Area Forecast Discussion
Issued by NWS Hastings, NE

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FXUS63 KGID 231037
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
537 AM CDT SAT AUG 23 2014

.UPDATE...
ISSUED AT 532 AM CDT SAT AUG 23 2014

STRATUS IS BEING TO DEVELOP EARLY THIS MORNING AND THE HRRR IS
DOING A DECENT JOB WITH THE LOW CLOUD DEPICTION. THE MODEL
INDICATES THE MORE WIDESPREAD LOW CLOUD POTENTIAL PRIMARILY ALONG
AND NORTH OF THE PLATTE RIVER...BUT CIGS ARE ALSO STARTING TO
LOWER FARTHER SOUTH INTO NORTH CENTRAL KANSAS. CONFIDENCE IS NOT
HIGH ON THE DEVELOPMENT OF FOG AS WINDS ARE FARILY STEADY FROM THE
SOUTHEAST. MODELS SUGGEST THE LOW CLOUDS WILL PERSIST FOR AROUND
THREE HOURS OR SO...BREAKING UP BY MID MORNING.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CDT SAT AUG 23 2014

EARLY MORNING CONVECTION WAS LIFTING OUT OF OUR CWA ON THE NOSE
OF THE LLVL AND AS THE WARM FRONTAL BOUNDARY LIFTS NORTHWARD AHEAD
OF AN UPPER LOW EDGING EAST FM IDAHO. SEVERE WEATHER REPORTS FROM
THE EVENING CONVECTION WERE LIMITED HOWEVER RAINFALL WAS
WIDESPREAD WITH SEVERAL LOCATIONS RECEIVING AMOUNTS NEAR OR ABOVE
ONE INCH.

WINDS WILL TRANSITION SOUTHERLY AS THE WARM FRONTAL BOUNDARY LIFTS
INTO THE DAKOTAS TODAY AND A PERIOD OF BREEZY CONDITIONS ARE
FORECAST DURING THE AFTERNOON WITH GUSTS OF 25 TO 30 MPH
POSSIBLE...ESPECIALLY FOR OUR SOUTHEASTERN ZONES.  AFTERNOON TEMPS
ARE LOOKING SIMILAR TO THE LAST FEW DAYS WITH HIGHS RANGING FROM THE
UPPER 80S TO THE MID/UPPER 90S...AIDED BY DEEPER MIXING. CANNOT RULE
OUT AN ISOLATED TSTM IN THE AFTN IN WAA AHEAD OF THE UPPER TROUGH
MOVING INTO MT/WY.

UNCERTAINTY EXISTS IN THE CONVECTIVE POTENTIAL TONIGHT AS THE UPPER
LOW EDGES INTO THE WESTERN DAKOTAS AND A COLD FRONTAL BOUNDARY
ADVANCES EASTWARD FM THE HIGH PLAINS AND REACHES OUR WESTERN CWA
PRIOR TO DAYBREAK.  WAA AHEAD OF THE FRONT AND CONVERGENCE/DYNAMICS
ALONG THE BAROCLINIC ZONE MAY LEAD TO ISOLATED/SCATTERED STORMS. IF
STORMS DEVELOP...LACK OF GOOD SHEAR AND MARGINAL INSTABILITY SHOULD
LIMIT STORMS FROM BECOMING SEVERE. AS THE COLD FRONT ARRIVES LATE
TONIGHT...DRIER AIR ADVECTS SOUTHEAST BEHIND THE BOUNDARY WITH DPS
DROPPING OFF TO THE 50S BY SUNDAY MORNING IN OUR WESTERN ZONES.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 402 AM CDT SAT AUG 23 2014

ALOFT: A FAIRLY AMPLIFIED ERN USA RIDGE/WRN USA TROF SUN WILL
GRADUALLY DEAMPLIFY NEXT WEEK AND BECOME PROGRESSIVE. A POTENT
CLOSED LOW WILL WILL BE EJECTING OUT OF THE TROF...CROSSING THE
DAKOTAS SUN. THIS WILL LEAVE A +TILT TROF BEHIND OVER THE WRN USA
MON-TUE. THIS TROF WILL ADVANCE INTO THE PLAINS WED AND THE LAST 2-3
RUNS OF THE EC/GFS/GEM/UKMET ARE IN DECENT AGREEMENT THRU THIS TIME
FRAME. AGREEMENT BREAKS DOWN THU AND WE SAW HINTS OF THIS 24 HRS
AGO. THE GFS KEEPS THE TROF PROGRESSIVE WHILE THE UKMET/EC AND SOME
OF THE PAST 4 GEM CYCLES BREAK THE BASE OF THE TROF OFF FROM THE
WESTERLIES WHICH BECOME RE-ESTABLISHED OVER SRN CANADA. THE GFS
DEVELOPS NW FLOW OVER THE PLAINS WHILE MOST OTHER MODELS HAVE THE
TROF AXIS OVERHEAD.

SURFACE: A COOL FRONT WILL BE CROSSING THE FCST AREA SUN MORNING.
THIS FRONT WILL BECOME STATIONARY ACROSS NRN KS MON AS IT BECOMES
PARALLEL WITH THE FLOW ALOFT. THE SRN FRINGE OF CANADIAN HIGH PRES
WILL BUILD IN MON-TUE. HOWEVER...WITH THE TROF REMAINING TO THE W
THE FRONT WILL BE CONVECTIVELY ACTIVE

HAZARDS: MULTIPLE ROUNDS OF TSTMS APPEAR LIKELY WITH MON NIGHT
CONTINUING AS THE HIGHEST CONFIDENCE. EXCESSIVE RAINFALL COULD BE A
PROBLEM IF THESE TSTM CLUSTERS TRACK OVER SIMILAR AREAS AND WE MAY
SEE HYDRO/FLOODING CONCERNS.

THE DAILY DETAILS...

SUN: WHILE THE BEST LOW-LVL DEWPOINTS WILL BE WHISKED AWAY BY THIS
TIME FRAME...THERE IS A NARROW TONGUE OF 10-12C 850 MB DWPTS ALONG
THE COOL FRONT. A COUPLE OF SHWRS/TSTMS MAY BE ON-GOING JUST NW OF
THE FCST AREA AT DAYBREAK. PRESENT INDICATIONS ARE THAT THEY WILL
DISSIPATE. BY AFTERNOON THIS MOIST TONGUE WILL BE OVER THE SE FRINGE
OF THE FCST AREA...AND COULD SUPPORT DEVELOPMENT A TSTM OR TWO.

SREF MLCAPE 2000-3000 J/KG. DEEP LAYER SHEAR AROUND 25 KTS WILL
SUPPORT SEVERE MULTI-CELL CONVECTIVE MODE.

SUN NIGHT: A LEE-SIDE LOW WILL BECOME ESTABLISHED NEAR PUB IN THE
RIGHT REAR QUADRANT OF AN 80 KT ULJ. THE RESULT WILL BE UPSLOPE
FLOW...THE DEVELOPMENT OF A LLJ AND ENHANCED THETA-E ADVECTION. RICH
850 MB DWPTS WILL ADVECT BACK INTO THE REGION LEADING TO
DESTABILIZATION AND TSTM DEVELOPMENT OVER THE HIGH PLAINS. SOME OF
THIS SHOULD FILTER E INTO THE FCST AREA AFTER MIDNIGHT.

MON: LOTS OF UNCERTAINTY ON TEMPS. DEPENDENT ON THE AMT OF CLOUD
COVER AND LINGERING TSTM ACTIVITY FROM SUN NIGHT. THIS WILL ACT TO
REINFORCE THE FRONT VIA DIFFERENTIAL HEATING. AREAS N OF I-80 COULD
STAY IN THE 70S WHILE N-CNTRL KS WILL BAKE INTO THE MID 90S. ANY
LEFTOVER TSTM ACTIVITY SHOULD WANE DURING THE DAY. CANT RULE OUT AN
ISOLATED LATE DAY TSTM OR TWO.

MON NIGHT: THE MODELS CONT TO ADVERTISE MCS DEVELOPMENT AT THE NOSE
OF THE LLJ. HIGH POPS ARE IN ORDER ESPECIALLY N OF HWY 6.

TUE: PROBABLY A LULL IN TSTM ACTIVITY IN THE WAKE OF THE MCS. AGAIN
TEMPS ARE HIGHLY UNCERTAIN. WITH CONVECTIVELY REINFORCED FRONT STILL
NEAR THE KS-NEB BORDER...LATE DAY TSTM DEVELOPMENT CANT BE RULED
OUT.

WED-THU: FOR WHAT IT`S WORTH POTENTIAL EXISTS FOR MORE TSTMS AND IF
MCS ACTIVITY IS PLACED JUST RIGHT...MULTIPLE EPISODES COULD RESULT
IN EXCESSIVELY HEAVY RAINFALL.

THE 18Z/22 GFS ENSEMBLES SHOW ABOVE NORMAL UNCERTAINTY IN TEMPS WED-
THU. IF THE EC TURNS OUT CORRECT...WE COULD SEE SUBSTANTIAL CLOUD
COVER/STRATUS TRAPPED BENEATH THE FRONT AS THE UPPER TROF MOVES IN.
THE GEM/EC/GFS/DGEX ALL INDICATE POTENTIAL FOR 1 OR BOTH DAYS WITH
DAYTIME TEMPS JAMMED WAYYYY BELOW NORMAL /AS COOL AS UPPER 60S TO
NEAR 70/.

FRI: DRY WITH SEASONABLE TEMPS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 512 AM CDT SAT AUG 23 2014

CONVECTION HAS DEPARTED THE TERMINALS AND FOR THE MOST PART DRY
WEATHER IS FORECAST. THERE IS AN OUTSIDE CHANCE FOR A STORM OR TWO
DURING THE AFTERNOON AND TONIGHT AHEAD OF AN APPROACHING COLD
FRONT AND UPPER LEVEL TROUGH BUT CHANCES ARE NOT GREAT ENOUGH TO
INCLUDE MENTION IN THE TAFS. THERE MAY BE A BRIEF VSBY RESTRICTION
AROUND DAYBREAK THIS MORNING...BUT VSBYS HAVE BEEN SLOW TO DROP.
OTHERWISE...LOOK FOR SOUTHERLY WINDS TO BE ON THE INCREASE WITH
WIND GUSTS AROUND 25KTS POSSIBLE DURING THE AFTERNOON.


&&

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

$$

UPDATE...FAY
SHORT TERM...FAY
LONG TERM...HALBLAUB
AVIATION...FAY


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