Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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157 FXUS63 KIND 221953 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 253 PM EST Fri Nov 22 2024 .KEY MESSAGES... - Light rain showers ending over eastern counties this evening - Clouds linger into Saturday before diminishing - Warming trend this weekend with a chance of light rain Monday - Lower than normal forecast confidence the second half of next week with some wintry precipitation potential && .SHORT TERM (This evening through Saturday)... Issued at 252 PM EST Fri Nov 22 2024 Rest of the Afternoon and Tonight... The stratus deck has remained entrenched across central Indiana, this afternoon, per GOES-16 visible satellite loop, with the clearing line all the way west across western Iowa and southwest Missouri, closer to the surface high pressure ridge. Otherwise, radar was showing a lake effect rain showers in the cyclonic flow on the back side of the east coast surface low. Gusty northwest winds and an upstream surface ridge across the Plains and Great Lakes has provided warm advection allowing temperatures to bounce back to the lower 40s over much of central Indiana. Surface high pressure will work its way toward southwestern Indiana overnight. This and a drying boundary layer could allow for a few breaks in the overcast toward daybreak over southwestern sections. Otherwise, the clouds should remain thick, and the lake-effect rain showers should end shortly after sunset as they settle eastward with backing boundary layer flow. The insolation from the thick cloud cover should keep temperatures from falling to freezing. Saturday... Surface high pressure will build in across central Indiana Saturday. Hi-Res soundings also are indicating good boundary layer drying which is expected to lead to gradual clearing from southwest to northeast. The breaks in the clouds and winds shifting to the west will allow temperatures to top out from around 45 to 50 degrees or near normal. && .LONG TERM (Saturday night through Friday)... Issued at 252 PM EST Fri Nov 22 2024 Dry and mild conditions will continue through the second half of the weekend as ridging aloft expands into the Ohio Valley before transitioning to a fast quasi-zonal regime for much of next week. Systems will quickly move along within the flow aloft bringing chances for precip at times next week with the continued possibility for a larger and more impactful storm by late in the period with potential amplification in the upper levels over the eastern U S. Saturday Night through Sunday Dry conditions will continue Saturday night and Sunday as surface flow transitions to a southerly direction. Skies will gradually clear Saturday night into Sunday before increasing again late day as a frontal boundary approaches from the west. Highs Saturday will largely hold in the 40s with the stratus limiting warming. With the onset of warm advection for Sunday though...will see a return to above normal readings mainly in the mid and upper 50s. Sunday Night through Tuesday Night The aforementioned cold front will sweep across the region on Monday with rain developing. Showers will arrive as early as Slate Sunday night across the Wabash Valley but the bulk of the widespread rain will come on Monday afternoon along the front and as stronger flow at 850mb translates across the Ohio Valley. Rainfall amounts will generally be a quarter inch or less with rain ending Monday evening as high pressure builds in. High temperatures will be mild ahead of the front on Monday...running from the mid 50s to around 60. Dry weather returns for Tuesday as the high tracks across the Great Lakes and Ohio Valley. A more robust signal for subsidence in the wake of the front should lead to stratus diminishing quickly Monday night. Despite the return of sunshine on Tuesday...gusty northwest winds and cold advection will make for a chillier day as highs remain in the low and mid 40s. Wednesday through Friday A surface low is set to eject out into the southern Plains Tuesday night and Wednesday and track east along a quasi-stationary boundary extending into the Tennessee and lower Ohio Valleys. Confidence continues to increase in precipitation returning by Wednesday and persisting through late week but low confidence exists within the details at this early stage. It appears central Indiana will be on the colder north side of the frontal boundary and displaced from the deepest moisture focused closer to the boundary over the Tennessee Valley. The presence of a colder airmass north of the boundary could potentially present precip type challenges at times as well... especially at night as temperatures near or go below freezing. Highs both Wednesday and Thursday are likely to range from the upper 30s to mid 40s...then shift colder Friday. Extended guidance continues to hint at a broader piece of energy aloft coming southeast late next week which would support the idea of a more amplified upper level pattern developing with an intensifying surface wave somewhere over the region. At this early stage...expect increased chances for precipitation throughout the second half of next week with impacts to travel possible. Will continue to fine tune details over the next several days. && .AVIATION (18Z TAF Issuance)... Issued at 1101 AM EST Fri Nov 22 2024 Impacts: - IFR ceilings will improve to MVFR by or very shortly after issuance time - Winds 290-320 degrees with gusts to 20+ knots through 23z at KBMG and later at the other terminals Discussion: Would not rule out a lake-effect rain shower at KIND this afternoon, otherwise confidence is good that IFR ceilings will improve to MVFR by or shortly after 18z. The cyclonic flow and moisture trapped below a strong inversion will keep skies cloudy until after 08z and later when drying lower levels support a trend towards VFR. Winds will be northwest and gusty through much of tonight and then west and northwest Saturday less than 10 knots as surface high pressure builds in. && .IND WATCHES/WARNINGS/ADVISORIES...None. && $$ SHORT TERM...MK LONG TERM...Ryan AVIATION...MK