Area Forecast Discussion
Issued by NWS Hastings, NE

Home | Current Version | Previous Version | Text Only | 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
497
FXUS63 KGID 291043
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
543 AM CDT FRI APR 29 2016

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT FRI APR 29 2016

OVERVIEW: A LARGE UPPER TROUGH WILL TRACK OUT OF THE ROCKIES AND
INTO THE HIGH PLAINS TODAY. THE UPPER LOW IS EXPECTED TO BE
SITUATED OVER EASTERN COLORADO BY EARLY THIS EVENING. SHOWERS AND
THUNDERSTORMS HAVE BEEN EXPANDING IN COVERAGE AREA THROUGH THE
OVERNIGHT AND EARLY MORNING HOURS ACROSS THE SOUTHERN AND CENTRAL
PLAINS WITH SOME OF THE HEAVIEST AND MOST WIDESPREAD RAINS
EXTENDING FROM THE TEXAS PANHANDLE INTO WESTERN KANSAS. HIGH
DEWPOINT MOISTURE LADEN AIR WILL BE LIFTED NORTHWARD THROUGH THE
PLAINS TODAY/TONIGHT AHEAD OF THIS VERY DYNAMIC UPPER SYSTEM. OVER
THE NEXT 24 HOURS THIS SYSTEM WILL BRING SEVERE THUNDERSTORMS TO
PORTIONS OF OKLAHOMA AND NORTH TEXAS...HEAVY RAIN TO MUCH OF OUR
FORECAST AREA...AND EVEN HEAVY SNOWFALL TO PORTIONS OF THE
NEBRASKA PANHANDLE.

THUNDERSTORM CHANCES: INSTABILITY IS REALLY LACKING IN OUR COOL
ENVIRONMENT WELL NORTH OF THE SFC LOW WHICH WILL TRACK ACROSS
TEXAS AND OKLAHOMA TODAY. MUCAPE VALUES WILL BE LESS THAN 50 J/KG
THROUGH TONIGHT ACROSS THE NORTHWESTERN HALF OF OUR FORECAST AREA.
HOWEVER...OUR FAR SOUTHEASTERN COUNTIES COULD SEE MUCAPE VALUES AS
HIGH AS 200-400 J/KG BY LATE AFTERNOON INTO EARLY THIS EVENING.
ALTHOUGH THESE VALUES ARE PRETTY LOW...GIVEN AT LEAST SOME
INSTABILITY WILL GO AHEAD AND CONTINUE WITH THE ISOLATED THUNDER
WORDING THIS AFTERNOON AND EVENING ACROSS NORTH CENTRAL KANSAS
AND OUR FAR SOUTHEASTERN NEBRASKA COUNTIES. RATHER THAN
THUNDERSTORMS...THIS REALLY APPEARS TO BE JUST A LONG DURATION
STEADY MODERATE RAIN EVENT.

HEAVY RAIN POSSIBLE: FORECAST MODEL GUIDANCE IS IN STRONG
AGREEMENT THAT WE WILL SEE VERY WIDESPREAD SIGNIFICANT RAINFALL
AMOUNTS THROUGH THE SHORT TERM PERIOD WHICH GOES THROUGH 7 AM
SATURDAY MORNING. LOOKING AT THE 00Z GFS/ECMWF AND 06Z NAM
RAINFALL AMOUNTS BY SATURDAY MORNING RANGE FROM 0.60 INCHES ON
THE LOW END TO 3.5 INCHES ON THE HIGH END. THE BEST CONSENSUS
APPROACH HAS MOST OF OUR FORECAST AREA RECEIVING BETWEEN 1 AND 2
INCHES OF RAINFALL BY EARLY SATURDAY MORNING WITH THE HIGHEST
AMOUNTS AND POSSIBLE LOCALIZED 3 PLUS INCH RAINFALL AMOUNTS MORE
LIKELY WEST OF HIGHWAY 281. OUR KANSAS ZONES WILL PRETTY MUCH BE A
RAIN OUT TODAY WITH RAIN THROUGH MUCH OF THE DAY. HOWEVER...MOST
OF THE RAIN MAY HOLD OFF UNTIL THIS AFTERNOON ACROSS NEBRASKA
ZONES WITH INCREASING RAIN CHANCES AS WE HEAD THROUGH THE
AFTERNOON. THE ENTIRE AREA CAN THEN EXPECT A MODERATE STEADY
RAINFALL THROUGH MUCH OF THE OVERNIGHT HOURS.

FLOOD POTENTIAL: THE GROUND HAS BECOME MORE SATURATED ACROSS MUCH
OF OUR FORECAST AREA THANKS TO OUR RECENT HEAVY RAINFALL EVENTS.
THIS SHOULD INCREASE RUNOFF...BUT THE NATURE OF THIS RAIN BEING
MORE SHOWERS AND NOT SO MUCH THUNDERSTORMS WILL RESULT IN LOWER
RAINFALL RATES. THAT MEANS THAT THE RAINFALL AMOUNTS WILL ADD UP
MORE SLOWLY OVER TIME...WHICH SHOULD STILL ALLOW MUCH OF THE RAIN
TO SOAK INTO THE SOIL. FLOODING IS STILL A CONCERN...BUT BELIEVE
THAT ANY FLOODING WILL BE MORE ISOLATED WITH THE MORE LIKELY
SCENARIO BEING RIVERS RUNNING RATHER FULL BUT WITH ONLY MINOR IF
ANY IMPACTS. THEREFORE...HAVE DECIDED NOT TO ISSUE ANY FLOOD
WATCHES AT THIS TIME. MOST AREAS SHOULD BE ABLE TO HANDLE A SLOWER
1 TO 2.5 INCHES OF RAIN. AREAS THAT END UP AROUND OR MORE THAN 3
INCHES WILL NEED TO KEEP A CLOSER EYE OUT FOR POSSIBLE MINOR
FLOODING.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 335 AM CDT FRI APR 29 2016

BIG STORY:

ALOFT: THE FLOW WILL BE INCREDIBLY COMPLEX UNTIL EARLY NEXT WEEK
WHEN SOME SEMBLANCE OF A REX BLOCK EVOLVES OVER WRN N AMERICA...
WITH A CLOSED HIGH OVER THE CANADIAN ROCKIES AND A FILLING LOW OVER
THE DESERT SW. THIS WILL SPLIT THE FLOW OVER N AMERICA. BY WED THE
FLOW IS FCST TO CONSOLIDATE WITH A RIDGE OVER THE CANADIAN/USA
ROCKIES AND TROFS OVER THE E PAC AND ERN USA. DEAMPLIFICATION AND
PROGRESSION OF THE FLOW SHOULD ALLOW FOR THE RIDGE TO MOVE OVER THE
PLAINS LATE NEXT WEEK.

THERE IS GOOD AGREEMENT ON THE LARGE SCALE EVOLUTION...BUT AS FOR
THE SHORTER WAVELENGTH DETAILS THERE IS UNCERTAINTY. MULTI-MODEL
CONSENSUS IS THAT THE UPR LOW (CURRENTLY OVER THE 4-CORNERS) WILL BE
OVER THE INTERSECTION OF THE CO/NEB/KS BORDERS AT DAYBREAK SAT. THIS
LOW WILL SLOWLY DRIFT E ALONG THE KS/NEB BORDER AND OPEN UP INTO A
TROF SUN AS IT HEADS INTO IA. THERE IS SIGNIFICANT DISAGREEMENT ON
WHAT THE TROF DOES OVER THE CANADIAN PRAIRIES SUN-MON AS THE RIDGE
BUILDS IN ITS WAKE. THE 12Z UKMET/EC AND 00Z EC/GEM BRING A SMALL
CLOSED LOW S INTO OR JUST W OF THE CNTRL PLAINS MON-TUE. THE 12Z/00Z
EC ARE SLOWER WITH ITS DEPARTURE.

SURFACE: OCCLUDING LOW PRES WILL BE OVER ERN OR NRN KS AT DAYBREAK
SAT. THIS LOW WILL FILL AS THE TRIPLE PT LOW OVER MO BECOME DOMINANT
BY SAT EVE AND HEADS INTO THE OH VALLEY SUN. CANADIAN HIGH PRES WILL
SINK INTO THE NRN PLAINS SUN...SETTLING OVER THE CNTRL PLAINS MON...
ON ITS WAY INTO THE SRN PLAINS TUE. WED A CANADIAN COLD FRONT WILL
PLUNGE S INTO THE NRN PLAINS/GREAT LAKES. PRESENT INDICATIONS ARE
THAT THIS FRONT WILL REMAIN JUST E OF THE FCST AREA. HIGH PRES WILL
SLIDE FROM THE NRN PLAINS INTO THE MID MS VALLEY THU WITH RETURN
FLOW OVER THE CNTRL PLAINS.

SOME DAILY DETAILS...

SAT: THE HEAVIEST RAIN AND HIGHEST RAINFALL AMTS SHOULD BE DONE. THE
MID-UPR LVLS WILL BE DRYING OUT AS THE DRY SLOT WRAPS CYCLONICALLY
AROUND THE LOW. THE LARGE DEFORMATION RAIN BAND SHOULD BE OVER THE
SANDHILLS AT DAWN.

PERIODS OF DRZL OR POSSIBLY SOME LIGHT RAIN (-RA) WILL LINGER...
MAINLY N OF HWY 6. A CLOUDY/COOL/NASTY DAY WITH N-NE WINDS GUSTING
25-30 MPH. HIGHS WILL BE JAMMED IN THE 40S FOR MOST OF THE FCST
AREA. THERE IS A CHANCE SOME SUNNY BREAKS COULD DEVELOP OVER THE FAR
SE FRINGE OF THE FCST AREA...CLOSE TO THE SFC LOW. THIS WOULD ALLOW
FOR TEMPS TO CLIMB INTO THE 50S.

THE FCST IS PROBABLY TOO HIGH ON QPF/POPS FOR SAT.

THE 18Z/00Z GFS WERE ON THE S OF THE MODEL CONSENSUS...STILL DUMPING
SIGNIFICANT RAIN OVER THE FCST AREA. THESE RUNS WERE NOT
INCORPORATED INTO THE FCST.

PERIODS OF DRZL OR -RA WILL CONT INTO SAT NIGHT...MAINLY OVER S-
CNTRL NEB.

SUN: ANY DRZL/-RA LINGERING INTO THE MORNING SHOULD END. HIGH PRES
WILL BE BUILDING IN WITH DRY AIR ADVECTING IN FROM THE NE. THIS WILL
ERODE THE LOW STRATUS IN THE AFTERNOON. BUT WITH THE COOL AIR ALOFT
...STRATOCU WILL DEVELOP WITHIN ANY SUNSHINE...FILLING CLOUDS BACK
IN.

ANOTHER COOL DAY WITH HIGHS IN THE 50S. LIGHTER N WINDS.

SUN NIGHT: WE MAY HAVE A PROBLEM WITH FOG OVER THE NE 1/2 OF THE
FCST AREA WHERE CLEARING IS EXPECTED. ABUNDANT LOW-LVL MOISTURE IN
PLACE/LIGHT WINDS.

THERE COULD BE SOME SPOTTY -RA SUN NIGHT THRU TUE DEPENDING ON HOW
THE VARIOUS FEATURES ALOFT EVOLVE. THERE IS A LOT OF UNCERTAINTY. WE
MAY NOT HAVE ENOUGH CLOUDS/RAIN IN THE FCST AND TEMPS COULD BE A
LITTLE TOO WARM.

WED-THU: LOOKING VERY NICE AS THE PATTERN TURNS SUNNY AND DRIER WITH
A WARMING TREND.

&&

.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 529 AM CDT FRI APR 29 2016

EXPECT SOME LOWER CEILINGS TO PERSIST THROUGHOUT MUCH OF THE TAF
VALID PERIOD WITH MVFR CEILINGS THE GENERAL RULE. WE MAY SHIFT
BACK AND FORTH BETWEEN VFR AND MVFR FOR AWHILE THIS MORNING.
EVENTUALLY...IFR CEILINGS BECOME MORE LIKELY BY THIS EVENING AS
RAIN CHANCES ALSO INCREASE. MVFR VISIBILITY AND LIFR CEILINGS ARE
ALSO A POSSIBILITY DURING PERIODS OF HEAVIER RAIN THIS EVENING.

&&

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

$$

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



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