textproduct: Des Moines

KEY MESSAGES

- Warm, dry conditions with breezy winds today leading to elevated fire weather concerns through the afternoon.

- Severe thunderstorm potential over central Iowa, generally after 7 pm tonight. Hail and damaging winds are the primary concerns.

- Rain and thunderstorm chances develop again Tuesday afternoon into the evening, with a few strong storms possible in southeastern Iowa.

- Additional precipitation chances Wednesday through Friday, with rain and wintry precipitation Wednesday night into Thursday and more severe potential Friday.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 256 PM CDT Mon Mar 30 2026

Temperatures have warmed nicely this afternoon, with most of the area in the upper 70s to low 80s as of 2 pm. With multiple hours of sunlight left and efficient mixing taking place (as evidenced by the breezy winds), record temperatures are still in reach. That said, cloud cover has started to drift in from the west, filtering sunshine. Should This continue, we could see clouds put an early damper on temperatures. Regardless of whether we reach the record highs, I'm sure nobody is complaining about temperatures in the upper 70s and 80s in March.

With the warmer temperatures and efficient mixing, relative humidities have fallen into the upper 20 to 30 percent range. Winds have also been quite breezy, sustained around 15 to 20 mph with gusts up to 30 mph in some locations. This has sites flirting with red flag criteria, and while it's unlikely we reach the sustained 25 mph with < 25% humidity, elevated fire weather conditions are ongoing across the area. Satellite has already detected numerous hot spots through the day, signaling the dry conditions and increased ignition potential in fuels. For these reasons, a special weather statement for elevated fire weather conditions is out through 00z (7pm CDT) this evening for all of central Iowa.

Moving forward through the day, we continue to watch the potential for thunderstorms developing as warm, moist air streams northward ahead of a weak surface low and kicks off storms along a subtle convergence zone. Given the lack of any robust features for guidance to latch onto, convective initiation has been a bit inconsistent among the short range guidance, likely due to the warm mid-level air. That said, if convective initiation does occur, it seems the most likely time will be right around to just after sunset (after 7pm), with the most likely corridor being between US Highway 20 and Interstate 80 tracking east northeastward. These storms will be occurring in a rather robust environment, with 1500 to 2000 J/kg of MLCAPE and 40 to 50 kts of deep layer shear, conducive for organized convection and even a few supercells. That said, while the low levels have plenty of rotation, hodographs farther aloft are messy and lack the speed and directional changes one would typically look for in a robust supercell environment. Likewise, despite the 50+ dewpoints streaming into the area, model soundings for central Iowa depict a deep "inverted-V" sounding, characteristic of a well mixed and dry-sub cloud layer. All of these features point toward a large hail and gusty wind threat, with little threat for tornadoes given the high LCLs and eventual elevated nature of storms occurring after sunset. Strong downburst winds are certainly possible with any stronger updrafts as heavy rain/hail falls into the dry layer, evaporates and cools. Finally, given the CAPE and shear present, hail to potentially large hail is possible, with larger hail (2"+) only being a threat if any supercells develop. Severe storm chances then diminish into the late evening hours, likely around midnight. A low potential exists for elevated showers/storms to persist through the overnight hours, mainly over southeastern Iowa, given the stout low level jet nosed up into a weakly unstable environment. However, this is a low confidence scenario at this time.

A cold front will drop southward through the area overnight tonight into Tuesday, shoving the low level moisture southeastward and flipping our flow to southerly. Gusty winds will accompany the cold air advection behind the front, but height rises and winds aloft behind the front aren't overly strong, which should limit any headline worthy winds on Tuesday. Much cooler temperatures will of course also fill in behind the cold front, leading to a sharp gradient in highs across the state tomorrow. The surface front makes it's way completely through the area by late Tuesday afternoon, with a few stronger storms possible along the boundary in the afternoon. Wind and hail will again be the primary concerns with these storms before the front pushes out of the area. Moisture advection and a low level jet nosed into Iowa will keep scattered showers and isolated storms percolating over the area through Tuesday night into early Wednesday, albeit likely not severe.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 256 PM CDT Mon Mar 30 2026

The active forecast continues on Wednesday through the end of the week. While a deepening trough develops over the western U.S. Wednesday, a low ejecting out of the southwest will keep showery precipitation continuing off and on through the day Wednesday in the state before the upper level support arrives into early Thursday. This precipitation will be mostly rain as warm air advection begins to flow back into the southern half to two thirds of the state as midlevel winds turn southwesterly and increase. In saying this, we won't be looking at overly warm temperatures Wednesday as highs only reach into the 40s to near 50 in the south after falling into the 30s to low 40s to start the day behind the cold front passage Tuesday. In northern Iowa, mid level winds will keep the colder air reinforced, however, which may allow for a short period of a wintry mix to start the day. The signal in forecast soundings is not overly robust though with the easterly winds reinforcing low to mid level dry air as well. Thus, northern Iowa is more likely to stay dry early Wednesday. This unfortunately is not the end of a discussion on winter weather as top down saturation continues to occur through the day Wednesday with the wintry precipitation reentering the conversation in northern Iowa on Wednesday evening into early Thursday morning. There remains some disagreement in forecast soundings in how the temperature profiles play out which will have a big impact on precipitation type at the surface. As noted in the previous discussion, afternoon cold rain potentially changing to a wet snow or even staying as cold rain remains the most plausible forecast at this point with deep saturation through the DGZ, near isothermal temperatures to only slightly warming above 0C at times and near freezing temperatures at the surface. There are some soundings in northern Iowa, though certainly closer to north central Iowa, with a warmer, nearing 2-3C warm nose and then dropping below freezing at the surface. This is showing up as a precipitation type of freezing rain in many cases, but does not really scream freezing rain soundings. Won't completely rule out some freezing rain or minimal icing on an elevated surface, but not expecting much in the way of accumulating ice at this time with rain to start, precipitation rate and the overall temperature profiles near to only slightly below freezing limiting icing efficiency. As such, have limited the overall icing amounts in the forecast but kept with wintry mix wording with the cold rain/wet snow the main forecast in northern Iowa.

After a short break later Thursday into early Friday, a stronger system moves in by later Friday into Saturday. This will bring another round of thunderstorms later Friday and a transition to showery precipitation into Saturday with temperatures cooling once again and potentially another round of cold rain mixed with wet snow in northern Iowa. Will continue to monitor the details into later this week, but some severe weather may be possible in the region as well to end the week. Dry weather looks to return Sunday. Temperatures will continue to fluctuate warming Thursday/Friday, cooling Saturday and warming again Sunday with northern Iowa remaining on the cold side and in the 30s-40s and southern Iowa in the 60s-70s then 50s.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1241 PM CDT Mon Mar 30 2026

VFR conditions prevail today with breezy winds out of the south. Winds will continue to increase this afternoon, with gusts in the 20 to 25 kt range possible at all sites. Late this afternoon and into the evening, scattered showers and thunderstorms are expected to develop and track from west to east. Strong winds and hail may result from storms. However, there remains some uncertainty on where storms will develop,with KDSM and KALO the two most likely sites to be impacted. Given the limited coverage of showers/storms, have kept mention as PROB30s for both these sites. Some additional showers/storms may develop later in the evening near KOTM, so have included SHRA mention there as well. However, this is a lower confidence scenario. MVFR to IFR cloud cover will drop south into northern Iowa tomorrow morning, most likely impacting KMCW and KALO.

CLIMATE

Issued at 256 AM CDT Mon Mar 30 2026

Forecast and Record High Temperatures for Select Central Iowa Cities...

============================================= | Monday | Period | Forecast Record/ | of City | High Year | Record ============================================= Des Moines 85 83/1968 1878- Mason City 80 78/1967 1903- Ottumwa 85 83/1967 1923- Waterloo 81 84/1967 1895- =============================================

DMX WATCHES/WARNINGS/ADVISORIES

None.