Marine Weather and Tide Forecast for Johns, NE

SHORT TERM /THROUGH TUESDAY NIGHT/
Issued at 342 AM CDT Mon Apr 20 2026

Currently, temperatures range from the upper 30s in north central Nebraska to the lower 50s in southwest Nebraska under clear skies.
Winds are from the southeast at 5 to 10 miles per hour. Surface high pressure is currently centered off to the east of the area over the upper Midwest.

For today, expect critical fire weather concerns for much of western and north central Nebraska. This is due to yet another warm and very dry day, as persistent and increasing southwesterly flow promotes increasing warm advection and ample diurnal mixing. Highs today return to the upper 70s t0 80s, and with the very dry airmass in place, this pushes humidity values into the upper single digits to teens for the entire area. Enough higher momentum flow aloft exists as well (H7-H85 flow ~20-25kts) to promote gusts approaching 20 to 30 miles per hour this afternoon for areas generally near and north of I-80. This looks to be more than adequate to support the inherited Red Flag Warning for much of the area. Did opt to expand this warning to Fire Zone 219 (eastern Frontier/southeastern Lincoln counties) in collaboration with neighboring offices, as gusts approaching 20 to 25 miles per hour seem likely enough in the aforementioned area. A weak frontal boundary then pushes through the area overnight, leading to weak west-northwest winds with its passage. Lows tonight fall into the lower 40s, much warmer than that of the previous few mornings.

A similarly warm and very dry day awaits us again on Tuesday, albeit even a few degrees warmer than today. Broad lee cyclogenesis across eastern Wyoming and Colorado will lead to increasing southerly winds by Tuesday afternoon across the area, again boosting warm advection.
This will promote H85 temperatures warming to as high as 23-25C by late Tuesday afternoon, and highs in the middle to upper 80s for all. Portions of southwest Nebraska may even approach the low 90s.
Again, very low relative humidity is expected Tuesday afternoon, as low as 10 to 15 percent across all of western and north central Nebraska. Luckily, winds look to largely remain below 25 miles per hour, though this will need to be monitored closely. Still, elevated to near critical fire weather concerns can be expected across the area again on Tuesday.

LONG TERM /WEDNESDAY THROUGH SUNDAY/
Issued at 342 AM CDT Mon Apr 20 2026

An upper level trough approaches the area from the west Wednesday, as the upper level ridge axis shifts eastward over the Mississippi Valley region. Surface low pressure will deepen in response to the approaching trough across eastern Colorado/Wyoming. In fact, most ensemble members support a fairly deep low center down to around 990mb. This tightens the surface pressure gradient from east to west and will bring strong southerly/southeasterly winds across the region. A very warm day once again, with highs in the mid to upper 80s. Potential set-up for fire weather concerns. However, low-level moisture/humidity will be on the increase from the Gulf, with dew points climbing into the lower and middle 50s by afternoon. The moisture, at least initially, is fairly shallow and appears will mix out some. Models are struggling somewhat with how much mixes out, and at least portions of the area could see near-critical or even critical fire weather conditions develop, depending on the amount of mixing.

Attention then turns to thunderstorm potential later Wednesday afternoon and Wednesday night. Surface instability will increase along pr near the Highway 83 corridor where higher surface dew points appear to be maximized. Again, some concern on dew points/moisture mixing out, but should be a narrow corridor of better moisture and instability by late afternoon as deeper moisture arrives. NAM supports this with H85 dew points reaching 10-12C by very late afternoon into the evening. Appears to be a narrow window for convection to initiate near the dry line across the western Sandhills. A strong capping inversion appears to weaken just enough for a few isolated cells to develop. Models then strengthen the capping inversion quickly during the evening. So both coverage and intensity is questionable at this point. Nevertheless, hodographs support a supercell or two if storms can get going.

The deep surface low will quickly track into the Dakotas Thursday, with a return to strong west/northwest winds and low humidity.
Thursday will likely see near-critical to critical fire weather conditions develop once again. Friday will see a cool down, but still appears that fire weather concerns will be present as gusty northwest winds and low humidity continue.

A change in the weather occurs this weekend. An upper level trough will move eastward across the Rockies. A warm front develops eastward across Kansas from a deepening eastern Colorado surface low.
Appears to be plenty of moisture, with strong mid-level FGEN developing. ENS probabilities for some decent precipitation amounts are increasing later Saturday night into Sunday night. Colder air will be drawn southward Sunday as the Colorado surface low moves into Kansas. Appears that some accumulating wet snow could materialize Sunday and especially Sunday night. Will continue to monitor.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
Issued at 629 AM CDT Mon Apr 20 2026

VFR conditions will continue to prevail across all of western and north central Nebraska through today and into tonight.
Southwest surface winds will increase 10-20 kts, with the strongest winds north of I-80. Clear skies this morning will give way to an increase in high cloudiness this afternoon into tonight. Winds become light tonight.

FIRE WEATHER
Issued at 342 AM CDT Mon Apr 20 2026

A Red Flag Warning is in effect today for all but far southwest Nebraska. High temperatures this afternoon will climb into the upper 70s to lower 80s, along with humidity dropping into the teens all areas. In fact, locations west of Highway 183 will likely see humidity as low as 8-12%. Southwest winds will increase by late morning and continue this afternoon. Gusts up to 30 mph will be possible, especially for areas north of I-80 across the Sandhills, central into north central Nebraska. Although far southwest Nebraska will see the very low humidity values, winds will be lighter and no fire weather headlines appear to be needed in that area. Humidity recovery will be poor tonight, especially across portions of the Sandhills, north central and northwest Nebraska.

LBF WATCHES/WARNINGS/ADVISORIES
Red Flag Warning from noon CDT /11 AM MDT/ today to 9 PM CDT /8 PM MDT/ this evening for NEZ204-206-208-209-219.