Iowa Weather Report April 29th 2013 – Iowa Weather Network Archives

[youtube http://www.youtube.com/watch?v=wZl6bw3gAXA&w=480&h=360]

COMPLICATED WEATHER PATTERN AHEAD: The next week across the state is going to be the most challenging and possibly interesting weeks we’ve seen in quite a while. First off we have a cold front moving through the state today with some showers and thunderstorms mainly in the morning and then again in the afternoon over the eastern counties. Highs today will be in the upper 60s through the 70s with some sunshine intermixed with the chance of rain. The front washes out and/or moves back north as a warm front Monday night into Tuesday. Another front swings into the state from the northwest Tuesday bringing cooler air down that will drop readings back into the 60s in NW Iowa, however readings well be in the lower to possibly middle 80s in the eastern and southeastern counties of the state. Showers and thunderstorms will fire along the slowly advancing front however, it will not be quick to move out and this is where the upper level cold core low comes into play. As a High Pressure over New England through the Canadian Maritimes is blocking the flow, the front will stall. The cold air will be forced out of Canada southward through Minnesota into Iowa and an upper level system will form somewhere over MO by Thursday into Friday. There is a chance of rain throughout the week off and on as temperatures are likely heading to the 50s for highs, perhaps even upper 40s, with lows in the upper 30s through the 40s. Thursday night into Friday morning could get interesting as the 540 line (on the 500mb chart known as the approx freezing line) moves through the state at that time, some of the precipitation may change over to a wintry mix of rain/sleet or rain/snow during that time over the eastern half of the state. 850mb temperatures according to the GFS are expected to be at or just below 0°C which would be conducive to the possibility of seeing some wintry precipitation. However, ground temperatures are expected to remain above freezing, likely in the upper 30s to lower 40s, so any wintry precip that may occur, would likely only accumulate on metal objects, such as cars, signs and perhaps in some grassy areas in shaded locations. Continue to monitor the blog for any drastic changes regarding this abnormal spring storm upcoming.

STUBBORN LOW: Continuing with the theme of the upper level cold core low, it is looking like this system will effect our weekend as well. The GFS has the low meandering around northern Missouri Saturday and Sunday. This will keep the chance of a few showers, perhaps with some embedded thunder in areas that could get some brief sunshine, with the chance of some graupel falling in the heavier showers. This coming weekend as of now does not look ANYTHING like this past weekend with warmth and readings at or above seasonal levels. Readings look to remain in the 50s with lows around 40 both Saturday and Sunday at this time. Next Monday the low finally begins to move off to the east, but it looks like that day will bring more rain showers as well mainly over the eastern counties as skies begin to clear in the west.

ANYTHING ELSE?: Looking passed the abnormal part of the forecast, the weather turns seasonal again…around the 8th or 9th of May, but several shots of cooler air from Canada look to break that with a few shower and thunderstorm chances at that time.