Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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557 FXUS63 KIND 282349 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 749 PM EDT Sun Apr 28 2024 .KEY MESSAGES... - Showers and storms return to the Wabash Valley overnight. - Warmer than normal conditions continue through the week. - Additional thunderstorms expected Friday into Saturday. && .SHORT TERM (This evening through Monday)... Issued at 252 PM EDT Sun Apr 28 2024 GOES-16 visible loop and obs were showing filtered sunshine across central Indiana this afternoon along with some fair weather cu. Lack of synoptic lift and only weak instability and a mid level cap have cap convection from going up. In addition, the southerly breeze with gusts to near 30 knots has resulted in well above normal temperatures in the upper 70s to lower 80s early this afternoon. H20 vapor imagery and upper air data was showing a percent ridge of high pressure over the Appalachians with a low spinning over southern South Dakota and northern Minnesota. The latter feature will move into the eastern Dakotas by Monday morning and Lake Superior Monday evening. This will bring an associated cold front to near a western Chicago suburb to St. Louis line Monday evening. Sufficient instability and deep moisture combined with the approaching system and any impulses ahead of it will bring widespread showers to the Wabash Valley overnight and all of central Indiana Monday. Went with 70% coverage over the Wabash Valley to 20% or less east central tonight and 70-80% over all of central Indiana Monday. Ensembles 25th percentile 24 hour QPF ending 00z Tuesday for the upper Wabash Valley is 0.25 inches and the 75th percentile near and inch. Most other locales ranged from 0.20 inches to 0.60 inches in the respective percentiles. This should not lead to anything more than perhaps some brief river flooding along the lower Wabash early next week. The widespread cloud cover and convection should keep temperatures down more tomorrow but with breezy southerly winds continuing, they will still be above normal with highs in the 70s expected. && .LONG TERM (Monday night through Sunday)... Issued at 252 PM EDT Sun Apr 28 2024 Monday Night Through Wednesday. Precipitation will quickly come to an end Monday night into early Tuesday as the line of convection continues to weaken as it pushes further east and away from the forcing associated with the low pressure system that has brought severe weather to much of the Central Plains for the last few days. This will bring a brief break in rain chances for central Indiana through early Wednesday when the next system looks to push through the Dakotas into the Great Lakes region. Rainfall from this low pressure system is expected to stay to the north and west of central Indiana, but a decaying storm complex may linger just long enough to reach the northwestern counties Wednesday morning, but either way some enhancement in low and mid level clouds looks likely for much of the day Wednesday. Thursday Through Sunday. Forecast confidence into the second half of the work week and weekend begins to lessen with significant model spread on the cyclogenesis timing and location of the next system that ejects from the Rockies with spatial differences in the order of multiple states between the 00Z GFS and 12Z GFS. That being said, the large scale nature of this low will be enough that there is higher confidence in precipitation Friday into Saturday but details on the severe potential or QPF would be more determined by the track that the system ends up taking. Conditions then return closer to normal in the aftermath of the late week system with low rain chances continuing into Saturday with highs in the low 70s and lows near 50. && .AVIATION (00Z TAF Issuance)... Issued at 747 PM EDT Sun Apr 28 2024 Impacts: - Showers after 08z-12z, thunderstorms also possible - MVFR and very brief IFR conditions possible in convection; MVFR CIGs tomorrow - Non-convective low level wind shear 06z-10z Discussion: The terminals will start off with VFR flying conditions but then convection will move in from the west toward daybreak as a cold front approaches. Thunder will also be possible along with MVFR and brief IFR conditions. Most likely location for thunder will be at KLAF between 07-12Z. Periodic showers are expected to continue tomorrow. More detailed precipitation timing/intensity will be added in later issuances as confidence increases. Non-convective low level wind shear will be possible 08z-12z as a 40 knot low level jet moves across, and the near surface calms associated with cooling. In addition, southerly winds will gusts to 25 knots for a few more hours tonight and then return once again tomorrow morning. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...MK LONG TERM...White AVIATION...Updike