Past IEM Features tagged: nov
Won't be Warmest November
18 Nov 2023 06:48 AMOur recent November weather has featured rather warm temperatures and the month to date average temperature has been somewhere near the 10th to 20th warmest on record. If you ignore the cold forecast next week, one may wonder if we had any chance of setting a warmest November on record. The featured chart attempts to do just that by combing the month to date average temperature for Ames and appending on each previous year for the 19th through 30th period. None of these scenarios are able to top the warmest November of 2001. The cold first day of the month and having seasonal overnight temperatures dug a bit of a hole for the month to date metric to rise out of, if there was any chance of catching 2001.
Voting:
Good: 8
Bad: 0
Tags: nov
November 70+ Hours
09 Nov 2023 05:30 AMVery warm air was just to the south of Iowa on Wednesday with record high temperatures found in places like St Louis (84) and Springfield, IL (79). The very far southeast corner of the state at Keokuk was able to reach 71 degrees. The featured chart looks into the November frequency of having an hourly temperature of at least 70 degrees for the site. This observation site only has data back to 1996, but shows an interesting story that having such warm temperatures during November is not a given with a number of years having zero hours. The overall and simple average is 21 hours. The forecast for next week continues to look very warm, so perhaps this total can be added to at this site and others in the state.
Voting:
Good: 11
Bad: 0
Tags: nov
Warm November Combo
07 Nov 2023 05:30 AMVery nice temperatures on Sunday were surpassed by even warmer temperatures on Monday with highs reaching the low 70s over much of the state. This followed very mild morning low temperatures. The featured chart presents a histogram of daily high and low temperatures during November for Des Moines. The left panel shows the frequency of a given high and low temperature combination. The right panel presents some metrics for the daily range between the two. For low temperature, you can see frequency clustering around 32 degrees as freezing of water is exothermic and tends to slow down cooling along with soil temperatures that are still comfortably above freezing.
Voting:
Good: 5
Bad: 2
Tags: nov
November Hours of 70+
03 Nov 2022 05:27 AMNovember has gotten off to a wonderful start with 70s common over Iowa during the afternoon hours and another day of it expected today. The featured chart presents an accounting of hours at or above 70 during November for Des Moines. The 2022 total of thirteen hours is already way above a long term and simple average of five. The top panels shows that a number of years, including last year, failed to even once reach 70, so this year is a bit of a treat. Even with a significant rainfall event arriving on Friday, temperatures next week do not look all that bad. The pessimist here is certain we will "pay for this" with much worse weather sooner than later!
Voting:
Good: 11
Bad: 0
Tags: nov
November Wind
19 Nov 2020 05:35 AMWednesday was another very windy day. The winds were out of the south helping temperatures to warm nicely above average. It seems we have had more than our fair share of windy days this month, but does the data validate that impression? The featured chart presents the average daily wind speed between 1 and 18 November for Des Moines. Long term wind climatology plots are fraught with caveats and this plot nicely illustrates one of those caveats. The chart clearly shows a regime shift around the year 1960. This isn't natural variability, but rather a change in observation methods and/or IEM coding bugs! It turns out that recording a wind speed is not necessarily straight forward but subject to many variances including the height of the sensor, type of sensor, dynamic response time, averaging method, and sampling period for a sustained wind measurement. Well that got off into the weeds, but assuming that the past few years are directly comparable, indeed this November has seen more wind than the previous few. Ironically, the 2020 value comes up near long term average shown by the plot!
Voting:
Good: 12
Bad: 1
Tags: nov
Muggy for November
09 Nov 2020 05:33 AMOur crazy nice November weather will come to an end later today with the passage of a cold front sweeping the state. Moisture has been streaming into the state ahead of this passing storm system with dew point temperatures noticeably higher around 60 degrees. In fact, you may have noticed various surfaces, like shaded pavement, being wet from having a temperature below the dew point and thus condensing water onto it. Having such warm and muggy temperatures for November is a bit rare as shown by the featured chart presenting dew point climatology by air temperature for Des Moines during November. Having dew point readings near 60 degrees is at the 95th percentile for temperatures that can support such dew points.
Voting:
Good: 10
Bad: 51
Abstain: 1
Tags: nov
November Hourly Temps
15 Nov 2019 12:03 AMWith the recent stretch of cold weather you may think we are in the dead of winter already, but it is only the middle of November! The featured chart presents the hourly frequency of having a sub freezing temperature during November based on available data for Ames back to 1996. Of note here is that the highest frequency at 7 AM is just under 50%. So the most common temperature during November is above freezing even during the overnight hours!
Voting:
Good: 13
Bad: 1
Tags: nov
November Highs and Lows
01 Dec 2017 05:33 AMThe calendar has turned to December, so it is a good time to look back on November. The featured chart displays a heatmap of daily high and low temperatures for November for Ames. Actual observations for this past November are overlaid. Temperatures were generally within the higher frequencies based on long term data, even though the actual time series of data for the month featured a chilly start and warm end to the month. The heatmap also shows the combination with the highest frequencies, which is a high between 47 and 50 along with a low between 29 and 32.
Voting:
Good: 8
Bad: 0
Abstain: 1
Tags: nov
Tale of Two Novembers
28 Nov 2017 05:33 AMWhile the first half of November was cold, the second half has been rather warm. The featured chart looks at the combination of Des Moines average high temperature for the 1- 13 Nov period against the 15-27 Nov period. The 2017 value is highlighted and would indicate that such dichotomies are not that uncommon. The chart also contains some diagnostics looking at quadrant frequencies with the quadrants delineated by the means. While there is some correlation between the periods, a cold start to November did not doom us for a cold end of November.
Voting:
Good: 6
Bad: 2
Tags: nov
60+ in November
21 Nov 2017 05:33 AMIt took until the 20th day of November to breach 60 degrees for places like Des Moines. Strong south/southwesterly winds helped to push temperatures finally well above normal. The featured chart is a wind rose and looks at wind speeds and directions during November when the air temperature is at or above 60 degrees for Des Moines. The wind rose is a wonderful way to see direction and speed frequencies. The longest bars coincide with what we experienced yesterday, which were winds from the SSW. Of course, not many occurrences of NW winds are shown as that is typically a source of cold air.
Voting:
Good: 5
Bad: 0
Tags: nov
November Clouds at Temp
09 Nov 2016 05:32 AMYesterday was yet another pleasant day this November with highs reaching into the 60s for much of the state. This was with mostly sunny skies overhead. The featured chart looks at the observed frequencies of overcast clouds at a given temperature in November for Des Moines. It is interesting to note the three regimes depicted in the chart. For really warm or cool temperatures, it is clear that less cloudiness needs to be present. This makes physical sense as the presence of clouds at night traps heat and during the day, limits heating by the sun.
Voting:
Good: 5
Bad: 3
Tags: nov clouds
November Winds + Dew Points
05 Nov 2015 05:34 AMHumidity levels have been on the increase with the approach of the storm system that will make its way through Iowa today. As you'd expect, these increased humidity levels have been thanks to transport from our south. The featured chart displays the average dew point by a given wind direction for November for Des Moines. There is a large difference in humidity levels when the wind direction switches from south to northwest. The source region of air masses from those directions easily explains the difference. With southerly air masses influenced by the humid Gulf of Mexico and the northwesterly air masses coming from the arid high plains.
Voting:
Good: 16
Bad: 5
Abstain: 3
Tags: nov
Above 70 in November
02 Nov 2015 05:31 AMThe first day of November felt more like early fall with highs into the 70s. The featured chart presents a wind rose during times when the temperature was at or above 70 in November for Des Moines. As you may expect, the winds are predominantly from the south and west during these warm temperatures. Having winds from this direction are important to help bring warmer air into the state and mix down warmer air from above. The warm and breezy weather looks to continue this week until Thursday, so enjoy!
Voting:
Good: 18
Bad: 7
Abstain: 4
Tags: nov
Frozen November Periods
02 Dec 2013 05:37 AMMuch of the last part of November was rather cold with high temperatures some days struggling to break freezing. For Des Moines, a period of 92 hours experienced sub freezing temperatures during the month. The featured chart presents the longest such period during November for each year back to 1936. This year's period was the longest since 1996. The first week of December looks rather interesting with some portions of the state experiencing very warm temperatures and others stuck with colder temps. Everybody will be cold by the coming weekend with daily highs back below freezing.
Voting:
Good: 26
Bad: 6
Abstain: 5
Tags: freezing nov
Wetter November
17 Nov 2011 05:56 AMThe precipitation total for this November has already exceeded the total for all of October for Ames. The featured chart presents the difference in precipitation between October and November each year for Ames. 37 of the total 119 years have seen a wetter November than October, so having this happen is about an one in three years chance. There are only small rainfall chances in the forecast.
Voting:
Good: 11
Bad: 1
Tags: nov11 nov
60s are nice for November
08 Nov 2010 05:48 AMHigh temperatures on Sunday soared well into the 60s and approached 70 degrees in some locations. The featured chart presents the number of days for the past 31 years that the high was above either 60 or 70 degrees for November at Ames. This year has seen two days over 60 with none over 70 for Ames. Our recent history shows that days over 70 in November were rare in the 80s and 90s. Highs this week are expected to continue in the 60s as our nice fall season rolls on.
Voting:
Good: 23
Bad: 1
Tags: nov
Just 17 degrees
01 Dec 2009 06:08 AMThe featured chart displays the minimum observed temperature in the state for the month of November. This November's minimum was a mere 17 degrees recorded at Atlantic and is the warmest minimum on record as shown by the chart. Low temperatures this morning to start off December are on the mild side mostly above freezing. Colder weather will arrive tomorrow.
Voting:
Good: 17
Bad: 9
Tags: nov nov09
Upper End
30 Nov 2009 06:07 AMThe featured chart is a plot of observed daily high and low temperatures for Ames during November from this year and all previous recorded years. The plot shows how variable the weather in November can be with highs from the teens to near 80. The red dots, signifying this year, appear mostly on the upper end of the chart with only one day having a high temperature below 40. Temperatures today will finish out November on the mild side as well with highs near 50.
Voting:
Good: 23
Bad: 11
Tags: nov
View larger image
Next day temperature change after a day with a high temperature over 60 in late November
30 degree swings common?
29 Nov 2006 07:09 AMHigh temperatures today will be around 30 degrees colder than Tuesday. How often does this happen? The featured image displays the next day temperature change after a day in late November (after the 20th) which had a high temperature over 60 degrees. So for each temperature over 60 degrees, the range of temperature change for the next day is displayed. The overall mean change is around 10 degrees with a 30 degree change rather uncommon (~5% quantile).
Voting:
Good: 16
Bad: 9
Tags: nov
Warm southwest winds
22 Nov 2006 12:36 AMThe featured plot is of observed afternoon air temperatures versus the direction of the wind for hourly observations during November back to 1970 when the wind speed was greater than 3 knots from the Des Moines Airport. Confused yet? The black line is a fit by wind direction and the contours are quantile densities, which indicate areas with large number of clustered observations. The plot confirms what we expect with cooler temperatures when the wind is from the Northwest (values 300-360) and warmer when the wind is from the Southwest (values 170-220). The two concentrated areas can be infered from a histogram plot of temperatures observed for 22 Nov with two modes of high temperatures due mostly to these two dominate wind regimes.
Voting:
Good: 40
Bad: 19
Tags: nov