textproduct: Hastings

KEY MESSAGES

- A Severe Thunderstorm Watch is in effect for portions of south central Nebraska until 4 AM this morning.

- Showers and storms will continue across portions of the area through much, if not all, of the morning daylight hours.

- Strong to severe storms may develop across mainly southern portions of the forecast area later today but there is uncertainty in location and timing.

- Large hail and damaging winds will be the main threats with any storm later today.

- Some locations in north central Kansas may experience heat index values today around 100 to 104 degrees.

UPDATE

Issued at 237 AM CDT Tue Aug 18 2026

Currently watching storms move southeastward across the forecast area. A cluster of severe storms previously across eastern portions of the forecast area are now east of the forecast area. A Severe Thunderstorm Watch is in effect for areas in Nebraska along and east of Highway 281 and along and south of Highway 30 until 4 AM. Other storms are developing along the outflow boundary to the west of the previously mentioned storms. Additional storms are developing to the northwest of the forecast area and are expected to move into northern portions of the area around 3 or 4 AM. These storms will continue to develop and move off to the southeast for the remainder of the overnight period and into the daytime period. There is some uncertainty as to how strong these additional storms will be when they move into and through the area. Not expecting widespread severe weather with the additional storms but isolated strong to severe storms are possible (20% to 30% chance). Low temperatures overnight are expected to be in the 60s and low 70s.

Most, if not all, of the storms should be out of the area by this afternoon. A cold front will move into/through the area this afternoon resulting in high temperatures today ranging from near 80 degrees across northern portions of the area to near 100 degrees across portions of north central Kansas. Heat index values today for portions of north central Kansas may get up to 100 to 104 degrees. Storms are expected to develop this afternoon/evening along/near the frontal boundary. These storms may become strong to severe with large hail and damaging winds. There is some uncertainty as to where these storms will develop. It will depend on how far south the cold front gets and where outflow boundaries are from morning convection. Areas in north central Kansas and in Nebraska near the Kansas border will be at most risk for severe weather later today. It is also possible that the storms will develop south of the forecast area. Some models are showing the convection developing late this evening into tonight along/near the Nebraska/Kansas border as a shortwave moves overhead. High temperatures behind the front on Wednesday are expected to be in the mid/upper 70s to the mid 80s. Showers and storms may develop (20% to 40% chance) Wednesday into Wednesday night. There is quite a bit of uncertainty as to where this convection would develop (if it does at all).

DISCUSSION

Issued at 500 PM CDT Mon Aug 17 2026

-- FORECAST CHANGES OF NOTE/BIG PICTURE COMMENTS:

- Certainly no truly "major" changes of note versus previous 7-day "forecast package). As hopefully made clear in the Key Messages above, the varied thunderstorm chances these next ~ 60 hours (through Wed evening) without a doubt carry above- average uncertainty...not just regarding likelihood/areal coverage, but also severe potential (cannot really fault SPC for assigning Slight Risk to our entire CWA for Tuesday, but taking consensus of latest higher-res models (CAMs) at face value...it arguably could warrant more of a Marginal designation.

- Big picture overview of the upper air pattern through the next 7 days: Latest ECMWF/GFS agree that we will reside under either west-northwesterly or more "true" northwesterly flow...as we continue being positioned along the broad interface between dominant upper level ridging/high pressure off to our south or southwest...and broad low pressure/troughing off to our north or northeast. Given that we'll reside within this interface, we'll be prone to continued/intermittent rain/thunderstorm chances, and experience temperatures that are fairly typical/normal for mid-late August...with no noteworthy heat or coolness.

-- 7-DAY FORECAST CHRONOLOGICAL DETAILS (through Mon. Aug. 24) - CURRENT/RECENT WEATHER SITUATION AS OF 4 PM: Other than high temps ending up a few degrees warmer than our initial early-AM forecast (most of our CWA on track to top out 85-90), today is turning out very much as expected. Under sunny to mostly sunny skies, breezes are predominantly southerly and not overly-strong...sustained speeds mainly 6-13 MPH with occasional stronger gusts (especially north and west).

In the mid-upper levels, water vapor satellite imagery and short term model data confirm that we reside under west-northwesterly flow, with the next low-amplitude shortwave disturbance migrating out of WY into western NE.

- THIS EVENING-OVERNIGHT: Let the rain/thunderstorm chances and severe storm potential uncertainties begin! Leaning heavily on latest HRRR runs (this model performed quite well when this forecaster was on shift last week) along with 12Z RRFS, our entire CWA likely remains storm-free until at least 7-8 PM. Then, between then and roughly midnight, mainly isolated/spotty storms could work into mainly the northwestern 1/3rd of our CWA out of western NE (counties mainly north and/or west of the Tri Cities). Should storms get in, severe is certainly possible, with miexed-layer CAPE (instability) of at least 1500-2500 J/kg and sufficient deep- layer shear of 35-40KT suggestive of supercells with hail potential to around ping pong ball size/wind gusts to around 60 MPH.

Turning to beyond 12-1 AM, while any earlier activity south of I-80 should mostly fade away, attention turns to especially our northern/northeast counties (mainly north of I-80), as those counties are most favored to PERHAPS be clipped by the southern/southwestern fringes of a small convective cluster (or two) that should MAINLY track just off to our north-through- northeast. However, should any of this activity affect our area, at least marginally severe hail/wind is again possible.

In other departments overnight, low temps aimed mid 60s most areas (more so upper 60s in KS), with fairly light-but-steady southerly to southeasterly breezes persisting UNLESS an outflow boundary surges through and abruptly turns winds northerly/easterly.

- TUESDAY DAYTIME (through around 7 PM): Overall high-confidence in the "big picture"...as aloft a series of disturbances will track overhead...while at the surface a cold front will gradually pass through from north-to- south...turning winds more north-northeasterly in its wake.

Unfortunately, confidence in the "finer details" is admittedly fairly low. Right off the bat in the morning, the first question is whether a potentially strong (maybe even marginally-severe?) cluster of storms is might be tracking south-southeastward through mainly our northeastern/eastern counties? If this occurs, it should exit our CWA off to the southeast by mid- morning, with plenty of question marks whether any additional strong/severe activity is able to form during the afternoon. Again, latest higher-res models (namely HRRR/RRFS, but with support from 18Z NAM) show very little afternoon activity within our CWA...possibly due to residual weak capping as we reside "in between" disturbances.

Otherwise, high temps were changed little, as we call for a halfway decent gradient ranging from low 80s far north- northeast, to mid 80s central...to low-mid 90s mainly in KS (and even upper 90s in especially southern Rooks/Osborne). In fact, parts of our far southern KS counties (Rooks/Osborne/Mitchell) could see heat index climb to at least 100-102 degrees (but should hold slightly short of Advisory criteria).

- TUESDAY EVENING-OVERNIGHT (mainly after 7 PM): The big question right away in the evening is whether potentially strong/severe storms erupt along/near the cold front mainly in/near our far southern CWA. Leaning on the same higher- res models, the short answer is that MOST of our CWA appears to be spared...with the MAIN zone of severe potential focusing at least slightly off to our south-through southeast along the main frontal convergence zone. Of course, should this cold front slow down in later model runs, severe potential could increase into our area accordingly. Again, this is best described as a CONDITIONAL severe threat for our CWA...as IF storms can get going a few supercells with large hail/damaging winds cannot be ruled out.

For the post-midnight hours, we'll have to watch to see if any activity rolling in from the west (headed primarily toward counties along/south of the state line) has much intensity or instead remains fairly weak. Low temps aimed from low 60s far north to upper 60s far south-southeast (most places mid 60s).

- WEDNESDAY-WED NIGHT: Once again, the big question is whether we see any potentially severe convection? While instability looks to be a bit lower than Tuesday, deep-layer shear is still seasonably-strong (40-50KT)...plenty sufficient for supercells. There will also be decent forcing/lift aloft, as a somewhat stronger (compared to Tuesday) shortwave trough passes through. Taking 12Z RRFS "literally", at least a few/spotty severe storms (possibly supercells) could pass south-southeastward through our CWA at any point mainly late-morning through mid-evening...and thus cannot argue against SPC expanding a Marginal Risk to our entire CWA.

Temperature-wise, high temps were bumped up slightly, with most places ranging upper 70s-low 80s except mid 80s far southwest.

- THURSDAY-FRIDAY: Very briefly/in general...most of these 48 hours (especially Thurs-Thurs night) look drier/quieter, as upper ridging edges a bit farther eastward into our region from the southwest. In turn, temperatures slowly warm...with highs mainly mid 80s Thursday and mid-80s to low-90s Friday.

- SATURDAY-MONDAY: Much the same continues...with mainly low/highly uncertain rain/thunderstorm chances on an occasional basis. High temps are currently expected to be quite similar each of these days...ranging low-mid 80s northeast, to mainly mid-80s to low-90s southwest.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1237 AM CDT Tue Aug 18 2026

For KGRI/KEAR Airports:

Storms are expected to hit KGRI within the next hour. These storms will likely have wind gusts of around 40 knots. KEAR may get hit with storms within the next hour, but it is less likely. Another round of storms may impact both airports from around 10z to 14z but there is less confidence of this occurring. MVFR ceilings may develop overnight but confidence is too low to include at this time. Wind shear is possible between now and 14z. Winds (outside of convection) will mostly be out of the southeast to south then will switch to the northeast around 18z.

GID WATCHES/WARNINGS/ADVISORIES

NE...None. KS...None.