000
FXUS63 KGID 131812
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1212 PM CST FRI DEC 13 2013

.UPDATE...
ISSUED AT 1212 PM CST FRI DEC 13 2013

HAVING TROUBLE WITH FCST HOURLY TEMPS DUE TO DIFFERENTIAL HEATING
AND LEFTOVER SNOW ON THE GROUND. TEMPS AT LEXINGTON AND ORD ARE
NOW 40F OR ABOVE. SO HIGHS WERE INCREASED NW TODAY. IT REMAINS
HIGHLY UNCERTAIN HOW WARM THESE LOCATIONS WILL GET WITH THE FRONT
DROPPING IN THIS AFTERNOON.

SFC OBS AND 3-HR PRES RISES SUGGEST THE FRONT IS LOCATED PARALLEL
TO AND ROUGHLY 70 MI N OF I-80.


UPDATE ISSUED AT 946 AM CST FRI DEC 13 2013

STILL EVALUATING THE SITUATION REGARDING TEMPS TODAY AND AGREE
WITH THE MID SHIFT THAT IT IS FRAUGHT WITH UNCERTAINTY. OTHER THAN
SOME MINOR ADJUSTMENTS TO KEEP HOURLY TEMPS/DWPTS/WINDS IN CHECK
WITH REALITY...THE ONLY OTHER CHANGE WAS TO MODIFY CLOUD COVER
BASED ON CURRENT TRENDS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 424 AM CST FRI DEC 13 2013

THE BIGGEST CHALLENGE WILL BE DETERMINING CHANCES OF PRECIPITATION
CHANCES...IF ANY...TOWARD THE SOUTHEASTERN CWA TODAY AND ALSO
TEMPERATURES FOR TODAY.

THE UPPER AIR PATTERN IS SPLIT FLOW WITH A TROUGH PASSING THROUGH
THE PLAINS TODAY. MOST OF THE SYNOPTIC SCALE ENERGY IS FOCUSED TO
THE SOUTH WITH THIS WAVE.

AT THE SURFACE...A COLD FRONT OVER SOUTHERN SOUTH DAKOTA WILL
CONTINUE TO MAKE ITS WAY SOUTH TODAY AND MOVE THROUGH THE CWA DURING
THE DAY...BRINGING COLDER AIR AND STRATUS WITH IT. THIS SITUATION
WOULD BE A TOUGH ENOUGH CALL ON ITS OWN...BUT DEALING WITH AN
IRREGULARLY SHAPED LEFTOVER SNOWPACK OVER PART OF THE CWA WILL
FURTHER COMPLICATE MATTERS. WENT WITH A COMBINATION OF BCCONSRAW AND
ADJUSTMENTS FOR WHERE THE SNOW PACK IS EXPECTED TO BE TO COME UP
WITH HIGHS FOR TODAY. THERE IS LOW CONFIDENCE IN THIS FORECAST...BUT
DID THE BEST WITH THE INFORMATION THAT IS AVAILABLE. THE NAM
INDICATES THAT SOME VERY LIGHT NON-MEASURABLE PRECIPITATION MAY
OCCUR IN OUR EASTERN TIER OF NEBRASKA COUNTIES THIS EVENING. TAKING
A LOOK AT MODEL SOUNDINGS...THE INVERTED SATURATED LAYER IS FAIRLY
SHALLOW AND THE NAM APPEARS TO BE A BIT OF AN OUTLIER WITH THIS
PLACEMENT OF PRECIPITATION THIS FAR WEST. FLURRIES LOOK VERY UNLIKELY
DUE TO DRY AIR ABOVE 850 MB AND LACK OF A SATURATED DENDRITIC
LAYER...SO  IF VERY LIGHT PRECIPITATION WERE TO DEVELOP...IT WOULD
BE FREEZING DRIZZLE. THIS STILL APPEARS UNLIKELY THIS FAR WEST WITH
SUCH A SHALLOW SATURATED LAYER AND CONTINUED COLD AIR ADVECTION
ALOFT.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 424 AM CST FRI DEC 13 2013

PRIMARY FORECAST CONCERN THROUGH THE LONG TERM LIES WITH
TEMPERATURES.

THE START OF THE PERIOD SHOWS MODELS IN PRETTY GOOD AGREEMENT...WITH
NORTHWESTERLY FLOW BECOMING BETTER ESTABLISHED ACROSS THE REGION AS
AN UPPER LEVEL TROUGH AXIS IS EXPECTED TO HAVE SHIFTED TO THE EAST
OF THE CWA SATURDAY MORNING...WITH RIDGING AFFECTING THE WEST COAST.
THROUGH THE WEEKEND AND INTO THE EARLY PART OF THE NEXT WORK
WEEK...MODELS REMAIN IN GOOD AGREEMENT NOT SHOWING SIGNIFICANT
CHANGES IN THE OVERALL UPPER LEVEL PATTERN ACROSS THE CENTRAL
CONUS...WITH THE FORECAST REMAINING DRY WITH ANY DISTURBANCES
EXPECTED TO REMAIN WELL TO THE NORTH OF THE AREA. AT THE
SURFACE...THE PERIOD STARTS WITH THE PRIMARY COLD FRONT WELL TO THE
SE OF THE CWA...WITH HIGHER PRESSURE BUILDING IN FROM THE WEST...AND
SETTLED IN OVER THE CWA THROUGH THE AFTERNOON/EVENING HOURS.
EXPECTING THE NORTHWESTERLY WINDS TO DIMINISH WITH TIME...GRADUALLY
BECOMING WESTERLY WITH TIME AS THE SFC HIGH SLIDES EAST. AS WE GET
INTO SUNDAY...WHILE THE DISTURBANCES TO THE NORTH DONT LOOK TO BRING
PRECIPITATION...ONE SLIDING TOWARD THE GREAT LAKES OUT OF CANADA
WILL PUSH A BOUNDARY THROUGH THE CWA...REINFORCING THE WESTERLY
WINDS EXPECTED TO BE IN PLACE.  WHILE A COOLER AIRMASS IS EXPECTED
TO BE IN PLACE FOR SATURDAY...KEEPING HIGHS IN THE 20S/30S...WARMING
TEMPS ALOFT CONTINUE TO BE SHOWN INTO NEXT WEEK.  THE WARMING TEMPS
COMBINED WITH THE DOWNSLOPING COMPONENT TO THE WINDS IS EXPECTED TO
RESULT IN A BOUNCE UP IN HIGHS ALREADY FOR SUNDAY...THOUGH
CONFIDENCE TAKES A LITTLE HIT DUE TO UNCERTAINTY WITH HOW MUCH OF
THE SNOWPACK WILL BE LEFT BY THEN...AND HOW IT WILL AFFECT TEMPS.
CURRENTLY HAVE UPPER 30S TO MID/UPPER 40S FROM EAST TO WEST FOR
SUNDAY...WITH MID TO UPPER 40S FOR MONDAY.

AS WE GET INTO TUESDAY THROUGH THURSDAY...THE UPPER LEVEL PATTERN
BEGINS TO BECOME MORE ZONAL IN NATURE...AS AN AREA OF LOW PRESSURE
SYSTEM WHICH HAD BEEN ANCHORED OFF THE WEST COAST BEGINS TO MOVE
INLAND.  THOUGH IT LOOKS TO WEAKEN AS IT SLIDES EAST...ANOTHER PIECE
OF ENERGY IS MOVING IN FROM THE PAC NW.  KEPT THE DRY FORECAST
GOING...BUT CONFIDENCE IS LOWER IN THE THURSDAY PERIOD...WITH THE
GFS HINT AT INCREASING LIFT AHEAD OF THIS SYSTEM POSSIBLY BRINGING
SOME PRECIP TO THE CWA.  NOT EXPECTING A SIGNIFICANT CHANGE IN
CONDITIONS FOR TUESDAY...THOUGH WINDS ARE EXPECTED TO LIGHTEN AND
STARTING TO TRANSITION TO THE SOUTH...SO WHILE THOSE BETTER WEST
WINDS WONT BE IN PLACE...STILL LOOKING AT 40S FOR HIGHS.  FOR
WEDNESDAY...SURFACE LOW PRESSURE IS BECOMING BETTER ORGANIZED OFF TO
THE W/NW...SO THE S/SWRLY WINDS WILL REMAIN IN PLACE.  SOME
UNCERTAINTY WITH HIGHS TEMPS ON WEDNESDAY...AS MODELS ARENT IN THE
BEST OF AGREEMENT WITH TEMPS ALOFT /THE ECMWF IS WARMER/.  CURRENT
FORECAST CONTINUES THE 40S...BUT IF THINGS TREND TOWARD THE
ECMWF...TEMPS MAY NEED TO BE ADJUSTED UP A BIT.  AS MENTIONED
ABOVE...MORE QUESTIONS ARISE FOR THURSDAY...NOT ONLY WITH PRECIP
CHANCES BUT WITH TEMPERATURES.  A SURFACE COLD FRONT WILL BE MAKING
ITS WAY IN FROM THE NW...BUT THERE ARE TIMING DIFFERENCES...WITH THE
ECMWF SHOWING THE FRONT THROUGH MOST OF THE CWA BY 00Z FRIDAY...AND
THE GFS SHOWING IT CLOSER TO THE NE/SD BORDER.  CURRENT FORECAST IS
A BLEND...AND DOES HAVE COOLER HIGHS AFFECTING THE CWA...ESP ACROSS
THE NORTH. PLENTY OF TIME TO IRON OUT THOSE DETAILS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1212 PM CST FRI DEC 13 2013

REST OF THIS AFTERNOON: VFR 25K FT CIRRUS CIGS. A COLD FRONT WILL
MOVE THRU 20Z-22Z. WINDS ARE ALREADY NE AND WILL REMAIN AROUND 10
KTS. CONFIDENCE: HIGH.

TONIGHT: THE INFLUX OF COLDER AIR IS EXPECTED TO LEAD TO MVFR
STRATUS DEVELOPMENT EARLY AND IT IS EXPECTED TO LAST THRU THE
NIGHT. N WINDS WILL INCREASE AND GUST UP TO 25 KTS...WITH A ONE-
TIME PEAK GUST UP TO 28 KTS POSSIBLE.

CONFIDENCE: MEDIUM EXCEPT LOW WITH THE ONSET OF MVFR CIGS. THEY
COULD DEVELOP AS EARLY AS 22Z OR AS LATE AS 03Z.

SAT MORNING: MVFR WITH OVC EXPECTED TO TURN BKN...AND THEN SCT/VFR
AFTER 18Z. WINDS WILL DECREASE TO AROUND 10 KTS FROM THE NNW.

&&

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

$$

UPDATE...HALBLAUB
SHORT TERM...HEINLEIN
LONG TERM...ADO
AVIATION...HALBLAUB