627 

AWUS01 KWNH 181846

FFGMPD

MOZ000-KSZ000-NEZ000-190000-



Mesoscale Precipitation Discussion 0185

NWS Weather Prediction Center College Park MD

246 PM EDT Mon May 18 2026



Areas affected...Central and Northeast Kansas...Far Southeast

Nebraska...



Concerning...Heavy rainfall...Flash flooding possible



Valid 181845Z - 190000Z



SUMMARY...Severe Super-cells will have significant moisture flux

convergence to support localized rates over 2"/hr.  Given

compromised upper soil conditions, localized flash flooding

conditions are considered possible in proximity to other severe

weather hazards.



DISCUSSION...SPC MCD 771 solidly describes the mesoscale setup to

produce strong updrafts and super-cell structures through the

afternoon period.  Strong updrafts supported by MLCAPEs in excess

of 3500 J/kg; while driven by steep/dry lapse rates are also being

fed in the surface to boundary layer by well above average

moisture values (CIRA LPW values are at period of record

[2013-present] maximum values for most of the area).  Values in

the .75-1" range confirmed by surface Tds of upper 60s to low 70s

are being advected at greater than 20-25kts into the front. 

Surface low west of KCNK has backed the flow slightly to increase

surface moisture convergence/flux to very strong values. Combined

through depth and IVT values are well over 1000 kg/m/s per CW3E

plots.



Convective initiation is occurring near the surface wave and

southward through the cold front to around KGRD.  Strong SRH will

allow for convective mode for super-cell structures, likely with

broad updrafts/downdrafts and given slight right turning, should

reduce forward cell motions increasing residency time. 

Additionally, the isallobaric influences will further accelerate

inflow and moisture flux convergence to overcome modest overall

deep moisture (~1.5 TPW, currently), but will steadily increase to

support 2"/hr rates...with HRRR 15-minute rainfall totals forecast

in excess of 1.25", eventually reaching 1.5"/15 minutes by 22-23z

time frame.



As they mature along the front and toward the northeast, some left

splitters and general northeast cell motions may allow for some

overlap/repeating...so spots of 2-3" totals are becoming possible

through 00z across NE KS into SE NEB. Given the recent heavy

rainfall in the area, the 0-40cm soils have become much further

saturated ranging from 50% to near 75% in far SE NEB.  As such,

FFG values are reduced with 1hr values less than 1.5" across much

of NE KS, SE NEB, SW IA and N MO; with a narrow axis  across

Ottawa to Ness county that saw over 5" in spots.  Given the

scattered nature of the super-cells initially (before sunset)

localized flash flooding is considered possible.



Gallina



...Please see www.wpc.ncep.noaa.gov for graphic product...



ATTN...WFO...DDC...EAX...ICT...OAX...TOP...



ATTN...RFC...KRF...TUA...NWC...



LAT...LON   40559578 40119531 39249571 38679693 38309783 

            38009886 38419904 39229789 39689744 40549667