Marine Weather and Tide Forecast for Johns, NE

SHORT TERM /THROUGH FRIDAY NIGHT/
Issued at 337 PM CDT Thu May 22 2025

The main concern in the short term will be the chance for isolated to scattered thunderstorms late tonight. Did keep some of the inherited slight PoPs for late this evening, before 06z, but confidence is low in any convection developing before midnight.
Convection after midnight is expected to develop as a SW trof translates eastward. The greatest threat for convection will be across northern Nebraska into north central Nebraska by morning. Generally expect more scattered development across the northern Sandhills with convection tonight to be mostly north of HWY 92, with lesser more isolated convection south into the southern Sandhills and southwest Nebraska. The better forcing and instability is across the northern Sandhills into north central Nebraska. Convection will be mostly showers and some isolated thunderstorms possible through the early morning hours with more thunderstorm activity during the morning hours across north central Nebraska. Convection across north central Nebraska may linger into the late afternoon hours as focus then turn to possible convection to across western Nebraska.

There is a potential for severe thunderstorms Friday evening across western Nebraska, however the severe setup is largely conditional.
The main hazards will be hail and strong winds, with an isolated tornado threat. A sfc low will strengthen across the Rockies as it moves eastward with a triple point access to the west of the forecast area with the warm front lifting northeast and a dry line advancing eastward, although low there is an isolated chance for the potential to see a tornadic threat. Winds will be backed across the area and help to draw in moisture. However it does appear it will be a fairly narrow corridor where the tornadic threat exist. There will also be a threat for large hail should a storm develop with 0 to 3 km MU CAPE values around 1500 to 2000 J/kg and steep lapse rates.
The best environment is generally along and west of HWY 61. However, as mentioned earlier the severe threat is largely conditional as stratus that moves in tonight may be rather persistent and stay in place through most of the afternoon across western Nebraska keeping a more stable environment. However should far western Nebraska see clearing tomorrow, enough for daytime heating to warm temperatures will likely see supercell development, with potentially splitting cells. Will have to continue to monitor throughout the day to see if sunshine will prevail or stratus persist. Storms will likely develop across Colorado and the Panhandle and move eastward, however there will be a low-level jet later in the evening that could potential aid in some additional development across western Nebraska.

LONG TERM /SATURDAY THROUGH THURSDAY/
Issued at 337 PM CDT Thu May 22 2025

Temperatures will remain cool over the holiday weekend with highs in the 50s and 60s through early next week. Climatology wise this is around 10 to 20 degrees below normal for this time of year. Although the holiday weekend may not be a complete wash out, chances for showers and thunderstorms exist everyday, Saturday, Sunday, and Memorial Day. The risk for any potential flooding is low as rainfall is not expected to be heavy rainfall, but could see the potential of a half inch to an inch of total rainfall across the area from Thursday night through Sunday.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
Issued at 1233 PM CDT Thu May 22 2025

Mid-level clouds will continue to move in across southwest Nebraska including KLBF terminal this afternoon. Cigs will lower across southwest Nebraska after midnight with MVFR or lower conditions possible towards sunrise and continuing through the rest of the forecast period. For the northern Sandhills into north central Nebraska including KVTN terminal, isolated to scattered showers and thunderstorms will develop after midnight and lower cigs moving in. MVFR or lower conditions will be possible by early morning. Winds will be light and variable this afternoon, less than 10 kts. Winds will shift to the southeast tonight and increase to 10 to 15 kts with gust up to 25 kts by morning.

LBF WATCHES/WARNINGS/ADVISORIES
None.