Area Forecast Discussion
Issued by NWS Louisville, KY
Issued by NWS Louisville, KY
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
923 FXUS63 KLMK 021742 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 142 PM EDT Sun Jun 2 2024 ...Updated Aviation Discussion... .KEY MESSAGES... * Shower and storm chances Sunday and each day Tuesday through Thursday. A few strong to severe storms may form Tuesday, with slightly better chances for a few severe storms later Wednesday. && .UPDATE... Issued at 142 PM EDT Sun Jun 2 2024 Current VWX radar continues to show scattered light rain showers pinwheeling around the southern edge of a low pressure system currently located over Indiana. Latest surface analysis reveals a weak warm front stretching NW-SE across the Commonwealth with a cold front draped along the MS River. Expect to see these conditions persist until the low stratus advects to the east allowing for some breaks in the clouds, currently evident on GOES-16 imagery over SW Indiana. Once we get some breaks in the clouds, temperatures should be able to meet or surpass convective temps, upon which we could start to see isolated showers and thunderstorms begin to develop. All of this is covered well by this morning`s forecast, with no major changes needed at this time. && .SHORT TERM /THROUGH MONDAY/... Issued at 313 AM EDT Sun Jun 2 2024 Weak sfc low will continue to push northeastward across southern Indiana today and towards Lake Erie, with the upper shortwave weakening by this evening. Scattered light showers will continue within a weak WAA axis this morning, but overall rainfall amounts will be manageable. A good amount of cloud cover will continue through this morning, though southerly flow will still allow temps to reach the low to mid 70s by lunchtime. Model agreement has remained consistent for this afternoon, which still calls for isolated to scattered pulse thunderstorms. Temperatures will peak in the upper 70s and near 80 this afternoon, which will help us realize marginal instability in a humid airmass. We could actually see some breaks in the cloud cover this afternoon as the upper wave shifts to our east, which would influence differential heating boundaries to fire up some convection. HREF paints the greater probability for SBCAPE over 1000 J/kg east of I- 65, which is where we will have the slightly higher PoPs this afternoon. We`ll likely see an axis of 1000-1500 J/kg of SBCAPE between I-65 and I-75 this afternoon. Model soundings show very weak flow in the column, so storm motions will be pretty slow. With a lack of shear, pop-up storms will be unorganized and short-lived, likely collapsing on itself not long after towering up. Soundings do show some dry air aloft, which could get brought down to the sfc. Not expecting any severe storms, but perhaps we could get some strong gusts under some storms later today. Around or after sunset, any remaining convective activity will dwindle with the loss of daytime heating. It`ll be a dry night as upper ridging approaches from the west overnight. Expect another normal night with temps in the mid-60s. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Issued at 313 AM EDT Sun Jun 2 2024 Monday - Thursday... Looking for a mostly dry Monday/Monday night as a brief period of upper ridging builds over the area. Deterministic models do try to paint some light qpf in spots just ahead of the upper ridge axis, but tend to lean on the majority of data and upper pattern supporting a dry period. Highs on Monday should be notably warmer and solidly in the mid 80s. Expect mild overnight lows in the mid/upper 60s. The upper ridge axis begrudgingly slides east on Tuesday, allowing shortwave energy to try and impinge on our area from the west by Tuesday afternoon and evening. Highs will likely reach mid to upper 80s given the mostly dry first part of the day. Forecast soundings show a deeply moist and moderately unstable atmospheric profile ahead of this next shortwave. Overall deep layer shear isn`t that impressive, but suppose a few marginally organized updrafts would be possible across our NW CWA. The majority of storm modes would likely be more pulse in nature. Outside of any wet microburst threat, would also be concerned about some locally heavy rainfall potential as efficiency would be high and motion would be relatively slow. The Wednesday/Thursday timeframe continues to be the most intriguing of the long term forecast, at least with respect to strong/severe storm chances. Anomalously strong troughing will develop southeastward from central Canada down toward the Great Lakes region through this time frame. As a result, a cold front extending from this system is expected to move through our region sometime later Wednesday into Thursday. Ahead of that cold front, forecast soundings show us becoming strongly unstable, with increasing deep layer shear in the NW flow regime over our area. Details on timing are a bit lower confidence at this point given some inconsistency in model timing, however the best chance for any strong to severe weather would likely be later Wednesday afternoon into Wednesday night. 02/00z GFS has a much slower cold front passage, and redevelops storms on Thursday afternoon, but this seems to be on the slow side of the guidance envelop for now. Thursday Night - Saturday... Lower confidence for the late week into the weekend timeframe. The anomalous closed low is expected to remain quasi-stationary over the northern Great Lakes region, and we`ll likely have a drier period of post frontal and dry NW flow aloft setup. Will have to keep some shower and storm chances in the forecast heading back into Saturday as models disagree how far south the front makes it, and how much southward influence the closed upper low has on our region. Overall temps should be a bit cooler late week into the weekend as highs fall back into he mid to upper 70s for most. && .AVIATION /18Z TAFS THROUGH 00Z TUESDAY/... Issued at 142 PM EDT Sun Jun 2 2024 Latest surface analysis reveals low pressure over Indiana with a weak cold front stretching south across the TN Valley, while current radar shows scattered showers moving generally west to east across the region. Breaks in the cloud cover will allow for increased diurnal heating, which will help spark additional showers and possible thunderstorms this afternoon. AMDAR soundings out of SDF continue to show light wind columns with meager lapse rates, which adds to low confidence in thunderstorms. Tonight, expect winds to slacken and clouds to clear leading to potential fog development by early Monday morning. VFR conditions are expected shortly after sunrise. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ UPDATE...CG SHORT TERM...CJP LONG TERM...BJS AVIATION...CG