Area Forecast Discussion
Issued by NWS Hastings, NE

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000
FXUS63 KGID 230526
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1226 AM CDT SAT AUG 23 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 256 PM CDT FRI AUG 22 2014

THE HIGHLIGHT OF THE SHORT TERM PERIOD WILL BE THE FACT WE ARE
EXPECTING THUNDERSTORMS TODAY/TONIGHT. THERE STILL REMAINS SOME
UNCERTAINTY FOR TIMING...LOCATION...AND OVERALL DEVELOPMENT. THE
WARM FRONT TO OUR SOUTH...WHICH IS SITUATED OVER THE KANSAS/NEBRASKA
BORDER...IS JUST MOSEYING ALONG TODAY AND HAS CAUSED SOME CONCERN
FOR DEVELOPMENT. SHOWERS/STORMS SHOULD DEVELOP ALONG THIS BOUNDARY AS
THE CAP BEGINS TO BREAK. SPC MESOSCALE ANALYSIS PAGE HAS US CAPPED
UNTIL ABOUT 22-23Z. AT THIS TIME WE SHOULD SEE THE BEGINNING STAGES
FOR INITIATION ALONG THE BOUNDARY TO OUR SOUTH. AMPLE INSTABILITY OF
ABOUT 2000-3000 J/KG WILL BE IN PLACE...DUE TO A VERY MOIST BOUNDARY
LAYER AND STEEP LAPSE RATES. MOST UNSTABLE CAPE COULD BE AS HIGH AS
4000 J/KG. BULK SHEAR 0-6 KM WILL BE AROUND 30 KNOTS...AND THIS IS
NOT TOO IMPRESSIVE...HOWEVER...LOW LEVEL SHEAR WILL BE STRONG.
EARLIER RUNS OF THE RAP INDICATED HELICITY VALUES NEAR 400 M2/S2
WOULD BE IN PLACE AROUND 23Z FOR WESTERN PORTIONS OF THE CWA. THESE
VALUES WILL PUSH EASTWARD THROUGH THE AFTERNOON/EVENING. THESE LOW
LEVEL HELICITY VALUES COUPLED WITH AMPLE INSTABILITY WILL POSE A
THREAT FOR SOME ISOLATED TORNADOES...MAINLY FOR OUR NEBRASKA
COUNTIES. WITH THAT BEING...WIND AND HAIL WILL BE THE MAIN THREATS
TODAY/TONIGHT. THE BEST CHANCE FOR SEVERE WEATHER WILL BE ACROSS OUR
NEBRASKA COUNTIES...BUT THE ENTIRE CWA DOES HAVE THE POTENTIAL FOR
SEVERE WEATHER. I DO EXPECT THUNDERSTORM ACTIVITY TO KICK INTO GEAR
AROUND 6 OR 7 PM...IF NOT SOONER.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 PM CDT FRI AUG 22 2014

VARIOUS RAIN CHANCES FOR THE WEEKEND AND IN TO THE FIRST PART OF
THE WORK WEEK...ALONG WITH FLUCTUATING TEMPERATURES ARE PRIMARY
FORECAST CONCERNS. WILL KEEP THIS FAIRLY SHORT DUE TO POSSIBLE
SEVERE WEATHER DEVELOPING LATER THIS AFTERNOON.

STARTING OUT SATURDAY EVENING IN THE MID/UPPER LEVELS...THERE SHOULD
BE A LARGE AMPLITUDE TROUGH OVER THE ROCKIES WITH A CLOSED LOW
SITUATED OVER EAST CENTRAL MONTANA...AS THE CURRENT SYSTEM OVER THE
PACIFIC NW DRIFTS EASTWARD. THIS WILL PUSH THE RIDGE A LITTLE EAST
AS WELL WITH THE AXIS STRETCHING FROM LAKE SUPERIOR TO MISSISSIPPI.
THE BETTER FORCING WITH THE LOW PRESSURE SHOULD BE TO THE WEST AND
NORTH OF OUR REGION. AT THE SURFACE...EXPECT A FRONTAL BOUNDARY TO
BE TO OUR NORTH ACROSS SDAK AT 00Z AND THEN THIS WILL PUSH INTO OUR
AREA BY SUNDAY MORNING. HAS NOT TAKEN A WHOLE LOT TO SET OFF
CONVECTION THE PAST WEEK AND WHILE THE SET UP FOR SATURDAY NIGHT IS
NOT AS GOOD AS TONIGHT...WILL PROBABLY STILL NEED SOME LOW POPS
GIVEN APPROACHING WEAK COLD FRONT AND ANTICIPATED LOW LEVEL JET.
PREVIOUS SHIFT AFD NOTED SOME HEAT BURST POTENTIAL WITH ANY
THUNDERSTORMS THAT DO DEVELOP AND THIS SCENARIO STILL IN PLACE.

WEATHER SHOULD BE QUIET DURING THE DAYTIME ON SUNDAY BEHIND THE COLD
FRONT AND POSSIBLE SUNDAY NIGHT ALTHOUGH BOTH THE NAM AND GFS ARE
DEVELOPING SOME PRECIPITATION TO THE WEST AND MOVING ACROSS THE CWA
SUNDAY NIGHT. GFS APPEARS TO OVERDEVELOP A VORTICITY MAX ALTHOUGH
DIFFICULT TO TOTALLY DISCOUNT WITH CYCLONIC FLOW IN UPPER LEVELS.

MONDAY NIGHT AND TUESDAY NIGHT STILL LOOK ACTIVE AS YET ANOTHER HIGH
AMPLITUDE TROUGH IS SLATED TO MOVE ACROSS THE ROCKIES AND INTO THE
PLAINS. AT THE SURFACE AN EAST/WEST STATIONARY FRONT WILL HANG OUT
OVER THE AREA RESULTING IN THE CLASSIC NIGHTTIME RAIN EVENTS. BY
WEDNESDAY THE EXTENDED MODELS IN DECENT AGREEMENT IN PUSHING THE
TROUGH EAST THROUGH THE CWA WITH RIDING THEN MOVING IN TO QUIET
THINGS DOWN FOR THE REMAINDER OF THE WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1206 AM CDT SAT AUG 23 2014

SHOWERS AND THUNDERSTORMS WILL LINGER AT THE TERMINALS FOR ANOTHER
HOUR OR SO THEN CONDITIONS WILL DRY OUT BY DAYBREAK. THERE MAY BE
A BRIEF PERIOD OF REDUCED VSBYS IN BR DUE TO THE WET GROUND...BUT
CONFIDENCE IS NOT HIGH FOR DEVELOPMENT OF FOG. LOOK FOR WINDS TO
TRANSITION SOUTHERLY DURING THE DAY WITH WIND SPEEDS INCREASING AS
THE SFC GRADIENT TIGHTENS. WIND GUSTS AROUND 25KTS ARE POSSIBLE.
THERE IS AN OUTSIDE CHC FOR A TSTM BUT CHCS ARE NOT GREAT ENOUGH
TO INCLUDE JUST YET.

&&

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

&&

$$

SHORT TERM...GUERRERO
LONG TERM...EWALD
AVIATION...FAY



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