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 141735
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1235 PM CDT SUN SEP 14 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT SUN SEP 14 2014

THE SLOW WARMING TREND WILL CONTINUE TODAY WITH HIGHS AROUND 6 TO
12F WARMER THAN YESTERDAY ACROSS THE FORECAST AREA. EXPECT
INCREASING CLOUDS THROUGH THE AFTERNOON AND A CHANCE OF SHOWERS AND
THUNDERSTORMS BY LATE EVENING INTO THE OVERNIGHT HOURS.

TODAY...MOST NOTABLE WILL BE THE INCREASING DEWPOINTS...WHICH WILL
RISE THROUGHOUT THE DAY THANKS TO WARM MOIST AIR ADVECTION OUT AHEAD
OF A HIGH PLAINS SFC LOW. THEREFORE...EXPECT SOUTHEAST WINDS IN THE
WARM SECTOR WILL ALLOW DEWPOINTS TO CLIMB FROM THE UPPER 30S AROUND
DAWN...TO THE MID AND UPPER 50S BY EARLY EVENING. MOST FORECAST
MODELS ARE DRY THROUGH 7 PM AND WILL CONTINUE TO CARRY A DRY
FORECAST THROUGH THE AFTERNOON HOURS...BUT CAN NOT COMPLETELY RULE
OUT AN ISOLATED SHOWER NORTH OF I-80 BY LATE AFTERNOON.

THIS EVENING INTO TONIGHT...THE SFC LOW WILL SLIDE SOUTHEAST FROM
EASTERN/NORTHEASTERN COLORADO INTO WESTERN/SOUTHWESTERN KANSAS. THIS
WILL TURN THE SFC WINDS TO THE EAST AND EVENTUALLY NORTHEAST ACROSS
OUR FORECAST AREA AS A COOL FRONT SAGS SOUTH ACROSS OUR FORECAST
AREA. MOISTURE WILL POOL NORTH OF THE FRONT AND LOW CLOUDS WILL
INCREASE AND THICKEN. IN ADDITION...THE LOW LEVEL JET WILL BE ON THE
INCREASE THROUGH THE EVENING HOURS WITH WARM AIR ADVECTION ACROSS
MUCH OF OUR FORECAST AREA...ESPECIALLY OVER NEBRASKA ZONES. FORECAST
SOUNDINGS INDICATE A DEEP SATURATED LAYER AFTER MIDNIGHT FROM THE
SFC TO OVER 850 MB AND THUS COULD SEE A LITTLE DRIZZLE IN THOSE LATE
NIGHT/EARLY MORNING HOURS. ELEVATED INSTABILITY AS INDICATED BY
MUCAPE VALUES OF 1500 TO 2000 J/KG AT THE NOSE OF THE LOW LEVEL JET
OVER OUR FORECAST AREA WOULD CERTAINLY SUPPORT THE POTENTIAL OF
THUNDERSTORMS...SOME POSSIBLY STRONG. HOWEVER...MODELS DIFFER ON
WHETHER OR NOT THIS INSTABILITY WILL BE TAPPED INTO TO ACTUALLY
CREATE THUNDERSTORMS...OR IF WE WILL JUST SEE SOME SCATTERED AREAS
OF DRIZZLE AND LIGHT RAIN.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT SUN SEP 14 2014

ALTHOUGH THIS 6-DAY PERIOD IS BECOMING INCREASINGLY-LITTERED WITH
FAIRLY SMALL 20-30 PERCENT CHANCES FOR SHOWERS/STORMS MAINLY FROM
TUESDAY NIGHT AND BEYOND...CONFIDENCE IS SLOWLY INCREASING THAT
THE "MAIN" CONVECTIVE EVENT OF THE WEEK IN TERMS OF
LIKELIHOOD/PRECIP COVERAGE APPEARS TO BE CENTERED ON THE FRIDAY-
FRIDAY NIGHT TIME FRAME AS A MORE ORGANIZED LARGE SCALE TROUGH AND
ASSOCIATED SURFACE COLD FRONT CROSSES THROUGH THE CENTRAL PLAINS.
PARTLY DUE TO THE LATEST MODEL TRENDS AND PARTLY DUE TO THE
LINGERING INFLUENCE OF PREVIOUS MODEL RUNS ON THE DEFAULT MULTI-
MODEL BLEND USED TO POPULATE THE DAY 4-7 FORECAST...THE HIGHEST
CONCENTRATION OF 30-40 POPS ARE CURRENTLY FOUND IN THE FRIDAY
NIGHT-SATURDAY DAYTIME TIME FRAME. HOWEVER...BARRING CHANGES IN
MODEL TRENDS...WOULD NOT BE SURPRISED TO SEE THE HIGHEST POPS
TRENDED UPWARD AND ALSO A TOUCH EARLIER MORE SO INTO THE FRIDAY
DAYTIME-FRIDAY NIGHT BLOCK WITH SATURDAY DAYTIME POTENTIALLY DRYING
OUT BEHIND THE SYSTEM. ALTHOUGH ITS PLENTY EARLY TO SPECULATE ON
THE SPECIFICS OF STRONG/SEVERE STORM POTENTIAL FOR THE MID-LATE
WEEK TIME FRAME...CERTAINLY THE RETURN OF DECENT LOW LEVEL
MOISTURE/INSTABILITY VALUES SUGGEST THAT A FEW TIME FRAMES HERE
COULD GET AT LEAST SLIGHTLY ACTIVE...AGAIN ESPECIALLY AROUND THE
AFOREMENTIONED FRIDAY/FRIDAY NIGHT PERIOD.

PRIOR TO THE PARADE OF MID-LATE WEEK PRECIP CHANCES...RIGHT AWAY
AT THE VERY START OF THE LONG TERM PERIOD MONDAY MORNING FEATURES
THE ENDING STAGES OF AT LEAST A MODEST CHANCE OF PRECIP THAT GETS
UNDERWAY TONIGHT AS DESCRIBED IN THE SHORT TERM SECTION ABOVE. SEE
BELOW FOR MORE DETAILS ON THIS MONDAY MORNING PRECIP POTENTIAL.

TEMP-WISE DURING THIS 6-DAY PERIOD...ALTHOUGH BY NO MEANS ARE
SEASONABLY HOT READINGS FORECAST...A GRADUAL REBOUND TO NEAR-TO-
SLIGHTLY ABOVE NORMAL READINGS IS EXPECTED...ALLOWING SOME SENSE
OF "EARLY FALL WEATHER NORMALCY" TO RETURN IN THE WAKE OF THESE
NOTABLY CHILLY PAST FEW DAYS. NEITHER DAILY HIGHS NOR LOWS WERE
ALTERED MORE THAN A FEW DEGREES FROM THE PREVIOUS FORECAST FOR ANY
GIVEN PERIOD. THUS TAKING A BROAD OVERVIEW...HIGH TEMPS ARE AIMED
INTO THE MID-UPPER 60S ON MONDAY BEHIND A FAIRLY WEAK COLD
FRONT...BEFORE REBOUNDING SOMEWHERE INTO THE 70S THROUGH MOST OF
THE REMAINDER OF THE TUES-SAT TIME FRAME. AT LEAST FOR
NOW...FRIDAY IS THE TOP CANDIDATE FOR WARMEST DAY OF THE WEEK AS
THE FORECAST REFLECTS LOW-MID 80S AHEAD OF THE APPROACHING COLD
FRONT. NIGHTLY LOW TEMPERATURES ARE AIMED INTO THE MID-50S TO LOW-
60S RANGE ON MOST NIGHTS...EXCEPT FOR CHILLIER 40S MONDAY NIGHT AS
A SURFACE RIDGE AXIS SETTLES IN. BESIDES INCREASING
TEMPERATURES...A NOTICEABLE INCREASE IN DEWPOINTS/HUMIDITY SHOULD
COMMENCE AS WELL DURING THE WEEK. ALTHOUGH WOULD NOT BE SURPRISED
IF MODELS MAY BE A BIT AGGRESSIVE IN MOISTURE RETURN AT LEAST
AT FIRST...THE CURRENT FORECAST DEPICTS PREVAILING LOW-MID 60S ON
A DAILY BASIS FROM WEDNESDAY ONWARD.

NOW TAKING THINGS IN A BIT MORE DETAIL IN MAINLY 24-36 HOUR
BLOCKS:

MONDAY DAYTIME-MONDAY NIGHT...AS ALREADY MENTIONED ABOVE THE
MONDAY MORNING HOURS FEATURE THE LATTER PART OF THE POTENTIAL
PRECIP EVENT THAT GETS GOING DURING THE SHORT TERM PERIOD TONIGHT.
IN THE BIG PICTURE OF THE MID-UPPER LEVELS OVER THE COURSE OF THE
DAY...AN ENERGETIC SHORTWAVE TROUGH WILL DIVE EAST-SOUTHEAST FROM
EASTERN SD TO THE SOUTHERN LAKE MICHIGAN AREA...WHILE AT THE
SURFACE A FAIRLY WEAK COLD FRONT WILL CONTINUE PASSING THROUGH THE
AREA KICKING UP SOMEWHAT GUSTY NORTH-NORTHEAST BREEZES DURING THE
DAY THAT WILL QUICKLY SUBSIDE BY EVENING AS A 1024 MILLIBAR HIGH
PRESSURE AXIS SETTLES IN FROM THE NORTH FOR THE OVERNIGHT HOURS.
PRECIP-WISE...COORDINATED WITH SHORT TERM FORECASTER TO INTRODUCE
A CHANCE OF PASSING LIGHT DRIZZLE UNDER A LOW STRATUS DECK TO THE
MONDAY MORNING FORECAST...ALONG WITH LINGERING LOW POPS GENERALLY
ACROSS THE SOUTHEAST 1/2 OF THE CWA FOR SHOWERS/A FEW
THUNDERSTORMS. ALTHOUGH EXPECT THE BULK OF POSSIBLE NEAR-SEVERE
HAIL POTENTIAL TO OCCUR DURING THE SUNDAY NIGHT PERIOD AS
DESCRIBED IN THE SHORT TERM SECTION ABOVE...CERTAINLY CANNOT RULE
OUT A FEW INSTANCES OF SMALL HAIL LINGERING INTO THE DAYLIGHT
HOURS. NO MATTER WHAT...BOTH THE CONVECTIVE AND DRIZZLY PRECIP
POTENTIAL SHOULD STEADILY END FROM NORTH-TO-SOUTH DURING THE
MORNING...AND HAVE PULLED ANY MENTION OF PRECIP CHANCES FROM THE
SOUTHERN CWA BEYOND 18Z/1PM AS MOST MODELS FIRMLY AGREE ON A DRY
AND MUCH SUNNIER AFTERNOON CWA-WIDE IN THE WAKE OF WIDESPREAD
MORNING CLOUDS. SUSTAINED DAYTIME WINDS SHOULD GENERALLY AVERAGE
10-15 MPH FROM THE NORTH-NORTHEAST WITH SOME HIGHER GUSTS.
CONFIDENCE IS QUITE HIGH IN DRY WEATHER FOR MONDAY NIGHT AS THE
SURFACE RIDGE AXIS MOVES IN...AND IF SKIES ARE TOTALLY CLEAR WOULD
NOT BE SURPRISED TO SEE LOW TEMPS FALL A FEW DEGREES COLDER THAN
FORECAST.

TUESDAY DAYTIME-NIGHT...SEASONABLY STRONG NORTHWESTERLY MID-UPPER
LEVEL FLOW WILL PREVAIL OVER THE CENTRAL PLAINS...DIRECTED BETWEEN
A LARGE SCALE TROUGH OVER SOUTHEASTERN CANADA AND A RIDGE OVER THE
SOUTHWESTERN CONUS. DESPITE A FEW BLIPS OF QPF SUGGESTED BY THE
GFS...CONFIDENCE REMAINS REASONABLY HIGH IN A DRY DAY AS 10-15 MPH
SOUTHERLY BREEZES BECOME ESTABLISHED IN THE WAKE OF THE DEPARTING
RIDGE AXIS. CONFIDENCE IN PRECIP POTENTIAL ALREADY TAKES A DIVE
THOUGH BY TUESDAY NIGHT...AS MODELS SUCH AS THE NAM ARE
ESSENTIALLY DRY WHILE BOTH THE 00Z ECMWF/GFS RUNS SUGGEST THAT A
PASSING LOW AMPLITUDE MID LEVEL WAVE/UPPER JET STREAK AND COULD
SPARK ENOUGH LOW-MID LEVEL THETA-E ADVECTION TO KICK UP A ROUND OF
SHOWERS/STORMS MAINLY WITHIN THE SOUTHERN 1/2 OF THE CWA. AS A
RESULT...CONTINUED AN AREA OF 20-30 POPS  MAINLY SOUTH OF
I-80...WITH NO PRECIP CHANCES FARTHER NORTH.

WEDNESDAY DAYTIME-NIGHT...NORTHWESTERLY FLOW REMAINS IN PLACE
ALOFT BUT SHOULD WEAKEN A BIT AS THE LARGE RIDGE CENTERED OVER THE
WESTERN CONUS EDGES NORTHWARD AND EASTWARD A BIT...IMPARTING A BIT
MORE INFLUENCE ON THE CENTRAL PLAINS. DESPITE FAIRLY NEGLIGIBLE
FORCING...BOTH THE ECMWF/GFS SUGGEST AT LEAST SOME SPOTTY
SHOWER/STORM POTENTIAL MAINLY IN SOUTHEAST ZONES...AND THIS IS
WHERE 20-30 POPS ARE ADVERTISED MAINLY WITHIN THE SOUTHEAST 1/3 OF
THE CWA.

THURSDAY DAYTIME-NIGHT...THINGS START TO TURN MORE ACTIVE IN THE
MID-UPPER LEVELS...AND ALTHOUGH TIMING IS STILL A BIT OFF BETWEEN
MODELS...THE PRIMARY ECMWF/GFS SOLUTION ARE IN BETTER AGREEMENT
THAN 24 HOURS AGO IN QUICKLY SHIFTING THE LARGE SCALE RIDGE AXIS
OVERHEAD DURING THE DAY AND QUICKLY USHERING IN AT LEAST A
GLANCING BLOW OF LEADING SHORTWAVE TROUGH ENERGY FROM THE WEST FOR
THURS NIGHT EJECTING OUT AHEAD OF THE MAIN WESTERN CONUS TROUGH.
AT LEAST FOR NOW...MAINTAINED A DRY FORECAST DURING THE DAY...WITH
ONLY SLIGHT SHOWER/STORM CHANCES IN ROUGHLY THE NORTHEAST 1/2 OF
THE CWA AT NIGHT.

FRIDAY DAYTIME-SATURDAY DAYTIME...THE OVERALL THEME OF THIS
36-HOUR PERIOD WAS ALREADY TOUCHED ON IN THE OPENING LONG TERM
PARAGRAPH ABOVE. REHASHING BRIEFLY...THE HIGHEST/MOST WIDESPREAD
THUNDERSTORM CHANCES OF THE WEEK SHOULD OCCUR DURING THE TIME AS A
LARGE SCALE TROUGH AXIS...LIKELY COMPRISED OF SEVERAL SMALLER
SHORTWAVES...DEEPENS AT LEAST SLIGHTLY AS IT TRAVERSES THE CENTRAL
CONUS. UNLESS MODEL TRENDS CHANGE...WOULD NOT BE SURPRISED TO SEE
POPS SLOWLY TREND UP FOR FRIDAY DAYTIME-NIGHT AND CONTINUE TO
TREND DOWN FOR SATURDAY DAYTIME. AGREE WITH THE LATEST SPC DAY 4-8
OUTLOOK THAT ALTHOUGH A POSSIBLE SEVERE EVENT COULD UNFOLD DURING
THIS TIME FRAME (ALONG WITH MAYBE LOCALLY HEAVY RAIN)...ITS STILL
TOO SOON TO PINPOINT ANY SPECIFICS GIVEN THE USUAL CONSIDERABLE
UNCERTAINTY AT THE DAY 6-7 RANGE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1227 PM CDT SUN SEP 14 2014

QUIET WEATHER AND VFR CONDITIONS EXPECTED THE REST OF THIS
AFTERNOON...WITH MAIN CONCERN COMING LATER THIS EVENING/OVERNIGHT
AS DETERIORATING CEILINGS ARE EXPECTED AS AN UPPER LEVEL TROUGH
AND COOL FRONT PASS THROUGH THE REGION. AS FAR AS PRECIPITATION
CHANCES GO...MODELS CONTINUE TO VARY WITH WHETHER THE AREA WILL
SEE SHOWERS/TSTORMS OR MORE IN THE WAY OF DZ...SO KEPT TS MENTION
JUST AS VC AT THIS POINT. THERE REMAINS BETTER AGREEMENT SHOWING
DROPPING CLOUD BASES...AND KEPT THE CEILINGS IN THE IFR CATEGORY
LATE TONIGHT/EARLY TOMORROW MORNING...BEFORE IMPROVING DURING THE
MID/LATE MORNING HOURS TOMORROW.

&&

.CLIMATE...
ISSUED AT 540 AM CDT SUN SEP 14 2014

IT SHOULD COME AS NO SURPRISE THAT THE "CUMULATIVE COOLNESS" OF
THE PAST 3 DAYS HAS RANKED UP THERE IN SOME PRETTY RARE TERRITORY
HISTORICALLY FOR COOL SNAPS THAT TOOK PLACE DURING THE FIRST HALF
OF SEPTEMBER.

HERE ARE A FEW NOTES REGARDING WHERE THE PAST 3 DAYS RANKED
VERSUS OTHER EARLY-SEPTEMBER COLD SNAPS AT OUR PRIMARY CLIMATE
RECORD SITE GRAND ISLAND AIRPORT...WHERE TEMPERATURE RECORDS DATE
BACK 119 YEARS TO 1896:

- THE 3-DAY STRETCH FROM SEP 11-13 FEATURED AN AVERAGE DAILY
TEMPERATURE OF 48.2 DEGREES...A NOTABLE AVERAGE OF 18.3 DEGREES
BELOW NORMAL FOR THAT PERIOD. FOR ALL NON-OVERLAPPING 3-DAY
STRETCHES ON RECORD THAT OCCURRED BETWEEN SEP 1-15...THIS RANKED
AS THE 3RD-COLDEST ON RECORD AND THE COLDEST SINCE 1989. HERE ARE
THE TOP-5 COOLEST:

1) 46.3 DEGREES...SEP 9-11, 1898
2) 47.8 DEGREES...SEP 11-13, 1989
3) 48.2 DEGREES...SEP 11-13, 2014
4) 48.8 DEGREES...SEP 13-15, 1970
5) 50.5 DEGREES...SEP 6-8, 1929

- ON A BROADER TIME SCOPE REACHING BACK TO THE START OF THE
MONTH...THE FIRST 13 DAYS OF SEPTEMBER HAVE RANKED AS THE 4TH-
COOLEST ON RECORD AT GRAND ISLAND WITH AN AVERAGE DAILY
TEMPERATURE OF 62.4 DEGREES...AND WAS THE OVERALL-COLDEST START TO
THE MONTH SINCE 1974. HERE ARE THE TOP-5 COOLEST OPENING 13 DAYS
OF SEPT. ON RECORD BASED ON AVERAGE DAILY TEMPERATURE:

1) 61.0 DEGREES...1974
2) 61.1 DEGREES...1962
3) 62.3 DEGREES...1920
4) 62.4 DEGREES...2014

- GIVEN THAT A CONTINUATION OF AT LEAST SLIGHTLY BELOW NORMAL
TEMPERATURE READINGS ARE PREDICTED FOR AT LEAST A FEW MORE
DAYS...THE SIGNIFICANCE OF THIS COOL SNAP ON BOTH THE SHORT AND
LONGER TERM TIME SCALES MAY CONTINUE TO GROW MORE IMPRESSIVE WITH
TIME.

&&

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

$$

SHORT TERM...WESELY
LONG TERM...PFANNKUCH
AVIATION...ADP
CLIMATE...PFANNKUCH


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