GFS Model as of 10/5/11 12:00Z , 96-hour estimated precipitation for: 10/8/11 through 10/12/11.

Heavy rainfall now appears likely to begin perhaps mid-day Saturday, occurring intermittently or perhaps even continuously for the region through Sunday.

For Saturday, best and heaviest rain chances will exist for areas west of I-35. Sunday, nearly the entire region will be subject to heavy rainfall. Monday and Tuesday look to have only scattered or isolated rain showers for areas east of I-35. The immediate D/FW Metroplex should remain rain free after Monday mid-day.

Wind shear profiles, hodographs, and instability look too weak to support any organized severe threat for our region on any day. I wouldn’t rule out an embedded thunderstorm however, but I don’t expect any to be severe.

GFS Model initialized 10/5/11 12:00z, showing the forecasted Skew-T chart for 10/9/11 18:00Z.

Looking at the Skew-T chart I referenced above, the dew point and the temperature are the same throughout about 600mb to 200mb, then again in the lowest few thousand feet of the atmosphere. This tells me to expect completely overcast skies and rain. Storm motion will be moving from S or SSW to N or NNE across the region.

This heavy rain event won’t break our drought by a long shot, but it might be enough to positively affect it. Soil in our region is so incredibly dry, that even very heavy rain concentrated on a small area may still be absorbed well by the soil and generate little runoff.

October is north Texas’ 2nd rainiest month of the year, so lets hope this gets us off on a positive start to drought recovery!

Currently the most influence this storm system is expected to have is increased cloud cover and increased moisture. The increased moisture alone does increase our rain chances for Friday and Saturday, but without any direct effects from this system and thus no boundaries or other lifting agents to initiate storms, storm coverage will still be isolated. The increased cloud cover may break our current 100+ degree day streak but won’t last for long.

Computer models on this storm are spread wide apart, so confidence on the exact storm track and intensity is somewhat low. If the storm takes a more northern approach, then of course north Texas will be influenced by it much more.

Right now the State of Texas is experiencing its worst drought in recorded history, with 100% of the state in some drought status. the Dallas/Fort Worth region was grasping onto D-0 drought status for awhile, but finally got downgraded to D-1 or worse. Tropical Storm Don should help a little bit with the drought in coastal, deep south, and central Texas.

Currently the heat streak in north Texas continues, with 26 days in a row of 100+ degree highs. This is the 3rd longest 100+ degree day streak on record. Again we may see afternoon high temperatures just below the 100 degree mark the next 2 or 3 days due to increased cloud cover, especially on Saturday.

After Tropical Storm Don clears the region, no storm systems show up on computer models the next 7 days. High pressure ridging will resume, and our 100 degree days with no rain and mostly clear skies will return.

Record Heat:

Already today we have tied a record high at D/FW Airport. This afternoon we reached 104 degrees, which ties the record set in 1918.

Weather the next 7 days:

Today Saturday 6/18/11, a weak cold front sits along northwest Texas and some scattered severe thunderstorms are possible this evening. Cloud bases are very high at around 10,000ft , with a dry slot of air just below it. This creates a very high risk of microburst/straight line wind damage from these thunderstorms. Additionally due to that lower atmosphere dry slot, most rain will likely evaporate before reaching the surface. This gives us the dry thunderstorm effect, where lightning can spark wildfires and have insufficient rain to stop it. These storms are likely to remain just NW of the immediate D/FW Metroplex, but one may slide through the area if it can survive long enough.

Sunday and Monday, expect continued hot and windy conditions. Temperatures won’t be quite as hot as Saturday, highs should top around 100. Thunderstorm development will remain northwest of the area, so the Metroplex will remain dry.

The upper level ridge will erode finally on Tuesday, as a trough develops and moves across the continental US. This trough will send a cold front through north Texas on Tuesday afternoon. An unstable and uncapped atmosphere should promote thunderstorm development during this time. Precipitation forecasts estimate anywhere between 0.5 to 2.0 inches of rain possible in isolated areas.

Additional small rain chances are in the forecast for Wednesday, before northerly upper level winds dry out the atmosphere once again.

Upper level high pressure will reestablish across the region late next week, and hot dry temperatures will resume once again. Temps late next week will be a few degrees colder than we have seen this week, with highs in the mid-upper 90s.

Long term climate outlook:

Above normal temperatures and far below normal precipitation have very strong signals in July climate forecasts. A short paragraph from the latest drought information statement regarding July climate forecasts:

THERE IS SOME POTENTIAL FOR THE UPPER RIDGE TO BREAK DOWN IN LATE
JUNE...WHICH COULD RESULT IN RAIN CHANCES. HOWEVER...THE NEWLY
RELEASED CLIMATE PREDICTION CENTER OUTLOOK FOR JULY PROJECTS AROUND
A 40 PERCENT CHANCE OF BEING IN THE DRIEST TERCILE...THE DRIEST
THIRD OF HISTORIC DATA. FOR MUCH OF NORTH TEXAS...A JULY WITHIN THE
DRIEST TERCILE WILL HAVE A RAINFALL TOTAL OF LESS THAN AN INCH.

A PRONOUNCED WARM SIGNAL...WHICH TYPICALLY ACCOMPANIES DROUGHT
CONDITIONS...CONTINUES TO PERMEATE THE SUMMER MONTHS. WARMER THAN
NORMAL TEMPERATURES WOULD FURTHER INTENSIFY THE DROUGHT BY
EVAPORATING SOIL MOISTURE AND WATER FROM AREA RESERVOIRS. WARM
TEMPERATURES ALSO LEAD TO INCREASED WATER USAGE.

Drought outlook for north Texas:

Drought conditions are expected to persist and worsen through at least the month of July. The state of Texas is experiencing the largest extent of extreme (D3) and exceptional (D4) drought conditions ever recorded. North Texas around the Metroplex and to the northeast remains the sole location in the state that is not experiencing any level of drought. This means that north Texas area water reservoirs are at adequate conservation levels and are best suited to withstand a hot and dry summer.

The drought & climate synopsis for the end of June:

THE 9-MONTH PERIOD OCTOBER 2010 TO JUNE 2011 IS ON PACE TO BE THE
DRIEST ON RECORD FOR TEXAS. THE STATEWIDE EXTENT OF EXTREME (D3) AND
EXCEPTIONAL DROUGHT (D4) ARE CURRENTLY AT ALL-TIME RECORD LEVELS.

THE YEAR-TO-DATE PRECIPITATION TOTAL AT HOUSTON HOBBY AIRPORT IS THE
DRIEST ON RECORD...ONLY 5.41 INCHES SINCE JANUARY 1...WHICH IS MORE
THAN 17 INCHES BELOW NORMAL. AMARILLO HAS TALLIED ONLY 0.68 INCHES
IN 2011...THE VAST MAJORITY OF WHICH WAS SNOWFALL (9.6 INCHES). IN
THE MOUNTAINS OF FAR WEST TEXAS...MARFA WENT OVER 8 MONTHS WITHOUT
ANY PRECIPITATION (SEPTEMBER 25, 2010 TO JUNE 4, 2011).

AFTER HEAVY RAIN IN MAY...NORTH TEXAS IS IN CONSIDERABLY BETTER
SHAPE THAN THE REST OF THE STATE. VERY LITTLE RAIN HAS FALLEN DURING
THE LAST THREE WEEKS...BUT AREAS FROM COLLIN COUNTY TO BONHAM AND
PARIS REMAIN FREE OF THE ABNORMALLY DRY (D0) DESIGNATION. HOWEVER...
MUCH OF CENTRAL TEXAS REMAINS MIRED IN EXCEPTIONAL DROUGHT (D4)...
INCLUDING LAMPASAS...TEMPLE/KILLEEN...CAMERON...AND HEARNE. ANOTHER
AREA OF EXCEPTIONAL DROUGHT ENCOMPASSES POSSUM KINGDOM LAKE AND
AREAS TO THE WEST...INCLUDING GRAHAM AND BRECKENRIDGE.

ON JUNE 16...THE TOTAL NUMBER OF BURN BANS STATEWIDE CLIMBED TO
217...MORE THAN AT ANY POINT DURING THE 2005-2006 DROUGHT. THIS
INCLUDES MORE THAN 85 PERCENT OF TEXAS COUNTIES...BUT ONLY ABOUT
HALF OF THE COUNTIES WITHIN THE NWS FORT WORTH AREA OF
RESPONSIBILITY.

ABOVE NORMAL TEMPERATURES ARE EXPECTED TO PERSIST THIS SUMMER. AREA
RESERVOIRS ARE GENERALLY AT ADEQUATE LEVELS...BUT THE HEAT WILL
LIKELY CONTINUE TO REDUCE LAKE LEVELS.

The complete end of June drought statement can be found on the NWS – Fort Worth, TX website here.
http://forecast.weather.gov/product.php?site=FWD&issuedby=FWD&product=DGT&format=CI&version=1

Agriculture is still suffering as soil moisture is still fairly low for the entire region, plus warmer than normal temps the past few weeks are causing substantial evaporation rates. Thankfully the region’s water reservoirs are mostly above 90% conservation, meaning there is plenty of water for the region to make it through summer without mandatory water restrictions. An amazing fact that I did not know, afternoon temperatures of 100 degrees can evaporate just as much water out of Lake Lewisville daily as all of Collin County uses in the same time period! That is 250 million gallons each, meaning possibly half a billion gallons are removed from Lake Lewisville every day, wow!

Long term climate forecasts show a fairly typical or possibly drier than normal Summer for north Texas. Anytime from maybe mid July through end of August at least is forecast to be very hot and mostly rain free. There is still a possibility of rain from now through mid July, including a cold front that will affect the area Monday-ish(7/6/09).

Areas west of Fort Worth in Palo Pinto, Stephens and Young counties are still in D1 drought designation, which simply means ‘Abnormally Dry’. Large areas of central Texas (to our south, areas around Austin) however are in a D4 classification which means ‘Exceptional Drought’, the most severe classification. Exceptional droughts are the type that have a return period of a half-century! For comparison, if you remember the extreme drought talks revolving around south Tennessee and Atlanta, Georgia running out of water last year, I only noticed them listed under a D3 classification.

Map showing the current drought classifications across the country. Note that Florida is now out of official drought classifications due to a rainy May and June. Good thing too, central Florida has been in either D1 or D2 status for a few years now.

Detailed information released by the National Weather Service regarding drought information in North Texas:

DROUGHT INFORMATION STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
1110 PM CDT THU JUL 2 2009

...CENTRAL TEXAS DROUGHT RE-INTENSIFIES...

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SYNOPSIS...

MAY AND JUNE WERE AMONG THE DRIEST ON RECORD IN PORTIONS OF CENTRAL
TEXAS...WHERE DROUGHT HAS BEEN LARGELY UNINTERRUPTED SINCE THE
SUMMER OF 2008. EXTREME DROUGHT (D3) HAS BEEN EXPANDED...AND
EXCEPTIONAL DROUGHT (D4) HAS RETURNED TO MILAM COUNTY. THE MOST
INTENSE CATEGORY...EXCEPTIONAL DROUGHT IS RESERVED FOR EVENTS WITH A
RETURN PERIOD OF A HALF CENTURY.

THE RECENT AREA OF CONCERN IN WESTERN NORTH TEXAS CONTINUES TO
IMPROVE...ALTHOUGH MODERATE DROUGHT (D1) REMAINS ACROSS YOUNG...
STEPHENS...AND PALO PINTO COUNTIES. THANKS IN PART TO ADEQUATE
SPRING RAINFALL (AND A DELUGE THE SECOND WEEK OF JUNE)...NEARLY HALF
OF THE NWS FORT WORTH AREA OF RESPONSIBILITY CURRENTLY HAS NO
DROUGHT DESIGNATION.

UNFORTUNATELY FOR THOSE AREAS STILL IN DROUGHT...NO SIGNIFICANT
RELIEF IS ANTICIPATED THIS SUMMER...AND THE CENTRAL TEXAS DROUGHT IS
LIKELY TO PERSIST. FORTUNATELY...NEARLY EVERY NORTH TEXAS LAKE IS
ABOVE 80 PERCENT CONSERVATION...WITH MOST OVER 90 PERCENT. EVEN
CENTRAL TEXAS RESERVOIRS ARE GENERALLY IN GOOD SHAPE...DESPITE
CONSIDERABLE PRECIPITATION DEFICITS.

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SUMMARY OF IMPACTS...

AGRICULTURAL IMPACTS

BY THE END OF JUNE...LESS THAN A QUARTER OF NORTH TEXAS FARMLAND HAD
ADEQUATE SOIL MOISTURE. THE WORST IMPACTS CONTINUE TO BE IN CENTRAL
TEXAS...WHERE THE CORN CROP IS STRUGGLING WITH EXTRAORDINARY HEAT.
ALTHOUGH GENERALLY DROUGHT RESISTANT...SORGHUM IS ALSO STRESSED.
SUPPLEMENTAL FEEDING CONTINUES IN AREAS WHERE FORAGE IS DEPLETED OR
OTHERWISE INADEQUATE.

FIRE DANGER

THE ABUNDANT EARLY SPRING RAINS GOT THE GROWING SEASON OFF TO A
BOOMING START...BUT NEARLY ALL OF NORTH TEXAS SAW BELOW NORMAL
RAINFALL DURING MAY AND JUNE. THE TURN OF FORTUNE WAS PARTICULARLY
NOTICEABLE IN CENTRAL TEXAS. MANY AREAS BETWEEN I-35 AND I-45
RECEIVED LESS THAN AN INCH OF RAIN DURING THE LAST TWO MONTHS
COMBINED.

THE DRY VEGETATION HAS BECOME A CONCERN AS INDEPENDENCE DAY
FESTIVITIES APPROACH. RESIDENTS ARE URGED TO BE VIGILANT ABOUT FIRE
USAGE. ADHERE TO LOCAL BURN BANS AND AERIAL FIREWORKS RESTRICTIONS.
EVEN WITH ELEVATED HUMIDITY AND LIGHT WINDS...WILDFIRES CAN QUICKLY
START WHERE SUMMER VEGETATION IS DORMANT. SEVERAL NEW BURN BANS WERE
ENACTED DURING JUNE...BRINGING THE TOTAL TO 14 IN THE NWS FORT WORTH
AREA OF RESPONSIBILITY. MOST OF THE NEW ADDITIONS WERE IN CENTRAL
TEXAS.

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CLIMATE SUMMARY...

ON JUNE 10 AND 11...TORRENTIAL RAINS FELL IN NORTH CENTRAL TEXAS.
WIDESPREAD TOTALS OF 7 TO 8 INCHES WERE RECORDED IN CENTRAL DALLAS.
HOWEVER...MUCH OF NORTH TEXAS MISSED OUT ON THE RAIN EVENT...AND
STRUGGLED THROUGH A SECOND STRAIGHT MONTH WITH BELOW NORMAL
PRECIPITATION.

CENTRAL TEXAS WAS PARTICULARLY HARD HIT...WITH MANY LOCATIONS
RECEIVING UNDER AN INCH IN THE LAST 60 DAYS. WACO REGIONAL AIRPORT
WENT 33 CONSECUTIVE DAYS WITHOUT MEASURABLE RAINFALL...BEFORE THE
STREAK WAS BROKEN ON JUNE 30. THE COOPERATIVE OBSERVER IN THORNTON
(LIMESTONE COUNTY) RECORDED 10.42 INCHES OF RAIN IN APRIL...BUT ONLY
0.05 INCHES IN JUNE. WITHIN THE EXTREME AND EXCEPTIONAL DROUGHT
AREAS OF CENTRAL TEXAS...SOME LOCATIONS HAVE AMASSED DEFICITS OF 20
INCHES SINCE LAST SUMMER.

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PRECIPITATION/TEMPERATURE OUTLOOK...

RIDGING ALOFT IS PROJECTED TO CONTINUE DOMINATING THE LONE STAR
STATE DURING THE FIRST HALF OF JULY. AS A RESULT...THE 6-10 DAY AND
8-14 DAY OUTLOOKS FROM THE CLIMATE PREDICTION CENTER (FOR EARLY TO
MID JULY) HAVE MAINTAINED THE LIKELIHOOD FOR PERSISTENT ABOVE NORMAL
TEMPERATURES AND BELOW NORMAL PRECIPITATION. BOTH WOULD ASSURE
FURTHER EVAPORATION...TAXING VEGETATION AND AREA RESERVOIRS. FADING
SOIL MOISTURE IS A POSITIVE FEEDBACK IN THE PROCESS...LEADING TO
ADDITIONAL WARMING.

STRONG PRECIPITATION SIGNALS ARE RARELY SEEN DURING THE SUMMER
MONTHS...AND NONE ARE PRESENT BEYOND THE NEXT COUPLE OF WEEKS.
THUS...IT IS UNLIKELY THAT THE WELL ENTRENCHED CENTRAL TEXAS DROUGHT
WILL ABATE BEFORE AUTUMN.

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HYDROLOGIC SUMMARY AND OUTLOOK...

THE RESERVOIR GAINS THAT FOLLOWED THE HEAVY RAINS OF EARLY JUNE WERE
LARGELY ERASED BY THE HOT WEATHER DURING THE LAST HALF OF THE MONTH.
ON THE HOTTEST OF DAYS...EVAPORATION ALONE CAN SKIM A HALF-INCH FROM
THE SURFACE OF A LAKE. FROM LAKE LEWISVILLE...THAT EQUATES TO A
QUARTER OF A BILLION GALLONS. THIS IS EQUIVALENT TO THE TOTAL WATER
USAGE IN COLLIN COUNTY ON A TYPICAL SUMMER DAY. NEEDLESS TO SAY...A
CONTINUATION OF HOT WEATHER WILL ALLOW BOTH USAGE AND EVAPORATION TO
TAKE THEIR TOLL ON NORTH TEXAS WATER RESOURCES. THANKFULLY...MOST
RESERVOIRS WERE ABOVE 90 PERCENT CONSERVATION AT THE BEGINNING OF
JULY.

                               RESERVOIR DATA - JULY 2, 2009

                         NORMAL     POOL     DEFICIT/    PERCENT OF
                          POOL     HEIGHT    SURPLUS    CONSERVATION

RED RIVER BASIN
  LAKE TEXOMA             619.0    618.92     -0.08          99
  PAY MAYSE LAKE          451.0    451.27     +0.27         101
  JIM CHAPMAN LAKE        440.0    439.42     -0.58          96

TRINITY RIVER BASIN
  LAKE BRIDGEPORT         836.0    827.46     -8.54          73
  EAGLE MOUNTAIN LAKE     649.0    645.15     -3.85          83
  LAKE WORTH              594.0    591.73     -2.27          80
  LAKE BENBROOK           694.0    692.58     -1.42          93
  LAKE RAY ROBERTS        632.5    632.50      0.00         100
  LAKE LEWISVILLE         522.0    521.67     -0.33          98
  LAKE GRAPEVINE          535.0    532.82     -2.18          90
  LAKE LAVON              492.0    491.31     -0.69          97
  LAKE RAY HUBBARD        435.5    435.34     -0.16          99
  JOE POOL LAKE           522.0    521.48     -0.52          97
  BARDWELL LAKE           421.0    419.78     -1.22          92
  NAVARRO MILLS LAKE      424.5    423.82     -0.68          94
  CEDAR CREEK RESERVOIR   322.0    321.63     -0.37          98
  RICHLAND CHAMBERS       315.0    311.83     -3.17          88

BRAZOS RIVER BASIN
  POSSUM KINGDOM LAKE    1000.0    996.18     -3.82          86
  PROCTOR LAKE           1162.0   1156.67     -5.33          57
  BELTON LAKE             594.0    591.22     -2.78          91
  STILLHOUSE HOLLOW       622.0    620.15     -1.85          95
  LAKE GRANBURY           693.0    690.59     -2.41          86
  LAKE WHITNEY            533.0    523.33     -9.67          21
  AQUILLA LAKE            537.5    536.46     -1.04          90
  WACO LAKE               462.0    461.68     -0.32          99
  LAKE LIMESTONE          363.0    361.74     -1.26          92

IN GENERAL...WATER SUPPLIES ARE ADEQUATE TO HANDLE SUMMER DEMAND.
NONETHELESS...MANY JURISDICTIONS HAVE MAINTAINED CALLS FOR VOLUNTARY
CONSERVATION. EVEN IF FORMAL WATER RESTRICTIONS ARE NOT CURRENTLY IN
PLACE FOR YOUR AREA...RESIDENTS ARE URGED TO BE SENSIBLE ABOUT WATER
USAGE. AVOID WATERING BETWEEN 10 AM AND 6 PM...WHEN EVAPORATION
LIMITS ITS EFFECTIVENESS.

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NEXT ISSUANCE DATE...

THE NEXT DROUGHT INFORMATION STATEMENT WILL BE ISSUED IN LATE JULY
OR EARLY AUGUST.

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&&

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RELATED WEB SITES...

NWS FORT WORTH DROUGHT PAGE - WEATHER.GOV/FORTWORTH/DROUGHT.HTML
NATIONAL INTEGRATED DROUGHT INFORMATION SYSTEM - DROUGHT.GOV
CLIMATE PREDICTION CENTER - WWW.CPC.NCEP.NOAA.GOV

NATIONAL DROUGHT MITIGATION CENTER - DROUGHT.UNL.EDU
U.S. DROUGHT MONITOR - DROUGHT.UNL.EDU/DM
DROUGHT IMPACT REPORTER - DROUGHTREPORTER.UNL.EDU

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ACKNOWLEDGEMENTS...

THE U.S. DROUGHT MONITOR FACILITATES CONTINUOUS DISCUSSION AMONG
NUMEROUS AGENCIES...ACADEMIA...AND OTHER LOCAL INTERESTS. THE
EXPERTISE OF ITS MEMBERS HAS BEEN INVALUABLE IN DEVELOPING DROUGHT
PRODUCTS AND SERVICES FOR OUR CUSTOMERS AND PARTNERS.

THE DROUGHT IMPACT REPORTER (MAINTAINED BY THE NATIONAL DROUGHT
MITIGATION CENTER) HAS ALLOWED VARIOUS IMPACTS TO BE COMPILED WITHIN
ONE CLEARING HOUSE. THESE IMPACTS INCLUDE AGRICULTURAL ISSUES...
HYDROLOGIC DEFICITS...FIRE DANGER...AND OTHER SOCIAL AND ECONOMIC
CONSEQUENCES. A SUMMARY OF THE SUBMITTED IMPACTS IS INCLUDED IN EACH
DROUGHT INFORMATION STATEMENT.

THE TEXAS DEPARTMENT OF AGRICULTURE AND THE TEXAS AGRILIFE EXTENSION
SERVICE PROVIDE ROUTINE ASSESSMENTS OF CROP AND PASTURE CONDITIONS
TO THE NATIONAL AGRICULTURAL STATISTICS SERVICE (NASS)...PART OF THE
UNITED STATES DEPARTMENT OF AGRICULTURE (USDA). THE PERIODIC
STATEWIDE SUMMARIES THAT RESULT ARE USED AS A PRIMARY SOURCE FOR THE
AGRICULTURAL IMPACTS SECTION.

THE TEXAS FOREST SERVICE (TFS) CONTINUALLY MONITORS VEGETATION
CONDITIONS AND WILDFIRE POTENTIAL. THE STATE AGENCY ALSO MAINTAINS A
CURRENT LIST OF COUNTYWIDE BURN BANS.

OUTLOOKS OF TEMPERATURE AND PRECIPITATION ARE SUMMARIZED FROM A
VARIETY OF PRODUCTS CREATED BY THE CLIMATE PREDICTION CENTER (CPC).
CPC IS A NATIONAL WEATHER SERVICE (NWS) ENTITY WITHIN THE NATIONAL
CENTERS FOR ENVIRONMENTAL PREDICTION (NCEP).

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QUESTIONS OR COMMENTS...

FOR ADDITIONAL INFORMATION OR TO PROVIDE FEEDBACK ON OUR DROUGHT
PRODUCTS AND SERVICES...PLEASE CONTACT...

NATIONAL WEATHER SERVICE
WEATHER FORECAST OFFICE
3401 NORTHERN CROSS BLVD.
FORT WORTH, TX 76137

PHONE: (817) 429-2631
E-MAIL: SR-FWD.WEBMASTER@NOAA.GOV