Area Forecast Discussion
Issued by NWS Hastings, NE
Issued by NWS Hastings, NE
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598 FXUS63 KGID 120037 AFDGID Area Forecast Discussion National Weather Service Hastings NE 737 PM CDT Tue Jun 11 2024 ...Aviation, Short Term and Key Messages Update... .KEY MESSAGES... - Very spotty/sneaky isolated storms into this evening mainly along the I-80/Hwy 6 corridor counties (see UPDATE section below). - Temperatures heat up on Wednesday with highs in the 90s to possibly around 100 degrees. Heat index values between 100 to 105 degrees are expected on Thursday across portions of north central Kansas. - Wednesday late afternoon-evening roughly the northeast 1/4 of our coverage area is under a Marginal Risk of severe, BUT a strengthening cap COULD keep us storm-free (a conditional threat). - Storm chances (15% to around 25%) increase Thursday evening and night along the leading edge of a cold front. Some of these storms may be strong to severe. - Rain and storm chances continue Friday through early next week with the highest chances (20% to near 70%) Friday night. && .UPDATE... Issued at 736 PM CDT Tue Jun 11 2024 -- Regarding very isolated convection over the last few hours and likely next few hours: - Although fortunately not reaching severe thresholds (largely due to fairly weak deep layer shear and poor mid level lapse rates), we have nonetheless had to do a few somewhat unexpected forecast/Hazardous Weather Outlook updates already since late afternoon to account for very "sneaky", spotty storms developing along a weak warm front slowly lifting north through our central coverage area (CWA). Instability is decent, with mixed-layer CAPE into the 1000-2000 J/kg range. - Through sunset, expect the majority of this VERY SPOTTY activity to focus within counties along the I-80/Hwy 6 corridors, with small hail/gusty winds not out of the question, but truly severe storms fairly unlikely. - Current expectation is for ongoing activity to fade away with loss of diurnal heating and largely be gone by 10 PM, but with at least a modest southwesterly low level jet gradually increasing through the night, would not be surprised to see additional activity flare up in our northern zones later in the night and/or Wednesday AM (will take a closer look at this a bit later for another possible update to rain/storm chances). && .DISCUSSION... Issued at 342 PM CDT Tue Jun 11 2024 Today and tonight... Light and mostly variable winds along with mostly sunny to partly cloudy skies are across south central and central Nebraska and north central Kansas. High temperatures today are expected to mostly be in the mid to upper 80s. Winds will increase out of the south tonight with clear to mostly clear skies. Low temperatures tonight will be in the 60s. Wednesday through Saturday night... An upper level ridge will be centered over Arizona and New Mexico on Wednesday. Winds will increase out of the south to southwest Wednesday afternoon as a surface low to the north of the area strengthens. Temperatures Wednesday afternoon are expected to heat up into the 90s with some places possibly reaching the triple digits. The areas most likely to reach the triple digits will be south and west of a line from Lexington to Holdrege to Phillipsburg and Stockton. Some areas in central Nebraska may have heat index values that are around or at 100 degrees. A cold front will begin moving into Nebraska Wednesday night. Low temperatures Wednesday night across south central and central Nebraska and north central Kansas will be in the mid 60s to mid 70s. The front will continue moving through the area on Thursday with breezy northeasterly winds. Temperatures will be cooler from the previous day with highs ranging from the mid 80s to around 100 degrees. Heat index values across portions of north central Kansas may get over 100 degrees but will likely stay under 105 degrees. Low temperatures Thursday night will range from the upper 50s to near 70 degrees. Rain and storm chances (15% to around 25%) will increase Thursday evening and night along the leading edge of the front. Some of these storms may become strong to severe. Upper ridging will be over the southern and central Plains on Friday with upper disturbances moving over Nebraska and Kansas. These disturbances will allow for continued chances (15% to around 30%) of showers and thunderstorms on Friday. Winds will be gusty out of the southeast. Temperatures will continue cooling from the previous day with highs mostly in the 80s. Upper disturbances will move over the area Friday night with chances (20% to near 70%) of showers and thunderstorms increasing. Low temperatures Friday night will be in the low 60s to low 70s. An upper trough will continue over the southern and central Plains on Saturday. This will result in continued chances (15% to near 40%) of showers and thunderstorms. High temperatures on Saturday will range from the mid 80s to mid 90s. Low temperatures Saturday night will be similar to those from the previous night. Sunday through Monday night... A cold front will approach or begin passing through the area on Sunday. This uncertainty in frontal position will impact high temperatures on Sunday. At this time, am expecting high temperatures on Sunday to range from the upper 80s to the upper 90s. Rain and storms are expected along and behind the front. High temperatures on Monday are expected to be in the low 80s to mid 90s with rain and storm chances (15% to near 25%). Low temperatures early next week will generally be in the low 60s to mid 70s. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 736 PM CDT Tue Jun 11 2024 For KGRI/KEAR Airports: - General overview: Confidence is high in VFR ceiling/visibility and "probably" rain/thunderstorm-free conditions. That being said, especially KGRI could flirt with a very rogue thunderstorm right away this evening. Overall though, winds will be the primary aviation concern through the period, starting with a modest (not overly- strong) round of low level wind shear (LLWS) late tonight into Wed AM, and then fairly strong south-southwesterly surface winds (at least by June standards) during the day Wednesday. - Ceiling/visibility/thunderstorm details: Right out of the gate this evening, have gone with a few hours of "vicinity thunderstorm" (VCTS) at KGRI as an isolated/rogue storm could easily pass within 5 miles. Beyond this though, odds strongly favor the remainder of the period being dry/storm-free, although very late Wednesday afternoon (mainly after 22Z there is a very low (10% or less) chance of additional isolated convection, so this will need monitored. Any possible ceiling during the period should be brief and well up into VFR range. - Wind details: - Surface winds: The very lightest winds of the period are right away these first 6 hours (except for possible/brief thunderstorm outflow at KGRI), with speeds mainly under 8KT from the southeast. Then, as the night wears on, speeds will modestly increase as direction trends more southerly with sustained speeds up around 10KT (gusts possibly closer to 15KT). However, winds will definitely kick up another gear during the day Wednesday, as especially 16-21Z will feature several hours of sustained southwesterly speeds around 20KT/gusts 25-30KT before an approaching surface trough allows speeds to start diminishing mainly after 21Z. - Low level wind shear (LLWS): Although admittedly only marginally-worthy of formal TAF inclusion, opted to introduce a LLWS group 06-13Z as winds within the lowest 1K ft. AGL will accelerate to around 36KT from the south-southwest, resulting in as much as 25-30KT of shear magnitude between the surface and this level. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ UPDATE...Pfannkuch DISCUSSION...Schuldt AVIATION...Pfannkuch