Marine Weather and Tide Forecast for Newton, IA

SHORT TERM /THROUGH MONDAY/
Issued at 252 PM CDT Sat Jun 13 2026

This morning's storms have moved out of the area and, as one would expect, they've left a rather messy environment behind. Cooler, more stable air is left sitting over much of Iowa, with an outflow boundary pushed well south into Missouri. The synoptic boundary appears to still reside over northwestern Iowa where occasional showers and non-severe storms are lingering, although this is likely an elevated boundary. Surface flow in southern Iowa has increased again out of the south, suggesting this is likely still prefrontal, but temperatures aren't nearly as warm or moist as ahead of the outflow in Missouri. Given this messy post-storm environment, mesoscale trends will be crucial for convection and potential severe weather this afternoon.

High resolution model guidance is trying to recover the atmosphere still this afternoon, and given the clearing already ongoing, we will likely see some degree of increased instability later today.
However, it's tough to see us get the full degree of recovery that was being shown in guidance yesterday or even earlier this morning.
Expectation at this point will be storms still firing later this afternoon and into the evening, generally around and after 5 pm and over far southern and southwestern Iowa. With increased sun this afternoon, instability values should still rebound into the 1000 to 2000 J/kg range with 40+ kts of effective shear, meaning organized storms will be possible ahead of the cold front. Model soundings in southern Iowa show unidirectional flow through the layer with fairly straight hodographs aloft, indicating potential for splitting supercells and efficient hail producers. There is a small amount of turning in the low levels ahead of the surface front where winds are more southerly, suggesting the tornado threat isn't zero along the Iowa/Missouri border. However, any post-frontal storms will be elevated, effectively eliminating any tornado threat. Therefore, the main hazards this afternoon will be large hail and strong winds, with a lower probability risk for tornadoes in far southern Iowa.

In addition to the above hazards, there is still a threat for some flash flooding as multiple storms may train over southern Iowa given the easterly storm motions. QPF amounts of 1 to 2" seem likely, with a few pockets of 2"+ amounts possible. This by itself likely won't cause flash flooding for most areas, especially now that the crops have started to establish themselves over much of rural Iowa.
However, there are a few areas in southern Iowa still working to filter water out from previous rains this week. These areas could be exacerbated by additional moderate to heavy rainfall this afternoon/evening, prolonging or slightly worsening current conditions. If this rain were to fall over urban areas, ponding of water on roadways could also occur.

Severe storm potential should begin to wane through mid- to late- evening as instability diminishes after sunset. Showers and elevated, non-severe storms may linger until around midnight over far southern Iowa as the elevated boundary works itself out of the area, but rain will be wrapped up in Iowa by early Sunday morning.
High pressure fills in behind the activity this evening, clearing out skies and making way for a pleasant end to the weekend in Iowa.
Temperatures will be cooler Sunday and Monday, with highs reaching the mid to upper 70s. Breezy north northwesterly winds also develop on Sunday, sustained around 15 to 20 mph and gusts up to around 25 mph.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/
Issued at 252 PM CDT Sat Jun 13 2026

Temperatures in the upper 70s to low 80s continue through the first half of the work week, with a steady warming trend through Wednesday. Precipitation chances look to return as soon as Tuesday, although the highest chances will be on Wednesday.
Severe weather potential may also return on Wednesday. The storm prediction center has already started to hone in on this threat, with a 15% risk (equivalent to a slight risk, level 2 of 5) for severe weather over the southern half of Iowa for Wednesday afternoon.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/
Issued at 1042 PM CDT Sat Jun 13 2026

VFR conditions are expected to prevail through the end of this TAF period. Rain/thunderstorms have moved out of Central Iowa, but clouds are still present at OTM. Over the next couple of hours, all terminals will have very few clouds with light winds. Winds will, however, increase out of the NW late morning at 12-15 kts, with gusts reaching up to 25 kts.


DMX WATCHES/WARNINGS/ADVISORIES
None.