Area Forecast Discussion
Issued by NWS Little Rock, AR
Issued by NWS Little Rock, AR
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780 FXUS64 KLZK 161727 AFDLZK Area Forecast Discussion National Weather Service Little Rock AR 1227 PM CDT Fri Aug 16 2024 ...New AVIATION... .SHORT TERM... (This afternoon through Sunday) Issued at 640 AM CDT Fri Aug 16 2024 Regional WSR-88D radars depicted a complex of showers and thunderstorms ongoing across far Nrn AR into much of Srn MO. This activity was located and moving along and adjacent to a quasi- stationary boundary draped roughly W to E through Srn MO. Secondly, a small area of precipitation was lingering over Ern OK associated with a remnant MCV. Locally, conditions were fairly quiet but hot and humid conditions persisted overnight. Predawn temperatures were holding steady in the upper 70s to mid 80s. Synoptically, the upper ridge will begin to retrograde today and be replaced with subtle NWrly flow heading into Saturday. Today, the complex of showers and thunderstorm over Nrn AR will move E of the area by mid-day with mostly sunny skies returning by this afternoon. Temperatures are expected to be very hot, ranging from the mid 90s over N AR, to 100-105 degrees over Cntrl/S AR. When factoring in the forecast dew points with these expected hot temperatures, excessive heat warnings are in effect across much of the state except for the Boston Mtns and portions of NW AR where heat advisories are in place. Across the heat advisory area, heat indices are expected to range from 105 to 110 degrees. Across the excessive heat warning area, heat indices are expected to range from 110 to 120 degrees. Hi-Res CAM has been persistent run-to-run with firing up isolated thunderstorms over portions of Cntrl and portions of S-Cntrl AR late this afternoon. The aforementioned MCV over Ern OK could be the triggering mechanism being picked up with this guidance. Given the expected timing of this convective initiation, high temperatures should still be realized before clouds and thunderstorm cold-pools are generated. Confidence is low in coverage of this activity, therefore went with slight PoPs for the afternoon. If these storms do occur, DCAPE will be impressive by late afternoon, therefore damaging winds would be the primary hazard followed by large hail thanks to high CAPE values and steep lapse rates. Tonight into Saturday, another round of showers and thunderstorms are possible over N AR beginning as early as tonight. This activity is currently forecast to drop SE into Cntrl sections of the state on Saturday morning as the frontal boundary dips into Nrn AR. By late morning this activity should dissipate with ample sunshine returning during the afternoon. Overnight lows will be hot and humid once again in locations that stay rain-free and away from thunderstorm generated cold-pools. This will set the stage for more triple digit heat across W/ portions of Cntrl/S/and SW AR. Lower 90s are expected over N/NE/far E AR. Heat headlines will likely be needed for Saturday over a good portion of AR which will likely be address with the next forecast update. Relief is on the way however as we head into the long term period. && .LONG TERM... (Sunday Night through next Friday) Issued at 640 AM CDT Fri Aug 16 2024 Long term PD cont to advertise a cooler PD, w/ much of the FA expected to see near-normal to below-normal temps by early next week. Sun, perturbed and amplified H500 flow wl be prevalent over the CONUS, w/ ridging over the Cont Divide and deep troughing acrs the Great Lakes region yielding a strong meridional component of Nrly to N/Wrly flow aloft. This fetch of stronger upper flow is currently progged to extend from the Midwest/Nrn Plains, S/Ewrd towards the Mid-MS River Valley. A sfc cdfrnt wl lkly be moving Swrd thru the Cntrl Plains on Sun, and be approaching Nrn AR by later Sun night. Ahead of this frnt, a sultry airmass is fcst, w/ sfc buoyancy progs of 3000 to 4000 J/kg acrs much of Cntrl to Srn AR Sun aftn. For now, medium range model guidance has not been very consistent, and often origins of convective clusters and larger complexes are not well resolved until we reach CAM range. Of note, some recent runs of global guidance have suggested the initiation of cold pools along the aforementioned frnt, and possibly accelerating into the FA thru the aftn, capitalizing on a mid-August overlap of buoyancy, and prominent vertical shear, possibly in excess of 40 to 50 knots. Should model consistency bcm more apparent, stronger wording for severe weather potential, including damaging winds from convective complexes and MCS`s, may bcm necessary for Sun aftn/evng. For now, the ingredients wl be in place, and wl cont to monitor for severe weather potential. Thru the remainder of the PD, sfc high pressure over the Midwest and N/Erly sfc winds look to drive the local pattern, w/ rain chances bcmg negligible, and a PD of near-normal to slightly cooler than normal temps prevailing over much of the FA, before upper ridging begins to shift Ewrd again by late next week. && .AVIATION... (18Z TAFS) Issued at 1225 PM CDT Fri Aug 16 2024 Latest CAM output has supported forecaster confidence regarding overnight convection potential. Forecasts reflect this confidence, with highest probabilities across the northern third of the forecast area, between 6-12z. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 99 75 94 72 / 20 40 50 20 Camden AR 101 77 101 75 / 10 10 10 0 Harrison AR 95 71 93 68 / 10 50 40 10 Hot Springs AR 104 77 103 77 / 10 10 10 10 Little Rock AR 103 79 100 77 / 10 10 20 10 Monticello AR 101 79 101 78 / 10 10 10 10 Mount Ida AR 103 74 102 74 / 20 10 10 10 Mountain Home AR 95 72 92 69 / 10 50 40 20 Newport AR 99 75 95 72 / 20 30 40 20 Pine Bluff AR 101 78 100 75 / 10 10 10 10 Russellville AR 101 75 99 75 / 10 20 20 10 Searcy AR 101 75 96 73 / 20 20 40 10 Stuttgart AR 100 78 98 75 / 10 10 20 10 && .LZK WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 9 PM CDT this evening for ARZ004>006-103-112- 113-203-212-213-221>223-313. Excessive Heat Warning until 9 PM CDT this evening for ARZ007- 008-014>017-024-025-031>034-039-042>047-052>057-062>069-121>123- 130-137-138-140-141-230-237-238-240-241-340-341. && $$ SHORT TERM...55 LONG TERM....72 AVIATION...55