Camden AR 79 57 80 57 / 0 60 0 0 Harrison AR 79 53 78 56 / 0 30 0 0 Hot Springs AR 78 55 77 55 / 0 70 0 0 Little Rock AR 79 57 78 57 / 0 70 10 0 Monticello AR 79 60 79 58 / 0 60 10 0 Mount Ida AR 79 54 79 55 / 10 60 0 0 Mountain Home AR 79 55 78 56 / 0 40 0 0 Newport AR 76 58 75 57 / 0 50 20 0 Pine Bluff AR 79 59 78 57 / 0 70 10 0 Russellville AR 81 54 80 55 / 0 60 0 0 Searcy AR 78 55 77 55 / 0 60 10 0 Stuttgart AR 77 59 76 59 / 0 70 10 0 && .LZK WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...46 LONG TERM....72 AVIATION...46