Mild Temps Now but Coolest Air of The Season Is Coming

Good Evening! This is my 1st blog of the month. Sorry, I took a long 2 week break but I felt it was time to catch up on the past few weeks.

SEPTEMBER 2013 INDIANAPOLIS CLIMATE SUMMARY
We did open the month warm. We were caught up in the passage of 2 frontal systems. The high temp of 85 on the 1st was knocked back to 76 on the 3rd. Though we only recorded a trace of precipitation, the cool down was very brief and warmer temperatures quickly returned. Its interesting to note that the 1st 11 days (execpt September 3rd) saw a high 84+. This was actually nearly a continuous streak that started back on August 19th (23 of 24 days). We reached the 90s from September 9th-11th. On September 10th we reached a record 96° & tied the warmest low temp of 74. This was the hottest day since August 8, 2012. Then On September 11th, we tied the record high of 95 and tied the warmest low of 72. The daily average temp during the period of Sept 9th-11th was 80+, the last time this occurred so late in the year was 74 years ago in 1939.

DAY OF THE WEEK	RECORD HIGH TEMP	PREVIOUS RECORD TEMP	HIGHEST MINIMUM TEMP	PREVIOUS RECORD TEMP
TUES SEPT. 10th	96° (NEW RECORD)	95° (1964/1983)	74° (TIED)	74° (1919)
WEDS SEPT. 11th	95° (TIED)	95° (1897)	72° (TIED)	72° (1900/1931)

A series of four cold fronts quickly moved in behind the record heat. The high temperature was 95 on the 11th, 83 on the 12th, & then 69 on the 13th. This was a 26° drop in the highs in 48 hours. The low temperature was 72 on the 11th, 63 on the 12th, and 53 on the 13th. This was a 19° drop in the lows in 48 hours. Overall, temps drops 20-25° in 48 hours but the drop doesn't stop there. The AM low temperature on the 14th was 48°. This was the coolest low since June 3rd. The 69° high on the 13th was also the coolest high since June 3rd. Even after several of these frontal systems, we only recorded a quarter of an inch of precipitation during the 1st 19 days of the month. There was a slight warm up back to the low 80s as a warm front pushed through but this was associated with a storm system that brought severe weather or rather thundery downpours to the state on the 19th. Indianapolis recorded 1.53" of rain on the 19th w/ an additional 0.49" on the 20th ending with 0.02" early on the 21st (see breakdown in image below). 2.04" of rain for September 19-21 is the wettest at one time since 2.29" fell on April 18th.
Since the average temperature was decreasing during the month, we were able to finish the month warm enough to be 1-7ˌ above normal from the 24th-30th. This put the months average temperature at 69.5° which was 2.6° above normal (66.9°)
On the 29th, another cold front moved through that also generated a half inch of precipitation. This brought's the months final rainfall tally to 2.86". The month finished 0.26" below normal (3.12").
Overall, September 2013 finished as the 36th warmest and 69th wettest on record.



Here's a look back at this year's temp and precip rankings.

MONTH	AVG TEMP	TEMP DEPARTURE FROM NORMAL	TEMP RANKING	TOTAL PRECIP	PRECIP DEPARTURE FROM NORMAL	PRECIP RANKING	TOTAL SNOWFALL	SNOWFALL DEPARTURE FROM NORMAL	SNOWFALL RANKING
JANUARY	29.9°	+1.8°	58th Warmest	5.51"	+2.85"	16th Wettest	2.4"	-6.2"	35th least snowiest
FEBRUARY	30.9°	-1.2°	66th Coolest	2.27"	-0.05"	71st Driest	2.6"	-3.9"	46th least snowiest
MARCH	35.5°	-6.7°	14th Coolest	1.96"	-1.60"	30th Driest	14.5"	+11.9"	4th Snowiest
APRIL	52.5°	-0.5°	74th Coolest	8.59"	+4.78"	2nd Wettest	TRACE	-0.2"	N/A
MAY	65.4°	+2.7°	34th Warmest	3.50"	-1.55"	60th Driest	NONE	0.00"	N/A
JUNE	72°	0.0°	71st Warmest	3.66"	-0.59"	69th Driest	NONE	0.00"	N/A
JULY	73.9°	-1.5°	30th Coolest	3.29"	-1.26"	71st Driest	NONE	0.00"	N/A
AUGUST	74.9°	+0.7°	43rd Warmest	1.15"	-1.98"	12th Driest	NONE	0.00"	N/A
SEPTEMBER	69.5°	+2.6°	36th Warmest	2.86"	-0.26"	69th Wettest	NONE	0.00"	N/A
JAN-SEPT	56°	-0.2°	N/A	32.79	+0.34"	N/A	19.5"	+1.6"	N/A

SKYWATCH
There was sightings of fireballs late September. The AMS received nearly 700 reports of a large fireball the morning of September 26th around 7:05 am local time. Witnesses from Ohio, Illinois, Indiana, Kentucky, Missouri and Wisconsin reported a bright light moving across the morning sky. Check out this heat map.



The AMS is always receiving reports of fireballs, some of which have yet to be reviewed or confirmed. You can check the reports at the following url address:
http://www.amsmeteors.org/fireballs/fireball-report/

Some areas got a glimpse of the Northern Lights and Draconid meteor showers over the past week. Next up..the Orionid meteor shows. This becomes visible October 20-21st. They'll be coming in at 10-20 meteors per hour. Meteors are best viewable away from city lights and before dawn. You may see some early AM on October 20th, 21st, & 22nd. I will note though, they'll be a little harder to see as the moon will be about 95% visible. The full (hunter's) moon comes right before it on October 18th. The next meteor shower event is the South Taurids on November 4-5.
The moon is 100% full on October 18th (7:38pm). This month's moon is called Hunter's Moon as it is the time to hunt in preparation for winter. Other names is Harvest Moon, Travel Moon, Dying Grass Moon, and Blood Moon.

METEOROLOGICAL FALL & OCTOBER 2013

September 1st marked the start of meteorological fall and so far it has been a mild Fall season. 68% (27) out the past 40 days have been above normal. 30% (12 days) have been below normal. The remaining 2% (1) of this fall's days has finished normal. The warmest high was 96° back on September 10th. The lowest low temperature was 44° on October 6th. So far the the warmest temperature this October is 82° recorded both on the 3rd & 4th. The average temperature for the first 5 days of October was 71°. This was good for the 12th warmest open to an October on record. A few fronts allowed high temperatures to drop into the mid to low 60s for October 6th & 7th. These cool temps were a response to a passage of a powerhouse frontal system that 1st dropped 2+ feet of snow in the Plains and spawned tornadoes in the upper midwest, and later generated nearly 3" of rain in Indianapolis. We set a daily record rainfall on October 6th. The 1.45" of rain we received bested a 15 yr old record of 1.41" set in 1998. The total precipitation for the month so far is 2.57". We received 82% of our average month's rainfall within the 1st 10 days of the month. The average total precipitation amount for October is 3.12". We are currently running 1.52" ahead of this month's normal pace. The average precipitation amount for the 1st 10 days of this month is 1.05". As for this month's average temperature (64.4°) we are running 5.8° above normal (58.6).

DROUGHT ANALYSIS
Latest drought map was released this morning. Most areas around the state received some beneficial rain over the past week, therefore, the 3% of the state that was in a moderate drought has been downgraded. 53% of the state that was abnormally dry has been cut back to 46%. Here's a look at the precipitation maps for October 4th, 5th, & 6th when over 2" fell here in Indianapolis. Even higher totals to the South. Bloomington received over 4". Central parts of the state are now no longer abnormally dry.
(THESE IMAGES MAY BE BETTER VIEWED IF CLICKED TO ENLARGE)


Here's a look at the latest drought map.



Here's a look at the updated Indiana rainfall deficit table (valid thru October 9). Lots of areas are above normal in precipitation not only for this month but for the fall season so far.

LOCATION	YEAR TO DATE PRECIP (thru Oct. 9)	DEPARTURE FROM NORMAL	PRECIP SINCE SEPT. 1st	DEPARTURE FROM NORMAL	MONTH TO DATE PRECIP	DEPARTURE FROM NORMAL
BLOOMINGTON	36.45	-1.11	6.13	+1.76	4.27	+3.25
EVANSVILLE	42.41	+7.51	7.08	+3.10	4.27	+3.34
FT. WAYNE	35.49	+4.99	3.15	-0.51	1.26	+0.40
INDIANAPOLIS	35.36	+1.96	5.43	+1.36	2.57	+1.62
INDIANAPOLIS EAGLE CREEK	32.84	+1.00	5.35	+2.16	3.04	+2.10
LAFAYETTE	33.38	+4.27	5.75	+2.19	1.82	+0.92
MUNCIE	30.45	-1.33	5.57	+1.70	1.78	+0.87
SHELBYVILLE	25.65	-8.77	4.24	+0.10	2.21	+1.24
SOUTH BEND	32.19	+2.39	5.27	+0.74	1.15	+0.15
TERRE HAUTE	35.42	-0.28	2.39	-2.03	1.19	+0.19

THIS WEEK
October is generally ranked as the 4th most sunniest month of the year and indeed there was more sunshine on tap for us today. There was a few clouds so it broke our 2 day streak we had going. October 8th & 9th saw 100% of its possible sun with NOT A SINGLE CLOUD IN THE SKY. This was the most sunniest back to back days since December 10 & 11th of 2011.
Each of the days this weeks has been warmer than the previous after the storm system passed last weekend. Monday's high of 62 jumped to 70 for Tuesday then 72 yesterday. Today, we started with a low temperature of 50 but warmed up to a high of 74. Today did finish above normal. 7 out of 10 days so far this month have been above normal. The normal high for today is 67° and the normal low is 46. No precipitation was recorded.

TONIGHT
Skies will continue to be clear and temperatures will drop to a low in the mid to low 50s. The targeted (forecast) low is 52.

FRIDAY
Sunny, pleasant, mild, & warmer. High 75.

UPCOMING...
There are indications that we have some even chillier air than Monday's high of 62 coming our way. Temps look to drop back into the 50s and before months end, we may see our 1st freeze which could came at the earliest on October 21st or 22nd. You can see the cool down that headed our way at the latter part of my 10 day forecast at the end of the blog. Before I get to that, I want to share with you 1st freeze dates over the past 10 years and other "chilling" stats.

• Last day w/ a high temp in the 50s: May 12, 2013 (57°)
• Last day w/ a high temp in the 40s: April 20, 2013 (48°)
• Last day w/ a high temp in the 30s: March 26, 2013 (39°)
• Last day w/ a high temp in the 20s: February 10, 2013 (17°)
• Last day w/ a high temp in the teens: February 1st, 2013 (16°)
• Last day w/ a high temp in the single digits: February 15, 2009 (7°)
• Last subzero high: January 18, 1994 (-4°)
• Last low temp in the 30s: May 13, 2013 (37°)
• Last low temp in the 20s: April 3, 2013 (25°)
• Last low temp in the teens: March 21, 2013 (16°)
• Last low temp in the single digits : February 1, 2013 (5°)
• Last subzero low February 10, 2011 (-1°)
• Last Freeze Date: April 20, 2013 (30°)
• Last Hard Freeze: April 3, 2013 (25°)
• Last day w/ measurable snow: March 26, 2013 (0.1”)
• Last day w/ a trace of snow: April 19th
• Last years 1st Freeze: October 8, 2012 (31°)
• Last years 1st Hard Freeze: November 6, 2012 (28°)
• Last years 1st trace of snow: October 30, 2012
• Last years 1st measurable snow: November 12, 2012 (0.2")

Check out the 500mb Height, Temperature, & Wind map from this mornings ECMWF (European) 12z run. Note the chilly air diving into the (upper) midwest region. This is a look at Sunday, October 20th at 8AM. If you look at the lines you also see the 540 line up in Michigan. Good indication that temps may be at or near the freeze point. Again, there's a possibility sometime between October 20th-26th we will see our 1st freeze of the season. This will be something to watch. I will monitor and update in the coming days. My 10 day weather outlook is posted afterwards.