864 
FXUS64 KFWD 221205 AAA
AFDFWD

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
605 AM CST SAT DEC 22 2012

.AVIATION...
/12Z TAFS/

CONCERNS...GUSTY WINDS TODAY...STRATUS TONIGHT.

IN ADVANCE OF A SHORTWAVE SWINGING THROUGH THE SOUTHERN ROCKIES...
A LEE SURFACE TROUGH WILL DEEPEN TODAY...INCREASING SOUTHERLY
WINDS AT TAF SITES. GUIDANCE IS SUGGESTING SUSTAINED SPEEDS MAY
APPROACH 20KTS MID AFTERNOON WHEN THE MIXING HEIGHT REACHES 850MB
WINDS PROGGED TO BE NEAR 35KTS. GUSTS WILL BE PRIMARILY WITHIN
10KTS OF SUSTAINED SPEEDS...BUT PEAK GUSTS WILL LIKELY TOP 30KTS.

DESPITE SOUTH WINDS...THE 40-DEGREE ISODROSOTHERM REMAINS OFFSHORE
(AND IN DEEP SOUTH TEXAS). EVEN WITH DEW POINTS CURRENTLY IN THE
SINGLE DIGITS AND TEENS...THE VIGOROUS SOUTH WINDS TODAY AND
TONIGHT WILL STEADILY INCREASE LOW-LEVEL MOISTURE. STRATUS WILL
SURGE NORTHWARD TONIGHT BENEATH DRY 850MB AIR.

AS THE SHORTWAVE RACES PAST EARLY SUNDAY...SURFACE WINDS WILL
VEER. THE STRATUS DECK WILL BE SHUNTED INTO EAST TEXAS EARLIER THAN
CLIMO WOULD SUGGEST SUCH CEILINGS SHOULD ABATE. SOUTHWESTERLY
WINDS WILL MAINTAIN VFR CONDITIONS THE REMAINDER OF THE DAY SUNDAY.

EXTENDED (BEYOND CURRENT FORECAST)...
FROPA AROUND SUNSET SUNDAY.

25

&&

.PREV DISCUSSION... /ISSUED 405 AM CST SAT DEC 22 2012/
LOW LEVEL WARM AIR ADVECTION WILL BE ON THE INCREASE ACROSS NORTH
TEXAS TODAY AS SURFACE LOW PRESSURE DEEPENS OVER THE HIGH PLAINS.
THIS WILL RESULT IN INCREASING SOUTHERLY WINDS AND INCREASING DEW
POINTS. ALTHOUGH LOW LEVEL MOISTURE WILL BE ON THE INCREASE...
AFTERNOON RELATIVE HUMIDITIES WILL STILL BE BELOW 30 PERCENT IN
MOST LOCATIONS AS HIGH TEMPERATURES WARM INTO THE 60S.
THEREFORE...ELEVATED GRASS FIRE CONDITIONS ARE EXPECTED IN MOST 
ZONES THIS AFTERNOON. THE INCREASE IN LOW LEVEL MOISTURE WILL
RESULT IN A MUCH WARMER NIGHT TONIGHT WITH LOWS MAINLY IN THE
MIDDLE 40S TO THE MIDDLE 50S.

SUNDAY WILL BE A WARM DAY FOR MOST LOCATIONS AS THE WINDS TURN TO
THE SOUTHWEST AND WEST AHEAD OF A COLD FRONT. EXPECT AFTERNOON
HIGHS SUNDAY FROM THE UPPER 60S TO THE MIDDLE 70S. THE ONLY
EXCEPTION WILL BE THE NORTHWEST ZONES WHERE THE COLD FRONT IS
EXPECTED IN THE AFTERNOON. THE COLD FRONT WILL MOVE ACROSS ALL OF
NORTH TEXAS SUNDAY NIGHT AND BRING DRIER AND COOLER AIR WITH
OVERNIGHT LOWS RANGING FROM THE UPPER 20S IN THE NORTHWEST TO THE
MIDDLE 40S IN THE SOUTH.  

MONDAY WILL BE A DAY OF TRANSITION AS UPPER LEVEL HIGH PRESSURE
BUILDS TO THE EAST AND AN UPPER LEVEL TROUGH MOVES INTO THE 4
CORNERS REGION. THIS UPPER LEVEL SYSTEM WILL BRING SNOW TO THE
ROCKIES DURING THE DAY MONDAY AND INTO FRONT RANGE CHRISTMAS EVE.
NORTH TEXAS WILL SEE THE COLD FRONT THAT MOVED THROUGH SUNDAY
NIGHT LIFT QUICKLY NORTHWEST IN RESPONSE TO DEEPENING SURFACE LOW
PRESSURE ACROSS THE SOUTHERN HIGH PLAINS. SOME WARM AIR ADVECTION
SHOWERS ARE POSSIBLE CHRISTMAS EVE INTO CHRISTMAS MORNING AS
LARGE SCALE LIFT INCREASES IN RESPONSE TO THE APPROACHING UPPER
TROUGH.

MEDIUM RANGE GUIDANCE IS FINALLY STARTING TO AGREE FAIRLY WELL
WITH REGARDS TO THE MOVEMENT OF THE UPPER TROUGH AND THE ARRIVAL
OF MUCH COLDER AIR INTO NORTH TEXAS. ALTHOUGH THE MODELS DO VARY A
BIT ON THE EXACT TRACK OF THE UPPER LOW...THE GENERAL CONSENSUS IS
THAT THE CENTER OF THE LOW WILL REMAIN JUST SOUTH OF THE RED RIVER
CHRISTMAS DAY. ALL MODELS ARE HOLDING OFF ON THE INTRUSION OF COLD
AIR UNTIL THE UPPER TROUGH AXIS PASSES. THIS IS IN LINE WITH THE
PREVIOUS FORECAST PACKAGE AND WE HAVE MADE VERY LITTLE
MODIFICATIONS TO POPS OR PRECIP TYPE CHRISTMAS AFTERNOON/CHRISTMAS
NIGHT. SO IN SUMMARY...EXPECT SHOWERS CHRISTMAS MORNING WITH A MIX
OR CHANGE OVER TO LIGHT SNOW GENERALLY NORTH OF INTERSTATE 20
CHRISTMAS AFTERNOON. SOME LINGERING WRAP AROUND LIGHT SNOW IS
POSSIBLE IN THE NORTH/NORTHEAST DURING THE EVENING OF THE 25TH BEFORE
THE SYSTEM MOVES INTO THE CENTRAL PLAINS. GIVEN THIS SCENARIO...LITTLE
OR NO ACCUMULATIONS OR TRAVEL IMPACTS IN NORTH TEXAS ARE EXPECTED.
ALTHOUGH STRONG AND GUSTY WIND IS EXPECTED CHRISTMAS EVENING
BEHIND THE COLD FRONT...WE FEEL THAT ANY SNOW THAT FALLS SHOULD BE
WET AND BLOWING SNOW SHOULD NOT CREATE ANY MAJOR IMPACTS.

THERE IS ONE FLY IN THE OINTMENT THAT HAS OUR ATTENTION AND THAT
IS THE POSSIBILITY THAT THE COLD AIR COULD ARRIVE EARLIER THAN
EXPECTED AS OFTEN HAPPENS WITH ARCTIC INTRUSIONS SINCE THEY
PROPAGATE ON THEIR OWN WEIGHT. THEREFORE....CAREFUL SURFACE
ANALYSIS MUST CONTINUE OVER THE NEXT TWO DAYS. IF THE COLD AIR
DOES ARRIVE EARLIER THAN PROGGED IT COULD HAVE SUBSTANTIAL IMPACTS
TO THE FORECAST SUCH AS THE POSSIBILITY OF A DEEPER AND SLOWER
UPPER LOW...LONGER DURATION OF PRECIPITATION...AND POTENTIAL FOR
SNOW ACCUMULATIONS. FOR NOW...WE WILL KEEP THE FORECAST IN LINE
WITH MODEL CONSENSUS BUT THIS SYSTEM NEEDS TO BE WATCHED VERY
CLOSELY.

COLDER AND DRY CONDITIONS ARE EXPECTED WEDNESDAY AND THURSDAY.
HOWEVER...ANOTHER STRONG STORM SYSTEM IS EXPECTED TO APPROACH FROM
THE WEST LATE IN THE WEEK AND WILL RESULT IN AN INCREASE IN LOW
LEVEL MOISTURE AND A CHANCE FOR SHOWERS ON FRIDAY. A COLD FRONT
SHOULD MOVE ACROSS THE REGION NEXT WEEKEND AND BRING ANOTHER SHOT
OF COLDER AND DRY AIR.

79

&&

.FIRE WEATHER...
THE GREATEST CONCERN FOR HIGH FIRE DANGER TODAY WILL BE IN AREAS
ALONG AND WEST OF A LINE FROM SHERMAN/DENISON...TO DALLAS...TO
WACO...TO TEMPLE. IN THESE AREAS...SUSTAINED WIND SPEEDS WILL
REACH OR EXCEED 15 MPH WITH RELATIVE HUMIDITY VALUES BETWEEN 15
AND 30 PERCENT.

MINIMAL PRECIPITATION HAS FALLEN DURING THE LAST SEVERAL WEEKS...
AND VEGETATION IS DORMANT OR OTHERWISE STRESSED. WHEN LOW
HUMIDITY COMBINES ABOVE NORMAL TEMPERATURES...THIS DRY VEGETATION
IS CONDUCIVE TO FIRE INITIATION. WITH GUSTY WINDS...ANY WILDFIRE
THAT FORMS CAN RAPIDLY SPREAD AND BECOME DIFFICULT TO CONTAIN.

25

&&

.CLIMATE...
THROUGH DECEMBER 21...2012 IS THE WARMEST ON RECORD YEAR TO DATE.

DALLAS/FORT WORTH - WARMEST AVERAGE TEMPERATURES (JAN 1 - DEC 21)

   1   70.2   2012*
   2   70.0   2006   WARMEST YEAR ON RECORD
   3   69.3   2011        4TH WARMEST
       69.3   1998        5TH WARMEST
   5   69.2   2008        2ND WARMEST
       69.2   1999        3RD WARMEST
   7   69.0   1933
   8   68.7   1954
       68.7   1939
       68.7   1925

&&

.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX  65  51  68  39  57 /   0   5   0   5   5 
WACO, TX              68  52  72  42  60 /   0   5   0   5   5 
PARIS, TX             63  49  66  38  56 /   0  10  10  10  10 
DENTON, TX            67  47  66  34  54 /   0   5   0   5   5 
MCKINNEY, TX          64  52  67  37  56 /   0   5   0   5   5 
DALLAS, TX            65  53  67  41  57 /   0   5   0   5   5 
TERRELL, TX           67  53  67  41  58 /   0   5   5   5   5 
CORSICANA, TX         67  54  72  44  60 /   0   5   5   5   5 
TEMPLE, TX            68  52  73  44  62 /   0   5   0   5   5 
MINERAL WELLS, TX     65  43  69  28  57 /   0   0   0   5   5 

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

25/79