Area Forecast Discussion
Issued by NWS North Platte, NE

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 KLBF 301812
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
112 PM CDT TUE JUN 30 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT TUE JUN 30 2015

TODAY AND TONIGHT...TIMING TOOLS AND THE HRRR SUGGEST THE
CONVECTION ACROSS CNTL SD COULD BRUSH BOYD COUNTY FOR A FEW HOURS
THIS MORNING. THIS CONVECTION WAS FORMING JUST BEHIND A COLD FRONT
WHICH WILL SAG PART WAY INTO THE FCST AREA THIS MORNING. LOW
PRESSURE ASSOCIATED WITH THE FRONT SHOULD DROP INTO SCNTL NEB THIS
AFTN AND THEN KS TONIGHT. THE FRONT AND UPPER/LOWER LEVEL MOISTURE
COULD MAKE FOR A FERTILE THUNDERSTORM ENVIRONMENT TONIGHT...MAINLY
NORTH OF NEBRASKA HIGHWAY 2 WHERE AMBIENT PWAT INCREASES TO 1.5
INCHES OR MORE.

SEVERE WEATHER POTENTIAL HINGES ON SOME VERY RICH MOISTURE ALOFT
AT 500-100 MB AND THE POTENTIAL FOR STRONG DOWN DRAFTS WITH DRY
AIR BELOW THAT LEVEL. THIS SORT OF THING HAS BEEN COMMON ACROSS
THE WRN U.S. LATELY AND LATE THIS AFTN AND THIS EVENING COULD OUR
TURN. SPC SUGGESTED SWRN SD FOR SEVERE WEATHER.

THE TEMPERATURE FORECAST IS VERY MODEST GIVEN ALL MODELS SHOW THE
BANK OF CIRRUS ACROSS THE MT WILL MOVE INTO THE FCST AREA THIS
MORNING. 80S TO MID 90S IS TO BE EXPECTED. THE HIGH CLOUDS LIMIT
MIXING TO 700 MB AND SHOULD PREVENT SUPER ADIABATIC LAPSE RATES
NEAR THE SFC.

WINDS BACK AROUND TO THE NORTH TONIGHT WHICH COULD DRAW SMOKE INTO
THE FCST AREA. HUNDREDS OF WILDFIRES ARE BURNING ACROSS CNTL/WRN
CANADA AND ALASKA. LOWS FALL INTO THE 60S AND THE SREF SHOWS
STRATUS AROUND VALENTINE AND ONEILL BY MORNING.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM CDT TUE JUN 30 2015

UPPER LEVEL RIDGE REMAINS FIRMLY IN PLACE OVER THE INTERMOUNTAIN
WEST THROUGH MUCH OF THE LONG TERM PERIOD. DRY AND PARTLY CLOUDY
CONDITIONS EXPECTED WEDNESDAY WITH SUBTLE HEIGHT RISES AND LARGE
SCALE SUBSIDENCE IN THE WAKE OF A DEPARTING SHORTWAVE TROUGH. COLD
FRONT FROM TUESDAY WILL MODERATE TEMPERATURES SOMEWHAT...BUT
AFTERNOON MIXING TO AROUND 700MB WILL STILL LEAD TO A WARM DAY IN
SOUTHWEST NEBRASKA WITH HIGHS IN THE LOW TO MID 90S. FURTHER NORTH
AND EAST COOLER 850MB TEMPS WILL LIKELY KEEP HIGHS IN THE 80S.

THE NEXT IN THE SERIES OF SHORTWAVE TROUGHS TO TOP THE WESTERN
CONUS RIDGE BEGINS TO APPROACH THE CWA FROM THE NORTHWEST
WEDNESDAY NIGHT. LOW LEVEL FLOW BECOMES SOUTHERLY IN ADVANCE OF
THE APPROACHING WAVE WHICH WILL RETURN SURFACE DEWPOINTS INTO THE
60S. COLD FRONT SURGES  SOUTHEAST INTO THE CWA BY THURSDAY
MORNING. MODELS SHOW CONVECTION FIRING WEDNESDAY EVENING/NIGHT AS
THE FRONT MOVES THROUGH WESTERN SOUTH DAKOTA...EVENTUALLY MAKING
IT INTO NORTHERN NEBRASKA BY THURSDAY MORNING. ADDITIONAL
DEVELOPMENT IS LIKELY BY EARLY AFTERNOON AS THE MID-LEVEL CAP
WEAKENS ALONG THE FRONT. THE SEVERE THREAT REMAINS SOMEWHAT
UNCLEAR AS MODELS CONTINUE TO FIGHT OVER THE DEGREE OF
DESTABILIZATION AHEAD OF THE FRONT. THE NAM IS THE MOST
AGGRESSIVE WITH BRINGING RICH SURFACE THETA-E AIR NORTHWARD AND
POOLING IT ALONG THE FRONTAL AXIS...LEADING TO SBCAPE VALUES
APPROACHING 3000 J/KG BY THE AFTERNOON. THE GFS IS A DRIER
SOLUTION AND MUCH LESS UNSTABLE. EITHER WAY...THE PRESENCE OF
35-45 KNOTS OF DEEP LAYER SHEAR WILL PROMOTE THE POTENTIAL FOR AT
LEAST A FEW STRONG TO SEVERE STORMS BY THE TIME THE FRONT CLEARS
THE CWA THURSDAY NIGHT.

FORECAST TURNS DRY FOR FRIDAY AS THE UPPER LEVEL SHORTWAVE MOVES
SOUTHEAST. MODELS ARE IN FAIR AGREEMENT WITH A STRONG NORTHERN
STREAM UPPER LEVEL LOW DIGGING INTO CENTRAL CANADA OVER THE
WEEKEND. LOW LEVEL SOUTHERLY FLOW BECOMES REESTABLISHED ACROSS
THE CENTRAL CONUS IN RESPONSE TO A DEEPENING SURFACE LOW NEAR THE
US/CANADIAN BORDER. LOW LEVEL MOISTURE RETURN AND AMPLE SYNOPTIC
SCALE LIFT WILL SET THE STAGE FOR MORE THUNDERSTORM CHANCES AS A
COLD FRONT MOVES THROUGH THE CWA SUNDAY OR MONDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 108 PM CDT TUE JUN 30 2015

ISOLATED TO SCATTERED THUNDERSTORMS POSSIBLE THIS EVENING AND
OVERNIGHT. GREATEST CHANCES WILL BE NORTH OF INTERSTATE 80 LATE
THIS AFTERNOON INTO THE EARLY OVERNIGHT HOURS. THIS SHIFTS EAST
AFTER MIDNIGHT...MAINLY EAST OF AN KVTN TO KBBW LINE. CHANCES
DIMINISH IN THE MORNING.

THIS EVENING INTO EARLY TONIGHT SOME THUNDERSTORMS COULD PRODUCE
GUSTY DOWNDRAFT WINDS. THE THREAT FOR SIGNIFICANT OUTFLOW GREATLY
DIMINISHES AFTER MIDNIGHT.

WILL ALSO HAVE TO MONITOR FOR POSSIBLE REDUCTION OF VISIBILITY
TOWARDS MORNING DUE TO PATCHY FOG. LOW CONFIDENCE AT THIS TIME SO
NO MENTION IN THE TAF YET.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...CDC
LONG TERM...MARTIN
AVIATION...MASEK




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