Past 4th Of July Temperatures

Purdue Airport (1964 to 2010)
Warmest high temps
98º - 1990
97º - 1969
96º - 1988

Coolest high temps
69º - 2009
70º - 1972
75º - 1967

West Lafayette COOP (1901 to 2010)
Warmest high temps
104º - 1911
99º - 1936
97º - 1921

Coolest high temps
64º - 1982
71º - 1932
72º - 1992

A Look Ahead To The 4th Of July Weekend

High heat and humidity look to be around for the entire extended 4th of July weekend. Temps in the 90's with dewpoints well into the 70's, making for sticky conditions. As for storm chances, looks like they pick up as we get into Sunday and Monday. As usual though, it's not a sure thing it'll rain.

A quick update on the chase for the hottest summer on record (2011 vs 1936).
The chase for the hottest summer on record at LAF* (thru June 28th)
Year.....Avg Temp.....90º+.....100º+....Hottest Temp To Date
2011........73.1º........5..........0.............97º (6/4)
1936........72.3º........7..........0.............98º (6/20) 

June Heat Waves Of Yesteryear

When looking back through historical data for the Lafayette area, one things stands out with respect to summer temperatures...evidently the early 20th century featured hot summers. Not all of them of course, but there are some real impressive heat waves. To what degree these readings are accurate I don't know (i.e. where was the thermometer located, etc.). It's only from one source as well, the West Lafayette COOP. The temperatures in the 1930's summer are real eye openers...those were during the dust bowl days after all. Anyways, here are some of the past heat waves in June at the WL COOP (heat wave defined as at least 3 consecutive days of 95º or more, for this purpose).

June 9-11, 1911: 96º, 101º, 96º
June 15-17, 1913: 95º, 99º, 97º
June 27-30, 1913: 96º, 100º, 101º, 97º
June 9-11, 1914: 96º, 95º, 97º
June 21-23, 1923: 95º, 100º, 98º
June 4-7, 1925: 95º, 97º, 99º, 96º
June 25-30, 1931: 97º, 100º, 101º, 101º, 99º, 99º
June 5-11, 1933: 95º, 98º, 101º, 100º, 98º, 100º, 99º
June 17-22, 1933: 96º, 98º, 99º, 99º, 99º, 97º
June 26-30, 1933: 99º, 98º, 98º, 95º, 98º
June 1-4, 1934: 104º, 101º, 96º, 96º
June 26-30, 1934: 97º, 102º, 103º, 103º, 95º

For comparison's sake, I could find only one such streak/heat wave at the airport for June (data from 1964 to present):
June 20-22, 1988: 99º, 100º, 98º

Update On The Severe Weather Threat For Today

SPC day 1 outlook has updated and taken us out of the slight risk for severe storms this afternoon and tonight.  Text of their update pertaining to our area below:

MODIFICATIONS WERE MADE TO THE EARLIER SLIGHT RISK AREA FROM THE
GREAT LAKES INTO THE MID MS VALLEY AND NRN TN VALLEY.  SATELLITE
IMAGERY INDICATES APPARENT STABILIZATION HAS OCCURRED IN ASSOCIATION
WITH A SURGE OF WESTERLY LOW LEVEL WINDS IN ADVANCE OF THE COLD
FRONT OVER NRN/CENTRAL IL AND NRN MO...AND THE THREAT FOR ORGANIZED
SEVERE STORMS HAS DIMINISHED ACROSS THIS REGION.

Using A Computer Model For A 7 Day Forecast

We're going to use a global computer model (GFS-MEX MOS) to see how well it does with temperatures during a 7 day period. This is just a guide mind you, and shouldn't be used literally by meteorologists or anyone...but it's just an example of the tools used in forecasting. Note that days 5-7 usually skew towards climo, or what is normal for this time of year, with this model. I'll post the 0z run and 12z runs (when it comes in this afternoon), and we'll follow the progress as the week goes on. Temperatures bolded below.

LAFAYETTE           
 KLAF   GFSX MOS GUIDANCE   6/27/2011  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192      
 MON  27| TUE 28| WED 29| THU 30| FRI 01| SAT 02| SUN 03| MON 04 CLIMO
 X/N  82| 67  83| 57  84| 61  86| 70  92| 73  91| 65  86| 62  86 63 84
 TMP  79| 70  76| 62  78| 65  80| 74  87| 76  84| 68  80| 66  80      
 DPT  73| 65  57| 57  56| 59  63| 67  70| 71  68| 64  63| 62  63      
 CLD  OV| OV  PC| CL  CL| CL  CL| CL  PC| PC  PC| CL  PC| CL  PC      
 WND  10|  8  11|  7   6|  4   9|  6  10|  7   9|  8   8|  6   8      
 P12  54| 77   5|  7   5|  7   5| 12  18| 35  30| 34  21| 26  21999999
 P24    |     77|      7|     15|     18|     51|     46|     38   999
 Q12   2|  5   0|  0   0|  0   0|  0   0|  1   1|  1    |             
 Q24    |      4|      0|      0|      0|      3|       |             
 T12  84| 73   0|  3   0| 10  19| 21  29| 45  40| 30  16| 19  19      
 T24    | 87    |  3    | 11    | 31    | 59    | 48    | 32

LAFAYETTE           
 KLAF   GFSX MOS GUIDANCE   6/27/2011  1200 UTC                       
 FHR  24  36| 48  60| 72  84| 96 108|120 132|144 156|168 180|192      
      TUE 28| WED 29| THU 30| FRI 01| SAT 02| SUN 03| MON 04|TUE CLIMO
 N/X  64  84| 60  84| 62  85| 69  93| 74  91| 66  87| 65  86| 66 63 84
 TMP  67  78| 63  77| 66  80| 73  88| 76  84| 70  81| 68  81| 70      
 DPT  63  56| 60  59| 62  67| 66  72| 72  71| 65  64| 64  65| 65      
 WND   7   8|  5   6|  5   8|  6  12|  6   8|  6   8|  5   8|  5      
 P12   9   5|  4   4|  4   9| 34   7| 14  18| 19  19| 24  25| 24999999
 P24      12|      7|     13|     37|     20|     32|     40|      999
 Q12   0   0|  0   0|  0   0|  0   0|  0   0|  0   0|       |         
 Q24       0|      0|      0|      0|      0|      0|       |         
 T12  18   0|  3   4| 10  19| 45  37| 34  21| 26  27| 22  37| 27      

T24        |  3    | 10    | 53    | 55    | 41    | 36    | 46 

Severe Weather For Today

The newest update from the Storm Prediction Center has LAF under a slight risk for severe weather this afternoon/evening. Damaging winds and even a low threat for tornadoes being the threats outlined. Key to all of this is if we can clear out from this morning's clouds/rainfall, as well as back into Illinois where initiation should occur. There's currently some sun breaking out here this morning, but there's a large canopy of clouds stretching back to Iowa at the moment. Stay tuned.

Forecast "Contest" Wrap Up

All of these 7 day forecasts were from June 18th. Granted it's just one forecast from one day, but you get the idea. I'm a little surprised how most of them were too warm for high temps on a consistent basis...some way too warm. Anyway, the results below.


June 18
WLFI: 92º/75º (+10º/+7º)
NWS IND: 84º/71º (+2º/+3º)
TWC: 87º/69º (+5º/+1º)
AccuWx: 85º/69º (+3º/+1º)
Actual: 82º/68º

June 19th
WLFI: 93º/73º (+12/+6)
NWS: 83º/67º (+2/0)
TWC: 83º/67º (+2/0)
AccuWx: 88º/72º (+7/+5)
Actual: 81º/67º

June 20th
WLFI: 93º/73º (+15/+7)
NWS: 88º/72º (+10/+6)
TWC: 86º/72º (+8/+6)
AccuWx: 87º/71º (+9/+5)
Actual: 78º/66º

June 21st
WLFI: 91º/65º (+4/-6)
NWS: 89º/72º (+2/+1)
TWC: 91º/72º (+4/+1)
AccuWx: 87º/70º (0/-1)
Actual: 87º/71º

June 22nd
WLFI: 87º/62º (+7/-6)
NWS: 83º/65º (+3/-3)
TWC: 85º/66º (+5/-2)
AccuWx: 83º/65º (+3/-3)
Actual: 80º/68º


June 23rd
WLFI: 87º/61º (+16/-2)
NWS: 77º/57º (+6/-6)
TWC: 76º/58º (+5/-5)
AccuWx: 76º/60º (+5/-3)
Actual: 71º/63º


June 24th
WLFI: 84º/59º (+16/-3)
NWS: 74º/NA (+6/NA)
TWC: 74º/59º (+6/-3)
AccuWx: 79º/59º (+11/-3)
Actual: 68º/62º


Using the high temps only, which honestly who cares about the overnight low temps in the summer, here are the total degrees errors and the average error for the period.
June 18-24
WLFI: +80 (+11.4 per day)
NWS: +31 (+4.4 per day)
TWC: +35 (+5.0 per day)
AccuWx: +38 (+5.4 per day)

First Sub 70 Degree June High Temp Since...

...June 3, 2009, as yesterday the temp at LAF only got to 68º. A fairly impressive feat when the normal high is 85º for the 24th of June. We'll get into the upper 70's today, but still below average for the date. A good chance of thunderstorms exist overnight/Sunday morning.

Cool Yesterday, Cool Today

The high temp at LAF only reached 71º, which is 14º below the normal high at the airport. 0.08" of rainfall was recorded at LAF, which brings the June total to an even 6.00"...well above normal to date. Today looks to feature similar temps, with again a chance of showers.


Yesterday's scorecard for the forecast contest:
WLFI: 87º/61º (+16/-2)
NWS: 77º/57º (+6/-6)
TWC: 76º/58º (+5/-5)
AccuWx: 76º/60º (+5/-3)
Actual: 71º/63º

Cool Temps In The Short Term

Looks rather cool for the next two to three days here, with temps staying in the 70's. A 50/50 shot of some scattered showers today as the ULL rotates through the Midwest. In the extended (days 7+), the models are trying to create our next round of intense heat. Still out in fantasy land, so stay tuned.


Below are the updated tallies for the forecast "contest". Remember, forecasts were from June 18th. 


June 18
WLFI: 92º/75º (+10º/+7º)
NWS IND: 84º/71º (+2º/+3º)
TWC: 87º/69º (+5º/+1º)
AccuWx: 85º/69º (+3º/+1º)
Actual: 82º/68º


June 19th
WLFI: 93º/73º (+12/+6)
NWS: 83º/67º (+2/0)
TWC: 83º/67º (+2/0)
AccuWx: 88º/72º (+7/+5)
Actual: 81º/67º


June 20th
WLFI: 93º/73º (+15/+7)
NWS: 88º/72º (+10/+6)
TWC: 86º/72º (+8/+6)
AccuWx: 87º/71º (+9/+5)
Actual: 78º/66º


June 21st
WLFI: 91º/65º (+4/-6)
NWS: 89º/72º (+2/+1)
TWC: 91º/72º (+4/+1)
AccuWx: 87º/70º (0/-1)
Actual: 87º/71º


June 22nd
WLFI: 87º/62º (+7/-6)
NWS: 83º/65º (+3/-3)
TWC: 85º/66º (+5/-2)
AccuWx: 83º/65º (+3/-3)
Actual: 80º/68º

June Rainfall

0.35" of rainfall was measured at the airport yesterday, bringing the June total to 5.92". The normal June rainfall at LAF is 4.24". There's a chance of showers and scattered thunderstorms today and tomorrow, although the chances are under 50%.

Severe Weather Update

Tornado Watch has gone up to our southwest for central and southern IL. Storms are starting to break out in southeast MO, southern IL, and southern IN. We'll have to watch how the lines organize as these storms mature in the coming hours. Severe threat for us this evening remains damaging winds and hail, along with heavy rainfall.

Stay up to date by visiting the Storm Prediction Center website for watch and warning info.

Rainfall Totals From Monday

LAF - Purdue Airport: 3.14"
Lafayette 1.2 WSW: 3.20"
West Lafayette 5.1 WSW: 3.55"
Lafayette 1.3 W: 3.56"
Lafayette 2.2 S: 3.63"

*totals from CoCoRahs observers and the Purdue Airport.

Storm Chances Today And Tomorrow

Looks like a decent chance for scattered thunderstorms later today/tonight and then again tomorrow. SPC has us in a slight risk for severe weather both days (for damaging winds and hail). I guess I'd be somewhat surprised if we didn't have storms, but it is possible we get shut out despite the evidence pointing towards convection. We could probably miss out and be fine after yesterday's torrential rains. Today will be hot and sticky, with highs reaching the low 90's with dewpoints in the low to mid 70's.

Tallying the results for the past two days from the "contest" between the four weather sources (forecasts from 6/18).

June 19th
WLFI: 93º/73º (+12/+6)
NWS: 83º/67º (+2/0)
TWC: 83º/67º (+2/0)
AccuWx: 88º/72º (+7/+5)
Actual: 81º/67º


June 20th
WLFI: 93º/73º (+15/+7)
NWS: 88º/72º (+10/+6)
TWC: 86º/72º (+8/+6)
AccuWx: 87º/71º (+9/+5)
Actual: 78º/66º


Today's forecast
WLFI: 91º/65º
NWS: 89º/72º
TWC: 91º/72º
AccuWx: 87º/70º

Record Daily Precipitation Broken

3.14" has been measured at LAF today through 11:00AM. This breaks the daily record for today, which was 2.92" in 1964.

Of all the daily records for June, the 3.14" today is the 5th highest ever recorded at the airport (since 1944).
1) 4.10" - 6/25/1978
2) 3.95" - 6/12/2004
3) 3.30" - 6/11/2004
4) 3.18" - 6/4/1973
5) 3.14" - 6/20/2011

Heavy Rainfall This Morning

A morning MCS has brought heavy rainfall, over 2.00" so far, along with quite the lightning show. I had pea size hail here at my place earlier. There could be another line that moves through in the next hour. Just to the north of here, there is a nasty bow echo producing high winds that should miss us. Very active morning. There is potential for severe weather this afternoon/evening with the warm front moving though, but to what degree the atmosphere can recover after this morning's storms is always a concern. As well, the threat looks to be mainly north of Lafayette, but it would be wise to stay vigilant later today. More severe weather and thunderstorms are possible tomorrow.

Updated rainfall totals: 2.82" at LAF and 2.93" at WLFI through 10:00AM this morning.
11:00AM update: Up to 3.13" at LAF, which breaks the daily record for today of 2.92" set back in 1964.

Comparing 4 Different Weather Forecasts

I jotted down weather forecasts for Lafayette from 4 different sources: WLFI, the National Weather Service in Indianapolis, the Weather Channel, and AccuWeather on the evening of June 17th to see they would do with a 7 day forecast. I'm just using temperatures for this "contest". Here are the forecasts for yesterday and the actual numbers, plus the margin of error for each in ( ).

June 18
WLFI: 92º/75º (+10º/+7º)
NWS IND: 84º/71º (+2º/+3º)
TWC: 87º/69º (+5º/+1º)
AccuWx: 85º/69º (+3º/+1º)
Actual: 82º/68º


Forecasts for today (again from 6/17):
WLFI: 93º/73º
NWS IND: 83º/67º
TWC: 83º/67º
AccuWx: 88º/72º

Storms Cancel...So Far

Well looks like we'll miss the thunderstorms to the south again today. After looking like we were in the crosshairs a couple of days ago, the computer models were quite wrong. I guess that's a good reminder of how clueless they can be during the summer months with respect to storms, etc. Looks like our next best chance at t'storms will be Tuesday night or Wednesday with a cold front passage, though it is still wise to keep small chances of rain for today and Monday. Of course as usual, it's a wait and see situation.

June 2011 stats through the 18th:
Average temperature: 73.8º
90º+ days: 5
Precipitation: 2.43"

Potentially Stormy Next Couple Of Days

The computer models were a little to quick to move the warm front north it seems, which has kept the storms south of us the past couple of days, including this morning. That being said, it should eventually lift north and with that our thunderstorm prospects should increase. Today looks to have a less than 50% chance of seeing storms, but there is a bow echo moving through western IL this morning that if it held together, would be here late this morning/early afternoon. As for severe weather, The Storm Prediction Center has in a slight risk for both today and tomorrow.  http://www.spc.noaa.gov/

90º Days In June

So far this June, we've had 5 days with temps of 90º or more. Here is a list of prior Junes with the highest number of 90º+ temps at LAF (highest temp for that month):

14 - 1988 (104º)
12 - 1991 (98º)
11 - 1971 (96º)
11 - 1994 (97º)
10 - 1984 (95º)
10 - 2005 (96º)
9 - 1964 (98º)
9 - 1966 (95º)
9 - 1978 (97º)
9 - 1995 (97º)

On the other hand, here are the fewest 90º+ days in June at LAF:
0 - 1982
0 - 2004
1 - 1992
1 - 2008
2 - 1965
2 - 1974
2 - 1980
2 - 1993
2 - 2003

Updated June Stats

Through the 15th of the month at LAF:
Average Temp: 73.8º
Highest Temp: 97º (6/4)
Rainfall: 2.41"


Comparison to 1936 through the same date at the WL COOP:
Average temperature: 70.7º
Highest temperature: 93º (6/14)
Rainfall: 0.35"

Outlook for the last half of June: Above normal temps and above normal precipitation.
Near term: chance of thunderstorms today through Sunday, with Friday and Saturday being currently outlooked by SPC for a slight chance of severe weather. Heat and high humidity return Sunday through early next week.

Morning Thunderstorms

Nothing like early morning thunderstorms to start the day. These storms are producing a good amount of lightning and thunder as they roll through the area. Just shy of 0.60" of rainfall so far at the airport, with it still coming down as I type.

Winds have gusted to 43MPH at LAF:

SPECI KLAF 151143Z 33025G37KT 7SM -TSRA FEW021 BKN028 OVC055 16/13 A2991 RMK AO2 PK WND 30037/1135 WSHFT 1124 LTG DSNT ALQDS RAE10B28 PRESRR P0013

More June Precipitation Records

1 day, 2 day, and 3 day highest rainfall totals in June at the WL COOP (1901-present).

1 day highest rainfall
1) 4.27" - 6/26/1978
2) 4.22" - 6/12/2004
3) 3.89" - 6/12/1929
4) 3.75" - 6/10/1958
5) 3.38" - 6/19/1928
6) 3.19" - 6/11/2004
7) 3.14" - 6/15/1974
8) 3.01" - 6/22/2010
9) 2.75" - 6/1/1907
10) 2.65" - 6/13/1952

2 day highest rainfall
1) 7.41" - 6/11-12/2004
2) 5.69" - 6/9-10/1958
3) 4.62" - 6/28-29/1902
4) 3.99" - 6/1-2/1907
5) 3.93" - 6/12-13/1929

3 day highest rainfall
1) 8.51" - 6/11-13/2004
2) 6.14" - 6/9-11/1958
3) 4.75" - 6/28-30/1902

June Precipitation Records

All precipitation amounts/totals from the WL COOP (1901 to present).

Top 10 Wettest
1) 11.70" - 1958
2) 11.37" - 1902
3) 9.90" - 2010
4) 9.89" - 2004
5) 9.82" - 1928
6) 8.41" - 1998
7) 7.70" - 1976
8) 7.34" - 1909
9) 7.14" - 1941
10) 6.92" - 1960

Top 10 Driest
1) 0.25" - 1988
2) 0.32" - 1933
3) 0.50" - 1915
4) 0.64" - 1936
5) 0.65" - 1991
6) 1.02" - 1992
7) 1.07" - 1967
7) 1.07" - 1984
9) 1.13" - 1959
10) 1.26" - 1923

Where We're At, And Where We're Going

June stats at LAF through yesterday
Average temperature: 76.5º (+7.2º)
90º+ high temperatures: 5
Highest daily high temperature: 97º on 6/4
Precipitation: 1.15"(-0.40")


As for the upcoming week, we look to start off this first couple of days with below average temps and dry conditions. Warmth looks to start coming back by Wednesday through the end of the week...nothing extreme, but seasonably warm. Thunderstorm chances also increase by mid to late week. As for severe prospects, too soon to tell as usual.

5th Hottest First 10 Days Of June In History

The first 10 days of this June averaged 77.2º, which places it as the 5th hottest in history. As usual, I'm using the WL COOP for the historical list but LAF for the current numbers.


1) 80.1º - 1933
2) 79.9º - 1925
3) 79.3º - 1934
4) 78.0º - 1942
5) 77.2º - 2011
6) 76.6º - 1914
7) 75.7º - 1963
8) 75.2º - 1911
9) 75.0º - 1940
10) 74.9º - 2005

Severe Weather Threat For Today-Tonight

Looks like a good wind and hail threat for this evening for us, as painted below by the Storm Prediction Center. There's also a low tornado threat (2%). Also if we get any training thunderstorms, localized flooding could develop.

EDIT: New day one outlook has raised the tornado threat to 5%, which basically borders Tippecanoe County on north.


Details here: http://www.spc.noaa.gov/products/outlook/day1otlk.html

Severe Weather For Today

Slight chance of severe thunderstorms for LAF today. Damaging winds and hail are the main threats.

Find more here: http://www.spc.noaa.gov/products/outlook/

More Heat Today

Temps are expected to reach the mid 90's here today. Yesterday's high at LAF was 94º, a little lower than I expected. Minneapolis hit 102º on Tuesday, their first triple digit high since 1988. Which begs the question, when is the last time it hit 100º in Lafayette? And the answer is...1988.

At LAF: July 15, 1988 (100º)
At the WL COOP: June 26, 1988 (103º)

How Does The Recent Heat Stack Up?

Since May 30th through yesterday, we've been in a bit of a hot streak recording high temperatures of 91º, 91º, 86º, 81º, 88º, 97º, 82º, and 90º at LAF...for an average of 88.3º So how does this compare to past hot streaks using the same dates? We'll use the WL COOP for this exercise, with data going back to 1901, and only daytime high temperatures.

1) 96.0º - 1934 (includes all time June record of 104º on 6/1)
2) 91.9º - 1925
3) 91.4º - 1942
4) 86.8º - 1933
5) 86.5º - 1919, 1988, and 1991

I guess it's not a fair fight to compare LAF and the WL COOP for various reasons, but this just gives a historical context to the recent high temperatures.

Record High Temp Watch This Tuesday and Wednesday

Extreme heat is forecasted for this Tuesday and Wednesday. At this point mid to upper 90's look probable, so here's the daily record highs at the WL COOP (1901 to present) and Purdue Airport (1944 to present) for both days.

June 7th
WL COOP Record High Temp: 101º - 1933
Purdue Airport Record High Temp: 95º - 1988

June 8th
WL COOP Record High Temp: 100º - 1933
Purdue Airport Record High Temp: 94º - 1988

Top 10 Warmest Junes On Record

Hottest Junes on record at the West Lafayette COOP (1901 to present)
1) 79.3º - 1933
2) 78.9º - 1934
3) 76.6º - 1921
4) 75.9º - 1944
5) 75.7º - 1925
6) 75.5º - 1941
7) 75.4º - 1919
8) 75.0º - 1931
9) 74.8º - 1939
10) 74.7º - 1991

No surprise, the 1930's dominate again. Who knows if there was some "fuzzy" recording or measuring back in those days, but there's also some "fuzziness" to LAF's numbers these days as well. Regardless those are the numbers to shoot for. 

As well, we're obviously off to a hot start through the first 4 days of June, with more heat in the next several days, so I looked for the hottest first 10 days of June throughout history.

1) 80.1º - 1933
2) 79.9º - 1925
3) 79.3º - 1934
4) 78.0º - 1942
5) 76.6º - 1914
6) 75.7º - 1963
7) 75.2º - 1911
8) 75.0º - 1940
9) 74.9º - 2005
10) 74.6º - 2008

LAF with an average of 75.9º through yesterday. 0z MEX MOS for the 6th through 10th: 87/60, 93/67, 94/69, 89/69, 79/65. Assuming a 88/64 for today and using the MEX numbers (no doubt they won't be exactly right, but will be for this purpose), the 10 day average will ballpark at 76.6º.