Area Forecast Discussion
Issued by NWS Oklahoma City, OK
Issued by NWS Oklahoma City, OK
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726 FXUS64 KOUN 182337 AFDOUN Area Forecast Discussion National Weather Service Norman OK 637 PM CDT Thu Jul 18 2024 ...New AVIATION... .SHORT TERM... (This evening through Friday) Issued at 342 PM CDT Thu Jul 18 2024 Only issue in the short term will be a potential for convection late tonight across northwest Oklahoma. All CAMs along with latest NAM & ECMWF suggesting QPF developing across our west after midnight perhaps due to mid-level moisture upglide seen on the 310 K isentropic surface. Forecast soundings suggest a mid-level moisture layer but dry in the lower levels with low confidence if the lower levels saturate. As a result, will introduce very low POPs for tonight across northwest Oklahoma should the lower levels moisten up. && .LONG TERM... (Friday night through next Wednesday) Issued at 342 PM CDT Thu Jul 18 2024 The forecast remains on track with our next system starting to come through resulting in a wet weekend, especially Saturday. A weak upper trough from the main jet flow up in Canada will be digging across the U.S. Great Plains and into the Southern Plains by Friday night when our pressure heights start falling. Although models have been performing poorly with the moisture fields in the short term, they do suggest an additional boost of moisture advection/increase from southerly winds on Saturday with a lifting warm front so still expecting robust surface moisture for this weekend. Forecast soundings showing deep moisture from the mid-levels up being transported within the upper trough, while a fairly weak but adequate low-level jet over the Southern High Plains may also provide some additional low-level moisture and ascent in the 925-850 mb layer across our western CWA. The first of a series of shortwaves embedded in the trough is expected to reach our western CWA on Friday night as well and over our remaining CWA during the day. In addition to the elevated convection, low-level moist air overrunning the warm front may also increase rain shower coverage on Saturday while potentially uncapped across our western CWA by late afternoon could result in more surface based convection developing there. Lots of moisture fuel and lifting mechanisms will be in place but instability will be limited. With the location of Friday nights low-level jet and mid-level shortwave across our western CWA, will start but restrict POPs across northern and western Oklahoma and adjacent western north Texas starting early Saturday morning into the afternoon eventually into portions of central Oklahoma (and OKC Metro) toward the evening hours keeping them generally west and north of the I-44 corridor. As Saturday evening progresses, will see the rain/storms increase eastward through the overnight hours. Although indistinguishable to see in the models, there still appears to be a weak cold front pushing through late Sunday with POPs briefly ending behind it. With the synoptic boundary across northern Texas perhaps stalling out, will restore POPs for Monday and Tuesday keeping the probabilities highest (20-30%) across our southern CWA. Expected rain total accumulations this weekend through Monday range from 0.10 to 1.0 inches with the higher amounts across our southern and eastern CWA. Grand Ensemble probabilities are less than 20% for total rainfall accumulation over 1 inch. Although the main energy will have moved out, we`ll still remain under the trough through the end of next week keeping our temperatures just below seasonably average. && .AVIATION... (00Z TAFS) Issued at 637 PM CDT Thu Jul 18 2024 Widely scattered showers across southeast Oklahoma have generally dissipated, and the potential to see any more is rather low this evening. There are also low chances (20%) of showers or storms across northwest Oklahoma Friday morning including the KWWR area, but too low to include in the TAFs. Otherwise, VFR conditions are expected through this forecast period. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 65 88 67 87 / 0 0 0 20 Hobart OK 66 92 69 90 / 0 0 20 40 Wichita Falls TX 68 92 70 94 / 0 0 0 10 Gage OK 65 89 66 88 / 20 20 30 50 Ponca City OK 63 90 66 87 / 0 0 10 30 Durant OK 68 90 65 92 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ SHORT TERM...68 LONG TERM....68 AVIATION...26