FXUS64 KAMA 080413 AAB
AFDAMA
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE AMARILLO TX
1013 PM CST MON DEC 7 2009
.UPDATE...
WILL KEEP CURRENT HIGHLIGHTS FOR WINTER WEATHER AND HIGH WIND GOING.
LATEST AMA UPPER AIR SOUNDING STILL SUPPORTS THE IDEA OF FREEZING
DRIZZLE OR LIGHT FREEZING RAIN ONCE THE COLUMN NEAR THE SURFACE
MOISTENS EARLY THIS MORNING. LATEST MODELS CONTINUE ON TRACK WITH A
VERY WINDY DAY ON TUESDAY. WE DID GO AHEAD AND ADD THE MENTION OF FOG
DUE TO CURRENT AND EXPECTED TRENDS.
&&
.PREV DISCUSSION... /ISSUED 618 PM CST MON DEC 7 2009/
AVIATION...
0000 UTC TAFS...MAIN AVIATION CONCERN THIS EVENING WILL FOCUS ON IFR
CIGS/VIS THE NEXT 6-12 HOURS ALONG WITH INCREASING WINDS OVER THE
SECOND HALF OF THE FORECAST PERIOD. HIGHLY AMPLIFIED UPPER TROUGH WAS
LOCATED OVER THE GREAT BASIN THIS EVENING AND IS FORECAST TO MOVE
ACROSS THE FOUR CORNERS REGION EARLY TUESDAY AND ACROSS THE CENTRAL
HIGH PLAINS DURING THE DAY. WARMER AIR WILL INCREASE AT THE MID
LEVELS TONIGHT IN ADVANCE OF THIS SYSTEM WHICH WILL LEAD TO
INCREASING CHANCES OF PRECIP AT THE TERMINALS. PRECIP TYPE CAN BE
TRICKY ALTHOUGH FAIRLY DRY AIR AT THE DENDRITIC GROWTH ZONE AND TEMPS
AT THE SFC NEAR OR JUST BELOW FREEZING SUGGEST MAINLY FREEZING
DRIZZLE. HOWEVER CONFIDENCE IS LOW ON TIMING WHEN AND EVEN IF THIS
WILL AFFECT THE TERMINALS. SO HAVE INCLUDED TEMPO GROUPS TO COVER FOR
THIS POSSIBILITY. FOG IS POSSIBLE OVERNIGHT WITH LIGHT UPSLOPE FLOW
LEADING TO AN INCREASE IN LOW LEVEL MOISTURE. HAVE CONDITIONS
DETERIORATING TO IFR WITH ANY FZDZ BUT MAY BE TOO OPTIMISTIC WITH THIS
FORECAST SO WILL NEED TO MONITOR CONDITIONS AND AMEND AS NECESSARY.
SFC LOW ASSOCIATED WITH THE UPPER TROUGH WILL MOVE ACROSS THE OK
PANHANDLE TUESDAY AFTERNOON. THE SFC PRESSURE GRADIENT WILL TIGHTEN
AS THIS SYSTEM FURTHER DEEPENS AS IT HEADS TO THE EAST. ALTHOUGH
THICK CLOUD COVER WILL TEMPER THE DEGREE OF MIXING...CONFIDENCE IS
HIGH THAT STRONG SOUTHERLY WINDS WILL OCCUR WITH THIS SYNOPTIC SET
UP. THUS HAVE INCREASED WIND SPEEDS DURING THE DAY WITH SUSTAINED
WINDS AROUND 25-30 KTS AND GUSTS UP TO NEAR 40 KTS. RIGHT NOW HELD
OFF ON ISSUING AN AVIATION WEATHER WARNING AT KAMA BUT MAY HAVE TO
LOOK INTO ISSUING ONE LATER THIS EVENING OR OVERNIGHT. STRONG COLD
FRONT ASSOCIATED WITH THIS LOW WILL PUSH ACROSS THE AREA AND TIMED
FROPA AROUND 20Z AT KGUY/KDHT AND 22Z AT KAMA WITH WINDS VEERING TO
THE NORTHWEST. SHOULD CONTINUE TO SEE STRONG WINDS AT THIS TIME BUT
WINDS SHOULD GRADUALLY DIMINISH JUST BEYOND THIS FORECAST. CLK
PREV DISCUSSION... /ISSUED 421 PM CST MON DEC 7 2009/
DISCUSSION...
12Z MODEL RUNS CAME IN VERY CONSISTENT WITH THE SYSTEM CURRENTLY
CHURNING OVER SOUTHERN CALIFORNIA. APPEARS THE LOW WILL DIG SOUTHEAST
INTO ARIZONA AND LIFT NORTHEAST INTO KANSAS ON TUESDAY. THE BIG
CONCERN INITIALLY IS PRECIP TYPE AND AMOUNT FOR THE PANHANDLES. AFTER
SCOURING THE FORECAST SOUNDINGS ACROSS MULTIPLE LOCATIONS IN AND
AROUND THE PANHANDLES...DECIDED THAT THE PRIMARY IMPACT WILL BE
FREEZING DRIZZLE. THROUGH TONIGHT...THERE IS A WINDOW FOR LIGHT SNOW
MAINLY ACROSS THE NORTHERN HALF OF THE CWA WITH FREEZING RAIN IN THE
SOUTH AS THE SOUNDINGS EXHIBIT SUFFICIENT MOISTURE IN THE DENDRITIC
GROWTH ZONE. BUT THE UPPER SUPPORT WILL BE LIMITED SO ACCUMULATIONS
SHOULD STAY ON THE LOW SIDE. BY 06Z...STRONG WEST WINDS BEGIN TO
DEVELOP AT 700 MB BRINGING WARM LOW LEVEL AIR ABOVE THE SHALLOW COLD
DOME. AT THE SAME TIME...MOISTURE LEVELS IN THE DENDRITIC GROWTH ZONE
DECREASE SLIGHTLY. THUS...THINKING THE LIMITED ICE CRYSTALS ALOFT
WILL BRING MAINLY FREEZING DRIZZLE DURING THE OVERNIGHT AND EARLY
MORNING HOURS. WE DECIDED TO ISSUE A WINTER WEATHER ADVISORY TO COVER
THE MIXED BAG OF PRECIP. PLUS...WE WERE THINKING THAT SINCE THE
SURFACE HAS BEEN VERY COLD LATELY...THAT MOST SURFACES SHOULD EASILY
ALLOW FOR ICE OR SNOW ACCUMULATIONS. WE ARE ONLY EXPECTED ICE
ACCUMULATIONS OF LESS THAN A QUARTER INCH IN ANY LOCATION.
AS FOR THE WINDS TOMORROW...WE DECIDED TO LET THE MIDNIGHT SHIFT
HANDLE THE STRONG WINDS WHICH ALLOWED US TO FOCUS ON THE WINTER
PRECIP. HOWEVER...MODELS CONTINUE TO INDICATE A STRONG PRESSURE
GRADIENT AT THE SURFACE AND ALSO AT 700MB. IN ADDITION...THE SURFACE
LOW WILL BE DEEPEN AS IT MOVES INTO THE PANHANDLES BRINGING AN EVEN
GREATER SHOT AT STRONG WINDS. SO THE PREVIOUS FORECAST LOOKED TO BE
IN GREAT SHAPE WITH THE EMPHASIS ON THE STRONGEST WINDS DIRECTED AT
THE SOUTHWEST AND SOUTH CENTRAL TEXAS PANHANDLE.
UPPER LEVEL SHORTWAVE TROUGH ALONG WITH SURFACE LOW WILL HAVE PUSHED
EAST OF THE PANHANDLES BY THE START OF THE PERIOD. SURFACE HIGH
PRESSURE WILL BEGIN TO SETTLE IN FROM THE NORTH...WITH COLD
TEMPERATURES IN STORE ON WEDNESDAY. LOWEST TEMPS CAN BE ANTICIPATED
ACROSS THE NORTHEAST ZONES WITH MIDDLE 20S WHILE THE SOUTHWEST ZONES
WILL ATTEMPT TO WARM UP INTO THE LOWER 40S. ANOTHER VERY COLD NIGHT
IN STORE FOR WEDNESDAY NIGHT AS FRIGID AIRMASS WILL BE DIFFICULT TO
ERODE. CURRENTLY...HAVE SINGLE DIGITS ACROSS THE NORTH AND MIDDLE
TEENS ACROSS THE SOUTH. BELIEVE THE MET GUIDANCE IS TRYING TO WARM
THINGS UP TOO QUICKLY AND HAVE SIDED WITH THE COOLER MAV NUMBERS.
SURFACE HIGH WILL BEGIN TO GRADUALLY SHIFT OFF TO EAST THURSDAY INTO
FRIDAY...WITH SLOWLY MODERATING TEMPERATURES. HOWEVER...KEPT SOME
COLDER TEMPS ACROSS THE EASTERN ZONES ON THURSDAY AS SOME
RECIRCULATED COOLER AIR AROUND THE HIGH MAKE SNEAK BACK INTO THE
PANHANDLES. LARGELY ZONAL FLOW WILL BE IN PLACE ACROSS THE REGION
HEADING TOWARDS THE WEEKEND AND EARLY PART OF NEXT WEEK. MEDIUM
RANGE MODELS HINTING AT A FAST MOVING SHORTWAVE IN THIS FLOW
TRAVERSING THE PANHANDLES FRIDAY INTO SATURDAY...BUT HAVE KEPT THE
FORECAST DRY.
FIRE WEATHER...
FIRE WEATHER CONCERNS WILL INCREASE ON TUESDAY AS STRONG WEST WINDS
DEVELOP DURING THE DAY. WIND SPEEDS OF 25 TO 35 MPH WITH GUSTS AS
HIGH AS 60 MPH WILL BE POSSIBLE IN SOME AREA. HOWEVER...RELATIVE
HUMIDITY VALUES SHOULD REMAIN ABOVE 25 PERCENT AND LIGHT WINTRY
PRECIPITATION IS EXPECTED OVERNIGHT TONIGHT. THUS...RED FLAG
CONDITIONS ARE NOT YET EXPECTED. FIRE WEATHER CONCERNS ARE THEN
EXPECTED TO REMAIN LOW THROUGH THE REST OF THE WEEK.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR THE FOLLOWING
ZONES: ARMSTRONG...CARSON...COLLINGSWORTH...DALLAM...DEAF
SMITH...DONLEY...GRAY...HANSFORD...HARTLEY...HEMPHILL...
HUTCHINSON...LIPSCOMB...MOORE...OCHILTREE...OLDHAM...
POTTER...RANDALL...ROBERTS...SHERMAN...WHEELER.
HIGH WIND WATCH FROM 10 AM CST TUESDAY THROUGH TUESDAY AFTERNOON
FOR THE FOLLOWING ZONES: ARMSTRONG...DEAF SMITH...OLDHAM...
POTTER...RANDALL.
OK...WINTER WEATHER ADVISORY UNTIL NOON CST TUESDAY FOR THE FOLLOWING
ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
05/15
