Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
551 FXUS63 KIND 071319 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 919 AM EDT Fri Jun 7 2024 .KEY MESSAGES... - Breezy today. - Chance of showers Saturday. - Near-average temps through midweek, then warming trend late next week. && .FORECAST UPDATE... Issued at 919 AM EDT Fri Jun 7 2024 Beautiful morning in progress as a surface ridge approaches from the west. Temperatures have warmed nicely since sunrise with the dry air across central Indiana. 13Z temperatures were in the 60s. Forecast is in excellent shape for the rest of the day. The cu field that develops later will be at a much lower coverage than Thursday and focused particularly over the northeast half of the region. The main issue for today will be the winds as the combination of a well mixed boundary layer and a tight surface pressure gradient will be enough to generate peak gusts up to 35 mph by the afternoon. Gusts will then drop off near sunset. Low level thermals support highs ranging from the mid 70s in our northeast to the lower 80s in the Wabash Valley. Zone and grid updates out. && .SHORT TERM (Today and tonight)... Issued at 300 AM EDT Fri Jun 7 2024 Rest of the Overnight and Today... GOES-16 IR satellite loop and obs were showing a patch of mid clouds dropping southeast across the Kokomo and Muncie areas in fast northwest flow aloft. Between the northwest flow, there was elongated low pressure from the eastern Great Lakes to northern Alberta with embedded upper lows over the northern Great Lakes and northern parts of Manitoba and Saskatchewan. Meanwhile, there was a dome of high pressure over West Texas and New Mexico. At the surface, high pressure was centered over southwestern Missouri and eastern Kansas while a cold front was dropping southeast across the South. Temperatures were still in the 60s. Large temperature and dew point depressions existed with dew points only in the middle 40s to lower 50s. That and Hi-Res soundings suggest fog will not be an issue early this morning. Look for the surface high to move into the Mississippi Valley late today. Relate subsidence and the dry column will support plenty of sunshine. Alas, cu development progs were suggesting little to no diurnal cu. However, Hi-res soundings are indicating deep mixing down from 5K feet and higher, where 25+ knot winds will likely mix down to the surface late this morning and afternoon. With mixing easing up and eventually ceasing, there will be a big drop off of winds by evening. DESI graphics have only a small spread between the 25th and 75th percentile of 2m temperatures with mean temperatures supportive of afternoon highs in the upper 70s northeast to the lower 80s southwest. Tonight... Although the night will start off clear as winds drop off, CAMs are suggesting an MCS, over Nebraska and Kansas will move this way overnight with a decent chance that dying remnants will move into the Wabash Valley after 5 AM. Hi-RES soundings are showing the column becoming quickly moist. That said, instability progs are showing any elevated instability will be well west of the area, so will only put showers in the grids over mainly southwest sections with PoPs to 30 to 40 percent. Due to the difficulty forecasting MCS evolution that far out, did not yet jump on better coverage per some of the CAMs but the possibility is there. && .LONG TERM (Saturday through Thursday)... Issued at 300 AM EDT Fri Jun 7 2024 The long range will start off with potentially active weather as a an MCS passes through early Saturday. There are some questions regarding this feature including where it develops and how long it persists. There are reasons to believe that the MCS will decay as it heads into Indiana. First, the low-level jet feeding it is positioned more to our SW and as the system progresses eastward it may outrun its source of buoyant air. If anything the system may experience preferential growth on its southwesterly flank. An area of stratiform rain could still pass over large portions of the CWA in this scenario. Second, poor lapse rates and weakening upper-level flow may cause the downshear portions of the MCS to decay with eastward extent. Guidance has trended slightly faster bringing a warm front across the state Saturday morning, which is in part fed by the low-level jet mentioned above. Should this boundary end up further north there may be a bit more buoyancy for the potential MCS to work with. Still, given all the negatives mentioned above the MCS would likely be in a decaying state regardless. Beyond that, guidance generally shows northwesterly flow aloft and east coast troughing through about midweek. Precip chances remain low as dry northerly flow dominates. A wave embedded in the broader upper flow may pass by Monday or Tuesday but the bulk of guidance remains mostly dry. Only the GFS shows a more wrapped up low with greater precip chances...but this is an outlier. Will carry slight chance PoPs Monday into Tuesday, however. Temperatures look to be near average through much of the coming week again due to northerly flow. Towards the end of next week, and next weekend, ensemble guidance is showing an increasingly coherent signal for ridging over the eastern CONUS. Ensemble 500mb jet stream lies well to our north across Canada. Such a pattern would favor increasingly warm and humid conditions with fewer chances for organized precipitation (as storm systems generally pass to our north). Air mass convection would still be possible depending the magnitude and axis of best moisture return. && .AVIATION (12Z TAF Issuance)... Issued at 546 AM EDT Fri Jun 7 2024 Impacts: - Winds 280-310 degrees to near 15 knots and gusts 21 to 27 knots from 15z-23z Discussion: Gusty NW winds late this morning and afternoon will be the main concern to aviation due to diurnal mixing. Otherwise, a dry column and high pressure building in from the Ozarks will provide VFR flying conditions through the TAF period, although would not rule out a shower at KHUF and KBMG after 09z Saturday. && .IND WATCHES/WARNINGS/ADVISORIES...None. && $$ UPDATE...Ryan SHORT TERM...MK LONG TERM...Eckhoff AVIATION...MK