Area Forecast Discussion
Issued by NWS Hastings, NE

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FXUS63 KGID 292212
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
412 PM CST THU JAN 29 2015

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 412 PM CST THU JAN 29 2015

THE SHORT TERM PERIODS REMAIN QUIET AND DRY...WITH THE WEATHER
TURNING MORE ACTIVE OVER THE WEEKEND. THE PATTERN ALOFT FEATURED
NORTHWEST FLOW ACROSS THE CENTRAL PLAINS...RIDGING OVER THE ROCKIES
AND A TROUGH MOVING ONSHORE ALONG THE WEST COAST.  AT THE
SURFACE...A 1034MB SURFACE HIGH WAS BUILDING SOUTH FROM THE DAKOTAS
BEHIND A COLD FRONT WHICH MOVED THRU LAST NIGHT.  WINDS REMAIN
STEADY FROM THE NORTHWEST EARLY THIS AFTN BUT AS THE GRADIENT
CONTINUES TO RELAX WITH THE BUILDING RIDGE...WIND SPEEDS WILL
DIMINISH.

IN THE COLDER AIRMASS AND WITH GOOD RADIATIONAL CONDITIONS
OVERNIGHT...WE ARE LOOKING FOR CHILLY OVERNIGHT LOW TEMPERATURE
READINGS IN THE TEENS AND 20S.  THESE TEMPS ARE ACTUALLY FAIRLY
CLOSE OR SLIGHTLY ABOVE NORMAL LOWS FOR THIS TIME OF YEAR.

AS THE SURFACE RIDGE AXIS SHIFTS EASTWARD TONIGHT...RETURN FLOW OF
SOUTHERLY WINDS SET UP W/E EARLY FRIDAY.  A WARMER AIRMASS WILL
ADVECT IN DURING THE DAY AND SOUTHERLY WINDS WILL BE ON THE INCREASE
DURING THE AFTERNOON HOURS.  TEMPS ARE TRICKY DUE TO THE WARMER
AIRMASS VS INCREASING CLOUD COVER DURING THE AFTN WITH THE WESTERN
SYSTEM MOVING FURTHER INLAND IN THE SW CONUS.  HAVE RAISED TEMPS
ONLY SLIGHTLY AS CONFIDENCE IS NOT HIGH ON HOW MANY AREAS WILL REACH
THE 50S...BUT THE POTENTIAL IS THERE FOR WARMER READINGS IF CLOUD
COVER IS NOT AS THICK OR IF WE MIX DEEPER THAN WHAT CURRENT MODEL
FORECAST SOUNDINGS INDICATE.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 412 PM CST THU JAN 29 2015

RIGHT OFF THE TOP...THE VAST MAJORITY OF FORECAST FOCUS WAS SPENT
ON THE PRECIPITATION/SNOWFALL/TEMPERATURE TRENDS FROM FRIDAY NIGHT
THROUGH SUNDAY MORNING. UNFORTUNATELY...FOR ONLY BEING 2-3 DAYS
AWAY...THIS WEEKEND PRECIP EVENT IS STILL CARRYING A HIGH DEGREE
OF UNCERTAINTY. HOWEVER...BASED ON THE OVERALL TRENDS DURING THE
PAST 24 HOURS...WE CAN AT LEAST SAY THAT THE POTENTIAL FOR AT
LEAST LIGHT ACCUMULATING SNOW HAS GONE UP FOR THE MAJORITY OF THE
CWA. SEE BELOW FOR MORE DETAILS...BUT VERY GENERALLY THE LATEST
"OFFICIAL" SNOWFALL FORECAST NOW CALLS FOR 1-2 INCHES OF FAIRLY
SLUSHY ACCUMULATION IN MOST AREAS...WITH EASTERN COUNTIES SLIGHTLY
FAVORED TOWARD THE HIGHER END OF THIS RANGE AND WESTERN COUNTIES
TOWARD THE LOW END. HOPEFULLY THESE NEXT 24 HOURS PAINT A MORE
CONSISTENT SCENARIO IN THE MODEL WORLD...SO THAT WE CAN HAVE MORE
CONFIDENCE IN THE DETAILS BY THE TIME FRIDAY AFTERNOON ARRIVES.
ALAS...WE ARE JUST NOT TO THAT POINT YET...AS THIS ULTIMATELY
HINGES ON A COMPLEX INTERACTION BETWEEN SOUTHERN AND NORTHERN
STREAM ENERGY. PROBABLY THE MOST BASIC/PARAMOUNT UNCERTAINTY
REGARDING SNOW ACCUMULATION AT THIS TIME IS:

- HOW WILL THE BATTLE BETWEEN THE SUB-FREEZING TEMPS SLIGHTLY
ABOVE THE SURFACE PLAY OUT WITH THE NEAR-TO-ABOVE FREEZING SURFACE
TEMPS FORECAST DURING THE DAY ON SATURDAY? IF THE WARMER LOW-
LEVELS WIN OUT...IT MAY BE UNTIL SATURDAY EVENING THAT ANY
NOTICEABLE ACCUMULATION TAKES PLACE.

FOR NOW THOUGH...UNLESS SNOW AMOUNTS TREND UPWARD AND/OR THIS
SYSTEM ENDS UP THROWING A CURVEBALL SUCH AS FREEZING DRIZZLE INTO
THE MIX...AMOUNTS DO NOT APPEAR WORTHY OF A WINTER WEATHER
ADVISORY...AT LEAST FOR THE MAJORITY OF THE AREA. ALTHOUGH STEADY
NORTH WIND AROUND 20 MPH WITH HIGHER GUSTS WILL BE IN PLACE
ESPECIALLY SATURDAY NIGHT INTO SUNDAY...THE FAIRLY WET/SLUSHY
NATURE OF SNOW SHOULD MINIMIZE ANY BLOWING/DRIFTING CONCERNS. OF
COURSE ON A POSITIVE NOTE...THIS EVENT WILL HOPEFULLY PROVIDE SOME
MUCH-NEEDED LIQUID EQUIVALENT ON THE ORDER OF GENERALLY O.10 TO
0.30 INCH TO MANY PLACES.

BESIDES THE WEEKEND PRECIPITATION-MAKER...THE VAST MAJORITY OF THE
SUNDAY AFTERNOON-THURSDAY TIME FRAME REMAINS VOID OF ANY
PRECIP CHANCES...WITH THE CONTINUING SOLE EXCEPTION OF A LOW-
CONFIDENCE SLIGHT CHANCE OF RAIN/SNOW FOR TUESDAY DAYTIME WITHIN
MAINLY THE NORTHEAST 1/2 OF THE CWA. THERE ARE AT LEAST SOME HINTS
FROM THE LATEST ECMWF/GFS/GEM THAT SLIGHT CHANCES OF PRECIP MAY
EVENTUALLY BE WARRANTED FOR MONDAY NIGHT AND TUESDAY NIGHT AS
WELL...BUT FOR NOW THE DEFAULT MULTI-MODEL BLEND USED TO
INITIALIZE THE DAY 4-7 FORECAST ONLY PEGGED TUESDAY DAYTIME.

TEMPERATURE-WISE...WITH THE BLATANT EXCEPTION OF SUNDAY (WHICH
WILL BE THE COLDEST DAY SEEN AROUND HERE IN 4 WEEKS!)...THE
OVERALL THEME THROUGH THIS 6-DAY PERIOD IS THAT READINGS SHOULD
GENERALLY AVERAGE FAIRLY CLOSE TO THE SEASONAL NORM...WITH HIGHS
ON MOST DAYS SOMEWHERE IN THE LOW 30S TO MID 40S RANGE...WITH SOME
EXCEPTIONS ON EITHER SIDE OF THIS RANGE. MOST NOTABLY...HIGHS FOR
MONDAY WERE RAISED 4-5 DEGREES FROM PREVIOUS FORECAST...AS MONDAY
HAS NOW TRENDED ROUGHLY 12 DEGREES MILDER THAN IT APPEARED 36
HOURS AGO...ALTHOUGH OF COURSE ANY APPRECIABLE NEW SNOW COVER
COULD MODULATE THIS A BIT. GETTING BACK TO SUNDAY...THIS LOOKS TO
BE A LEGITIMATELY COLD DAY WITH HIGHS ONLY IN THE 20S COMBINING
WITH SUSTAINED NORTH WIND AROUND 20 MPH TO BRING WIND CHILL VALUES
GENERALLY DOWN INTO THE 5-15 RANGE.

NOW FOR ADDITIONAL METEOROLOGICAL/FORECAST DETAILS IN 12-24 HOURS
BLOCKS...

FRIDAY EVENING/NIGHT...AT LEAST THROUGH SUNRISE...THE PREDOMINANT
IF NOT ONLY PRECIPITATION TYPE IS EXPECTED TO BE PLAIN LIQUID
RAIN...AS BROAD ISENTROPIC LIFT OVERSPREADS THE AREA FROM
SOUTHWEST-TO-NORTHEAST...ALONG WITH A WEAK WAVE EMANATING OUT OF
LARGE/SLOW MOVING MID-UPPER LOW PRESSURE SYSTEM CENTERED OVER THE
DESERT SOUTHWEST/BAJA AREA. WITH SOUTHERLY SURFACE BREEZES AND
PLENTIFUL CLOUD COVER...LOW TEMPS SHOULD REALLY STRUGGLE TO DROP
BELOW FREEZING MOST AREAS...BUT IT COULD BE A CLOSE CALL. THE BEST
CHANCES FOR LIGHT MEASURABLE RAIN THROUGH THE NIGHT SHOULD FOCUS
ACROSS THE SOUTHERN HALF OF THE CWA...AND THE HIGHEST 60-70 POPS
WERE FOCUSED OVER KS ZONES. BASED ON TEMPS ALOFT...A BIT OF SNOW
COULD TRY MIXING IN POST-MIDNIGHT...BUT AT LEAST FOR NOW HAVE
REALLY TRIED TO DOWNPLAY SNOW ACCUMULATION FOR FRIDAY NIGHT.

SATURDAY DAYTIME-NIGHT...UNLESS LATER SHIFTS END UP EXTENDING
MEASURABLE SNOW CHANCES PAST SUNRISE SUNDAY (WHICH IS
POSSIBLE)...THIS IS THE MAIN 24 HOURS OF CONCERN. COMPARED TO
YESTERDAY...THERE APPEARS TO BE MORE FOCUSED MID LEVEL
CONVERGENCE/FRONTOGENESIS OVER AND NEAR THE CWA AND NO SHORTAGE OF
UPPER JET DYNAMICS AS A NORTHERN STREAM DISTURBANCE HEADS INTO THE
CENTRAL PLAINS FROM THE NORTHWEST. ALTHOUGH THE COLDER/DRIER LOW
LEVEL FLOW ASSOCIATED WITH THIS DISTURBANCE COULD ULTIMATELY SET
UP A "WALL" OF SORTS TO THE NORTH EDGE OF PRECIP
POTENTIAL...EXPECT A FAIRLY BROAD AREA OF LIGHT RAIN WILL MIX
WITH...AND EVENTUALLY CHANGE OVER TO SNOW OVER THE COURSE OF THESE
24 HOURS. ITS A TOUGH CALL HOW MUCH SLUSHY SNOW MIGHT ACCUMULATE
DURING THE DAY...AS HIGH TEMPS ARE FORECAST INTO THE MID 30S MOST
AREAS TO NEAR-40 FAR SOUTH...BUT ITS POSSIBLE THE COOLING ALOFT
COULD OVERCOME THIS TO SOME DEGREE. NEAR AND AFTER SUNSET INTO THE
NIGHT WOULD THEN BE THE MAIN WINDOW OF OPPORTUNITY FOR SNOW
ACCUMULATION THAT HAS A BETTER CHANCE OF STICKING...AS COLDER AIR
POURS IN.

SUNDAY DAYTIME-SUNDAY NIGHT...WHILE THINGS SHOULD LARGELY BE
WINDING DOWN BY SUNRISE AS THE NORTHERN STREAM WAVE PASSES BY AND
COLD LOW-LEVEL HIGH PRESSURE NOSES SOUTHWARD...FELT BETTER AT
LEAST INTRODUCING A CHANCE OF NON-MEASURABLE FLURRIES TO SUNDAY
MORNING TO ACCOUNT FOR POSSIBLE LINGERING SNOW AND/OR A SLOWER
SYSTEM DEPARTURE. THIS WILL NEED WATCHED CLOSELY. AT OUTLINED
ABOVE...THIS IS ALMOST ASSUREDLY THE COLDEST DAY OF THE LONG TERM.

MONDAY DAYTIME-NIGHT...BROAD NORTHWEST FLOW ALOFT AND A
SURPRISINGLY QUICK TURN AROUND OF LOW LEVEL FLOW TO SOUTHERLY IS
EXPECTED TO RESULT IN AT LEAST A 10-DEGREE BOOST IN HIGHS VERSUS
SUNDAY. HAVE KEPT IT DRY FOR NOW...BUT MONDAY NIGHT BEARS
WATCHING.

TUESDAY DAYTIME-NIGHT...MAINTAINED THE SLIGHT POPS FOR RAIN/SNOW
IN NORTHEAST ZONES...BUT CONFIDENCE IS LOW. HIGHS AIMED MID 30S
NORTH TO NEAR 50 SOUTH.

WEDNESDAY DAYTIME-NIGHT...DRY FORECAST CONTINUES. HIGH TEMPS WERE
LOWERED 2-4 DEGREES AND MAYBE NOT ENOUGH AS THE ECMWF SHOWS
ANOTHER COLD FRONT TRACKING THROUGH...BUT HAVE ALL AREAS SOMEWHERE
IN THE 30S.

THURSDAY DAYTIME...FOR BEING A WEEK OUT...CONFIDENCE REASONABLY
HIGH IN DRY CONDITIONS. HIGHS VERY PRELIMINARILY AIMED INTO THE
LOW 30S NORTHEAST TO MID 40S SOUTHWEST RANGE.

&&

.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1059 AM CST THU JAN 29 2015

GUSTY NORTHWEST WINDS WILL SUBSIDE DURING THE AFTERNOON HOURS AS A
SURFACE HIGH PRESSURE RIDGE BUILDS SOUTH ONTO THE CENTRAL PLAINS.
WINDS WILL BECOME LIGHT AND VARIABLE TONIGHT UNDER THE INFLUENCE
OF THE RIDGE AND THEN WINDS WILL TRANSITION SOUTHERLY ON FRIDAY IN
RETURN FLOW. CLOUDS WILL SCATTER THIS AFTN THEN LIMITED CLOUD
COVER IS EXPECTED THRU 18Z FRI.

&&

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

$$

SHORT TERM...FAY
LONG TERM...PFANNKUCH
AVIATION...FAY



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