Thursday, July 9, 2009

Early El Niño Emerges
Further Development Expected

NOAA's Climate Prediction Center released its monthly El Niño diagnostic discussion this morning. It reports that El Niño conditions have now developed in the Pacific:
During June 2009, conditions across the equatorial Pacific Ocean transitioned from ENSO-neutral to El Niño conditions. Sea surface temperature (SST) anomalies continued to increase, with the latest weekly departures exceeding +1.0°C along a narrow band in the eastern equatorial Pacific.
Sea surface temperatures have steadily increased across all of the monitored regions.

Model forecasts indicate a consensus for further development of El Niño conditions, although there is a range of indications for the maximum intensity. Current conditions and trends imply a "weak-to-moderate strength El Niño into the Northern Hemisphere Fall 2009" and possible further strengthening into the winter.

El Niño usually has weak impacts on the U.S. during summer and fall, but there is some tendency to suppress Atlantic hurricane activity because of increased wind shear. On the other hand, a recently published study shows that the effect on hurricane development may depend on whether the maximum temperature effects occur in the eastern or central Pacific. In years with eastern Pacific maximum warmth, tropical cyclone activity seems to be lower. So far, at least, the current pattern appears to be the eastern Pacific variety. NOAA's hurricane season forecast will be updated along with the next El Niño analysis on August 6.

By increasing the strength of the southern branch of the jet stream, El Niño tends to favor increased winter storminess on the U.S. Pacific Coast, more rainfall in the Southwest, and less wintry weather in the northern portion of the country. As a transitional zone, the Mid Atlantic region can be affected both positively and negatively in the winter depending on the particular pattern of strength and evolution of the El Niño conditions.

Images (click to enlarge): Latest equatorial Pacific sea-surface temperature (SST) departures from average, El Niño region SST history, El Niño model forecasts, all from NOAA/Climate Prediction Center

Wednesday, July 8, 2009

Record Texas Heat Continues Into July
June Monthly Average Records Set

Image (click to enlarge): U.S. daily maximum temperatures for July 8

See Record Heat for the latest updates.

July 12 Update: More July 9 reports:
A RECORD HIGH TEMPERATURE OF 104 DEGREES WAS SET AT MCALLEN TODAY.   
THIS EXCEEDS THE OLD RECORD OF 103 SET IN 2005.

THIS AFTERNOONS HIGH TEMPERATURE OF 106 IN ABILENE IS A NEW RECORD
HIGH FOR THIS DATE. THE PREVIOUS RECORD WAS 103 SET IN 1978.

THIS MORNINGS LOW TEMPERATURE OF 80 DEGREES IN ABILENE IS A RECORD
HIGH MINIMUM FOR THIS DATE. THE PREVIOUS RECORD WAS 79 DEGREES SET
IN 1980.

THIS AFTERNOONS HIGH TEMPERATURE OF 105 IN SAN ANGELO TIES THE
RECORD HIGH FOR THIS DATE SET IN 1917.

THIS MORNING LOW TEMPERATURE OF 79 DEGREES IN SAN ANGELO IS A RECORD
HIGH MINIMUM FOR THIS DATE. THE PREVIOUS RECORD WAS 78 DEGREES SET
IN 1962.
July 9 Update: Record reports for July 9:
THE OFFICIAL HIGH TEMPERATURE TODAY AT WICHITA FALLS HAS BEEN 109   
DEGREES. THIS TIES THE RECORD HIGH FOR TODAY OF 109 DEGREES...WHICH
WAS FIRST SET ON THIS DATE IN 1980.

TEMPERATURE RECORDS FOR WICHITA FALLS DATE BACK TO 1897.

A RECORD HIGH TEMPERATURE OF 104 DEGREES WAS SET AT AUSTIN BERGSTROM TODAY.
THIS BREAKS THE OLD RECORD OF 102 SET IN 1956.
Also for the month of June:
CORPUS CHRISTI INTERNATIONAL AIRPORT  
TIED OR BROKE 10 RECORD HIGH TEMPERATURES IN JUNE AND HAS ALREADY
TIED OR BROKEN 4 RECORD HIGHS IN JULY. VICTORIA TIED OR BROKE 5 RECORD
HIGHS IN JUNE AND HAS TIED OR BROKEN 4 MORE IN JULY.

CORPUS CHRISTI (PERIOD OF RECORD 1887-2009)...

HOTTEST AVERAGE MAXIMUM TEMPERATURE FOR JUNE

1. 95.5 2009
2. 95.3 1953
3. 93.6 1997

VICTORIA (PERIOD OF RECORD 1902-2009)...

HOTTEST AVERAGE MAXIMUM TEMPERATURE FOR JUNE

1. 96.6 2009
2. 96.2 2008
3. 95.0 1990

Original post:
Record daily temperatures were reported for the Texas panhandle on July 8. The Amarillo record had been tied 3 times since 1910, but it was blasted away by 2°:
VERY HOT TEMPERATURES WERE OBSERVED ACROSS THE TEXAS AND OKLAHOMA  
PANHANDLES ON WEDNESDAY JULY 8. BELOW ARE SOME HIGH TEMPERATURES FROM
AROUND THE REGION ALONG WITH THE RECORD HIGH TEMPERATURES FOR THE
DATE WHEN AVAILABLE.

LOCATION HIGH RECORD YEAR(S)

AMARILLO TX 102 100 2001, 1951, 1940, 1910
BORGER TX 104 102 2001
The Austin/San Antonio National Weather Service office yesterday put out a recap of the extreme heat wave continuing in Texas:
THE PERIOD FROM MID JUNE TO EARLY JULY OF 2009 CONTINUES TO SHOW  
AFTERNOON HIGHS AVERAGING NEAR 5 TO 10 DEGREES WARMER THAN USUAL.
SO FAR IN EARLY JULY OF 2009...THE AVERAGE DAYTIME HIGHS HAVE
BEEN AROUND 100 TO 102.

JUNE 2009 WAS THE 2ND WARMEST JUNE AT AUSTIN MABRY...THE 8TH WARMEST
AT AUSTIN BERGSTROM...THE 5TH WARMEST JUNE AT DEL RIO...AND A TIE
FOR THE 3RD WARMEST JUNE AT SAN ANTONIO WITH JUNE 1998.

OTHER RECORDS THAT ARE RARE EVENTS WAS THE 10 CONSECUTIVE 100
DEGREE DAYS FROM JUNE 20TH TO JUNE 29TH AT AUSTIN MABRY AND
AUSTIN BERGSTROM. PRIOR TO THIS YEAR...THIS BROKE THE OLD RECORD OF
6 IN A ROW IN JUNE 1953 AT AUSTIN BERGSTROM...AND THE RECORD OF
8 IN A ROW AT AUSTIN MABRY...IN JUNE 1925. SAN ANTONIO HAD 6 100
DEGREE DAYS IN A ROW FROM JUNE 24 TO 29...2009...JUST SHORT OF THE
RECORD 8 DAYS IN A ROW IN JUNE 1990. FOR THE MONTH OF JUNE...
SAN ANTONIO HAD 12 OVERALL 100 DEGREE DAYS IN JUNE...A RECORD FOR
THE MONTH OF JUNE. THE OLD RECORD WAS 11 DAYS IN JUNE 1990.

THE ALL TIME GREATEST NUMBER OF 100 DEGREE DAYS IN A ROW
AT AUSTIN...DEL RIO...AND SAN ANTONIO ARE LISTED BELOW.

DEL RIO............50 FROM JUNE 17 TO AUGUST 5...1980
AUSTIN BERGSTROM...23 FROM JULY 27 TO AUGUST 18...1951
AUSTIN MABRY.......21 FROM JULY 12 TO AUGUST 1...2001
SAN ANTONIO........21 FROM JULY 24 TO AUGUST 13...1962

More Florida Heat Records in July


Image (click to enlarge): U.S. maximum temperatures for July 7 from Unisys

The string of daily high temperature records set or tied in Florida during June is being extended in July. In the 30 days since June 7, Miami has had only 2 below average in temperature. Here are some National Weather Service record reports for July 7:
A RECORD HIGH MINIMUM TEMPERATURE OF 82 DEGREES WAS SET AT NAPLES   
YESTERDAY. THIS BREAKS THE PREVIOUS RECORD OF 77 SET IN 1949.

THE HIGH TEMPERATURE TODAY AT FORT LAUDERDALE REACHED 97 DEGREES AT
3:51 PM EDT. THIS BREAKS THE OLD RECORD HIGH TEMPERATURE FOR THIS
DATE...WHICH PREVIOUSLY WAS 96 DEGREES SET BACK IN 1924.

THE HIGH TEMPERATURE TODAY AT MIAMI REACHED 95 DEGREES. THIS TIES
THE OLD RECORD HIGH TEMPERATURE FOR THIS DATE...SET BACK IN 1992.
For July 6:
THE TEMPERATURE CLIMBED TO 95 DEGREES AT MIAMI INTERNATIONAL   
AIRPORT TODAY. THIS TIES THE OLD RECORD OF 95 SET IN 1992.
In addition to the numerous daily records, 18 all-time June high temperature records were tied or broken in Florida last month. In the first 7 days of July, 15 daily high temperature records, including the ones listed above, have been tied or broken in the state.

Tuesday, July 7, 2009

DC: Decisively Cool in First Week of July

July 8 Update: Added month-to-date chart. Today's cool high of 81° and low of 66° keeps the monthly average so far essentially unchanged at 73.4°.

Images (click to enlarge): July 2009 month-to-date average temperature vs. monthly normal and records; top 10 coolest, long-term normal, and warmest July average temperatures in Washington, DC; CapitalClimate charts from National Weather Service data

Original post:
With a daily high matching the long-term normal of 88°, Washington DC is closing out a very cool first week of July. The monthly average so far of 73.5°, if continued through the month, would put this July firmly in the top 10 coolest. The current average is just 0.1° ahead of the third place holder, 1888. The coolest July of this century has been the one in 2000; at an average of 74.7°, it's tied with 1909 for tenth place, ahead of all but 2 other years in the 20th Century, 1904 and 1918, both at 74.4°.

The long-term normal for July is 80°, and the warmest ever recorded was 83.1° in 1993.

Seasonal Outlook

Latest seasonal forecast: Click here.


Latest 3-month temperature outlook from Climate Prediction Center/NWS/NOAA.