Area Forecast Discussion
Issued by NWS Hastings, NE

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FXUS63 KGID 062156
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
356 PM CST SAT FEB 6 2016

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 356 PM CST SAT FEB 6 2016

ALTHOUGH THE MAJORITY (IF NOT THE ENTIRE) CWA WILL GET THROUGH
SUNDAY AFTERNOON WITHOUT SEEING ANY SNOW...THINGS DEFINITELY
REMAIN ON TRACK TO TAKE AN UNPLEASANT TURN BY SUNDAY AFTERNOON AS
WIND SPEEDS CRANK UP CONSIDERABLY OUT OF THE NORTHWEST...WITH MUCH
OF THE CWA EXPECTED TO SEE GUSTS OF 45+ MPH...AND MAYBE EVEN
AROUND 55 MPH IN NORTHERN/WESTERN COUNTIES.

AS MANY READING THIS PRODUCT HAVE KNOWN FOR WELL OVER 1 YEAR
KNOW...NWS HASTINGS (AND OTHER NEIGHBORING WEST/SOUTHWEST OFFICES)
NO LONGER ISSUE WIND ADVISORIES FOR SUSTAINED 30+ MPH/GUST 45+ MPH
EVENTS DUE TO THEM BEING FAIRLY COMMON CLIMATOLOGICALLY...BUT
BACK IN THE ADVISORY DAYS THIS WOULD HAVE LIKELY BEEN A "SLAM
DUNK" FOR MUCH OF THE CWA...AND WILL DEFINITELY CONTINUE TO
HIGHLIGHT IN THE LATEST HAZARDOUS WEATHER OUTLOOK (HWOGID).
ALTHOUGH AM NOT OVERLY-CONCERNED ABOUT BREACHING HIGH WIND WARNING
CRITERIA OF SUSTAINED 40+/GUST 58+ MPH...THIS COULD POTENTIALLY BE
A CLOSE CALL ESPECIALLY WITHIN A FEW FAR NORTHERN/WESTERN COUNTIES
ON SUNDAY AFTERNOON DEPENDING ON HOW EFFICIENT MIXING PROVES TO
BE. ALSO AM NOT OVERLY-CONCERNED ABOUT WIDESPREAD/IMPACTFUL
BLOWING SNOW GIVEN ITS CURRENT PHYSICAL STATE AFTER VARIOUS
MELT/RE-FREEZE CYCLES OVER THE PAST FEW DAYS...BUT SUPPOSE SOME
PATCHY BLOWING SNOW CANNOT BE RULED OUT AND HAVE ALSO INTRODUCED
THIS TO THE FORECAST FOR SUNDAY AFTERNOON. IN ADDITION TO
EVERYTHING ALREADY MENTIONED...A FAIRLY TRICKY TEMP FORECAST
CONTINUES THROUGH THESE NEXT 24 HOURS IN A BATTLE BETWEEN VARIOUS
FACTORS INCLUDING SNOW COVER...COLD AIR ADVECTION...DEEP MIXING
ETC.

TAKING A LOOK AT THE CURRENT SCENE AS OF 21Z/3PM...OTHER THAN SOME
AREAS FALLING A FEW DEGREES SHORT OF TEMPERATURE EXPECTATIONS FROM
WHAT WAS FORECASTED EARLY THIS MORNING...AND ALSO BECOMING A BIT
BREEZIER/GUSTIER OUT OF THE SOUTHWEST...IT`S BEEN A FAIRLY DECENT
AFTERNOON DESPITE INCREASING MID-HIGH CLOUD COVER SPILLING IN FROM
THE WEST. ACTUAL AFTERNOON HIGHS APPEAR ON TRACK TO RANGE FROM
35-42 ACROSS MOST OF THE CWA...BUT WITH THE NOTABLE EXCEPTION OF
MORE LIKE 48-51 IN THE SNOW-FREE...MITCHELL COUNTY KS AREA OF THE
FAR SOUTHEAST CWA. IN THE MID-UPPER LEVELS...WATER VAPOR SATELLITE
AND SHORT TERM MODEL DATA REVEAL A VERY POSITIVELY-TILTED AREA
AREA OF RIDGING EXTENDING NORTHEASTWARD OVER THE CENTRAL
PLAINS...BUT LURKING UPSTREAM OVER THE
ALBERTA/SASKATCHEWAN/MONTANA/ND REGION IS A "CLUSTER" (IF YOU
WILL) OF VIGOROUS MID LEVEL SHORTWAVE TROUGHS AND AN ASSOCIATED
UPPER JET STREAK...WHICH WILL BE A MAJOR FACTOR IN OUR WIND
SITUATION COMING UP. AT THE SURFACE...A MODEST PRESSURE GRADIENT
BETWEEN A SOUTHERN PLAINS HIGH AND A SOUTH CENTRAL CANADA LOW IS
PROMOTING SUSTAINED SOUTHWESTERLY BREEZES OF GENERALLY 10-15
(HIGHER GUSTS) IN MOST AREAS...WITH A FEW HIGHER EXCEPTIONS.

NOW LOOKING AHEAD FORECAST-WISE THROUGH AROUND SUNSET SUNDAY:

THIS EVENING/TONIGHT: HIGH CONFIDENCE IN CONTINUED PRECIP-FREE
WEATHER...ALONG WITH STAYING GENERALLY 10-15 DEGREES MILDER THAN
LAST NIGHT. IN THE MID-UPPER LEVELS...THE FIRST/LEADING OF THE
AFOREMENTIONED DISTURBANCES WILL MAINLY CHARGE EAST-SOUTHEAST
ACROSS THE DAKOTAS INTO MN/WI...THUS KEEPING ANY CHANCE OF PRECIP
WELL NORTHEAST OF THE LOCAL AREA. HOWEVER...OUR AREA WILL FEEL A
GLANCING INFLUENCE OF A PASSING...FAIRLY WEAK COLD FRONT DURING
THE NIGHT. EFFECTIVELY...THIS FRONTAL PASSAGE WILL ONLY FEATURE A
TRANSITION FROM SOUTHWESTERLY BREEZES TO MORE WEST-NORTHWESTERLY.
AT THE SURFACE...AM NOT EXPECTING WINDS TO GET VERY
STRONG...GENERALLY SUSTAINED SPEEDS NEAR/BELOW 15 MPH
OVERNIGHT...BUT AM A LITTLE CONCERNED THEY COULD GET STRONGER THAN
THIS AT LEAST FOR A BRIEF TIME AND ESPECIALLY NORTH OF I-80...AS
THERE WILL BE NOTABLY STRONG SURGE OF WINDS COMING IN SLIGHTLY
ABOVE THE SURFACE IN THE 1000-3000 FT LAYER OVERNIGHT. FOR NOW
THOUGH...WILL RUN WITH THE MAJORITY OF MODEL SOLUTIONS WHICH
STRONGLY SUGGEST THAT THESE VERY STRONG WINDS WILL STRUGGLE TO MIX
TO THE SURFACE OVERNIGHT. CLOUD-WISE...THE NIGHT AS A WHOLE SHOULD
AVERAGE SOMEWHERE BETWEEN PARTLY AND MOSTLY CLOUDY...AS VARIOUS
BATCHES OF MID-HIGH CLOUDS CONTINUE STREAMING EAST-SOUTHEAST
OVERHEAD. MADE ONLY VERY MINOR TWEAKS TO LOW TEMPS...WHICH ARE
AIMED INTO THE 24-28 RANGE ACROSS MOST OF THE CWA. ALTHOUGH NOT
EXPLICITLY INDICATED IN THE HOURLY FORECAST GRIDS...THERE COULD
EASILY BE SOME RISING TEMP TRENDS OVERNIGHT TOO IN
PLACES...ESPECIALLY IF WINDS KICK UP STRONGER THAN CURRENTLY
ADVERTISED.

SUNDAY DAYTIME: HOLD ONTO YOUR HATS...ESPECIALLY FOR THE
AFTERNOON. IN THE MID-UPPER LEVELS...THE NEXT STRONG CLIPPER WAVE
TAKES A MORE SOUTHERN TRACK OUT OF THE NORTHERN PLAINS AND ACROSS
NEB/KS DURING THE DAY. AT THE SURFACE...NOT ONLY WILL THE CWA LIE
WITHIN A DECENT PRESSURE GRADIENT BETWEEN A ROCKIES HIGH AND A
DEEP/ROUGHLY 996 MILLIBAR LOW/ TRACKING THROUGH THE LAKE SUPERIOR
AREA...BUT THE PASSING SYSTEM WILL PROMOTE GOOD DOWNWARD MOMENTUM
TRANSFER AND FAIRLY DEEP MIXING LIKELY UP TO AROUND 800MB OR
SO...WITH MODELS INDICATING NORTHWEST WINDS AT THE 850MB LEVEL
AVERAGING AT LEAST 45-55 MPH. ALTHOUGH THIS WILL ASSUREDLY PROMOTE
INCREASING NORTHWEST WINDS AS THE DAY WEARS ON...THE MILLION
DOLLAR QUESTION IS: JUST HOW STRONG WILL THEY GET? WITHOUT
EXTENSIVE REMAINING SNOW COVER...WOULD BE MORE CONCERNED ABOUT A
POSSIBLE HIGH WIND WARNING EVENT (ESPECIALLY IN THE WEST/NORTH
CWA)...BUT VARIOUS MODELS SEEM TO BE TAKING THE SNOW COVER INTO
ACCOUNT AND KEEPING FULL BLOWN MIXING TO THE SURFACE FROM TAKING
PLACE. EVEN SO...NUDGED UP WIND SPEEDS SLIGHTLY FROM PREVIOUS
FORECAST...WITH SPEEDS DURING THE AFTERNOON GENERALLY RANGING FROM
AROUND 35 MPH/GUSTS 45-55 MPH IN THE NORTHWESTERN HALF OF THE
CWA...AND MORE SO 30 MPH WITH GUSTS 40-45 MPH IN THE SOUTHEAST
HALF. AGAIN...THIS IS NOTICEABLY HIGHER THAN MOST TRADITIONAL
MODELS/GUIDANCE SETS SUGGEST...AND LEANED MORE TOWARD THE WRF-ARW
THAN ANYTHING. AS ALREADY DISCUSSED IN THE OPENING PARAGRAPH...WE
WILL HAVE TO MONITOR ESPECIALLY THE NORTHWESTERN CWA FOR A
POSSIBLE "NEAR HIGH WIND WARNING" SITUATION...BUT FOR NOW EXPECT
IT TO FALL SLIGHTLY SHORT. IN OTHER DEPARTMENTS...FORTUNATELY THE
VAST MAJORITY OF THE CWA SHOULD NOT SEE ANY FALLING SNOW WITH
THESE VERY STRONG WINDS...AS MUCH BETTER CHANCES FOR FLURRIES/SNOW
SHOWERS WILL RESIDE WITHIN IA/MN/FAR NORTHEAST NEB DURING THE
AFTERNOON. HOWEVER...WITH THE SOUTHWESTERN EDGES OF AN EXTENSIVE
BATCH OF LOW-MID CLOUDS INVADING MAINLY THE NORTHEAST 1/2 OF THE
CWA DURING THE AFTERNOON...CANNOT RULE OUT A FEW FLURRIES MAINLY
WITHIN THE FAR NORTHEAST CWA DURING AND HAVE ADDED THIS TO THE
FORECAST. AS ALSO MENTIONED IN THE OPENER...AM NOT OVERLY-
CONCERNED ABOUT BIG-TIME BLOWING SNOW ISSUE AFTER A FEW DAYS OF
DAYTIME MELTING...BUT AT LEAST WANTED TO HINT AT LOCALIZED/LIMITED
POTENTIAL WITH A "PATCHY BLOWING SNOW" MENTION. TEMP-WISE...HIGHS
ARE TRICKY AS DESPITE COLD AIR ADVECTION IN THE LOW LEVELS...DEEP-
MIXING/STRONG WINDS WILL LIKELY OFFSET THIS SOMEWHAT...WITH THE
EVER-PRESENT SNOW COVER OF COURSE A MITIGATING FACTOR AS WELL. IF
ANYTHING...NUDGED UP HIGHS A FEW DEGREES VERSUS PREVIOUS FORECAST
MOST PLACES...AIMING MOST NEB ZONES INTO THE MID-UPPER 30S AND
KS ZONES MAINLY INTO THE 38-43 RANGE...EXCEPT 45-ISH IN SOUTHEAST
MITCHELL.

.LONG TERM...(SUNDAY EVENING THROUGH SATURDAY)
ISSUED AT 356 PM CST SAT FEB 6 2016

CRAZY NORTHWEST WINDS WILL BE GOING STRONG SUNDAY NIGHT INTO MONDAY
IN A TIGHT PRESSURE GRADIENT IN BETWEEN A DEEP SFC LOW PRESSURE
SYSTEM (998MB) IN THE GREAT LAKES REGION AND A STRONG SURFACE HIGH
PRESSURE SYSTEM (1038MB) OVER THE ROCKIES. ALOFT...A LOW PRESSURE
SYSTEM WILL DEEPEN AS IT TRANSLATES FROM THE UPPER MIDWEST TO THE
LOWER GREAT LAKES/OHIO VALLEY REGION WITH FLOW BECOMING HIGHLY
AMPLIFIED TO A WESTERN CONUS RIDGE AND EASTERN CONUS TROUGH BY
MONDAY MORNING. MODEL FORECAST SOUNDINGS INDICATE THE POTENTIAL FOR
DEEP MIXING WITH WINDS AT THE TOP OF THE LAYER (850MB OR JUST ABOVE)
AVERAGING 50 TO 60KTS. THE STRONG WINDS AT H85 ARE NEARLY 4 STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. NOT CONFIDENT WE WILL
MIX AS DEEP AS MODELS SHOW WITH THE SNOW ON THE GROUND HOWEVER DO
EXPECT A PERIOD OF SIGNIFICANT WIND SPEEDS AND WIND GUSTS TO PERSIST
THROUGH SUNDAY NIGHT WITH THE DEEPENING SYSTEM TO THE EAST. LOOK FOR
WIND SPEEDS TO GRADUALLY DIMINISHING ON MONDAY MORE SO IN THE
EVENING TIME FRAME AS THE GRADIENT RELAXES WITH THE EASTERN LOW
MIGRATING FARTHER EAST AND HIGH PRESSURE BUILDS IN FROM THE WEST.

FOR PRECIPITATION CHANCES SUNDAY NIGHT...SNOW SHOWERS OR FLURRIES
STILL LOOK POSSIBLE FOR OUR EASTERN CWA IN INCREASING
LIFT/FRONTOGENETIC FORCING WITH COLD FROPA SUNDAY EVENING/NIGHT. THE
NAM INDICATES SOME INSTABILITY ACROSS OUR FAR EASTERN ZONES WITH
MOST UNSTABLE CAPE OF 25 TO 50 J/KG AND WILL GO WITH A COMBINATION
OF SNOW SHOWERS IN OUR EAST BUFFERED WITH FLURRIES.

TUESDAY WILL BE THE TRANSITION DAY BETWEEN SYSTEMS AND THE AIRMASS
WILL BEGIN TO MODERATE AS HEIGHTS RISE AS THE WESTERN RIDGE BUILDS
EAST ONTO THE PLAINS. THERE ARE SOME MODEL DIFFERENCES IN WHETHER OR
NOT LOW CLOUDS WILL DEVELOP AND THE TIMING OF THE CLOUDS EITHER LATE
MONDAY NIGHT OR DURING THE DAY TUESDAY. THE NAM IS THE FASTEST AND
MOST AGGRESSIVE...ALSO INDICATING THE POTENTIAL FOR A LIGHT PCPN IN
WAA OVER THE LOW CLOUDS. FORECAST SOUNDINGS SUGGEST THIS MAY BE
FREEZING DRIZZLE VS SNOW/FLURRIES DUE TO DENDRITIC MOISTURE LACKING.
OVERALL CONFIDENCE IN THIS IS LOW ATTM DUE TO MODEL DIFFERENCES AND
JUST THE NAM SUGGESTING PCPN POTENTIAL. WILL GO WITH SILENT POPS FOR
NOW AND MONITOR TRENDS AS THE MAIN FOCUS FOR THE FORECAST IS ON THE
STRONG WINDS THROUGH MONDAY.

TEMPS ARE EXPECTED TO TREND FOR THE MIDDLE TO LATTER PART OF THE
WORKWEEK WITH WARMER SPREADING ONTO THE PLAINS FROM THE WESTERN
RIDGE. THERE ARE UNCERTAINTY IN MODELS HEADING TOWARD AND INTO THE
WEEKEND AND DID NOT DEVIATE FROM INITIALIZATION.

&&

.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1207 PM CST SAT FEB 6 2016

CONFIDENCE REMAINS HIGH IN VFR CEILING/VISIBILITY AND
PRECIPITATION-FREE WEATHER THROUGHOUT THE PERIOD...WITH ONLY
VARIABLE COVERAGE OF PASSING MID-HIGH CLOUDS.

THAT LEAVES WINDS AS THE MAIN CONCERN...ESPECIALLY DURING THE
LATTER HALF OF THE PERIOD WHEN LOW LEVEL WIND SHEAR (LLWS) BECOMES
AN ISSUE. WILL TAKE A CLOSER LOOK AT THIS:

SURFACE WIND: AVERAGING AROUND 12KT FROM THE WEST-SOUTHWEST THIS
AFTERNOON...THEN REMAINING FAIRLY LIGHT BUT BECOMING MORE WEST-
NORTHWEST THIS EVENING/TONIGHT. A STEADY INCREASE IN WEST-
NORTHWEST SPEEDS WILL OCCUR SUNDAY MORNING...WITH GUST POTENTIAL
RAMPING UP INTO THE 25-30KT RANGE 15Z-18Z TIME FRAME.

LLWS ISSUES: HAVE MAINTAINED LLWS FROM PREVIOUS
ISSUANCE...FOCUSING ON THE 05Z/06Z THROUGH 15Z TIME FRAME...WHEN A
PUSH OF STRONG NORTHWEST WINDS WITH SUSTAINED SPEEDS AROUND 40KT
MOVES IN ABOVE THE SURFACE...CREATING ROUGHLY 30-35KT OF TOTAL
SHEAR MAGNITUDE BETWEEN THE SURFACE AND ROUGHLY 1500 FT AGL. THESE
WINDS ALOFT WILL CONTINUE TO STRENGTHEN INTO THE DAY SUNDAY...BUT
BY LATE MORNING THE SURFACE SPEEDS SHOULD START INCREASING ENOUGH
TO EASE THE SHEAR MAGNITUDE AT LEAST SLIGHTLY.

&&

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

$$

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


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