000
FXUS63 KGID 041722
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1122 AM CST WED DEC 4 2013

.UPDATE...
ISSUED AT 900 AM CST WED DEC 4 2013

THE WINTER WEATHER ADVISORY HAS BEEN ALLOWED TO EXPIRE AT 9 AM.
CALLS TO COUNTIES YIELD EITHER NO PCPN OR MAINLY FLURRIES WITH THE
FZDZ REPORTS RATHER ISOLATED...AND FZDZ WAS MORE OF AN ISSUE EARLIER
THIS MORNING. SNOW FLURRIES REMAIN POSSIBLE THROUGH AT LEAST THE
MORNING HOURS.

UPDATE ISSUED AT 654 AM CST WED DEC 4 2013

NO SUBSTANTIAL CHANGES. TEMPS CONTINUE THEIR DOWNWARD SLIDE. WE
ARE LOSING ABOUT 1 DEG/HR. SOME MINOR CHANGES WERE MADE TO KEEP
FCST HOURLY TEMPS ON TRACK WITH REALITY. ALSO NUDGED WINDS UP A
LITTLE THRU 18Z.

WE HAVE RECEIVED CALLS FROM OSBORNE AND MITCHELL COUNTIES /KS/
CONFIRMING ICY CONDITIONS.

VISIBILITIES HAVE BEEN INCREASING ACROSS S-CNTRL NEB. THE THREAT
MAY BE WANING AS SUBSIDENCE SETTLES IN BEHIND THE DEPARTING
SHORTWAVE TROF.

ADVISORY CONTINUES AS POSTED.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 436 AM CST WED DEC 4 2013

...CAUTION URGED FOR SLIPPERY TRAVEL IN SOME AREAS THIS MORNING...

WINTER WX ADVISORY POSTED AT 355 AM FOR AREAS OF ICING AND ITS
POTENTIAL HAZARD TO THE MORNING COMMUTE.

WE HAVE SEEN IT IN AUTOMATED AIRPORT OBS AND RECEIVED A COUPLE
REPORTS. IT IS ALSO FALLING HERE AT OUR OFFICE.

RADAR IS IN VCP31 /ITS MOST SENSITIVE MODE/ TO TRY AND DETECT THE
FINER PRECIP.

ALOFT: A POSITIVE-TILT TROF WITH SEVERAL EMBEDDED VORTICES WILL
ESSENTIALLY REMAIN FROM THE NRN PLAINS TO CA THRU TONIGHT. THE ONE
THAT WILL POTENTIALLY AFFECT THE CNTRL PLAINS WILL MOVE THRU THIS
EVENING.

SURFACE: THE ARCTIC COLD FRONT THAT MOVED THRU YESTERDAY WAS OVER
SRN KS WITH THE LEE-SIDE LOW NOW BEGINNING TO EJECT NE ALONG IT.
THIS LOW WILL REFORM OVER IA/WI TODAY AND INTENSIFY AS IT CROSSES
THE GREAT LAKE TONIGHT. IN THE MEANTIME...VERY STRONG ARCTIC HIGH
PRES /OVER WRN CANADA/ WILL CONTINUE TO PRESS INTO THE REGION.

TODAY: CLOUDY AND GLOOMY WITH WIDESPREAD LOW STRATUS. FREEZING
DRIZZLE HAS BEEN OCCURRING ON-AND-OFF AT VARIOUS LOCATIONS
OVERNIGHT. WHILE INITIAL REPORTS HAVE BEEN MORE LIKE FREEZING
MIST /IE SMALLER DROPLETS THAN TYPICAL OF DRIZZLE/...IT WONT TAKE
MUCH PERSISTENCE TO CREATE TROUBLE. SO WHILE NOT ALL AREAS WILL
SEE SIGNIFICANT IMPACTS...THE ADVISORY WAS ISSUED FOR THE ENTIRE
FCST AREA OUT OF AN ABUNDANCE OF CAUTION...AND BECAUSE WE CANT
KNOW WHAT AREAS WILL BE AFFECTED MORE THAN OTHERS.

SATELLITE SHOWS THAT SOME THICKER MID-LEVEL CLOUDS HAVE MOVED
INTO S-CNTRL NEB /14-20K FT BASED ON UEX 88D/. THESE ICE CRYSTALS
HAVE SURVIVED THE DRY LAYER...SEEDING THE STRATUS WHICH EXTENDS UP
TO 8K FT. SO WE/VE STARTED TO SEE SOME REPORTS OF LIGHT SNOW.

COLD AIR ADVECTION WILL CONTINUE AS PROGRESSIVELY COLDER AIR
POURS SOUTHWARD. OVER S-CNTRL NEB N OF HWY 6...HIGH TEMPS FOR THE
DAYLIGHT HRS WILL OCCUR AT SUNRISE...THEN CONTINUE A VERY SLOW
FALL. SOUTH OF HWY 6 INTO N-CNTRL KS...SOME VERY MODEST 3-7F RISE
IS "POSSIBLE" BUT THAT MAY BE DUE TO THE MODELS TRYING TO BREAK UP
THE STRATUS. IF THIS DOES NOT MATERIALIZE...TEMPS WILL LIKELY GO
NOWHERE.

BRISK N-NW WINDS WILL CONTINUE TO GUST 25-35 MPH...ADDING FURTHER
STING TO THE COLD.

BITTER ARCTIC COLD HAS ARRIVED AND IT WAS EXTREMELY VERY WELL
ADVERTISED MORE THAN A WEEK AGO. THIS IS A TESTAMENT TO CONTINUING
IMPROVEMENT IN NUMERICAL WX PREDICTION.

TONIGHT: MODELS CONTINUE TO ADVERTISE A NARROW FRONTOGENETIC BAND
OF LIGHT SNOW SWEEPING ACROSS KS 6 PM TO 12 AM. SHOULD BE NO MORE
THAN 1-2 HRS AT ANY ONE LOCATION "IF" IT OCCURS AT ALL. CONFIDENCE
IS AVERAGE. OTHERWISE...DECREASING CLOUDS AS MOISTURE IS STRIPPED
OUT IN THE SUBSIDENCE BEHIND THE DEPARTING TROF.

USED CONSENSUS OF ALL GUIDANCE FOR LOW TEMPS. CONTINUING BRISK
WINDS WILL PUT A CAP ON RADIATING TO THE COLDEST TEMPS POSSIBLE.
WIND CHILLS WILL FALL BELOW -10F NORTH OF I-80 PRIOR TO SUNRISE.

WITH THE SURFACE LOW DEEPENING DOWNSTREAM...THE LOW-LEVEL WIND MAX
ON THE BACKSIDE WILL STRENGTHEN AND EXPAND. THAT WILL ACTUALLY
STRENGTHEN WINDS A BIT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 436 AM CST WED DEC 4 2013

COLD WIND CHILL VALUES ARE EXPECTED ACROSS PORTIONS OF THE
OUTLOOK AREA EACH MORNING THURSDAY THROUGH NEXT TUESDAY. THE
COLDEST WIND CHILL VALUES EACH MORNING...COLDER THAN 15 DEGREES
BELOW ZERO...WILL GENERALLY BE OBSERVED ACROSS PORTIONS OF SOUTH
CENTRAL NEBRASKA GENERALLY NORTH OF I-80.

A MID TO UPPER LEVEL LONG WAVE TROUGH AXIS IS EXPECTED TO EXTEND
FROM CENTRAL CANADA INTO THE WESTERN CONUS AT 12Z THURSDAY. THIS
INITIAL LONG WAVE TROUGH HOWEVER IS EXPECTED WEAKEN 12Z THURSDAY
THROUGH 12Z FRIDAY IN RESPONSE TO A SECONDARY LONG WAVE TROUGH
AXIS WHICH IS EXPECTED TO DEVELOP FARTHER WEST OVER THE CONUS
THROUGH 12Z SATURDAY. THIS SECONDARY LONG WAVE TROUGH IS THEN
EXPECTED TO MOVE EAST INTO THE ROCKY MOUNTAIN RANGE BY 12Z
SUNDAY...AND MORE INTO THE CENTRAL CONUS BY 12Z MONDAY. THE
TROUGH AXIS IS THEN  EXPECTED TO MOVE FARTHER EAST ACROSS THE
CONUS HEADING INTO TUESDAY. MID TO UPPER LEVEL JET ENERGY IS
EXPECTED TO EXTEND FROM THE SOUTHWESTERN CONUS...NORTHEAST INTO
THE CENTRAL PLAINS...AS WELL AS THE MID TO UPPER MISSISSIPPI
VALLEY AND GREAT LAKES REGION AT 12Z THURSDAY. THIS AXIS OF JET
ENERGY IS THEN EXPECTED TO SHIFT SOMEWHAT TO THE SOUTHEAST BY 12Z
FRIDAY SO THAT IT WILL BE POSITIONED MORE FROM THE SOUTHERN PLAINS
INTO THE MID MISSISSIPPI VALLEY...AND THEN THE NORTHEASTERN CONUS
AND SOUTHEASTERN CANADA. THE AXIS OF MID TO UPPER LEVEL JET
ENERGY SHOULD THEN REMAIN FAIRLY STATIONARY THROUGH 12Z SUNDAY.
THE ADVANCEMENT OF THE WESTERN CONUS LONG WAVE TROUGH TO THE EAST
HOWEVER...SHOULD THEN ALLOW THE AXIS OF MID TO UPPER LEVEL JET
ENERGY TO SHIFT MORE INTO THE EASTERN CONUS MONDAY INTO TUESDAY. A
PAIR OF CLOSED MID LEVEL LOW SHOULD BE NOTED OVER SOUTHERN CANADA
AT 12Z THURSDAY. THE FIRST MID LEVEL LOW IS EXPECTED OVER
SOUTHWESTERN ONTARIO...BUT IS EXPECTED TO QUICKLY MOVE OFF TO THE
NORTHEAST...INTO QUEBEC...BY 12Z FRIDAY. THE SECOND MID LEVEL LOW
IS ALSO EXPECTED TO WEAKEN AND EJECT EAST...LIKELY NEARING THE
GREAT LAKES REGION BY 12Z SATURDAY. AN AREA OF LOW BAROMETRIC
PRESSURE IS EXPECTED OVER THE GREAT LAKES REGION AT 12Z
THURSDAY...WITH A SURFACE RIDGE EXTENDING ACROSS MUCH OF THE
PLAINS. THIS SURFACE RIDGE IS EXPECTED TO PERSIST OVER OUR AREA
THROUGH 00Z SATURDAY...BEFORE MOVING EAST/NORTHEAST 00Z SATURDAY
THROUGH 00Z SUNDAY. THE APPROACH OF THE WESTERN CONUS LONG WAVE
TROUGH IS THEN EXPECTED TO PROMOTE AN AREA OF LOW BAROMETRIC
PRESSURE OVER THE SOUTHEASTERN CONUS BY 00Z MONDAY...WITH SURFACE
RIDGING EXPECTED TO ONCE AGAIN INFILTRATE OUR AREA BOTH MONDAY AND
TUESDAY. RESULTANT LOW LEVEL FLOW SHOULD START FROM THE
NORTH/NORTHWEST AT 12Z THURSDAY...BECOMING MORE EAST/SOUTHEASTERLY
FRIDAY NIGHT INTO SATURDAY...AND FINALLY NORTH/NORTHWESTERLY
SUNDAY ONWARD.

MID LEVEL THERMAL ADVECTION AHEAD OF THE INITIAL WESTERN CONUS
LONG WAVE TROUGH SHOULD BE SUFFICIENT FOR PRECIPITATION PRODUCTION
FROM THE SOUTHERN PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY
THURSDAY INTO THURSDAY NIGHT...BUT THIS AXIS OF THERMAL ADVECTION
SHOULD REMAIN WELL SOUTHEAST OF OUR AREA. THAT BEING SAID...THE
RIGHT-REAR QUADRANT OF A MID LEVEL JET STREAK...EMBEDDED WITHIN
THE AFOREMENTIONED MID TO UPPER LEVEL JET STREAM AXIS...COULD
BRING CHANCES FOR PRECIPITATION SOMEWHAT CLOSER TO OUR CWA. IT
DOES APPEAR THAT THE MAJORITY PRECIPITATION WHICH RESULTS FROM
THIS JET STREAK WILL ALSO REMAIN SOUTH/SOUTHEAST OF OUR
AREA...MORE INTO KANSAS...BUT THERE IS AN OUTSIDE
CHANCE...ESPECIALLY IF THIS MID LEVEL JET STREAK SHIFTS TO THE
NORTHWEST BY ~100 MILES...THAT LIGHT MEASURABLE PRECIPITATION
COULD BE REALIZED ACROSS OUR EXTREME SOUTH HEADING INTO THURSDAY
EVENING. GIVEN THIS...WENT AHEAD AND KEPT THE ~20% POP INHERITED
ACROSS OUR EXTREME SOUTH FOR THURSDAY EVENING. WITH THE MID TO
UPPER LEVEL JET AXIS SHIFTING TO THE SOUTHEAST...AND AN OVERALL
LACK IN OMEGA OTHERWISE EXPECTED...DRY CONDITIONS ARE FORECAST
ACROSS OUR AREA FRIDAY THROUGH MUCH OF SATURDAY. SATURDAY NIGHT
INTO SUNDAY...MID LEVEL THERMAL ADVECTION AHEAD OF THE APPROACHING
MID LEVEL LONG WAVE TROUGH AXIS...AS WELL AS DPVA AS THE MID LEVEL
TROUGH AXIS DRAWS NEAR THE AREA...SHOULD PROVIDE SUFFICIENT OMEGA
FOR PRECIPITATION PRODUCTION ACROSS OUR AREA. THIS IS A SOLUTION
SUPPORTED BY THE OPERATIONAL GFS AND EC. ALLBLEND RESPONDED BY
PRESENTING 40-50% POPS TO OUR AREA SATURDAY NIGHT AND SUNDAY.
THESE POPS WERE LEFT UNCHANGED FOR THE MOST PART. THERE COULD ALSO
BE SOME LINGERING PRECIPITATION SUNDAY NIGHT...BUT FOR THE MOST
PART DRY CONDITIONS ARE THEN FORECAST MONDAY AND TUESDAY.

WITH THE ARCTIC AIR MASS PERSISTING ACROSS THE AREA...THE LOWER
TROPOSPHERE WILL REMAIN COLD ENOUGH FOR SNOW PRODUCTION IN
ASSOCIATION WITH ALL POPS DURING THE LONG TERM FORECAST PERIOD.
PRECIPITATION RATES SHOULD REMAIN EXTREMELY LOW SHOULD
PRECIPITATION BE REALIZED ACROSS OUR EXTREME SOUTH HEADING INTO
THURSDAY EVENING. AS A RESULT...NOTHING MORE THAN 0.1" SNOWFALL
ACCUMULATION IS ANTICIPATED THURSDAY. A DIFFERENT STORY PRESENTS
ITSELF SATURDAY NIGHT INTO SUNDAY AS LOWER TO MID TROPOSPHERIC
MOISTURE INCREASES ACROSS THE REGION. ALLBLEND RESPONDED BY
PROVIDING 0.10-0.20" LIQUID PRECIPITATION WHICH...IF
REALIZED...WOULD RESULT IN ACCUMULATING SNOWFALL ACROSS THE AREA.
CERTAINLY SOMETHING TO MONITOR AS WE APPROACH THE WEEKEND.

LITTLE CHANGE IN THE LOW LEVEL AIR MASS WILL PRESENT PERSISTENTLY-
COLD TEMPERATURES TO THE AREA THROUGH THE LONG TERM FORECAST
PERIOD. HIGHS GENERALLY IN THE TEENS WILL ACCOMPANY LOWS GENERALLY
IN THE SINGLE DIGITS.

FINALLY...THE FORECAST TEMPERATURES...WORKING IN CONCERT WITH THE
LOW LEVEL WIND FIELD...WILL PROMOTE VERY LOW WIND CHILL VALUES
THURSDAY MORNING...AS WELL AS FRIDAY MORNING AND SATURDAY MORNING.
WILL CONTINUE TO MENTION THIS IN THE HWO.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1120 AM CST WED DEC 4 2013

KGRI WILL REMAIN UNDER THE INFLUENCE OF AN ARCTIC AIRMASS THROUGH
THE TAF PERIOD. HAVE MAINTAINED MVFR CIGS INTO THE OVERNIGHT
PERIOD...THEN SCATTERED CLOUDS BY THURSDAY MORNING BEHIND PASSAGE
OF MID LEVEL TROUGH AXIS. WINDS WILL REMAIN STEADY/GUSTY FM THE
NORTHWEST...WITH WIND SPEEDS DIMINISHING TO SOME DEGREE THURSDAY
MORNING.

&&

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

&&

$$

UPDATE...FAY
SHORT TERM...HALBLAUB
LONG TERM...BRYANT
AVIATION...FAY