Graduation Day

After an evening of storms, today is turning out to be a great day for graduating. Overnight, severe storms moved across the state. There was a report of golf ball sized hail in Castleton and a tornado north of the city. I've not seen any damage reports yet, but imagine there will be some. As for today, highs will be in the upper 70's to low 80's with low humidity. A great day for an outdoor graduation.

Memorial Day Washout

Heavy rain this morning in Shelby County. Radar estimates show 5 inches of rain falling in a brief period of time this morning. A flash flood warning was issued for the storm which was moving to the north-northwest very slowly. More storms may develop this afternoon thanks to an area of low pressure over southern Illinois.
Locally, only 0.12" of rain has fallen today with cool temperatures in the mid 60's. If the sun is able to get through the clouds today, then the surface should heat up and develop more storms. The air is thick with moisture today, it just needs some instability to make things pop. Sunshine would do the trick nicely I believe.

Summer Heat

Although the summer season is not yet here, the summer heat has arrived. The high temperature reached 87F (31C) on Friday and was just as warm today. Fortunately, the humidity has been low, but that will soon change.
Portions of Florida have received Biblical amounts of rain over the last week. Flagler and Volusia counties have received over 24 inches (61cm) of rain from a tropical wave in the area. Although this is a tremendous amount of precipitation, it is welcomed news. A prolonged drought over northeastern Florida have encouraged wildfires and water shortages over the last few years.
The low pressure are bringing all of this rain is forecast to make it's way into our area over the next week bringing a daily chance of some heavy rain.

Frosty Night Ahead

A frosty night is in store for the eastern two-thirds of the state tonight. The overnight low temperature is forecast to be down to around 37. Frost is an interesting element of weather. Frost is formed when the dew point is near or below freezing and the temperature of the air falls to within a few degrees of the dew point. You might think that dew will form and then freeze, but that is incorrect. Frost forms through deposition, the change of water vapor in the air directly into a solid... ice.
Frost forms first on rock, glass, or metal surfaces that lose heat more rapidly through radiative cooling than the surrounding air. This is why car windshields frost over before frost forms on surrounding vegetation. If the surface on which it forms has a temperature below the dew point, frost may even appear when the officially reported air temperature is above freezing. Frost formation may be sporadic across an area, particularly in hilly or mountainous terrain. Since cold air is denser than warm air, it flows like water downhill to pool in low areas or hollows. Areas that are low-lying are thus more susceptible to frost formation. These areas are called frost pockets or frost hollows. They are undesirable places for planting gardens!

Kirksville, Missouri Tornado

It was a stormy day across much of the Midwest on Wednesday. Locally, the big story was the heavy rain that fell, but further west across Missouri several tornadoes touched down causing widespread damage and fatalities.
I measured 2.32" of rain beginning Wednesday morning here at home, but Bloomington had over 6 inches of rain in the same time period. Flooding was a major issue during the morning commute. I even saw on the news this morning an SUV being carried away by flood waters in Little Fall Creek. It was funny to watch. As the car rolled over, you could see the windshield wipers still moving. Today has been calm, but more storms are on their way for Friday night and Saturday.

Richmond, Kentucky Tornado

Friday afternoon and evening a strong line of storms drove through southern Illinois and Kentucky. No severe weather locally, but in Richmond, Kentucky an EF3 tornado touched down. A lot of damage occurred in the area. Take a look at the house above on the left. The brick was ripped off of the house. Also note the RV that was picked up and dropped on top of the house!
There were two deaths associated with the storm. Here's report from the NWS in Louisville, Kentucky about the events surrounding the deaths.
TWO ADULTS WERE KILLED WHEN THE MOBILE HOME THEY WERE IN WAS PICKED UP AND THROWN BY THE TORNADO. THE BODIES OF A 35 YEAR OLD MALE AND A 42 YEAR OLD FEMALE WERE RECOVERED FROM A NEARBY POND. FOUR OTHER OCCUPANTS OF THE MOBILE HOME...INCLUDING THREE CHILDREN ...WERE INJURED.

Fire in the West - Rain in the East

It wasn't supposed to rain today. That's what they said this morning anyway. However, by 10:30 a light mist began to fall and by 11:00 it was a steady rain. Interestingly, the month of May is starting off very much like the month of April. During the first six days of April 1.89" of rain had fallen and as of today, May 6, 1.59" of rain has fallen this month.

A wildfire began in the foothills above Santa Barbara, California on Tuesday May 5. Southern California authorities said early Wednesday the wildfire is threatening 2,000 Santa Barbara homes and had grown to 400 acres. Santa Barbara County spokeswoman Pat Wheatley says the fire has pulled within a half-mile of some neighborhoods. By midday on Wednesday, May 6, the fire was reported to down to only 196 acres in size. However, afternoon wind gusts of 50mph fanned the flames once more re-igniting area hotspots.

Update on April Rainfall Totals

In my last post I mentioned that the wettest April in my records was April 2002 when we had 12.82 inches of rain. That seemed high to me so I double checked with the Indiana Climate Office. Here were the results for towns around the area that provide Cooperative Observation reports.

Total Rainfall - April 2002
Liberty, IN......7.72"
Brookville, IN...6.97"
Greensburg, IN...7.63"
Rushville, IN...10.71"
Shelbyville, IN..7.72"
Morristown, IN...6.48"

Although the 12.82" of rain I recorded in my rain bucket seems high it is within the realm of possibility of being accurate based on the 10.71" of rain recorded in Rushville. I'll concede though, my measurement is probably high.

Wet End to April

April 2009 was wet with 6.32" of rain falling through the month. April '09 was far from the wettest month I have in my records though. That title goes to April 2002 when 12.85" of rain fell through the month! Unfortunately, I don't have any anecdotal records of that month. However, I am trying to check with the Indiana Climate Office website to confirm such heavy rainfall in the surrounding communities of Rushville, Greensburg, and Brookville, Indiana. It seems that their database isn't cooperating tonight. I'll try later and post an update to this entry.

In the meantime, here is an April summary from the NWS in Indianapolis...

April 2009: Wettest in 45 Years

April 2009 featured a lot of extremes in daily temperatures, as readings ranged from well below normal to well above, with very little in between. One constant for the month, however, was an overabundance of rainfall. The month ended up as the 7^th wettest April on record, and was the wettest since 1964. The month also featured some of the warmest April weather since 1990.

The following is a summary of everything that was weather at the Indianapolis International Airport during the month of April 2008.

Temperature

The average temperature for the month of April was 53.8 degrees. This was above the normal April value of 52.0 degrees by 1.8 degrees. However, by no means was every April day above normal, and in fact at times the weather seemed anything but spring like.

The month started out on a cool note, and this continued until mid-April. A cool snap bottomed out on the 6^th and 7^th of April, as both days were 10 degrees below normal, and a high of only 44 degrees was experienced on the 6^th.

Temperatures shifted sharply above normal by the 24^th. In fact, there was a “mini heat wave” this April. From the 24^th through the 27^th, the high temperature exceeded the 80 degree mark each day. The first three days of this warm spell were all in the middle 80s, with temperatures peaking at 85 degrees on the 25^th. No record high temperatures were broken, but there were two record “warmest minimum” temperatures set, on the 25^th and 27^th. The last time that at least three days in a row with high temperatures of 84 or higher were recorded in Indianapolis during April was back in 1990.

The low temperature of 69 degrees on the 25^th was not only a record for the warmest low temperature on that date, but it also tied the record for warmest low temperature ever recorded during the month of April in the Indianapolis area.

As is typical for April, the month featured also a few nights when frosts and freeze conditions occurred. During an early month cool snap, the 7^th and 8^th experienced lows below freezing, with a minimum of 29 degrees on the 8^th.

The warmest temperature of the month came on the 25th, with a high of 85, and the coldest temperature this April was the morning of the 8^th with a low of 29. Five days this month saw highs in the 40s, and 4 days saw highs in the 80s. 16 days experienced temperatures above normal for daily averages, and 14 days with below normal daily averages.

Precipitation

April 2009 brought an excessive amount of rainfall to the Indianapolis area. The monthly total was 7.23 inches, and this was above normal by 3.62 inches. Just last year in April, we experienced less than 2 inches of rainfall in what was the 8^th driest April on record. This year’s April stands as the wettest since 1964, when the monthly sum was 8.09 inches. April 2009 will now go down in the record books as the 7^th wettest April on record in the Indianapolis area.

The longest dry period this month was the April 22^nd – 27^th stretch that brought just a Trace of rain for the 6 day period. The heaviest one day rainfall this month came back on the 5^th, when showers and thunderstorms dumped 1.87 inches of rain at the Indianapolis International Airport. This broke the daily rainfall record for the 5^th, eclipsing the previous mark of 1.63 inches set in 1965. Another heavy rainfall was experienced on the 28^th of April when 1.45 inches fell, which was followed by an additional 0.78 inches just the next day.

Severe Weather

April 2009 was rather quiet in terms of numbers of Severe Weather reports. The most significant event came on the 13^th of April, when a series of storms moved across south central Indiana, producing funnel clouds and hail to golf ball size. Some minor flash flooding was observed late in the month with the heavy rain on the 28^th. Climatologically speaking, May usually brings an increase in total severe weather reports, so residents should keep alert to the rapidly changing weather conditions that May will bring to Central Indiana.

Snowfall

April 2009 experienced just a Trace of snowfall, compared to the normal value of 0.4 inches. Even though there is a “normal” value of snow in April, most years either see no snow or just a trace. The last year that measurable snowfall came in the Indianapolis area during April was 2001. The season’s final snowfall this year came on the 21st of April.

Miscellaneous

The peak wind gust measured this April was 51 mph from the west on April 20, and also occurred again on the 27^th from the southwest. Thunder was reported on 3 days during the month. Fog or haze was observed on 13 days, and dense fog was not recorded this month at Indianapolis International Airport. Sunshine this month was 57% of the possible maximum.

Outlook for May 2009

The official outlook from the Climate Prediction Center at http://www.cpc.ncep.noaa.gov for Central Indiana calls for equal chances of above, below, or near normal values of both precipitation and temperature.

Data Prepared by Logan Johnson, Climate Services Focal Point

With assistance from National Weather Service Forecast Team