Area Forecast Discussion
Issued by NWS Hastings, NE

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KGID 231746
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1146 AM CST SUN NOV 23 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CST SUN NOV 23 2014

THE NICE WEATHER WAS GREAT WHILE IT LASTED...BUT A STRONG COLD
FRONT WILL RACE SOUTHEAST ACROSS THE FORECAST AREA THIS MORNING
MAKING FOR A WINDY...WET...AND COLDER DAY. THE PRIMARY FORECAST
CONCERNS WILL CENTER AROUND THE STRONG NORTHWEST WINDS...WHICH
COULD BE AROUND 30 MPH GUSTING TO OVER 40 MPH...ALONG WITH THE
STRONG LIKELIHOOD OF RAIN. IN ADDITION...THERE IS AN OUTSIDE
CHANCE THAT SOME SNOW MAY MIX IN PRIOR TO THE PRECIPITATION COMING
TO AND END. FURTHERMORE...HIGH TEMPERATURES TODAY LIKELY ALREADY
OCCURRED AT MIDNIGHT WITH STEADY TO FALLING TEMPERATURES EXPECTED
FOR THE REMAINDER OF THE DAY BEHIND THE COLD FRONT.

TODAY...
THE WIND...THE COLD FRONT WILL ENTER OUR NORTHWESTERN ZONES (ORD
TO LEXINGTON) BY AROUND 5 TO 6 AM...PASS THROUGH THE TRI- CITIES
BY 8 OR 9 AM...AND EXIT OUR SOUTHEASTERN ZONES (BELOIT TO HEBRON)
BY 11 AM. THE WIND WILL STEADILY INCREASE BEHIND THE FRONT AS THE
PRESSURE GRADIENT TIGHTENS. THE STRONGEST NORTHWEST WINDS OF
AROUND 30 MPH GUSTING TO 40 MPH CAN BE EXPECTED BETWEEN NOON AND 5
PM.

TEMPERATURES...THE TEMPERATURES AT 4 AM WERE STILL 50F OR HIGHER
ALONG AND EAST OF HWY 281 WITH MOIST 50 DEGREE DEWPOINTS.
HOWEVER...THIS WILL QUICKLY CHANGE AS THE FRONT SLIDES THROUGH.
DEWPOINTS WILL PLUMMET AS THE FRONT PASSES THROUGH...BUT STRONG
MIXING RIGHT BEHIND THE FRONT MAY SLOW THE FALL IN AIR
TEMPERATURES. IT IS ALSO POSSIBLE THAT IN SOME AREAS TEMPERATURES
MIGHT ACTUALLY CLIMB A FEW DEGREES RIGHT BEHIND THE FRONT DUE TO
MIXING...BUT OVERALL EXPECT TEMPERATURES WILL START TO GRADUALLY
FALL OFF AND THEN HOLD FAIRLY STEADY THROUGH THE AFTERNOON.

PRECIPITATION...DECIDED TO INCREASE PRECIPITATION CHANCES FOR THE
EASTERN 2/3RDS OF THE FORECAST AREA WHERE RAIN IS LIKELY. THERE IS
GREAT FORECAST MODEL AGREEMENT THAT A FRONTOGENETIC BAND OF
PRECIPITATION WILL DEVELOP OVER OUR WESTERN FORECAST AREA
SOMEWHERE WEST OF THE TRI-CITES BETWEEN 7-9AM AND THEN SLIDE
EASTWARD INCREASING IN STRENGTH DURING THE LATE MORNING/EARLY
AFTERNOON HOURS. THE LIFT IS GOOD AND WE COLD SEE MODERATE RAIN
WHILE THE BAND COMES THROUGH...BUT IT SHOULD NOT LAST TOO
LONG...GENERALLY BETWEEN 2 TO 3 HOURS. THE TEMPERATURES ALOFT
AT AND ABOVE 850MB ARE COLD ENOUGH FOR SNOW. HOWEVER...MOST
FORECAST MODELS PUT OUR SFC TEMPERATURES IN THE 38 TO 43F RANGE
WHILE THE PRECIPITATION IS PASSING THROUGH WITH DEWPOINTS STARTING
IN THE MID 30S AND FALLING TO PERHAPS THE UPPER 20S. OVERALL...IT
SEEMS LIKELY THAT IT WILL BE TOO WARM AT THE SFC FOR SNOW. WHILE
RAIN IS LIKELY...WILL INCLUDE JUST A SLIGHT CHANCE OF SNOW ON THE
BACK SIDE OF THE PRECIPITATION SHIELD. EVEN IF SOME SNOW MIXES IN
SFC TEMPERATURES WOULD BE TOO WARM FOR ACCUMULATION.

TONIGHT...THE FRONTOGENETIC WAVE RESPONSIBLE FOR OUR PRECIPITATION
WILL HAVE PASSED EAST OF OUR FORECAST AREA. HOWEVER...A SECOND
LOBE OF VORTICITY WILL ROTATE DOWN INTO OUR FORECAST AREA AFTER
MIDNIGHT AND RESULT IN INCREASING CLOUDS AND PERHAPS SOME LIGHT
FLURRIES...ESPECIALLY ACROSS THE NORTHEASTERN HALF OF THE FORECAST
AREA. TEMPERATURES WILL CONTINUE TO FALL BEHIND THE COLD FRONT
MAKING FOR A COLD NIGHT WITH EVERYONE FALLING BACK BELOW FREEZING.
IN ADDITION...THE WIND WILL DIE DOWN SOME OVERNIGHT...BUT SHOULD
STILL BE RATHER BRISK AT AROUND 20 MPH GUSTING TO 30 MPH AT TIMES.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM CST SUN NOV 23 2014

ALOFT: NONE OF THE FCST PROBLEMS FROM 24 HRS AGO HAVE BEEN RESOLVED.
THERE IS STILL CONSIDERABLE UNCERTAINTY IN HOW THE MODELS HANDLE THE
SPLIT FLOW AROUND THE DIFLUENT BLOCKING HIGH OVER THE E PAC AND AK
THIS WEEK. WHAT WE DO KNOW IS AT LEAST MODERATELY AMPLIFIED NW FLOW
WILL REMAIN IN PLACE THRU THU. WHAT HAPPENS THEREAFTER IS UP FOR
GRABS. DOES THE FLOW OVER N AMERICA REMAIN HIGHLY AMPLIFIED AND
COLDER WITH A BROAD TROF E OF THE ROCKIES? OR DOES A SUBSTANTIAL
WARM-UP OCCUR WITH A BROAD QUASI-ZONAL RIDGE? THE UKMET/GEM ARE
SOLIDLY IN THE COLDER MORE AMPLIFIED CAMP. THE PAST SEVERAL GFS/EC
RUNS CAN`T DECIDE WHICH.

REVIEWED THE 512Z EXTENDED FCST DISCUSSION. WPC PREFERENCE WAS FOR
THE EC ENSEMBLE MEAN AND WE HAVE NO REASON TO DISAGREE. THE 12Z
OPERATIONAL EC RUN WAS IN EXCELLENT AGREEMENT. THE 00Z EC CAME IN
BACK IN THE COLDER CAMP.

THE NEWLY ESTABLISHED LONGWAVE TROF AXIS WILL BE E OF THE FCST AREA
BY DAYBREAK MON. THE NEXT SHORTWAVE TROF WILL MOVE THRU MON NIGHT
FOLLOWED BY ANOTHER TUE NIGHT. QUIET NW FLOW WED GRADUALLY
TRANSITIONS TO WNW FLOW THU-SAT WITH DECREASING AMPLITUDE.

SURFACE: A SECONDARY COLD FRONT WILL EXIT THE FCST AREA MON MORNING
WITH WRN USA HIGH PRES BUILDING IN BRIEFLY MON NIGHT. A WARM FRONT
WILL MOVE THRU TUE AHEAD OF AN ALBERTA CLIPPER THAT DIVES INTO ND.
ITS ASSOCIATED COLD FRONT WILL SLIDE THRU LATE TUE NIGHT WITH
CANADIAN HIGH PRES BUILDING IN BEHIND WED. THIS HIGH WILL SLOWLY
SETTLE OVER THE NRN PLAINS THXGVG DAY AND THEN BE REINFORCED BY
ANOTHER CANADIAN HIGH SLIDING DOWN THE FRONT RANGE FRI. THIS HIGH
WILL MOVE E OF THE REGION SAT. THEN EVEN THE 12Z/00Z EC DISAGREE ON
WHAT HAPPENS SUN. DOES ANOTHER REINFORCING COLD FRONT MOVE THRU OR
DOES A WARM FRONT MOVE THRU?

06Z-12Z/WED THE 00Z GFS IS AN OUTLIER...S OF THE BEST MODEL
CLUSTERING WHICH TAKES THE CLIPPER THRU THE DAKOTAS INTO MN BY 12Z.

FCST CONFIDENCE: MEDIUM MON-WED THEN LOW THU-SAT.

TEMPS: INTERNAL VERIFICATION INDICATES WE HAVE BEEN RUNNING TOO COOL
WITH OUR HIGHS FOR AT LEAST THE PAST 2 WEEKS. SO USED BIAS CORRECTED
TEMPS FOR MON-TUE WHICH RAISED HIGH TEMPS ABOVE THE PREVIOUS FCST.

THE DAILY DETAILS...

MON: ANY LEFTOVER EARLY MORNING FLURRIES DEPART FROM THE TRI-CITIES
N AND E. ASSOCIATED CLOUDS WILL CLEAR AS WELL...BUT THEN INCREASING
MULTI-LAYERED MID-HIGH CLOUDS IN THE AFTERNOON AHEAD OF THE NEXT
TROF. WINDY IN CAA WITH NW WINDS GUSTING 35-45 MPH N OF HWY 6.

MON NIGHT: SHORTWAVE TROF OF LITTLE CONSEQUENCE OTHER THAN CLOUDS.

TUE: PROBABLY A FAIR AMOUNT OF SUN TO START...BUT INCREASING WARM
FRONTAL CLOUDS. IF THE EC/GFS CROSS SECTIONS ARE CORRECT...THE FCST
MIGHT NOT BE CLOUDY ENOUGH.

TUE NIGHT: LOOKS LIKE A FAIRLY MILD NIGHT IN THE WARM SECTOR...UNTIL
THE COLD FRONTAL PASSAGE LATE. CAN`T RULE OUT SOME SPRINKLES BUT
IT`S NOT IN THE FCST YET. WE COULD SEE A NARROW ARC OF R/S SHWRS
ACCOMPANY THE FRONT...BUT NOT ALL MODELS HAVE IT. FOR NOW FOLLOWED
THE HINTS FROM THE 12Z/00Z EC AND INCLUDED A SLGT CHANCE OF R/S.
THERE IS DISAGREEMENT ON FCST TEMP PROFILES. IF I HAD TO CHOOSE I`D
SAY THIS ENDS UP SPRINKLES OR A BRIEF RAIN SHWR.

WED: PROBABLY M/CLOUDY WITH PLENTY OF MULTI-LAYERED MID-HIGH CLOUDS
WITH THE JET AXIS OVERHEAD. ONE THING IS CERTAIN...THIS BUSIEST
TRAVEL DAY OF THE YEAR WAS LOOKING A MUCH NASTIER A FEW DAYS AGO.

WED NIGHT INTO THU AM: MULTIPLE MODELS ARE SUGGESTING A TOUCH OF
LIGHT SNOW N OF I-80. THIS WILL NEED TO BE WATCHED. CONFIDENCE IS
NOT HIGH ENOUGH TO INCLUDE IN THE FCST YET.

THXGVG DAY-SAT: P-M/CLOUDY AND COLDER. CAN`T RULE OUT A FEW FLURRIES
OR SKIFFS OF LIGHT SNOW.

4-5 DAYS AGO WE WERE SEEING A STRONG COLD SIGNAL IN THE EC 2M TEMPS
WITH SEVERAL DAYS OF MUCH COLDER THAN NORMAL HIGHS IN THE 20S. IT
THEN BACKED OFF...JUST LEAVING ONE DAY OF BITTER COLD ON THXGVG DAY.
NOW THE LAST 2 RUNS ARE BACK TO MULTIPLE DAYS OF COLD THU-SAT WITH
ONLY SLOW RECOVERY THEREAFTER.

WE CONT TO SEE SIGNS OF A SUBSTANTIAL CHANGE IN THE PATTERN AND A
BREAK FROM MID-WINTER COLD IN THE BEGINNING OF DEC. HOWEVER...IT
REMAINS TO BE SEEN IF WE CAN GET ANY MEANINGFUL PRECIP.

&&

.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1143 AM CST SUN NOV 23 2014

THE BAND OF RAIN HAS SHIFTED EAST OF THE TERMINALS AND
PREDOMINATELY DRY WEATHER IS FORECAST THE NEXT 24 HOURS. THE MAIN
CONCERN FOR THE TAF PERIOD IS STRONG AND GUSTY NW WINDS WHICH WILL
REMAIN STRONG THRU TONIGHT AND INTO MONDAY MORNING WITH THE
PASSAGE OF A SECONDARY COLD FRONT. WIND GUSTS AROUND 30KTS ARE
POSSIBLE BEFORE THE GRADIENT RELAXES MID DAY ON MONDAY. WE COULD
SEE CLOUDS SCATTER FOR A TIME BUT HAVE HELD ONTO VFR CIGS. CIGS
COULD APPROACH MVFR LATE TONIGHT/TOWARD MONDAY.

&&

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

$$

SHORT TERM...WESELY
LONG TERM...HALBLAUB
AVIATION...FAY



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.