000
FXUS63 KGID 181706
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1106 AM CST WED DEC 18 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 449 AM CST WED DEC 18 2013

MAIN FORECAST CONCERN WILL BE TEMPERATURES.

SURFACE OBSERVATIONS AND SATELLITE SHOW CIRRUS STREAMING INTO THE
AREA EARLY THIS MORNING. ANALYSIS INDICATES A WARM FRONT ON THE HIGH
PLAINS.

TEMPERATURES WILL BE A CHALLENGE FOR TODAY. THE WARM FRONT WILL
MOVE TO THE EAST ACROSS THE AREA THIS MORNING BRINGING WARMER
TEMPERATURES...ALONG WITH WARM ADVECTION ACROSS THE AREA SHOULD
ACCOUNT FOR WARMER TEMPERATURES TODAY. ON THE OTHER HAND THE
CIRRUS THAT IS MOVING ACROSS THE AREA COULD KEEP THE TEMPERATURES
FROM REACHING THEIR FULL POTENTIAL. HAVE MADE FEW CHANGES TO THE
FORECAST HIGHS FOR TODAY. IF THERE IS MORE SUN...TEMPERATURES
COULD BE WARMER THAN FORECAST...MORE CLOUDS AND EXPECT COOLER
TEMPERATURES.

LATER THIS AFTERNOON THE WARM FRONT WASHES OUT AS COOLER AIR
MOVES IN FROM THE NORTH. THE BOUNDARY BECOMES MORE OF A BROAD
TROUGH AND DRIFTS TO THE SOUTH LATE THIS AFTERNOON AND INTO THE
EVENING. MODELS START TO BRING IN COOLER AIR DURING THE EVENING
AND OVERNIGHT. THE GFS IS A LITTLE FASTER WITH THE COOLER AIR THAN
THE NAM...BUT THE RESULTS ARE SIMILAR WITH TEMPERATURES A BIT
COOLER TONIGHT THAN THEY ARE CURRENTLY.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 449 AM CST WED DEC 18 2013

THE BIGGEST CHALLENGES WILL BE DETERMINING HIGH
TEMPERATURES...AND ALSO PRECIPITATION CHANCE FOR SATURDAY/SATURDAY
NIGHT IN OUR SOUTH...ALSO PRECIPITATION TYPE FOR NON-MEASURABLE
PRECIPITATION THURSDAY EVENING.

WE START OFF THURSDAY WITH A DIGGING TROUGH IN THE WEST AS WE
WILL BE SITUATED BEHIND A SURFACE COLD FRONT THAT SHOULD HAVE JUST
CLEARED THE CWA BY 12Z THURSDAY. THE COLD AIR LAGS BEHIND A BIT
AND EXPECT TEMPERATURES TO RISE A BIT DURING THE
MORNING...ESPECIALLY SOUTH BEFORE COLD AIR REALLY TAKES HOLD AND
HELPS TO SOCK US IN WITH A SOLID BLANKET OF STRATUS WITH
INCREASING COLD AIR ADVECTION. LOW TEMPERATURES MAY NOT ACTUALLY
GET THAT LOW TO BEGIN WITH...ESPECIALLY CENTRAL AND SOUTH. MODELS
ARE BACKING OFF OF THE COLDER AIR INTRUSION A BIT LATER AND AM
GOING ABOVE GENERAL GUIDANCE NUMBERS FOR THURSDAY HIGHS...BUT OUR
HIGH TEMPERATURE SHOULD OCCUR RELATIVELY EARLY AND DROP OFF
CONSIDERABLY FOR MUCH OF THE AFTERNOON INTO THE NIGHT.
ALSO...GOING ABOVE GUIDANCE FOR LOWS THURSDAY NIGHT/FRIDAY MORNING
AS WE WILL STILL BE SOCKED IN WITH STRATUS AND WIND SPEEDS WILL BE
ELEVATED. IN FACT...THE STRONGEST WIND SPEED SHOULD BE THURSDAY
NIGHT RATHER THAN DURING THE DAY ON THURSDAY AS HEIGHT RISES AND
COLD AIR ADVECTION WILL PEAK AT THIS TIME...QUITE A BIT BEHIND THE
SURFACE COLD FRONT PASSING MUCH EARLIER. THERE COULD BE JUST
ENOUGH LIFT...ESPECIALLY THURSDAY EVENING...FOR SOME VERY LIGHT
AND NON-MEASURABLE PRECIPITATION. AT FIRST GLANCE...ONE WOULD
THINK THAT WE COULD GET SOME FREEZING DRIZZLE AS SOUNDINGS
INDICATE AN INVERTED TEMPERATURE PROFILE SATURATED UP TO MID-
LEVELS AT ABOUT -7C AT THE TOP OF THE SATURATED LAYER. BUT ANY
PRECIPITATION FALLING THROUGH THE COLUMN OF AIR WILL HIT COLDER
TEMPERATURES TO -12 AND -14C ON THE WAY DOWN...TOO COLD TO SUSTAIN
SUPERCOOLED DROPLETS...AND ANY PRECIPITATION SHOULD BECOME SNOW
PELLETS OR SNOW GRAINS...OR SOMETHING CLOSE TO THIS.

SURFACE HIGH PRESSURE BUILDS IN FOR FRIDAY...BUT WE WILL NOT BEAR
THE BRUNT OF COLD AIR AS THE APPROACHING WAVE SPLITS...KEEPING MUCH
OF THE COLDER AIR BOTTLED TO THE NORTH AS A CLOSED LOW DIVES INTO
MEXICO.  SKY COVER MAY BE A BIT SLOW TO ERODE ACCORDING TO LATEST
MODEL SOLUTIONS. FRIDAY LOOKS COLD FOR SURE...BUT STILL GOING ABOVE
GUIDANCE BY A FEW DEGREES AS ENSEMBLES INDICATE THAT AGAIN...THE
BRUNT OF COLD AIR WILL NOT HIT US AS MUCH EARLIER MODEL FORECASTS
HAVE INDICATED.

SATURDAY COULD BE INTERESTING...ESPECIALLY IN OUR SOUTH AS THE
LOW TRACKS ACROSS THE SOUTHERN PLAINS AND EVENTUALLY INTO THE MID-
SOUTH ALONG A STALLED FRONT. THE LOW IS EXPECTED TO FILL IN AND
EVENTUALLY REJOIN ANOTHER WAVE FROM THE NORTH. THIS SYSTEM SHOULD
BE FAR ENOUGH SOUTH TO PRECLUDE MOST OF THE CWA FROM GETTING MUCH
PRECIPITATION...BUT TRENDS ARE NUDGING THIS SYSTEM JUST A BIT
FARTHER NORTH...WHICH LEAVES A GOOD CHANCE OF INVOLVING OUR FAR
SOUTHERN CWA. MODELS ARE RATHER UNCLEAR WITH POTENTIAL FOR DRY AIR
AT MID-LEVELS AND THERE VERY COULD BE SOME FREEZING DRIZZLE AT
ONSET...IF ANYTHING OCCURS...BUT CONFIDENCE IS RATHER LOW FOR
THIS...SO OPTING NOT TO INCLUDE THIS IN THE FORECAST. FOR NOW IT
LOOKS LIKE MAINLY SNOW IF ANYTHING IN OUR SOUTH FOR
SATURDAY/SATURDAY NIGHT...WITH AMOUNTS IN OUR FAR SOUTH POSSIBLY
REACHING ADVISORY LEVELS IF TRENDS CONTINUE.

SUNDAY IS LOOKING MORE AND MORE LIKE THE COLDEST DAY OF THE LONG
TERM FORECAST. GFS AND ECMWF ENSEMBLES ARE TRENDING COLDER AS THE
NORTHERN STREAM WAVE JOINS WITH THE SPLIT SOUTHERN PART AND WILL
ALLOW SIGNIFICANTLY COLDER AIR TO MARCH IN. THIS WAVE IS PROGRESSIVE
AND WE SHOULD GET RIDGING BY LATE MONDAY ALREADY WITH A WARM FRONT
APPROACHING. MONDAY WILL BE A MODEST WARM-UP FROM SUNDAY AND STILL
PROBABLY BELOW AVERAGE...BUT WE SHOULD BE BACK IN THE WARM SECTOR
BY TUESDAY...EXPERIENCING YET MORE MILD WEATHER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1106 AM CST WED DEC 18 2013

VFR CONDITIONS ARE FORECAST THROUGH THE NEXT 24 HOURS.

HIGH LEVEL CLOUDS WILL REMAIN POSSIBLE THROUGH THE NEXT 24
HOURS...GENERALLY BETWEEN 15000FT AGL AND 20000FT AGL. SOME SETS
OF GUIDANCE SUGGEST A LAYER OF STRATUS...WORKING IN FROM THE NORTH
BEHIND A LOW LEVEL BAROCLINIC ZONE...MAY IMPACT PORTIONS OF THE
REGION DURING THE DAY THURSDAY. AT THIS TIME HOWEVER CONFIDENCE IS
HIGHEST THAT ANY SUCH STRATUS WILL REMAIN NORTH AND EAST OF
GRI...THUS VFR CONDITIONS HAVE BEEN MAINTAINED IN THE TAF. THAT
BEING SAID...THIS IS SOMETHING WHICH WILL NEED TO BE MONITORED
CLOSELY THROUGH THE NEXT 24 HOURS TO MAKE SURE STRATUS DOES NOT
MAKE A PUSH FARTHER SOUTHWEST THAN WHAT IS CURRENTLY EXPECTED. THE
SURFACE WIND WILL REMAIN FAIRLY LIGHT THROUGH 12Z...VARYING FROM
THE SOUTHWEST TO THE NORTH. LOW LEVEL PRESSURE RISES AND A
RESULTANT STRENGTHENING IN THE LOW LEVEL PRESSURE GRADIENT POST
FROPA WILL THEN PROVIDE A STRONGER NORTH/NORTHEAST WIND DURING THE
DAY THURSDAY...SUSTAINED AT AROUND 15KTS AND GUSTING TO AROUND
23KTS. VISIBILITY RESTRICTION IS NOT EXPECTED AT GRI THROUGH THE
NEXT 24 HOURS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

SHORT TERM...JCB
LONG TERM...HEINLEIN
AVIATION...BRYANT