FXUS63 KGID 261749

AFDGID



Area Forecast Discussion

National Weather Service Hastings NE

1249 PM CDT Thu Jun 26 2025



...AVIATION UPDATE...



.KEY MESSAGES...



- Rain and thunderstorms dissipate from SW to NE this morning,

  but flooding impacts will continue for at least another 24-48

  hours for areas from around Wood River to Columbus, including

  the city of Grand Island. These locations have received at

  least 4-7 inches of rain over the past 24-36 hours.



- Flooding impacts will continue for at least another 24-48

  hours (likely several days in areas around/NE of Grand Island)

  due to an axis of at least 4-7 inches of rain that has fallen

  over the past 24-36 hours from Wood River to Columbus.



- Mainly dry and becoming hot for Friday into Saturday.



- Periodic thunderstorm chances return Saturday night and

  continue into early next week. It is too soon to determine

  specifics (timing, coverage, intensity), but locally heavy

  rainfall may be possible Sunday night into Monday morning.



&&



.UPDATE...

Issued at 648 AM CDT Thu Jun 26 2025



Have cancelled the Flood Watch as the threat for additional

heavy rain (and any new flood products not already covering

affected areas) is low.



&&



.DISCUSSION...

Issued at 430 AM CDT Thu Jun 26 2025



Ongoing rain event is finally starting to come to an end from SW

to NE as of 4AM CDT. Several MCVs are apparent in regional 

radar loops, which will continue to track NE in the 30-35 kt

850-300mb mean flow. These will provide increasing subsidence,

coincident with a weakening/veering low level jet, to bring an

end to the (locally extreme) heavy rain event. Latest

HRRR/RAP trends suggest any additional activity along a weak

cold front should stay mostly SE of the local forecast area, so

have trimmed PoPs considerably for the late AM to early eve time

frame. Clear skies and light winds will prevail overnight, which

could allow for some areas of fog to develop after midnight -

particularly in areas that have experienced recent heavy rain.

Will need to monitor trends as the pattern suggests a non-zero

chance the fog may become dense, in spots.



Main story Friday into Saturday will be the increasing

temperatures. Saturday continues to look the hottest with

widespread highs in the 90s, and even near 100F SW zones.

Factoring the typical late-June humidity and it will likely feel

as warm as low 100s where dew points are the highest (E half).

Models suggest convection will develop each afternoon over the

high plains, then shift E/SE during the evening into overnight

hours. Have slight chance (20%) in far NW-W zones Fri night,

but chances seem to be increasing for Sat night (now up to

30-40%) as the initial development likely occurs a bit further E

compared to Fri night - over central Neb vs Neb Panhandle.

New SPC Day 3 Outlook has spread the Marginal Risk into most of

south central Nebraska, and portions of the Slight Risk into the

Ord area. Damaging wind gusts would likely be the primary risk.

GFS isn't quite as robust as the EC, so still some differences

to iron out.



Deterministic and ensemble solutions have been highlighting Sun

eve/night for a few days now as the next "best" chance for 

organized convection. We're getting out into "questionable

predictability" time frame, but first guess is that strong

instability and fairly week deep layer shear would promote

semi-organized clusters with some gusty winds. PWATs briefly

spike to around +2 std devs, but this could be convectively

contaminated in the model. Regardless, it doesn't appear as

though we'll have high-end deep layer moisture present and

connections to both the Gulf and sub-tropical Pacific.

Confidence drops off thereafter, but synoptic generalities would

support a drop in temps back to around normal and mainly dry

conditions, for at least a day, or two.



&&



.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...

Issued at 1237 PM CDT Thu Jun 26 2025



For KGRI/KEAR Airports:



Temporary MVFR CIGS will continue at KGRI for about one more

hour, before VFR conditions become dominant at both terminals

for the rest of the afternoon. Winds today will be mainly

northwesterly at less than 15 KTS...rapidly diminishing by 

early evening as an area of surface high pressure slides into 

the Missouri River Valley. Return flow around this area of high 

pressure system will induce light southeasterly winds late in 

the night, which combined with clear skies, saturated soils and 

elevated dewpoints, will likely result in fog...potentially 

dense towards daybreak. Due to some uncertainty, kept worst 

conditions in a tempo group for the time being, but prevailing 

LIFR VSBYS/CIGS may eventually be needed. This fog should not 

stick around long into the daytime hours Friday, with VFR

CIGS/VSBYS again becoming predominant by 27/16Z at the latest.



&&



.HYDROLOGY...

Issued at 430 AM CDT Thu Jun 26 2025



Wow, what a night! Anticipated there could be some areas of

heavy rain, but the extreme 4-7" amounts over a 6-9 hour period

was obviously above the high-end of expectations. Also just so 

happened to evolve over our most populated city. Nonetheless,

the combination of PWATs in the 95th-99th percentile, weak

surface boundary, and deep layer flow largely parallel to this 

front, provided the necessary ingredients for a highly 

anomalous event. See Climate section below for details on the 

broken records. Radar estimates and automated weather stations

suggest a broad swath of at least 2-4" from Phelps and Kearney

Counties, northeast into Nance and Merrick Counties. Within this

swath, an even heavier corridor of 4-7" is evident roughly along

the Platte River corridor from Wood River to Genoa. MRMS peak

bullseye is near 8" in Merrick County, will still a little bit

more to go next 1-2 hours. Will obviously work to confirm this

with ground truth reports as the morning moves along.



Going forward...expect widespread aerial flooding to persist for

at least a day or two. Fortunately, a lot of this rain occurred

over the Platte River which can take quite a bit of volume. The

bad part, however, is that terrain is flat and it can take a

long time to get there. As such, would expect the Prairie Creek

and Silver Creek basins to be dealing with flooding for at least

several days - pending any potential additional rainfall Sat/Sun

eves/nights. The Wood River, Loup River downstream of St. Paul,

and other creeks and streams in Hall, Merrick and Nance Counties

will be dealing with some level of flooding over the coming

days. Expect updated river forecasts as new rainfall reports

gradually roll in through the morning hours.



&&



.CLIMATE...

Issued at 415 AM CDT Thu Jun 26 2025



Reposting information already released in the RERGRI products

given their significance:



     New Daily Rainfall Record For June 25th And Also The Month Of

June At Grand Island...



The Grand Island Central Nebraska Regional Airport recorded 6.41

inches of rain on June 25th. This set a new daily rainfall 

record for June 25th, shattering the previous record of 1.55 

inches, set in 1990. More notably, this set a new rainfall 

record for ANY day in the month of June, breaking the previous 

record of 4.18 inches, set on June 15, 1990. Finally, this was 

the 2nd highest daily rainfall on record for ANY day of the year

for Grand Island, trailing only 6.50 inches, which fell on May 

11, 2005. 



With the additional rainfall since midnight, the two-day 

rainfall record of 7.21", which also occurred with the heavy 

rain event from May of 2005, has been broken. As of 4AM CDT,

7.32" (and counting) has fallen between yesterday and this

morning. More information (and official RERGRI) to come once 

the rain (finally!) stops.



Precipitation records at Grand Island date back to 1895.



&&



.GID WATCHES/WARNINGS/ADVISORIES...

NE...None.

KS...None.



&&



$$



UPDATE...Thies

DISCUSSION...Rossi

AVIATION...Thies

HYDROLOGY...Thies

CLIMATE...Pfannkuch/Thies

