Area Forecast Discussion
Issued by NWS Indianapolis, IN
Issued by NWS Indianapolis, IN
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266 FXUS63 KIND 281638 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 1238 PM EDT Tue May 28 2024 .KEY MESSAGES... - Scattered showers and at least a few storms are possible late in the day and early tonight. Highs will be in the 70s. - Low precipitation chances linger into Wednesday across eastern portions of central IN - Dry and Seasonable Thursday and Friday, Rain chances late Saturday into Sunday && .FORECAST UPDATE... Issued at 1011 AM EDT Tue May 28 2024 Only minor change to the forecast was to bump wind gusts up a bit as diurnal mixing has been quite efficient this morning. Gusts at KIND have already been upwards of 20kt. Expect breezy conditions to continue as we progress into the afternoon, with readings as high as 25kt possible in a few places. Otherwise, forecast remains on track. && .SHORT TERM (Today and tonight)... Issued at 255 AM EDT Tue May 28 2024 Broad upper troughing will remain over the region today with a few embedded shortwaves traversing the region. Expect mostly quiet conditions through mid-afternoon as the first few upper level impulses should remain north of the area. Rain chances then begin to increase late this afternoon into the evening when another embedded shortwave and attendant surface wave move in. The best chance for rain will be north of I-70 where stronger forcing should be in place with lower chances further south. Weak cold air advection and increasing clouds late will help keep temperatures in the 70s again. Subtle moisture return and daytime heating will likely provide sufficient instability for at least a few storms. In addition, steep low-level lapse rates suggest gusty winds are possible in any heavier showers or storms. Precipitation should continue into the early overnight hours before the system begins to move east late. Low POPs linger through the overnight over far E/NE counties as broad cyclonic flow from the surface low could keep isolated showers around. A cold front associated with the surface wave is expected to move through tonight leading to slightly cooler lows in the low-mid 50s. && .LONG TERM (Wednesday through Monday)... Issued at 255 AM EDT Tue May 28 2024 As a deep troughing progress slowly eastward into New England the next few days, two embedded shortwaves will influence Indiana`s weather. One will pass through Wednesday and the other on Thursday. Neither will have a substantial impact on temperatures but the MSLP pattern will support northerly wind direction and temperatures that are 5-7 degrees below normal with low humidity. An accompanying lobe of increased moisture through a deep layer should be enough when combined with diurnal heating for a few convective showers and a low probability of a few lightning strikes. Coverage should be limited and this should impact mainly the northeast third of central Indiana. Mid-upper ridging will start building to our west Thursday and should nudge our temperatures up to near normal for late May by Friday as the ridge axis crosses Indiana. A weak shortwave is shown in most models crossing Saturday with a narrow ribbon of modified moisture and weak instability, sufficient for low-mid range probabilities of precipitation. Ensembles are all clustered around light precipitation amounts, generally a quarter inch or less with just a few outliers up to around an inch. Chaos in the ensemble suite grows Sunday into early next week. Most models show the larger scale pattern trending toward broad low- amplitude ridging and positive height anomalies, bringing a warmer pattern. The next somewhat organized precipitation event appears to be late Monday, but smaller scale details are unclear. GEFS-weighted clusters favor more troughing than EPS-weighted clusters and more than just one frontal convective scenario. Will refine details later this week. Days 8-14: Multi-model ensemble mean shows a ridge west / trough east pattern developing during this period. Some hold the ridge further west and linger troughing longer, and some are more progressive. Given the sensitivity of temperature to these pattern differences we cannot say above or below normal with any degree of confidence. This pattern would slightly favor drier than normal conditions. && .AVIATION (18Z TAF Issuance)... Issued at 1238 PM EDT Tue May 28 2024 Impacts: - Low probability showers and thundershowers between 22Z and 04Z. - Gusty winds and temporary MVFR conditions possible in showers/storms. - WNW wind gusts to 20-25kt possible today and tomorrow. - Period of MVFR ceilings possible early Wed morning. Discussion: VFR conditions should persist through this afternoon. A weak storm system diving down from the northwest may induce a few showers or thundershowers towards the evening. These look to arrive somewhere between 22Z and 04Z. Showers/storms will be fast-moving and will not persist in any one location for a prolonged period of time. Brief MVFR conditions along with gusty winds are possible with these. Ambient surface winds will be out of the west-northwest between 10- 15kt with gusts 20-25kt. Winds decrease a bit overnight as the boundary layer stabilizes but should pick up again Wednesday afternoon. A brief period of MVFR ceilings are possible Wed morning as the center of the weak storm system swings by. These clouds should diminish as the day progresses, due to boundary layer mixing and the system itself departing eastward. && .IND WATCHES/WARNINGS/ADVISORIES...None. && $$ UPDATE...Eckhoff SHORT TERM...Melo LONG TERM...BRB AVIATION...Eckhoff