Cold Weekend Continues

Cooler Below Normal Temperatures Continue, Freeze Possible Monday Morning, Rain Chance Wednesday, Warmer Next Weekend. Storms to Possibly Arrive the 13th.
More Details Below.

Here's a list of a few high and low temperatures observations around the state today:
Indianapolis:  High 53 Low 35
Lafeyette:      High 50 Low 32
Terre Haute:  High 55 Low 37
Muncie:         High 53 Low 34
Bloomington: High 53 Low 35
Shelbyville:    High 55 Low 37
Columbus:     High 54 Low 36
South Bend:  High 46 Low 34
Fort Wayne:  High 53 Low 34


The first of 2 cold fronts passed early Friday Morning (late Thursday Night). You can practically spot them in yesterdays observations below around Midnight when the winds switched from a southwestly air flow to a northwesterly air flow. Also, the rain played another factor in yesterdays temperatures. Yesterday high of 63° actually occured after midnight. Temps fell into the mid to upper 40s and remained fairly steady between 12PM-6PM.

A weak cold front (up to the North in photo below) will arrive tonight or early Sunday morning keeping Sunday afternoon temperatures from warming too much. In fact, some areas of the state could fail to reach the 50° mark. There is a temperature record to keep our eyes on tomorrow. The record for the lowest high temperature also referred to as lowest maximum temperature, is 48° set back in 1987. (Simply means the high for October 7th has not been 48° or below since then)
With increasing clouds tonight, there will be the possibility for some morning sprinkles or light drizzle. Yes, the reports will probably be pouring in for sights of winter precipitation. Could see some flurries or whats known as "graupel". Graupel is basically just soft ice pellets (frosted snowflakes). I really think this will fall up to the North where temperatures are expected to be lower but I wouldn't count out those in Central Portions of the state as well.



With the cool Sunday ahead, temperatures in some areas of the state away from the city will fall into the upper 20s for Monday Morning. A temperature of 28° or below is categorized as a "HARD FREEZE". Central Indiana will flirt with a "light freeze" with temperatures 32°-34°. Something that hasn't last happened since April 12th (33°). For now, mostly all of Indiana is under a freeze watch effective from 2AM to 9AM Monday Morning. Wouldn't be surprised to see that upgraded to a freeze warning later on.

Since we are heading into that time of the year I would like to go over a list of the all the winter watches and warnings that can be issued. What do they mean? When do they get issued?

FROST ADVISORY
Conditions are or will be favorable for frost to develop. The object or surface where frost will form will occur at 32°F/0°C. However, there is no specific air temperature for frost to form. Generally, frost develops when the air temperature is 32°-36°.

FREEZE WATCH
A freeze watch is issued when there is a "CHANCE" for temperatures to be at 32° or below. This can cover a wide length of time and be issued days in advance.

FREEZE WARNING
A freeze warning is issued when temperatures are very likely to reach 32° or below or is already occuring. It is not intended to cover a wide-length of time and not issued days in advance.

WINTER STORM OUTLOOK
This is a statement issued when there is a chance of a major winter storms from 3 to 5 days in the future. This is meant to assist people with their long range plans. However, since the outlook is issued so far in advance, the accuracy of the prediction may be limited.

WINTER STORM WATCH
This means there may be hazardous winter weather due to various elements such as heavy snow, sleet, or ice accumulation from freezing rain. In our region, heavy snow means 7 inches or more of accumulation in 24 hours or less. A "WATCH" is a long range prediction. They are issued at least 12 hours before the hazardous winter weather is expected to begin. When the storm becomes imminent, or has a high probability of occurring, the watch will be upgraded to a "WARNING".

WINTER STORM WARNING FOR HEAVY SNOW
Seven inches or more of snow will fall within a 24 hour period.

WINTER STORM WARNING FOR SEVERE ICING
Heavy accumulation of ice due to freezing rain will down trees and power lines. Electricity, or telephone communications, may be out for a long period of time. Roads may become impassable for most vehicles.

BLIZZARD WARNING
This is issued for a combination of strong winds averaging or frequently gusting to, or above, 35 miles an hour and very low visibility due to blowing or falling snow. These are the most dangerous winter storms and can be especially severe when combined with temperatures below 10 degrees.

WINTER STORM WARNING
This is issued when a dangerous combination of heavy snow, with sleet and/or freezing rain, will occur or has a high probability of occurring within the next 12 hours.

HIGH WIND WARNING
This means the expected winds will average 40 miles an hour or more for at least 1 hour or winds gusts will be greater than 58 miles an hour. Trees and power lines can be blown down. A High Wind Warning may be preceded by a HIGH WIND WATCH if the strong winds are not expected to occur for at least 12 hours.

WIND CHILL WARNING
This means life threatening cold with wind chill temperatures computed to be -40 degrees or less for at least 3 hours. Exposure to this combination of strong winds and low temperatures without protective clothing will quickly lead to frostbite and/or hypothermia. Longer exposures can be fatal.

WINTER WEATHER ADVISORY FOR SNOW
This is issued for snowfall greater than 4 (but less than 7) inches in a 24 hour period. The snowfall is usually expected to begin within the next 12 hours.

BLOWING SNOW ADVISORY
This is issued when the visibility will be significantly reduced, or when the roads become snow covered over a large area.

WIND CHILL ADVISORY
This is issued for cold temperatures and winds, with wind chill temperatures computed to be -25 degrees or less for at least 3 hours. Exposure to this combination of strong winds and low temperatures without protective clothing can lead to frostbite and/or hypothermia, Prolonged exposure may be fatal.

WINTER WEATHER ADVISORY
This is issued for a combination of snow, sleet, and/or freezing rain. Advisories, in general, are issued for weather conditions that are expected to cause significant inconveniences and may be hazardous, These situations are normally not life threatening if caution is exercised.

WIND ADVISORY
This is issued for average wind speeds between 31 and 39 miles an hour, or for frequent wind gusts between 46 and 57 miles an hour.

Here's a list of the some the different types of fall/winter precipitation and terms:

Drifting Snow - An uneven distribution of snowfall or existing snow caused by strong surface wind. Drifting snow may occur during or after a snowfall.

Freeze - A condition occurring over a large area when the surface air temperature remains below 32 degrees Fahrenheit for an extended period of time possibly leading to the damage of certain crops.

Freezing Drizzle - Drizzle that falls in liquid form and then freezes upon impact with the ground or an item with a temperature of 32 degrees Fahrenheit or less, possibly producing a thin coating of ice. Even in small amounts, freezing drizzle may cause traveling problems.

Freezing Rain - Rain that falls in liquid form and then freezes upon impact with the ground or an item with a temperature of 32 degrees Fahrenheit or less, possibly producing a thin coating of ice. Even in small amounts, freezing rain can cause traveling problems. Large amounts can pull down power lines and tree branches.

Frost - A covering of ice on exposed surfaces when the air temperature falls below the frost point.

Frozen Dew - When liquid dew changes into tiny beads of ice. The change occurs after dew formation and then the temperature falls below freezing.

Heating Degree Day - A form of degree day used to estimate the required energy for heating. One heating degree day occurs for each degree the daily mean temperature is below 65 degrees Fahrenheit.

Ice Crystals - A barely visible crystalline form of ice that has the shape of needles, columns or plates. Ice crystals are so small that they seem to be suspended in air. Ice crystals occur at very low temperatures in a stable atmosphere.

Ice Fog - Fog composed of ice crystals instead of water droplets. Ice fog forms when clear and calm conditions prevail in extremely cold arctic air.

Snow - Precipitation composed of white or translucent ice crystals. Snow forms in cold clouds by the direct transfer of water vapor to ice.

Snowflake - White ice crystals that have combined in a complex branched hexagonal form.

Snow Flurries - Intermittent snowfall of short duration. No measurable accumulation of snow occurs.

Snow Shower - A short duration of light to moderate snowfall. Accumulations of snow are possible.

Sleet - Precipitation consisting of transparent pellets of ice, 5 millimeters or less in diameter. Also called ice pellets. Forms when snow enters a warm layer of air above the surface and melts and then enters a deep layer of sub freezing air on the surface and refreezes.


Finally, here's a updated list of "Chilling Facts" I've been putting in some of my most recent blogs over the past month.

• Last Subzero Low-February 10, 2011 (-1°)
• Last Single Digit Low-February 9, 2011 (7°)
• Last low temp in teens-February 13, 2012 (18°)
• Last low temp in 20s-April 11, 2012 (29°)
• Last low temp in 30s-October 6, 2012 (35°) <-----RECENT CHANGE
• Last low temp in 40s-October 5, 2012 (41°) <-----RECENT CHANGE
• Last high temp in 50s-October 6, 2012 (53°)<----RECENT CHANGE
• Last high temp in 40s-March 9, 2012 (45°)
• Last high temp in 30s-March 3, 2012 (38°)
• Last high temp in 20s-February 11, 2012 (25°)
• Last high temp in the teens-February 13, 2012 (19°)
• Last single digit high-February 15, 2009 (7°)
• Last Subzero High-January 18, 1994 (-4°)
• Earliest First Freeze-September 30, 1899 (30°) & 1993 (33°)
• Latest First Freeze 32° or lower-November 8, 1956
• Latest First Hard Freeze 28° or lower-December 3, 2004
• Avg First Frost-October 7 (36° or lower)
• Avg First Freeze-October 16(32° or lower)
• Avg First Hard Freeze-October 30(28° or lower)
• Last years First Freeze-October 30, 2011 (31°:)
• Last years First Hard Freeze-November 11, 2011 (27°)
• Avg First Snowfall-November 19 (0.01 or higher)
• Earliest First Snowfall (0.01 or higher)-October 18, 1989
• Last years First Snowfall (0.01 or higher)-November 29, 2011 (0.2")

Now since that is out the way, lets talk about precipitation.
For the first 5 days of October, Indy records 1.76" of rainfall. That is 1.23" above the normal 0.53" of rain we should have. Only 4 out of the past 17 Octobers have opened up wet, and generally this a month that is ranked the 4th most sunniest month of the year with a avg of 19 sunny days in October. The average precipitation for the month is 3.12". Typically, August, September, and October are supposed to be the most driest but instead it seems this year, its been the most wettest. Of the 31.98" of rain we've received this year, half of it has been picked up between August 4th-October 5th (16"). We should stand at 32.98 so after a really dry summer we've rebounded quickly. This means the deficit is now only 1" and if this doesn't take us out of a moderate drought next week, i classify this as a weak moderate drought. Although we are still abnormally dry, we will have wiped the slate clean by Halloween. Its not just dry conditions the past summer but we've also had a mild winter last year with only 9.8" of snowfall. Thats only half of the average winter's snowfall. We will certainly have to see where the upcoming winter will go. The drought could return next Spring if we end up with a repeat. It's still uncertain as to where the winter will go, but given the recent trend, winter could arrive early. This could either mean colder temperatures or more importantly, more snowfall. Only time will tell, anything can change. We saw how big of a change there was from a Dry, Hot July, to a wet, cool August. We can certainly reverse back to a dry, mild pattern. Nothing is guaranteed at the moment but for atleast the next 2 weeks I don't see that happening. One interesting fact that I kept a track of, from September 2011-June 2012 (10 consecutive months). We've had atleast one day with a high in the 60s (even in winter 2011). That just shows how much of a mild pattern we had. I highly doubt that will happen again though.

	This Week	Last Week	Difference
Abnormally Dry	99.83%	100%	-0.17%
Moderate Drought	77.19%	87.81%	+10.62%
Severe Drought	14.67%	25.47%	-10.80%

If you look at the bottom of the map above, in the center, you can see a very small area of white. This accounts for the 0.17% of the state that is NOT abnormally dry or in any kind of drought. This is certainly good news. These means that they have an adequate supply of water and have plenty of rain for the year. They are NOT in a rainfall deficit. This is on the extreme Southeast side of Harrison County near the IN/KY borderline.

Here's a look at the updated Indiana rainfall deficit chart:

Location	Year to Date Precipitation (through Oct. 5)	Departure from Average	Precip since Sept 1	Departure from Average	Precip since Oct 1	Departure from Average
Indianapolis	31.98	-  1.00	9.49	+5.84	1.76	+1.23
Evansville	26.52	-  7.98	8.55	+4.97	0.95	+0.42
Lafayette	22.50	-  6.22	5.09	+1.92	1.16	+0.65
Terre Haute	22.79	-12.46	5.25	+1.28	1.06	+0.51
Muncie	26.51	-  4.88	7.59	+4.11	1.95	+1.43
Bloomington	26.12	-11.01	9.82	+5.88	2.44	+1.85
Shelbyville	23.91	-10.12	7.19	+3.44	1.24	+0.66
Ft. Wayne	23.26	-  6.87	4.40	+1.11	0.79	+0.30
South Bend	26.80	-  2.55	2.22	-1.86	0.19	-0.36
Indy - Eagle Creek	31.21	-  0.21	9.08	+6.31	1.95	+1.43

NOTE: Precipitation not available on some days since January 1 in Lafeyette, Terre Haute, and Bloomington.

You can see last month and this month most of the much needed rainfall has fallen in Bloomington, which brings their deficit down to 11" but only 5.25" in Terre Haute since Sept 1 still keeps their deficit over a foot of rain for the year. The Severe drought remains in that area and will certainly take more time to recover heading into the winter months.

Here's the breakdown for the years monthly rainfall in Indy.

Month	Monthly Precip	Monthly Deficit	Precip Since JAN 1	Yearly Deficit
JAN	3.48"	+0.82"	3.48"	+0.82"
FEB	1.38"	-0.94"	4.86"	-0.12"
MAR	4.14"	+0.58"	9.00"	+0.46"
APR	3.36"	-0.45"	12.36"	+0.01"
MAY	2.70"	-2.35"	15.06"	-2.34"
JUN	0.09"	-4.16"	15.15"	-6.50"
JUL	0.83"	-3.72"	15.98"	-10.22"
AUG	6.51"	+3.38"	22.49"	-6.84"
SEPT	7.73"	+4.61"	30.22"	-2.23"
OCT 1-5	1.76"	+1.23"	31.98"	-1.00"

When we started the month of May we picked up 1.48" on the 1st. This brought the years rainfall total to 13.84". This was actually 1.33" above the normal 12.51" of where it should have been. Starting May 2nd, this is technically when the dry weather pattern began. We only recorded 6 days of measurable rain this month totaling another 1.22" bringing the final total to 2.70" for the month of May. Then we recorded 3 days of rain in June totaling 0.09" and another 3 days of rain in July totaling 0.83". This means during a 91 day period (May 2-July 31) only 12 days were recorded with measurable rain (0.01" or higher) totaling 2.14". If you add May 1st (1.48") then it totals 3.62". That brought the years rainfall to 15.98". This was (a) 10.22" (deficit) below the normal 26.20" that we should have had ending July.
The first 3 days of August were dry. We avg 0.33" of rain for those days. If you add this to the 10.22" deficit July 31st, this equals the peak rainfall deficit for the year of 10.55". This means we were 10.55" below the normal 26.63" we should have had for the date. The improvements then began.
From August 4th-August 27th, we recorded 6.51". Its not that we had a lot of days with a range of rainfall big or small but its more of a lot of rain squeezed into a low amount of days. Which means the months rainfall was not evenly distributed over a large period of time. The months 6.51" of rain was squeezed into only 8 days. There was trace amounts of rain recorded on another 2 days but they aren't measurable rain.
The same scenario sort of applies to the month of September. The months 7.73" of rain was squeezed into 12 days. Out of that, 2.70" fell on one day, 1.53" fell on another, and 1.32" fell on another. This leaves the remaining 2.18" to spread amongst the other 9 days which is helpful to have a more consistent rainfall. This adds up to an average of 0.24"-0.25" of rain a day for the remaining 9 wet days.
The first 5 days of October, we've picked up 1.76" of rain. This is 1.23" above the normal 0.53" we should have. This means since August 4th, 20 days out of past 63 days have been recorded with measurable rain totaling 16". Its interesting that we only average 3.13" of rain in August, 3.12" in September, and 3.12" in October totaling a 3 month average of 9.37" (3 least wettest months of year). So we are 6.63" above normal since August 4th. Typically, August-October are supposed to be the 3 least wettest months of the year. Can't speak for October just yet, but August and September are the 2 most wettest months this year. March is the 3rd wettest month so far this year.

Tonight
Cloudy with a chance for some sprinkles or light rain/drizzle. Low 35°-37°.

Tomorrow
Mostly Cloudy. Afternoon Clearing. Late Afternoon Sunshine. High 49°-52°.

Tomorrow Night
Clear Skies. Development of Frost. Cold. Freeze Watch 2AM-9AM. Low 32°-34°.

Monday
Clear. Sunny. Becoming a tad bit warmer. High 56°-60°.


***7 DAY FORECAST***

Colts vs Packers @ 1PM
OCT. 7	OCT. 8	OCT. 9	OCT.10	OCT.11	OCT.12	OCT.13
SUNDAY	MONDAY	TUESDAY	WEDNESDAY	THURSDAY	FRIDAY	SATURDAY
AM-Light Rain/Drizzle	Sunny	Mostly	Showers	Mixed Sun	Mixed Sun	Mixed Sun
FREEZE	WATCH 2AM-9AM	Sunny	Likely	& Clouds	& Clouds	& Clouds
SEASON'S COLDEST	MORNING OCCURS			PM RAIN		PM T'STORM?
AM	FROST	WARMER				MUCH WARMER
50	58	68	60	65	62	72
35                33	42	47	41	46	50	52

UPCOMING........
With the possible development of severe weather in the plains late week. This looks to move into our area Saturday Night or Early Sunday Morning. Temps get a boost as well into the low 70s for Next Saturday and Sunday. Rain and/or Storm Chances will hit the State starting Saturday and continue off and on through Wednesday Morning. The 6-10 day Rainfall totals between a quarter of inch to a half inch of rain. So the pattern won't be too wet. In fact, over the next 7 days, Wednesday looks to be the only wettest day.
CPC is calling for above normal precipitaton for the 8-14 day time period. The stormy pattern I spoke of above spans between October 13-17. During this time, I expect rain totals to tally up between 2" to as much as 3" under a strong thunderstorm. I will continue to monitor and update changes for the better or the worse in the coming days.
More Weather Blogs to come.