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 282049
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
249 PM CST SUN DEC 28 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 249 PM CST SUN DEC 28 2014

MAP ANALYSIS INDICATES A WEAK UPPER TROPOSPHERIC LONG WAVE TROUGH
OVER THE CENTRAL CONUS...WITH QUASI-ZONAL TO SOUTHWESTERLY UPPER
TROPOSPHERIC FLOW OVER MUCH OF THE CENTRAL PLAINS AS A RESULT.
ENHANCED UPPER TROPOSPHERIC JET ENERGY EXTENDS FROM THE
NORTHWESTERN CONUS...SOUTHEAST INTO THE SOUTHERN PLAINS...AND THEN
NORTHEAST INTO THE GREAT LAKES REGION AND NORTHEASTERN CONUS.
UPPER TROPOSPHERIC FLOW OVER OUR AREA REMAINS FAIRLY WEAK
HOWEVER...ONLY MAXING OUT AT AROUND 50KTS NEAR 27000FT AGL PER 12Z
SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY ALSO
INDICATES THE AFOREMENTIONED LONG WAVE TROUGH AXIS ACROSS THE
CENTRAL CONUS...AS WELL AS AN UPPER TROPOSPHERIC SHORT WAVE OVER
MONTANA. AT THE SURFACE A WEAK AREA OF HIGH BAROMETRIC PRESSURE
EXISTS OVER THE SOUTHERN PLAINS...THUS RESULTING LIGHT
SOUTHWESTERLY FLOW ACROSS MUCH OF OUR AREA.

GUIDANCE FROM THE NAM...OPERATIONAL GFS AND EC ALL SUGGEST THE
UPPER TROPOSPHERIC LONG WAVE TROUGH AXIS WILL QUICKLY DEPART TO
THE EAST AND WEAKEN TONIGHT WHILE THE UPPER TROPOSPHERIC SHORT
WAVE...CURRENTLY OVER MONTANA...MOVES SOUTHEAST. AT THIS TIME IT
APPEARS THIS SHORT WAVE WILL NEAR OUR AREA TONIGHT BEFORE PUSHING
OVERHEAD AND CLEARING OUR AREA DURING THE DAY MONDAY. AT THE
SURFACE...A WEAK AREA OF LOW BAROMETRIC PRESSURE IS EXPECTED TO
DEVELOP OVER THE SOUTHERN PLAINS TONIGHT...AHEAD OF THE
APPROACHING SHORT WAVE...BEFORE MOVING SOUTH/SOUTHEAST DURING THE
DAY MONDAY. SO ALTHOUGH A SOUTHERLY COMPONENT TO THE BOUNDARY-
LAYER WIND FIELD WILL BE NOTED ACROSS MUCH OF OUR AREA TO START
THE FORECAST PERIOD...A NORTHERLY WIND WILL OVERTAKE THE ENTIRE
AREA DURING THE DAY MONDAY AS A BAROCLINIC ZONE CLEARS THE AREA
BEHIND THE LOW.

GUIDANCE CONTINUES TO SUGGEST DPVA AND TROPOSPHERIC
MOISTURE...AND TO A LESSER EXTEND UPPER TROPOSPHERIC THERMAL
ADVECTION...AHEAD OF THE APPROACHING SHORT WAVE WILL BE SUFFICIENT
FOR PRECIPTIATION PRODUCTION ACROSS MUCH OF OUR AREA STARTING
AFTER MIDNIGHT TONIGHT AND CONTINUING THROUGH THE DAY
MONDAY...BEFORE TAPERING OFF MONDAY NIGHT.

TAKING A BLEND OF THE NAM...OPERATIONAL GFS AND EC PROVIDES
LIQUID PRECIPITATION AMOUNTS OF 0.05-0.15" ACROSS THE CWA BETWEEN
TONIGHT AND MONDAY NIGHT...WITH THE HIGHEST AMOUNTS ACROSS OUR
WEST/ NORTHWEST IN ASSOCIATION WITH THE STRONGEST OMEGA. FORECAST
PROXIMITY SOUNDINGS FROM ACROSS THE CWA...PER THE NAM AND
OPERATIONAL GFS...SUGGEST THE LOWER TROPOSPHERE WILL REMAIN
SUPPORTIVE OF SNOW. A BLEND OF THE NAM AND OPERATIONAL GFS ALSO
SUGGESTS SNOW-WATER RATIOS WILL START IN THE 12-15:1 RANGE
TONIGHT...BUT WILL INCREASE INTO THE 15-20:1 RANGE MONDAY INTO
MONDAY NIGHT. TAKING THE AFOREMENTIONED LIQUID PRECIPTIATION
AMOUNTS AND SNOW-WATER RATIOS INTO CONSIDERATION SUGGESTS ~0.5" OF
SNOW COULD BE REALIZED ACROSS OUR NORTH BEFORE DAYBREAK
MONDAY...WITH 0.5- 1.0" ACROSS MUCH OF THE CWA DURING THE DAY
MONDAY...AND THEN AN ADDITIONAL 0.5-1.0" MONDAY EVENING. AS A
RESULT...STORM-TOTAL SNOW ACCUMULATION BETWEEN TONIGHT AND MONDAY
NIGHT IS CURRENTLY FORECAST IN THE 1-2 INCH RANGE...WITH LOCALIZED
THREE INCH AMOUNTS ACROSS OUR WEST/NORTHWEST.

IN ADDITION TO THE SNOWFALL...AN INCREASING BAROMETRIC PRESSURE
GRADIENT IS STILL EXPECTED TO PROVIDE A STIFF BOUNDARY-LAYER WIND
FIELD MONDAY INTO MONDAY NIGHT...WITH GUIDANCE SUGGESTING A
SUSTAINED WIND OF 15-20KTS WITH LOCALLY HIGHER GUSTS WILL LIKELY
RESULT. AS A RESULT...PERIODIC VISIBILITY IN BLOWING SNOW ALSO
REMAINS POSSIBLE ACROSS OUR AREA MONDAY INTO MONDAY EVENING.

GIVEN ALL THIS...CONTEMPLATED GOING WITH AN ADVISORY FOR PORTIONS
OF THE CWA. THAT SAID...SNOW ACCUMULATION IS EXPECTED TO REMAIN
UNDER THREE INCHES FOR THE MOST PART ACROSS THE CWA...AND THE
WIND...ALTHOUGH STIFF...IS NOT CURRENTLY EXPECTED CREATE
PERSISTENT VISIBILITY RESTRICTION AND DIFFICULT DRIVING
CONDITIONS. OBVIOUSLY CONDITIONS WILL NEED TO BE CLOSELY MONITORED
THROUGH THE NEXT 24-36 HOURS TO ENSURE THE BOUNDARY-LAYER WIND
FIELD IS NOT GOING TO BE ANY STRONGER THAN CURRENT FORECAST...AND
THAT SNOW ACCUMULATION WILL NOT BE MUCH HIGHER THAN CURRENTLY
FORECAST...BUT FOR NOW WILL HOLD OFF FROM ANY HEADLINES AND
CONTINUE TO MENTION SNOW ACCUMULATION AND PERIODIC VISIBILITY
RESTRICTION IN THE HWO.

GUIDANCE ALSO CONTINUES TO SUGGEST A SURGE OF ARCTIC AIR POST-
FROPA ON MONDAY WILL PROMOTE VERY COLD TEMPERATURE READINGS ACROSS
THE REGION. PORTIONS OF THE CWA...PARTICULARLY ACROSS THE
SOUTHEAST...WILL STILL HAVE AN OPPORTUNITY TO WARM INTO THE UPPER
20S ON MONDAY...BUT TEMPERATURES WILL LIKELY STRUGGLE OUT OF THE
TEENS ELSEWHERE. ON MONDAY NIGHT...GUIDANCE SUGGESTS LOWS WILL
PLUMMET INTO THE -10 TO 4 DEGREE RANGE ACROSS THE CWA. THESE
TEMPERATURE READINGS...ALONG WITH THE WIND...WILL LIKELY CREATE
APPARENT TEMPERATURE READINGS IN THE -10 TO -25 DEGREE RANGE
ACROSS MUCH OF THE CWA AND AS A RESULT...WILL CONTINUE TO MENTION
SUCH CONDITIONS IN THE HWO.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 249 PM CST SUN DEC28 2014

OVERALL THE LONG TERM IS COLD. FOCUS WILL BE ON THE UPCOMING COLD
WEATHER PATTERN AND THE NEXT CHANCE FOR PRECIPITATION TOWARDS THE
END OF NEXT WEEK.

IN THE UPPER LEVELS...A VERY POSITIVELY TILTED TROUGH WILL BE
EVIDENT OVER THE WEST COAST TO BEGIN THE LONG TERM...WHILE MOSTLY
ZONAL FLOW WILL BE REALIZED FOR THE REST OF THE CONUS. THE TROUGH
OVER THE WEST COAST DEVELOPS A CUT OFF LOW WHICH BECOMES STAGNANT
OVER THE WEST COAST/DESERT SOUTHWEST FOR AT LEAST 72 HOURS. THERE
IS DECENT AGREEMENT BETWEEN THE GFS AND ECMWF AS WELL FOR THIS
FEATURE. THAT BEING SAID...CONFIDENCE IS HIGH IN A DRY FORECAST UP
UNTIL FRIDAY. DURING THIS TIME...THE CUT OFF LOW WILL RESULT IN
NORTHWESTERLY FLOW OVER THE OUTLOOK AREA...WHICH WILL USHER IN
PLENTY OF COLD AIR OVER THE CENTRAL PLAINS.

BEGINNING ON TUESDAY AFTERNOON...WE GET INTO A RATHER COLD
PATTERN WITH TEMPERATURES WELL BELOW NORMAL FOR THIS TIME OF YEAR.
ONE LOOK AT 850 MB TEMPERATURES AND YOU WILL KNOW THIS IS GOING TO
BE A COLD 24 HOUR PERIOD. HIGHS ARE GOING TO STRUGGLE TO GET ABOVE
ZERO DEGREES FAHRENHEIT TUESDAY AFTERNOON. TO PUT THIS INTO
PERSPECTIVE...THE TRI-CITES AVERAGE ABOUT 35 DEGREES FOR A HIGH
TOWARDS THE END OF DECEMBER...SO WE WILL BE ABOUT 30 DEGREES BELOW
NORMAL FOR THIS TIME OF YEAR. LOWS TUESDAY NIGHT WILL BE BELOW
ZERO...WITH ACTUAL AIR TEMPERATURES RANGING FROM ORD NEBRASKA AT
NEGATIVE 13 DEGREES...TO ABOUT NEGATIVE 3 DEGREES FOR BELOIT
KANSAS. THESE TEMPERATURES COUPLED WITH WIND SPEEDS WILL RESULT IN
WIND CHILL READINGS MINUS 20 TO MINUS 25 BELOW ZERO FOR AREAS
NORTH OF INTERSTATE 80. I WOULD NOT BE SURPRISED IF A WIND CHILL
ADVISORY IS ISSUED WITHIN THE NEXT 24 TO 36 HOURS. WE ARE
EXPECTING SNOW MONDAY INTO MONDAY NIGHT...SO DEPENDING ON HOW MUCH
SNOW COVER WE HAVE...WE COULD SEE THESE TEMPERATURES FLUCTUATE
SOMEWHAT OVER THE NEXT 48 HOURS. STAY TUNED TO SEE JUST HOW COLD
WE GET TO START NEXT WEEK. WE COULD SEE SOME LINGERING FLURRIES
AROUND AREAS TO OUR SOUTHWEST TUESDAY MORNING/AFTERNOON...AND
OPTED TO MENTION THIS THROUGH TUESDAY MORNING.

TEMPERATURES FOR THE REST OF THE WEEK: WEDNESDAY INTO THURSDAY WE
GET INTO A WARMING TREND. I USE THE TERM WARMING LOOSELY BECAUSE
WE ARE MOST LIKELY GOING TO STAY BELOW FREEZING FOR A MAJORITY OF
THE OUTLOOK AREA. THURSDAY AFTERNOON MAY GET TO AROUND FREEZING
FOR A FEW AREAS...HOWEVER...I WOULD NOT COUNT ON IT AS THE GENERAL
TREND IN TEMPERATURES AS BEEN DECREASING OVER THE LAST SEVERAL
DAYS. FRIDAY LOOKS TO BE OUR BEST CHANCE AT GETTING ABOVE
FREEZING...MAINLY FOR PLACES SOUTH OF INTERSTATE 80...ESPECIALLY
OUR COUNTIES IN NORTH CENTRAL KANSAS. OTHERWISE...WE GO BACK TO
TEMPERATURES FALLING THROUGH THE END OF THE WEEK.

AS WE GET INTO FRIDAY...THE PICTURE BECOMES LESS CLEAR AND
CONFIDENCE DWINDLES. THERE ARE NOTICEABLE DISCREPANCIES BETWEEN
THE GFS AND ECMWF. THE GFS IS MUCH MORE PROGRESSIVE WITH EJECTING
THAT UPPER LEVEL LOW INTO THE PLAINS. THIS ALSO RESULTS IN MAJOR
DIFFERENCES IN THE QPF FIELD ACROSS THE REGION...WHERE THE ECMWF
IS BASICALLY DRY AND THE GFS HAS NEARLY 0.40 INCHES OF QPF.
LOOKING AT SOUNDINGS...THE GFS WOULD SUGGEST THERE COULD BE A MIX
PRECIPITATION EVENT...OR WORSE CASE SCENARIO FREEZING
DRIZZLE/FREEZING RAIN FOR AREAS ACROSS OUR SOUTH AND SOUTHEAST.
THIS IS WAY TOO FAR OUT IN THE FORECAST TO INTRODUCE THESE TYPES
OF PRECIPITATION...AND CONFIDENCE TO LEAVE PRECIP TYPE AS SNOW IS
THE BEST OPTION AT THE MOMENT. WE WILL HAVE TO SEE IF THE MODELS
CAN COME TO AN AGREEMENT OVER THE NEXT FEW DAYS.

SUNDAY IS HINTING AT AN OFF CHANCE FOR SNOW FOR AREAS ACROSS OUR
NORTH...BUT THIS WILL BE ANOTHER LOW CONFIDENCE EVENT DUE
PRIMARILY TO DIFFERENT SOLUTIONS IN MODELS DURING THE EXTENDED
PERIODS. GOING TO LEAVE THE 20 POPS NORTH OF INTERSTATE 80 FOR
NOW. GFS IS SUGGESTING AROUND A QUARTER INCH OF QPF VERSUS ZERO
QPF FOR THE ECMWF. WE CANNOT HANG OUR HAT ON ANY SOLUTION UNTIL WE
GET AN IDEA OF UPPER LEVEL LOW TRACK TOWARDS THE END OF THE WEEK.

&&

.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1123 PM CST SAT DEC 27 2014

WRF CONDITIONS ARE FORECAST THROUGHOUT THE PERIOD. LATE IN THE
PERIOD MID/HIGH LEVEL CLOUDS WILL THICKEN. SOME CONCERN ABOUT
LOWER VISIBILITIES LATE THIS EVENING /LAST 3-4 HOURS OF FORECAST/
WITH A DEVELOPING NORTHEAST WIND AND SOME MELT...BUT WAIN/T
CONFIDENT ENOUGH TO PUT IT IN THE FORECAST AT THIS TIME.


&&

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

$$

SHORT TERM...BRYANT
LONG TERM...GUERRERO
AVIATION...BRYANT



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